NeuroRehabilitation ELSEVIER
NeuroRehabiIitation 8 (1997) 163-174
Diagnosis of conversion disorders in a rehabilitation setting Robert W. Teasell*,a Allan P. Shapiro b aDepartment of Physical Medicine and Rehabiltation,
University of Western Ontario and London Health Sciences Centre, University Campus, London, Ontario, Canada bPsychological Services, University of Western Ontario and London Health Sciences Centre, University Campus, London, Ontario, Canada
Abstract
Conversion disorders are unexplained symptoms or deficits that mimic neurological problems and affect voluntary motor and sensory functions. Historically, conversion symptoms were thought to reflect underlying psychological conflicts although recent behavioural theories view them as learned responses to stressful life circumstances and emphasize environmental contingencies in the maintenance of the disorder. Although early studies often revealed underlying organic disease in patients initially diagnosed with Conversion Disorder, this now occurs less frequently because of increased sophistication of diagnostic tools and better understanding of neurological disorders. However, misdiagnosis is still common because of reliance on 'negative' diagnostic testing and unvalidated 'positive signs' misinterpreted as indicative of hysteria. Psychological factors may affect the course of almost every major category of disease and in many cases a diagnosis of hysteria is not indicated and the more appropriate diagnosis is Psychological Factors Affecting A Medical Condition. It is not possible to definitively differentiate between conscious and unconscious production of symptoms thus blurring the distinction between Conversion and Factitious disorders. © 1997 Elsevier Science Ireland Ltd. Keywords: Conversion disorder; Factitious disorder; Psychological conflict
1. Introduction Conversion disorders and hysteria refer to organically unexplainable symptoms or neurological
* Corresponding author. Tel.: + 15196633235; fax: + 1519 6632941.
deficits that are linked primarily to psychological problems. This article will look at the current diagnostic criteria for defining hysterical disorders and proposed etiologies. The clinical presentations of patients with conversion disorders referred to a rehabilitation program specializing in management of these patients is presented. The potential danger of misdiagnosis of hysteria
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is important to recognize. Finally, the difficulties in distinguishing conversion (unconscious) and factitious (conscious) disorders are discussed. Management of conversion disorders and the controversial issue of chronic pain and hysteria are reviewed in future articles. 2. Defining hysteria and conversion disorders Historically, the term 'hysteria' was most often used to describe the occurrence of physical symptoms in the absence of organic disease. Hysteria has been regarded as an unsatisfactory term and in recent years was dropped from the American Psychiatric Association's taxonomy of mental disorders. It was replaced by the term Somatoform Disorder. Like its predecessor, the term somatoform is used to denote the presence of physical symptoms that suggest a medical condition but cannot fully be accounted for by an underlying organic problem. The most recent edition of the American Psychiatric Association's ~axonomy of mental disorders (DSM IV, 1994) includes a variety of diagnoses under the general category of Somatoform Disorder [1]. These diagnoses are presented below. There is considerable overlap between these conditions which can make differential diagnosis problematic and confusing.
2.1. Conversion disorder This diagnosis refers to medically unexplained symptoms or deficits that typically mimic neurological disorders and affect voluntary motor (e.g. paralysis) or sensory (e.g. blindness) functions. 2. 2. Somatization disorder
This disorder was previously referred to as 'Briquet's Syndrome' or 'Hysterical Neuroses'. Somatization Disorder is characterized by multiple physical complaints that are without apparent organic basis or are far in excess of any underlying medical condition that might be present. A defining criterion is that the disorder begins before the age of 30 and extends over many years. The following constellation of unexplained symptoms must be present to make such a diagnosis: a
history of pain related to at least four different sites or functions (e.g. hip pain, joint pain, pain during sexual intercourse, pain during urination); a history of at least two gastrointestinal symptoms (e.g. nausea, vomiting, bloating, etc.); a history of one sexual or reproduction symptom (e.g. irregular menses, vomiting throughout pregnancy); and a history of at least one pseudo neurological symptom (e.g. paralysis). That is, by definition, individuals with Somatization Disorder also have a history of Pain Disorder and Conversion Disorder. However, it is the myriad of symptoms, early onset, and chronic course that differentiates Somatization Disorder from Conversion or Pain Disorder. Merskey suggests that Somatization Disorder be conceptualized as one end of a continuum of hysterical disorders [2].
2.3. Hypochondriasis This refers to the preoccupation with, and fear of having, a serious disease despite repeated physical exams, diagnostic testing, and reassurance that no serious condition is present. The most common focus or preoccupation is with cardiac, respiratory, or gastrointestinal function. This preoccupation is thought to reflect a patient's misinterpretation of normal bodily signs or symptoms. Mai has observed that Hypochondriasis is sometimes confused with Somatization Disorder because of its chronicity and the occasional occurrence of multiple somatic symptoms [3]. 2.4. Pain disorder In this disorder, pain is the primary focus of attention and complaint. Psychological factors are judged to be important in either its onset, severity, exacerbation, or maintenance. The inclusion of Pain Disorder within the general category of somatoform disorders has been controversial and is discussed elsewhere in this issue [4].
2.5. Other related diagnoses There are two other diagnoses which, although not included under the category of Somatoform Disorder, involve the interface of psychological
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factors and somatic symptoms: Factitious Disorder and Psychological Factors Affecting A General Medical Condition.
2.5.1. Factitious disorder In Factitious Disorder, there is an intentional production of symptoms simulating a medical condition. This includes fabrication of subjective complaints in the absence of an underlying organic condition (e.g. complaints of abdominal pain in the absence of any such pain); self-inflicted conditions such as skin infections produced by injection of substances under the skin; and/or the exaggeration of a preexisting condition (e.g. the feigning of seizures in an individual with a history of actual seizure activity). Multiple factitious symptoms may be present concurrently. The underlying motivation is thought to be a psychological need to assume the sick role. The most extreme and chronic version of this is referred to as Munchausen Syndrome and is associated with multiple hospitalizations, repeated attempts to stay in or be admitted to hospital, and a willingness to undergo multiple surgical procedures. Factitious Disorder should be differentiated from malingering. In malingering, the motivation for the intentional production of symptoms is some external incentive (e.g. a place to stay on a cold night) rather than a psychological need to assume the sick role. The symptom is readily discontinued once it is clear that the external incentive is no longer available or necessary (e.g. the weather gets better). Factitious Disorders are also differentiated from Conversion Disorder in that the latter is thought to be unconscious. In contrast, Factitious Disorder is thought to involve the conscious and intentional production of symptoms. However, as will be discussed below, the observer must infer that which is conscious versus unconscious. Ultimately, this inference is impossible to definitively make, thus blurring the distinction between Chronic Conversion Disorders and Factitious Disorders. 2.5.2. Psychological factors affecting a medical condition In Psychological Factors Affecting A Medical Condition, there is an underlying organic condi-
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tion that is being adversely affected by psychological or behavioural factors. In a rehabilitation setting this is most commonly observed when depression or anxiety symptoms impede an individual's ability to engage in or optimally benefit from therapies. Other examples include the effect of personality traits on the course of a specific disease processes (e.g. the impact of 'Type A' behaviour on the course of cardiovascular disease). Similarly, stress-related physiological responses may exacerbate organic conditions as in the impact of stress on ulcers, hypertension, or inflammatory bowel disease. 3. Etiology
3.1. Psychoanalytic theories The term 'conversion' denotes an etiology by which anxiety associated with painful intrapsychic conflict is removed by somehow converting or transforming it into a physical complaint. For example, an individual, after an argument with a parent figure, experiences significant anger over what he perceives as a lack of nurturance and support. At the same time, he is 'quite conflicted about the outward expression of his rage for fear of retaliation and/or abandonment by this person. He develops paralysis of his arm. In this case, the conflict over expression of these forbidden impulses is symbolized by arm paralysis, i.e. an inability to strike out. Conversion of the emotional distress associated with this conflict into a physical symptom keeps the conflict out of awareness and at the same time provides an outlet for the psychic tension; this is referred to as 'primary gain'. In addition, the individual achieves 'secondary gain' when this parental figure responds to his medical problem with nurturance and support, the perceived absence of which was the precipitant to the original argument and ensuing conflict.
3.2. Behavioural/learning theories In contrast to traditional psychoanalytic formulations, behavioural (learning) theories of Conversion Disorder emphasize the importance of the
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external reinforcements (secondary gains) the patient derives by maintaining a physical dysfunction and associated disability. This may include escape from overwhelming or unwanted responsibilities or acquisition of support from family, friends, medical staff, or government agencies that would not be available otherwise. For instance, Treischman et a1. hypothesized that Conversion Disorders are a learned response to stressful circumstances [5]. Retreat into illness allows an individual to both avoid stressful circumstances and provides a great deal of support from the environment. Another behavioural concept that is helpful in understanding symptom development is 'modeling'. This refers to the observation that patients' symptom presentation is often consistent with the physical symptoms they have observed in others or have previously experienced themselves. The best example of the latter is occurrence of pseudo seizures in patients with a previous history of seizure disorder. Behavioural theories also distingujsh between factors involved in the original development of a disorder and those factors that are maintaining the response. In the case of a chronic Conversion Disorder, conflicts or environmental stressors that may have precipitated the disord9r may no longer be relevant and other factors may be maintaining the disorder. Sullivan and Buchanan argue that a critical factor in inhibiting resolution of chronic Conversion Disorders is that spontaneous remission may lead others to wonder if the symptoms had been feigned all along [6]. This is not inconsequential as any prolonged disability dramatically alters the life of all family members who often must make financial and emotional sacrifices. Shapiro and Teasell [7] delineate a number of other factors potentially inhibiting resolution of chronic conversion symptoms including: support and caring that the disability elicits; freedom from responsibility and expectations of others and anxiety regarding one's ability to meet these expectations upon resolution of disability; fears regarding loss of disability benefits and the anxiety about having to be successful in the work force once these benefits cease; and admiration from others for being 'strong' and apparently coping so well with the disability.
Table 1 DSM IV (1994) diagnostic criteria for conversion disorder [1] A.
One or more symptoms or deficits affecting voluntary motor or sensory function that suggest a neurological or other general medical condition.
B.
Psychological factors are judged to be associated with the symptom or deficit because the initiation or exacerbation of the symptom or deficit is preceded by conflicts or other stressors.
C.
The symptom or deficit is not intentionally produced or feigned (as in Factitious Disorder or Malingering).
D.
The symptom or deficit cannot, after appropriate. investigation, be fully explained by a general medical condition, or by the direct effects of a substance, or as a culturally sanctioned behaviour or experience.
E.
The symptom or deficit causes clinically significant distress or impairment in social, occupational, or other important areas of functioning or warrants medical evaluation.
F.
The symptom or deficit is not limited to pain or sexual dysfunction, does not occur exclusively during the course of Somatization Disorder, and is not better accounted for by another mental disorder. Subtypes With Motor Symptom or Deficit With Sensory Symptom or Deficit With Seizures or Convulsions With Mixed Presentation
4. Diagnostic criteria and associated features
4.1. Establishing the diagnosis DSM IV diagnostic criteria for Conversion Disorder appear in Table 1 [1]. Conversion Disorders typically present as symptoms or deficits affecting voluntary motor or sensory function. They usually mimic a neurological disorder. Within a Rehabilitation setting, one is most likely to see motor symptoms or deficits and particularly paralysis, paresis, and astasia-basia or ataxic-like symptoms. Merskey defines astasia-basia as unsteadiness of gait often presenting as bizarre incoordination especially in walking or standing still [2]. The defining criterion is that the symptoms cannot, after appropriate diagnostic investigations, be fully explained by an underlying organic condition. In
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addition to this 'negative' diagnostic finding, patients with conversion symptoms display 'positive' signs, i.e. symptoms that are quite inconsistent with known anatomical pathways and/or physiological mechanisms. This occurs because the symptoms follow the patient's conceptualization of the condition and the less medically sophisticated the individual, the more the symptoms will deviate from known physiological mechanisms. For instance, conversion 'paralysis' often presents as an inability to perform a particular movement or inability to move an entire body part rather than a deficit which corresponds to known patterns of motor innervation. MacKinnon identified four differentiating characteristics of hysterically based paralysis as opposed to organic paralysis: (1) paralysis not indicative of a particular nerve root pattern and tending to occur 'just below' major joints; (2) weakness of greater intensity proximally than distally; (3) normal reflexes; and (4) co-contractions, i.e. unacknowledged strength in antagonistic muscles during testing [8].
4.2. Specific epidemiologic features The onset of Conversion Disorders is believed to most commonly occur during late childhood to early adulthood, although occurrence in older adults is not infrequent. The female to male ratio has been reported as anywhere from 2:1 to 10:l. The incidence of Conversion Disorders is reported to be higher in rural areas, among lower socioeconomic groups, and following extreme psychological stress (e.g. in the military at time of war). Recurrence of conversIon symptomatology is thought to be common. Although Lazare reports increased incidence among certain immigrant populations, Conversion Disorder is not diagnosed if a symptom is fully explained as a culturally specific behaviour or sanctioned experi.ence [9]. For instance, in a variety of cultures, falling down with loss or alteration of consciousness has specialized and sanctioned functions.
4.3. Danger of misdiagnosis DSM IV cautions that even in the face of
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unexplained and physiologically inconsistent symptomatology, the diagnosis of Conversion Disorder should be viewed as provisional because 'knowledge of anatomical and physiological mechanisms is incomplete and available methods of objective assessment have limitations' (p. 453) [1]. Indeed, as discussed later, in early studies of patients diagnosed with Conversion Disorder, a substantial proportion were later found to have an underlying organic condition that accounted for their original problems. Historically, the medical conditions that were most likely to be misdiagnosed as Conversion Disorder, especially in their early phases, were multiple sclerosis, myasthenia gravis, and systemic lupus erythematosus. A premorbid history of unexplained physical symptomatology that has resolved as abruptly as it emerged and particularly symptoms associated with a diagnosis of Somatization Disorder increases the likelihood that the symptoms indeed reflect a non-organic condition.
4.4. Inconsistencies in symptom presentation An inpatient rehabilitation setting is particularly well suited for establishing the accuracy of a non-organic diagnosis. This is because in such a setting patients are closely monitored throughout the day by staff (physiotherapy, occupational therapy, nursing, medicine) who often are intricately familiar with the clinical manifestation of the actual organic disorder and therefore can identify symptoms that deviate significantly from true organic conditions. Moreover, during the course of such an inpatient admission, staff may observe dramatic inconsistencies in symptom presentation, especially between that demonstrated during formal examination versus informal (unobtrusive) observation when the patient is engaged in distracting activities (e.g. exercise programs, occupational therapy, etc.). These inconsistencies in symptoms are critical in definitively establishing a non-organic diagnosis. Although DSM IV offers other diagnostic signs to aid in differential diagnoses, in reality, they are not particularly helpful [1]. For instance, the second criterion (Table 1) that psychological factors are associated with ini-
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tiation or exacerbation of the symptom is also true for many medical conditions and therefore has limited diagnostic utility.
Table 2 Clinical features of patients diagnosed with conversion disorder
4.5. Lack of good research
Total number of patients Age of onset of symptoms Gender
Good empirical research on Conversion Disorder is not in abundance. This is likely due to two factors. Firstly, conversion symptoms tend to onset abruptly and remit quickly. Therefore, they are less likely to come to the attention of academics in tertiary care university hospital settings. Indeed, our experience is primarily with chronic conversion disorders. Historically, studies on conversion disorders likely included a large proportion of individuals who were misdiagnosed and actually had organic illness (see later section on misdiagnosis). Similarly, it is difficult to differentiate between Conversion Disorder and Psychological Factors Affecting Physical Conditions. As well, patients presenting with pain or somatic symptoms secondary to pain likely were also included in these early studies on Conversion Disorders. Thus, the heterogeneity of the population studied calls into question the validity of much of the early research generated. 5. Clinical presentation of patients referred to rehabilitation with a diagnosis of conversion disorder We undertook a retrospective chart review of 38 consecutive patients referred to Physical Medicine & Rehabilitation (RT) with a diagnosis of disabling Conversion Disorder between September 1989 and February 1995. Diagnosis was made on the basis of negative diagnostic testing and obvious inconsistencies in symptom presentation best explained as non-organic in nature. Two patients (discussed below) proved to have an organic disorder. Patients with a primary diagnosis of chronic pain with secondary pseudo neurological features or abnormal illness behaviour (e.g. grimacing, pulling away) were not included in this group. Table 2 summarizes demographics and presenting symptoms of the 36 patients with Conversion Disorder. Age at onset averaged 37.9 years (range
Primary clinical feature Paralysis Astasia-basia or ataxia
36 37.9 (17-70) 30 females (83%) 6 males (17%) 27 (75%) 9 (25%)
Secondary clinical features Paralysis' Astasia-basia or ataxia" Bladder Pain Dysarthria
9 (25%) 19 (53%) 4 (t 1%)
Total number with paralysis' Total number with astasia-basi a
28 (78%) 13 (36%)
4
• Some patients exhibited signs of both paralysis and astasiabasia.
17-70 years). Although this is considerably older than reported in the literature [1] our patients had predominantly chronic Conversion Disorders while, as noted above, the majority of Conversion Disorder patients resolved quite quickly. This suggests that patients with chronic symptomatology may represent a somewhat distinct subgroup. Consistent with previous literature, the majority (83%) were female. Paralysis was the primary presenting problem in 75% of the sample. Indeed, Merskey notes that in developed countries, motor symptoms are the most frequently seen by psychiatrists [2]. Paralysis was typically not complete and usually manifested as hemiparesis, paraparesis, or weakness. This was sometimes accompanied by spasticity and dystonic posturing. Non-organic paralysis or profound weakness is readily diagnosable. It is characterized by simultaneous contraction of agonist and antagonist muscles. Weakness is 'give-way' or ratchet like in nature with a give-way contraction quality. Reflexes are normal or purposely exaggerated. Another common test for leg weakness is Hoover's Sign. The patient is asked to lift the involved leg off the bed while lying supine. In true (organic) weakness the effort of attempting to lift
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the leg off the bed results in a strong downward force on the opposite heel. In hysterical weakness, the patient does not make a full effort and hence the downward force of the other heel is absent. Arm paralysis can also be tested. While the patient is supine the jnvolved arm is supported suspended above the face. In organic weakness releasing the arm will result in it falling and striking the face. With hysterical paralysis, the arm generally falls to the side of the face. After paralysis, the most common (25%) presenting complaint was astasia-basia, a form of unsteady gait which most resembles ataxia. It is characterized by bizarre incoordination where the patient staggers and sways acrobatically. Patients often stumble into walls but remain upright and rarely fall. The coordination and balance required to remain upright in contorted positions is often remarkable and is one way to distinguish astasiabasia from true ataxia. The unusual gait generally cannot be maintained while walking backwards or sideways. Leg movements are performed normally while lying down or sitting. Abnormal movements are sometimes seen apart from astasia-basia. Dystonic posturing and hysterical tremoring are common abnormal movements seen. Observing the patient when asleep or when they believe they are not being observed may allow discrepancies to be realized. However, there are obvious limitations given that some organic conditions may not manifest while sleeping or resting. Bladder problems, either incontinence or retention, was present in 25% of our sample. In our experience patients would allow bladder retention of up to almost 1 liter and several required intermittent catheterizations to empty their bladder. Foley indwelling catheters were present in others. One patient remarkably had an ileo-conduit where ureters were hooked up to an isolated piece of bowel emptying into a colostomy bag. Over half the patients reported pain of undetermined origin. It was of course, not possible to determine if they were experiencing any significant underlying pain. However, it is of note that their presentation was often quite distinct from that typically seen in chronic pain patients where pain is presumably musculoskeletal in origin.
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Specifically, conversion disorder patients routinely assumed static, dystonic postures or exhibited bizarre swaying and incoordination while walking. One never sees this in typical musculoskeletal pain patients because such postures and jerky movements would typically be associated with significant increases in pain. Accordingly, it was our impression that pain, if present, was likely not particularly severe or problematic. 'La belle indifference' is characterized by an inappropriate absence of distress despite the presence of a disorder which should normally elicit distress [3]. Emotional difficulties are similarly denied [3]. Although historically, la belle indifference was often considered a 'positive sign' for conversion, this is no longer the case. DSM IV notes that it mayor may not be present in Conversion Disorder patients [1]. Although we did not systematically enumerate its presence, it was our impression .that the great majority of our patients (approx. 75%) showed a relative lack of concern about their disability and insisted that they had no emotional problems and had adapted well to their disability. 6. Misdiagnosis The diagnosis of Conversion Disorder is often made erroneously. Misdiagnosis usually takes one of two forms: (1) patients are diagnosed with Conversion Disorder but later turn out to have an organic disorder accounting for their symptoms; or (2) conversion or hysteria is diagnosed when psychological factors are merely exacerbating a medical condition in which case the diagnosis Psychological Factors Affecting Medical Condition is more appropriate. Each of these misdiagnoses will be discussed in turn. 6.1. Patients with an organic disorder As noted above, DSM IV cautions that the diagnosis of Conversion Disorder should be provisional because our knowledge of physiological mechanisms is incomplete and therefore the apparent absence of underlying pathophysiology is not proof of an actual non-organic symptom [1]. As noted above, in non-organic motor disorders
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(paralysis, astasia-basia) seen in rehabilitation settings, there are certain 'positive' signs which are inconsistent with known physiological mechanisms (e.g. unacknowledged strength in antagonist muscles) and point very strongly to a nonorganic diagnosis. However, even in these cases we are typically cautious and a definitive diagnosis is only made once staff observe striking discrepancies in what patients can do when formally tested versus when engaged in distracting activities or are unaware that they are being observed. There are other 'positive' signs which are thought to reflect conversion disorder [10,11] but the validity of these signs has never been established. Table 3 lists a number of these signs. Gould et al. [12] carried out a systematic examination of neurologically impaired patients for seven of the supposed signs of hysteria which included: a history suggestive of hypochondriasis; potential secondary gain; la belle indifference; non-anatomic or patchy sensory loss; changing boundarie~ of analgesia; sensory loss to pinprick or vibratory stimulation that stopped at the midline; and giveway weakness. They examined 30 patients with cerebral injury, 29 of whom had suffered a stroke. Every patient had at least one of these signs, one patient had all seven and the mean number per patient was 3.4. They concluded that these signs lacked validity and if regarded as pathogonomic of hysteria, could easily lead to misdiagnosis. Elsewhere, we have criticized the 'non-organic' signs often misinterpreted as evidence that chronic musculoskeletal pain disorders are psychogenic [4]. Therefore, the diagnosis of Conver-
Table 3 Positive signs and symptoms of hysteria History suggestive of hypochondriasis Potential secondary gain 'La belle indifference' Failure of sensory loss to conform to recognized anatomical patterns Changing patterns of sensory loss on multiple examinations Alterations of sensory and motor findings with suggestion Hemianesthesia that splits the midline Unilateral loss of vibratory sense when the two sides of the forehead or of the sternum are sequentially stimulated Giveway weakness on motor testing
sion Disorder based solely upon traditional signs and symptoms must be made with great caution, as it may prove to be incorrect. Table 4 summarizes a number of studies which retrospectively followed previously diagnosed patients with Conversion Disorders to determine what percentage actually turned out to have undiagnosed organic conditions that accounted for the initial symptomatology. Although the studies were completed before CT and MRI scanning were available, they illustrate that reliance on 'negative' findings and unvalidated 'positive' signs often results in misdiagnosis. Specifically, these studies revealed that between 13% and 48% of patients had been erroneously diagnosed with Conversion Disorder [13-18]. Although the availability of modern diagnostic testing techniques (e.g. CT and MRI scanning) has made it easier to identify neurological dis-
Table 4 Retrospective follow-up of patients originally diagnosed as conversion disorder Study
No. of patients diagnosed as conversion disorder
Length of follow-up
%with organic illness
Slater [13] Slater and Glithero [14] Gatfield and Guze [15] Raskin et al. [16] Stcfansson et al. [17] Watson and Burenon [18]
112
10 years 7-11 years 2.5-10 years 6·-12 months 3.3 years 10 years
3D 21 14 13
99
24 50 64
40 - - - - - - - - - - - - - - _ .. _.......... _...._.. _ - - - - - -
48%
25
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orders such as multiple sclerosis, misdiagnosis still occurs. We have had two recent cases. One was a nursing assistant on a neurological ward who developed paraparesis secondary to transverse myelitis. Her exposure to patients with similar paralysis was mistakenly interpreted as providing a 'model' for her symptoms. The second case was a young woman with a bizarre gait pattern and chronic knee and back pain who had seen numerous specialists. She turned out to have a rare form of renal phosphate-wasting osteomalacia with long-standing bilateral fractured hips and avascular necrosis [19]. She later was found to have a scapular sarcoma, which was resected and accounted for the hypophosphatemia, a paraneoplastic phenomena. She had been attempting to walk on fractured hips for 3 years which accounted for her abnormal gait. Marked stoicism was misinterpreted as 'Ia belle indifference'. Miller et al. reviewed 25 cases of serious neurologic disease originally diagnosed by other physicians as hysteria or a functional disorder [20]. In most of these cases the eventual diagnosis was confirmed by either radiographic or pathologic examination. The following patient characteristics were associated with misdiagnosis: (1) female gender; (2) prior psychiatric illness; (3) plausible psychodynamic explanations for the medical problems; and (4) exaggerated physical presentation. This study suggests that a history of psychological difficulties combined with relative lack of stoicism in a female patient is often misinterpreted as suggestive of 'hysteria'.
Table 5 DSM IV (I994) diagnostic criteria for psychological factor affecting a general medical condition [I] A.
A general medical condition is present.
B.
Psychological factors adversely affect the general medical condition in one of the following ways: (I) the factors have influenced the course of the general medical condition as shown by a close temporal association between the psychological factors and the development or exacerbation of. or delayed recovery from. the general medical condition (2) the factors interfere with the treatment of the general medical condition (3) the factors constitute additional health risks for the individual (4) stress-related physiological responses precipitate or exacerbate symptoms of the general medical condition
Subtypes 1. Mental Disorder Affecting a General Medical Condition. For example. a mental disorder such a Major Depressive Disorder delaying recovery from a myocardial infarction. 2.
Psychological Symptoms Affecting a General Medical Condition. For example, depressive symptoms delaying recovery from surgery; anxiety exacerbating asthma.
3.
Personality Traits or Coping Style Affecting a General Medical Condition. For example, pathological denial of the need for surgery in a patient with cancer; hostile, pressured Type A behaviour contributing to cardiovascular disease.
4.
Maladaptive Health Behaviours Affecting a General Medical Condition. For example, overeating; lack of exercise; unsafe sex.
5.
Stress-Related Physiological Response Affecting a Gel/eral Medical Condition. For example, stress-related exacerbations of ulcer, hypertension, arrhythmia, or tension headache.
6.
Other or Unspecified Psychological Factors Affecting a General Medical Condition. For example, interpersonal, cultural, or religious factors.
6.2. Patients with psychological factors affecting a medical condition
Psychological factors often have a direct or indirect effect upon organic symptomatology but in the majority of cases, a diagnosis of hysteria is inappropriate. Table 5 lists diagnostic criteria for Psychological Factors Affecting A Medical Condition. Although this diagnosis is included in DSM IV it is not considered to be a mental disorder per se [1]. It is reserved for those situations in which psychological factors have a significant effect on the course or outcome of a medical condition or place the patient at higher risk for an
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adverse outcome. DSM IV notes that 'psychological and behavioural factors may affect the course of almost every major category of disease, including cardiovascular conditions, dermatological conditions, endocrinological conditions, gastrointestinal conditions, neoplastic conditions, neurological conditions, pulmonary conditions, renal condi-
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tions and rheumatological conditions.' (p. 676). Physicians need to remain cognizant of the multitude of ways in which psychological factors can impact upon an organic condition. These are listed in Table 5. For instance, a diagnosable mental disorder can affect the course of a condition as when a major affective (depression) disorder affects a rehabilitation patient's ability to engage in physical therapy. Psychological symptoms which do not constitute a mental disorder per se can affect a medical condition as when the effects of anxiety and depression on cognition further exacerbates cognitive function in a brain injured patient. Personality traits or a maladaptive coping style can affect the course of treatment as when highly perfectionist patients with chronic pain insist they are totally disabled because of an inability to maintain their premorbid extremely high levels of job performance. Maladaptive health behaviours can affect a general medical condition as when poor nutrition interferes with rehabilitation of elderly patients. Stress-related physiological responses can significantly affect the course or treatment of a condition as when stressful circumstances increase pain symptomatology in musculoskeletal pain patients. Elsewhere in this issue we argue that when psychological factors are significantly affecting musculoskeletal pain disorders, a more appropriate diagnosis is Psychological Factors Affecting A Medical Condition rather than the diagnosis of Pain Disorder With Psychological Factors [4]. The latter diagnosis is a vestige of historical misconceptions of chronic pain as hysterical in nature. In certain cases Conversion Disorder is a more appropriate diagnosis even when there is an underlying organic condition. As noted above, pseudoseizures in a patient with a history of seizure disorder is more appropriately diagnosed as Conversion Disorder. Similarly, a recent patient seen on our unit received a diagnosis of Conversion Disorder superimposed upon a diagnosis of primary lateral sclerosis. The latter caused her to experience some mild leg weakness. However, the gait, which resembled walking through thick mud, involved significant spasticity-like features, such as plantarflexion similar to cerebral palsy sufferers, with whom she had frequent contact. Formal
testing revealed almost normal strength with normal tone, reflexes and coordination. Mter careful assessment it was determined that the primary lateral sclerosis' accounted for only a minor proportion of her clinical presentation.
6.3. Diagnosis of conversion versus factitious disorder According to DSM IV in Conversion Disorder the symptoms are not consciously produced whereas in Factitious Disorder, the patient is consciously and thus intentionally feigning the symptoms [1]. Of course, the observer must infer that which is conscious versus that which is not conscious, an inference that is often difficult if not impossible to make. DSM IV suggests that the judgment that a symptom is intentionally produced should be based on direct evidence as when an individual with hematuria is found to have anticoagulants in his possession and blood studies are consistent with the ingestion of anticoagulants [1]. Although such evidence may be available in situations where actual organic symptoms are self-inflicted by the patient, there is no way to definitively distinguish conscious from unconscious intent in patients presenting with pseudo neurological symptoms like paralysis. In most patients with chronic 'conversion' motor disorders admitted to our inpatient unit, we have observed what appeared to be intentional production of symptoms [4,21]. Conscious intent was, by definition, inferred. For instance, a patient with ostensibly contracted fingers and paralyzed arms was unobtrusively observed propelling her own wheelchair. However, we wonder whether similar evidence for apparent intentional production of symptoms would be seen in most diagnosed Conversion Disorder patients during weeks of careful scrutiny in an inpatient rehabilitation setting. Miller has also addressed the difficulty in distinguishing between Conversion and Factitious Disorder [22]. ' .. .it is extremely difficult to find any way of discriminating between the behaviour of those with hysterical symptoms and the behaviour (actual or anticipated) of those who might be deliberately dissimulating ... Those with hysterical
R. W. Teasel!, A.P. Shapiro / NeuroRehabi/itation 8 (1997) 163-174 symptoms could still behave like those deliberately simulating in every possible way, yet the same behaviour could still represent a common end point resulting from two entirely different internal processes. While it is impossible to prove finally that any patient with a hysterical symptom is faking, it is equally impossible to prove that he is not, and the available evidence is consistent with the notion that hysterical symptoms might be nothing more than dissimulation. For those who wish to develop an empirically verifiable explanation of hysteria, basing the definition of the phenomenon itself on a criterion that cannot be reliably shown to be present or absent is, at best, highly unsatisfactory.' (p. 276)
Indeed, Miller has argued that the criterion of whether patients are consciously aware of producing their symptoms should be dropped from the definition of Conversion Disorder [22]. This would eliminate the distinction between Conversion and Factitious Disorder, at least for those patients whose symptoms are more specific to voluntary motor and sensory function (as opposed to selfinflicted organic conditions). Our experience with patients with conversion disorders in an inpatient rehabilitation setting also leads us to question the usefulness of this distinction. 7. Summary
Neurorehabilitation specialists often encounter chronic Conversion Disorders involving unexplained symptoms or deficits that mimic neurological disorders and affect voluntary motor and sensory functions. Historically, conversion symptoms were thought to reflect painful, intrapsychic conflict which was removed from awareness by converting it into a physical complaint. More recent behavioural theories view conversion disorders as a learned response to stressful circumstances and emphasize the influence of 'secondary gain' and particularly avoidance of noxious circumstances and positive environmental reinforcement in maintaining the condition. Historically, misdiagnosis was common with a significant number of patients initially diagnosed as suffering from Conversion Disorder later found to have an organic condition to account for their original symptoms. Although misdiagnosis can still occur, it is less likely given the availability of more sophisticated diagnostic instruments.
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Nonetheless, DSM IV cautions that the diagnosis of Conversion Disorder should be viewed as provisional because understanding of anatomical and physiological mechanisms is incomplete and there are inherent limitations in available methods for objective assessment [1]. Accurate diagnosis of Conversion Dis'order is facilitated by close observation of patients in an inpatient rehabilitation setting which usually reveals dramatic inconsistencies in symptom presentation, especially between that demonstrated during formal examination versus unobtrusive observations when the patient is engaged in distracting activities and/or is unaware of being observed. Traditional 'positive' signs of hysteria have not been validated and reliance on these signs especially in non-stoic female patients with a history of psychological difficulties will often result in a misdiagnosis of hysteria. Psychological and behavioural factors may affect the course of almost every major category of disease and in the majority of these cases, the correct diagnosis is Psychological Factors Affecting a Medical Condition, not Conversion or Somatoform Disorder. There are no definitive criteria that allow one to differentiate between intentional versus unconscious production of symptoms thus calling into question the distinction between Conversion and Factitious Disorders. References [1]
[2] [3] [4] [5]
[6]
Diagnostic and Statistical Manual of Mental Disorders (DSM IV). Washington: American Psychiatric Association, 1994. Merskey H. The Analysis of Hysteria. London: Royal College of Psychiatrists, 1995. Mai FM. 'Hysteria' in clinical neurology. Can J Neurol Sci 1995;22: 101-11 O. Shapiro AP, Teasell RW. Misdiagnosis of chronic pain as hysterical. NeuroRehabilitation 1997;8:201···222. Treischman RB, Stolov WC, Montgomery ED. An approach to the treatment of abnormal ambulation resulting from conversion reaction. Arch Phys Med Rehabil 1970. Sullivan MJL, Buchanan DC. The treatment of conversion disorder in a rehabilitation setting. Can J Rehabilitation 1989;2:175-180.
174 [7]
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Shapiro AP, Teasell RW. Strategic behavioural intervention in the inpatient rehabilitation of non-organic (factitious/conversion) motor disorders. NeuroRehabilitation 1997;8:183-192. [8] MacKinnon J. Physical therapy treatment of a patient with a conversion reaction: A case report. Physical Ther 1984;64: 1687. [9] Lazare A. Conversion symptoms. New Engl J Med 1981;305:745-748. [lO] Weintraub MI. Hysterical Conversion Reactions. A Clinical Guide to Diagnosis and Treatment. New York: Spectrum Publications, 1983. [11] Waddell G, McCulloch JA, Kummell E. Venner RM. Non-organic physical signs in low back pain. Spine 1980; 5: 117-125. [12] Gould R. Miller BL, Goldberg MA, Benson DF. The validity of hysterical signs and symptoms. J Nervous Mental Dis 1986; 174:593-597. [13] Slater E. Diagnosis of 'hysteria'. Br Med J 1965;i:1395-1399. [14] Slater E, Glithero E. A follow-up of patients diagnosed as suffering from hysteria. J Psychosom Res 1965;9:9-13.
[15]
[16]
[17]
[18]
[19]
[20] [21]
[22]
Gatfield PD, Guze PB. Prognosis and differential diagnosis of conversion reactions: a follow-up study. Dis Nerv Syst 1962;23:623-631. Raskin M, Talbott JA, Meyerson AT. Diagnosed conversion reactions: predictive value of psychiatric criteria. J Am Med Assoc 1966; 197: 150-154. Stefansson JG, Messina JA, Meyerowitz S. Hysterical neurosis, conversion type: clinical and epidemiological considerations. Acta Psychiatr Scan 1976;53:119-138. Watson CG, Burenen C. The frequency and identification of false positive conversion reactions. J Nerv Ment Dis 1979;167:243-247. Teasell RW, Sue-A-Quan G, Wolfe B. Osteomalacia as a cause of chronic pain: a case study. Pain Res Manag 1996;1 :69-72. Miller BL, Benson DB, Goldberg MA, Gould R. Misdiagnosis of hysteria. Am Fam Phys 1986;34:157-160. Teasell RW, Shapiro AP. Rehabilitation of chronic motor conversion disorders. Crit Rev Phys Rehab Med 1993;5:1-13. Miller E. Defining hysterical symptoms. Psycholog Med 1988;18:275-277.
NeuroRehabiIitation 8 (1997) 163-174
Diagnosis of conversion disorders in a rehabilitation setting Robert W. Teasell*,a Allan P. Shapiro b aDepartment of Physical Medicine and Rehabiltation,
University of Western Ontario and London Health Sciences Centre, University Campus, London, Ontario, Canada bPsychological Services, University of Western Ontario and London Health Sciences Centre, University Campus, London, Ontario, Canada
Abstract
Conversion disorders are unexplained symptoms or deficits that mimic neurological problems and affect voluntary motor and sensory functions. Historically, conversion symptoms were thought to reflect underlying psychological conflicts although recent behavioural theories view them as learned responses to stressful life circumstances and emphasize environmental contingencies in the maintenance of the disorder. Although early studies often revealed underlying organic disease in patients initially diagnosed with Conversion Disorder, this now occurs less frequently because of increased sophistication of diagnostic tools and better understanding of neurological disorders. However, misdiagnosis is still common because of reliance on 'negative' diagnostic testing and unvalidated 'positive signs' misinterpreted as indicative of hysteria. Psychological factors may affect the course of almost every major category of disease and in many cases a diagnosis of hysteria is not indicated and the more appropriate diagnosis is Psychological Factors Affecting A Medical Condition. It is not possible to definitively differentiate between conscious and unconscious production of symptoms thus blurring the distinction between Conversion and Factitious disorders. © 1997 Elsevier Science Ireland Ltd. Keywords: Conversion disorder; Factitious disorder; Psychological conflict
1. Introduction Conversion disorders and hysteria refer to organically unexplainable symptoms or neurological
* Corresponding author. Tel.: + 15196633235; fax: + 1519 6632941.
deficits that are linked primarily to psychological problems. This article will look at the current diagnostic criteria for defining hysterical disorders and proposed etiologies. The clinical presentations of patients with conversion disorders referred to a rehabilitation program specializing in management of these patients is presented. The potential danger of misdiagnosis of hysteria
1053-8135/97/$17.00 © 1997 Elsevier Science Ireland Ltd. All rights reserved. PH S 1 053-813 5(96) 00220-5
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is important to recognize. Finally, the difficulties in distinguishing conversion (unconscious) and factitious (conscious) disorders are discussed. Management of conversion disorders and the controversial issue of chronic pain and hysteria are reviewed in future articles. 2. Defining hysteria and conversion disorders Historically, the term 'hysteria' was most often used to describe the occurrence of physical symptoms in the absence of organic disease. Hysteria has been regarded as an unsatisfactory term and in recent years was dropped from the American Psychiatric Association's taxonomy of mental disorders. It was replaced by the term Somatoform Disorder. Like its predecessor, the term somatoform is used to denote the presence of physical symptoms that suggest a medical condition but cannot fully be accounted for by an underlying organic problem. The most recent edition of the American Psychiatric Association's ~axonomy of mental disorders (DSM IV, 1994) includes a variety of diagnoses under the general category of Somatoform Disorder [1]. These diagnoses are presented below. There is considerable overlap between these conditions which can make differential diagnosis problematic and confusing.
2.1. Conversion disorder This diagnosis refers to medically unexplained symptoms or deficits that typically mimic neurological disorders and affect voluntary motor (e.g. paralysis) or sensory (e.g. blindness) functions. 2. 2. Somatization disorder
This disorder was previously referred to as 'Briquet's Syndrome' or 'Hysterical Neuroses'. Somatization Disorder is characterized by multiple physical complaints that are without apparent organic basis or are far in excess of any underlying medical condition that might be present. A defining criterion is that the disorder begins before the age of 30 and extends over many years. The following constellation of unexplained symptoms must be present to make such a diagnosis: a
history of pain related to at least four different sites or functions (e.g. hip pain, joint pain, pain during sexual intercourse, pain during urination); a history of at least two gastrointestinal symptoms (e.g. nausea, vomiting, bloating, etc.); a history of one sexual or reproduction symptom (e.g. irregular menses, vomiting throughout pregnancy); and a history of at least one pseudo neurological symptom (e.g. paralysis). That is, by definition, individuals with Somatization Disorder also have a history of Pain Disorder and Conversion Disorder. However, it is the myriad of symptoms, early onset, and chronic course that differentiates Somatization Disorder from Conversion or Pain Disorder. Merskey suggests that Somatization Disorder be conceptualized as one end of a continuum of hysterical disorders [2].
2.3. Hypochondriasis This refers to the preoccupation with, and fear of having, a serious disease despite repeated physical exams, diagnostic testing, and reassurance that no serious condition is present. The most common focus or preoccupation is with cardiac, respiratory, or gastrointestinal function. This preoccupation is thought to reflect a patient's misinterpretation of normal bodily signs or symptoms. Mai has observed that Hypochondriasis is sometimes confused with Somatization Disorder because of its chronicity and the occasional occurrence of multiple somatic symptoms [3]. 2.4. Pain disorder In this disorder, pain is the primary focus of attention and complaint. Psychological factors are judged to be important in either its onset, severity, exacerbation, or maintenance. The inclusion of Pain Disorder within the general category of somatoform disorders has been controversial and is discussed elsewhere in this issue [4].
2.5. Other related diagnoses There are two other diagnoses which, although not included under the category of Somatoform Disorder, involve the interface of psychological
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factors and somatic symptoms: Factitious Disorder and Psychological Factors Affecting A General Medical Condition.
2.5.1. Factitious disorder In Factitious Disorder, there is an intentional production of symptoms simulating a medical condition. This includes fabrication of subjective complaints in the absence of an underlying organic condition (e.g. complaints of abdominal pain in the absence of any such pain); self-inflicted conditions such as skin infections produced by injection of substances under the skin; and/or the exaggeration of a preexisting condition (e.g. the feigning of seizures in an individual with a history of actual seizure activity). Multiple factitious symptoms may be present concurrently. The underlying motivation is thought to be a psychological need to assume the sick role. The most extreme and chronic version of this is referred to as Munchausen Syndrome and is associated with multiple hospitalizations, repeated attempts to stay in or be admitted to hospital, and a willingness to undergo multiple surgical procedures. Factitious Disorder should be differentiated from malingering. In malingering, the motivation for the intentional production of symptoms is some external incentive (e.g. a place to stay on a cold night) rather than a psychological need to assume the sick role. The symptom is readily discontinued once it is clear that the external incentive is no longer available or necessary (e.g. the weather gets better). Factitious Disorders are also differentiated from Conversion Disorder in that the latter is thought to be unconscious. In contrast, Factitious Disorder is thought to involve the conscious and intentional production of symptoms. However, as will be discussed below, the observer must infer that which is conscious versus unconscious. Ultimately, this inference is impossible to definitively make, thus blurring the distinction between Chronic Conversion Disorders and Factitious Disorders. 2.5.2. Psychological factors affecting a medical condition In Psychological Factors Affecting A Medical Condition, there is an underlying organic condi-
165
tion that is being adversely affected by psychological or behavioural factors. In a rehabilitation setting this is most commonly observed when depression or anxiety symptoms impede an individual's ability to engage in or optimally benefit from therapies. Other examples include the effect of personality traits on the course of a specific disease processes (e.g. the impact of 'Type A' behaviour on the course of cardiovascular disease). Similarly, stress-related physiological responses may exacerbate organic conditions as in the impact of stress on ulcers, hypertension, or inflammatory bowel disease. 3. Etiology
3.1. Psychoanalytic theories The term 'conversion' denotes an etiology by which anxiety associated with painful intrapsychic conflict is removed by somehow converting or transforming it into a physical complaint. For example, an individual, after an argument with a parent figure, experiences significant anger over what he perceives as a lack of nurturance and support. At the same time, he is 'quite conflicted about the outward expression of his rage for fear of retaliation and/or abandonment by this person. He develops paralysis of his arm. In this case, the conflict over expression of these forbidden impulses is symbolized by arm paralysis, i.e. an inability to strike out. Conversion of the emotional distress associated with this conflict into a physical symptom keeps the conflict out of awareness and at the same time provides an outlet for the psychic tension; this is referred to as 'primary gain'. In addition, the individual achieves 'secondary gain' when this parental figure responds to his medical problem with nurturance and support, the perceived absence of which was the precipitant to the original argument and ensuing conflict.
3.2. Behavioural/learning theories In contrast to traditional psychoanalytic formulations, behavioural (learning) theories of Conversion Disorder emphasize the importance of the
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external reinforcements (secondary gains) the patient derives by maintaining a physical dysfunction and associated disability. This may include escape from overwhelming or unwanted responsibilities or acquisition of support from family, friends, medical staff, or government agencies that would not be available otherwise. For instance, Treischman et a1. hypothesized that Conversion Disorders are a learned response to stressful circumstances [5]. Retreat into illness allows an individual to both avoid stressful circumstances and provides a great deal of support from the environment. Another behavioural concept that is helpful in understanding symptom development is 'modeling'. This refers to the observation that patients' symptom presentation is often consistent with the physical symptoms they have observed in others or have previously experienced themselves. The best example of the latter is occurrence of pseudo seizures in patients with a previous history of seizure disorder. Behavioural theories also distingujsh between factors involved in the original development of a disorder and those factors that are maintaining the response. In the case of a chronic Conversion Disorder, conflicts or environmental stressors that may have precipitated the disord9r may no longer be relevant and other factors may be maintaining the disorder. Sullivan and Buchanan argue that a critical factor in inhibiting resolution of chronic Conversion Disorders is that spontaneous remission may lead others to wonder if the symptoms had been feigned all along [6]. This is not inconsequential as any prolonged disability dramatically alters the life of all family members who often must make financial and emotional sacrifices. Shapiro and Teasell [7] delineate a number of other factors potentially inhibiting resolution of chronic conversion symptoms including: support and caring that the disability elicits; freedom from responsibility and expectations of others and anxiety regarding one's ability to meet these expectations upon resolution of disability; fears regarding loss of disability benefits and the anxiety about having to be successful in the work force once these benefits cease; and admiration from others for being 'strong' and apparently coping so well with the disability.
Table 1 DSM IV (1994) diagnostic criteria for conversion disorder [1] A.
One or more symptoms or deficits affecting voluntary motor or sensory function that suggest a neurological or other general medical condition.
B.
Psychological factors are judged to be associated with the symptom or deficit because the initiation or exacerbation of the symptom or deficit is preceded by conflicts or other stressors.
C.
The symptom or deficit is not intentionally produced or feigned (as in Factitious Disorder or Malingering).
D.
The symptom or deficit cannot, after appropriate. investigation, be fully explained by a general medical condition, or by the direct effects of a substance, or as a culturally sanctioned behaviour or experience.
E.
The symptom or deficit causes clinically significant distress or impairment in social, occupational, or other important areas of functioning or warrants medical evaluation.
F.
The symptom or deficit is not limited to pain or sexual dysfunction, does not occur exclusively during the course of Somatization Disorder, and is not better accounted for by another mental disorder. Subtypes With Motor Symptom or Deficit With Sensory Symptom or Deficit With Seizures or Convulsions With Mixed Presentation
4. Diagnostic criteria and associated features
4.1. Establishing the diagnosis DSM IV diagnostic criteria for Conversion Disorder appear in Table 1 [1]. Conversion Disorders typically present as symptoms or deficits affecting voluntary motor or sensory function. They usually mimic a neurological disorder. Within a Rehabilitation setting, one is most likely to see motor symptoms or deficits and particularly paralysis, paresis, and astasia-basia or ataxic-like symptoms. Merskey defines astasia-basia as unsteadiness of gait often presenting as bizarre incoordination especially in walking or standing still [2]. The defining criterion is that the symptoms cannot, after appropriate diagnostic investigations, be fully explained by an underlying organic condition. In
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addition to this 'negative' diagnostic finding, patients with conversion symptoms display 'positive' signs, i.e. symptoms that are quite inconsistent with known anatomical pathways and/or physiological mechanisms. This occurs because the symptoms follow the patient's conceptualization of the condition and the less medically sophisticated the individual, the more the symptoms will deviate from known physiological mechanisms. For instance, conversion 'paralysis' often presents as an inability to perform a particular movement or inability to move an entire body part rather than a deficit which corresponds to known patterns of motor innervation. MacKinnon identified four differentiating characteristics of hysterically based paralysis as opposed to organic paralysis: (1) paralysis not indicative of a particular nerve root pattern and tending to occur 'just below' major joints; (2) weakness of greater intensity proximally than distally; (3) normal reflexes; and (4) co-contractions, i.e. unacknowledged strength in antagonistic muscles during testing [8].
4.2. Specific epidemiologic features The onset of Conversion Disorders is believed to most commonly occur during late childhood to early adulthood, although occurrence in older adults is not infrequent. The female to male ratio has been reported as anywhere from 2:1 to 10:l. The incidence of Conversion Disorders is reported to be higher in rural areas, among lower socioeconomic groups, and following extreme psychological stress (e.g. in the military at time of war). Recurrence of conversIon symptomatology is thought to be common. Although Lazare reports increased incidence among certain immigrant populations, Conversion Disorder is not diagnosed if a symptom is fully explained as a culturally specific behaviour or sanctioned experi.ence [9]. For instance, in a variety of cultures, falling down with loss or alteration of consciousness has specialized and sanctioned functions.
4.3. Danger of misdiagnosis DSM IV cautions that even in the face of
167
unexplained and physiologically inconsistent symptomatology, the diagnosis of Conversion Disorder should be viewed as provisional because 'knowledge of anatomical and physiological mechanisms is incomplete and available methods of objective assessment have limitations' (p. 453) [1]. Indeed, as discussed later, in early studies of patients diagnosed with Conversion Disorder, a substantial proportion were later found to have an underlying organic condition that accounted for their original problems. Historically, the medical conditions that were most likely to be misdiagnosed as Conversion Disorder, especially in their early phases, were multiple sclerosis, myasthenia gravis, and systemic lupus erythematosus. A premorbid history of unexplained physical symptomatology that has resolved as abruptly as it emerged and particularly symptoms associated with a diagnosis of Somatization Disorder increases the likelihood that the symptoms indeed reflect a non-organic condition.
4.4. Inconsistencies in symptom presentation An inpatient rehabilitation setting is particularly well suited for establishing the accuracy of a non-organic diagnosis. This is because in such a setting patients are closely monitored throughout the day by staff (physiotherapy, occupational therapy, nursing, medicine) who often are intricately familiar with the clinical manifestation of the actual organic disorder and therefore can identify symptoms that deviate significantly from true organic conditions. Moreover, during the course of such an inpatient admission, staff may observe dramatic inconsistencies in symptom presentation, especially between that demonstrated during formal examination versus informal (unobtrusive) observation when the patient is engaged in distracting activities (e.g. exercise programs, occupational therapy, etc.). These inconsistencies in symptoms are critical in definitively establishing a non-organic diagnosis. Although DSM IV offers other diagnostic signs to aid in differential diagnoses, in reality, they are not particularly helpful [1]. For instance, the second criterion (Table 1) that psychological factors are associated with ini-
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tiation or exacerbation of the symptom is also true for many medical conditions and therefore has limited diagnostic utility.
Table 2 Clinical features of patients diagnosed with conversion disorder
4.5. Lack of good research
Total number of patients Age of onset of symptoms Gender
Good empirical research on Conversion Disorder is not in abundance. This is likely due to two factors. Firstly, conversion symptoms tend to onset abruptly and remit quickly. Therefore, they are less likely to come to the attention of academics in tertiary care university hospital settings. Indeed, our experience is primarily with chronic conversion disorders. Historically, studies on conversion disorders likely included a large proportion of individuals who were misdiagnosed and actually had organic illness (see later section on misdiagnosis). Similarly, it is difficult to differentiate between Conversion Disorder and Psychological Factors Affecting Physical Conditions. As well, patients presenting with pain or somatic symptoms secondary to pain likely were also included in these early studies on Conversion Disorders. Thus, the heterogeneity of the population studied calls into question the validity of much of the early research generated. 5. Clinical presentation of patients referred to rehabilitation with a diagnosis of conversion disorder We undertook a retrospective chart review of 38 consecutive patients referred to Physical Medicine & Rehabilitation (RT) with a diagnosis of disabling Conversion Disorder between September 1989 and February 1995. Diagnosis was made on the basis of negative diagnostic testing and obvious inconsistencies in symptom presentation best explained as non-organic in nature. Two patients (discussed below) proved to have an organic disorder. Patients with a primary diagnosis of chronic pain with secondary pseudo neurological features or abnormal illness behaviour (e.g. grimacing, pulling away) were not included in this group. Table 2 summarizes demographics and presenting symptoms of the 36 patients with Conversion Disorder. Age at onset averaged 37.9 years (range
Primary clinical feature Paralysis Astasia-basia or ataxia
36 37.9 (17-70) 30 females (83%) 6 males (17%) 27 (75%) 9 (25%)
Secondary clinical features Paralysis' Astasia-basia or ataxia" Bladder Pain Dysarthria
9 (25%) 19 (53%) 4 (t 1%)
Total number with paralysis' Total number with astasia-basi a
28 (78%) 13 (36%)
4
• Some patients exhibited signs of both paralysis and astasiabasia.
17-70 years). Although this is considerably older than reported in the literature [1] our patients had predominantly chronic Conversion Disorders while, as noted above, the majority of Conversion Disorder patients resolved quite quickly. This suggests that patients with chronic symptomatology may represent a somewhat distinct subgroup. Consistent with previous literature, the majority (83%) were female. Paralysis was the primary presenting problem in 75% of the sample. Indeed, Merskey notes that in developed countries, motor symptoms are the most frequently seen by psychiatrists [2]. Paralysis was typically not complete and usually manifested as hemiparesis, paraparesis, or weakness. This was sometimes accompanied by spasticity and dystonic posturing. Non-organic paralysis or profound weakness is readily diagnosable. It is characterized by simultaneous contraction of agonist and antagonist muscles. Weakness is 'give-way' or ratchet like in nature with a give-way contraction quality. Reflexes are normal or purposely exaggerated. Another common test for leg weakness is Hoover's Sign. The patient is asked to lift the involved leg off the bed while lying supine. In true (organic) weakness the effort of attempting to lift
R. W. Teasel!, A. P. Shapiro I NeliroRehabilitation 8 (1997) 163-174
the leg off the bed results in a strong downward force on the opposite heel. In hysterical weakness, the patient does not make a full effort and hence the downward force of the other heel is absent. Arm paralysis can also be tested. While the patient is supine the jnvolved arm is supported suspended above the face. In organic weakness releasing the arm will result in it falling and striking the face. With hysterical paralysis, the arm generally falls to the side of the face. After paralysis, the most common (25%) presenting complaint was astasia-basia, a form of unsteady gait which most resembles ataxia. It is characterized by bizarre incoordination where the patient staggers and sways acrobatically. Patients often stumble into walls but remain upright and rarely fall. The coordination and balance required to remain upright in contorted positions is often remarkable and is one way to distinguish astasiabasia from true ataxia. The unusual gait generally cannot be maintained while walking backwards or sideways. Leg movements are performed normally while lying down or sitting. Abnormal movements are sometimes seen apart from astasia-basia. Dystonic posturing and hysterical tremoring are common abnormal movements seen. Observing the patient when asleep or when they believe they are not being observed may allow discrepancies to be realized. However, there are obvious limitations given that some organic conditions may not manifest while sleeping or resting. Bladder problems, either incontinence or retention, was present in 25% of our sample. In our experience patients would allow bladder retention of up to almost 1 liter and several required intermittent catheterizations to empty their bladder. Foley indwelling catheters were present in others. One patient remarkably had an ileo-conduit where ureters were hooked up to an isolated piece of bowel emptying into a colostomy bag. Over half the patients reported pain of undetermined origin. It was of course, not possible to determine if they were experiencing any significant underlying pain. However, it is of note that their presentation was often quite distinct from that typically seen in chronic pain patients where pain is presumably musculoskeletal in origin.
169
Specifically, conversion disorder patients routinely assumed static, dystonic postures or exhibited bizarre swaying and incoordination while walking. One never sees this in typical musculoskeletal pain patients because such postures and jerky movements would typically be associated with significant increases in pain. Accordingly, it was our impression that pain, if present, was likely not particularly severe or problematic. 'La belle indifference' is characterized by an inappropriate absence of distress despite the presence of a disorder which should normally elicit distress [3]. Emotional difficulties are similarly denied [3]. Although historically, la belle indifference was often considered a 'positive sign' for conversion, this is no longer the case. DSM IV notes that it mayor may not be present in Conversion Disorder patients [1]. Although we did not systematically enumerate its presence, it was our impression .that the great majority of our patients (approx. 75%) showed a relative lack of concern about their disability and insisted that they had no emotional problems and had adapted well to their disability. 6. Misdiagnosis The diagnosis of Conversion Disorder is often made erroneously. Misdiagnosis usually takes one of two forms: (1) patients are diagnosed with Conversion Disorder but later turn out to have an organic disorder accounting for their symptoms; or (2) conversion or hysteria is diagnosed when psychological factors are merely exacerbating a medical condition in which case the diagnosis Psychological Factors Affecting Medical Condition is more appropriate. Each of these misdiagnoses will be discussed in turn. 6.1. Patients with an organic disorder As noted above, DSM IV cautions that the diagnosis of Conversion Disorder should be provisional because our knowledge of physiological mechanisms is incomplete and therefore the apparent absence of underlying pathophysiology is not proof of an actual non-organic symptom [1]. As noted above, in non-organic motor disorders
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(paralysis, astasia-basia) seen in rehabilitation settings, there are certain 'positive' signs which are inconsistent with known physiological mechanisms (e.g. unacknowledged strength in antagonist muscles) and point very strongly to a nonorganic diagnosis. However, even in these cases we are typically cautious and a definitive diagnosis is only made once staff observe striking discrepancies in what patients can do when formally tested versus when engaged in distracting activities or are unaware that they are being observed. There are other 'positive' signs which are thought to reflect conversion disorder [10,11] but the validity of these signs has never been established. Table 3 lists a number of these signs. Gould et al. [12] carried out a systematic examination of neurologically impaired patients for seven of the supposed signs of hysteria which included: a history suggestive of hypochondriasis; potential secondary gain; la belle indifference; non-anatomic or patchy sensory loss; changing boundarie~ of analgesia; sensory loss to pinprick or vibratory stimulation that stopped at the midline; and giveway weakness. They examined 30 patients with cerebral injury, 29 of whom had suffered a stroke. Every patient had at least one of these signs, one patient had all seven and the mean number per patient was 3.4. They concluded that these signs lacked validity and if regarded as pathogonomic of hysteria, could easily lead to misdiagnosis. Elsewhere, we have criticized the 'non-organic' signs often misinterpreted as evidence that chronic musculoskeletal pain disorders are psychogenic [4]. Therefore, the diagnosis of Conver-
Table 3 Positive signs and symptoms of hysteria History suggestive of hypochondriasis Potential secondary gain 'La belle indifference' Failure of sensory loss to conform to recognized anatomical patterns Changing patterns of sensory loss on multiple examinations Alterations of sensory and motor findings with suggestion Hemianesthesia that splits the midline Unilateral loss of vibratory sense when the two sides of the forehead or of the sternum are sequentially stimulated Giveway weakness on motor testing
sion Disorder based solely upon traditional signs and symptoms must be made with great caution, as it may prove to be incorrect. Table 4 summarizes a number of studies which retrospectively followed previously diagnosed patients with Conversion Disorders to determine what percentage actually turned out to have undiagnosed organic conditions that accounted for the initial symptomatology. Although the studies were completed before CT and MRI scanning were available, they illustrate that reliance on 'negative' findings and unvalidated 'positive' signs often results in misdiagnosis. Specifically, these studies revealed that between 13% and 48% of patients had been erroneously diagnosed with Conversion Disorder [13-18]. Although the availability of modern diagnostic testing techniques (e.g. CT and MRI scanning) has made it easier to identify neurological dis-
Table 4 Retrospective follow-up of patients originally diagnosed as conversion disorder Study
No. of patients diagnosed as conversion disorder
Length of follow-up
%with organic illness
Slater [13] Slater and Glithero [14] Gatfield and Guze [15] Raskin et al. [16] Stcfansson et al. [17] Watson and Burenon [18]
112
10 years 7-11 years 2.5-10 years 6·-12 months 3.3 years 10 years
3D 21 14 13
99
24 50 64
40 - - - - - - - - - - - - - - _ .. _.......... _...._.. _ - - - - - -
48%
25
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orders such as multiple sclerosis, misdiagnosis still occurs. We have had two recent cases. One was a nursing assistant on a neurological ward who developed paraparesis secondary to transverse myelitis. Her exposure to patients with similar paralysis was mistakenly interpreted as providing a 'model' for her symptoms. The second case was a young woman with a bizarre gait pattern and chronic knee and back pain who had seen numerous specialists. She turned out to have a rare form of renal phosphate-wasting osteomalacia with long-standing bilateral fractured hips and avascular necrosis [19]. She later was found to have a scapular sarcoma, which was resected and accounted for the hypophosphatemia, a paraneoplastic phenomena. She had been attempting to walk on fractured hips for 3 years which accounted for her abnormal gait. Marked stoicism was misinterpreted as 'Ia belle indifference'. Miller et al. reviewed 25 cases of serious neurologic disease originally diagnosed by other physicians as hysteria or a functional disorder [20]. In most of these cases the eventual diagnosis was confirmed by either radiographic or pathologic examination. The following patient characteristics were associated with misdiagnosis: (1) female gender; (2) prior psychiatric illness; (3) plausible psychodynamic explanations for the medical problems; and (4) exaggerated physical presentation. This study suggests that a history of psychological difficulties combined with relative lack of stoicism in a female patient is often misinterpreted as suggestive of 'hysteria'.
Table 5 DSM IV (I994) diagnostic criteria for psychological factor affecting a general medical condition [I] A.
A general medical condition is present.
B.
Psychological factors adversely affect the general medical condition in one of the following ways: (I) the factors have influenced the course of the general medical condition as shown by a close temporal association between the psychological factors and the development or exacerbation of. or delayed recovery from. the general medical condition (2) the factors interfere with the treatment of the general medical condition (3) the factors constitute additional health risks for the individual (4) stress-related physiological responses precipitate or exacerbate symptoms of the general medical condition
Subtypes 1. Mental Disorder Affecting a General Medical Condition. For example. a mental disorder such a Major Depressive Disorder delaying recovery from a myocardial infarction. 2.
Psychological Symptoms Affecting a General Medical Condition. For example, depressive symptoms delaying recovery from surgery; anxiety exacerbating asthma.
3.
Personality Traits or Coping Style Affecting a General Medical Condition. For example, pathological denial of the need for surgery in a patient with cancer; hostile, pressured Type A behaviour contributing to cardiovascular disease.
4.
Maladaptive Health Behaviours Affecting a General Medical Condition. For example, overeating; lack of exercise; unsafe sex.
5.
Stress-Related Physiological Response Affecting a Gel/eral Medical Condition. For example, stress-related exacerbations of ulcer, hypertension, arrhythmia, or tension headache.
6.
Other or Unspecified Psychological Factors Affecting a General Medical Condition. For example, interpersonal, cultural, or religious factors.
6.2. Patients with psychological factors affecting a medical condition
Psychological factors often have a direct or indirect effect upon organic symptomatology but in the majority of cases, a diagnosis of hysteria is inappropriate. Table 5 lists diagnostic criteria for Psychological Factors Affecting A Medical Condition. Although this diagnosis is included in DSM IV it is not considered to be a mental disorder per se [1]. It is reserved for those situations in which psychological factors have a significant effect on the course or outcome of a medical condition or place the patient at higher risk for an
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adverse outcome. DSM IV notes that 'psychological and behavioural factors may affect the course of almost every major category of disease, including cardiovascular conditions, dermatological conditions, endocrinological conditions, gastrointestinal conditions, neoplastic conditions, neurological conditions, pulmonary conditions, renal condi-
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tions and rheumatological conditions.' (p. 676). Physicians need to remain cognizant of the multitude of ways in which psychological factors can impact upon an organic condition. These are listed in Table 5. For instance, a diagnosable mental disorder can affect the course of a condition as when a major affective (depression) disorder affects a rehabilitation patient's ability to engage in physical therapy. Psychological symptoms which do not constitute a mental disorder per se can affect a medical condition as when the effects of anxiety and depression on cognition further exacerbates cognitive function in a brain injured patient. Personality traits or a maladaptive coping style can affect the course of treatment as when highly perfectionist patients with chronic pain insist they are totally disabled because of an inability to maintain their premorbid extremely high levels of job performance. Maladaptive health behaviours can affect a general medical condition as when poor nutrition interferes with rehabilitation of elderly patients. Stress-related physiological responses can significantly affect the course or treatment of a condition as when stressful circumstances increase pain symptomatology in musculoskeletal pain patients. Elsewhere in this issue we argue that when psychological factors are significantly affecting musculoskeletal pain disorders, a more appropriate diagnosis is Psychological Factors Affecting A Medical Condition rather than the diagnosis of Pain Disorder With Psychological Factors [4]. The latter diagnosis is a vestige of historical misconceptions of chronic pain as hysterical in nature. In certain cases Conversion Disorder is a more appropriate diagnosis even when there is an underlying organic condition. As noted above, pseudoseizures in a patient with a history of seizure disorder is more appropriately diagnosed as Conversion Disorder. Similarly, a recent patient seen on our unit received a diagnosis of Conversion Disorder superimposed upon a diagnosis of primary lateral sclerosis. The latter caused her to experience some mild leg weakness. However, the gait, which resembled walking through thick mud, involved significant spasticity-like features, such as plantarflexion similar to cerebral palsy sufferers, with whom she had frequent contact. Formal
testing revealed almost normal strength with normal tone, reflexes and coordination. Mter careful assessment it was determined that the primary lateral sclerosis' accounted for only a minor proportion of her clinical presentation.
6.3. Diagnosis of conversion versus factitious disorder According to DSM IV in Conversion Disorder the symptoms are not consciously produced whereas in Factitious Disorder, the patient is consciously and thus intentionally feigning the symptoms [1]. Of course, the observer must infer that which is conscious versus that which is not conscious, an inference that is often difficult if not impossible to make. DSM IV suggests that the judgment that a symptom is intentionally produced should be based on direct evidence as when an individual with hematuria is found to have anticoagulants in his possession and blood studies are consistent with the ingestion of anticoagulants [1]. Although such evidence may be available in situations where actual organic symptoms are self-inflicted by the patient, there is no way to definitively distinguish conscious from unconscious intent in patients presenting with pseudo neurological symptoms like paralysis. In most patients with chronic 'conversion' motor disorders admitted to our inpatient unit, we have observed what appeared to be intentional production of symptoms [4,21]. Conscious intent was, by definition, inferred. For instance, a patient with ostensibly contracted fingers and paralyzed arms was unobtrusively observed propelling her own wheelchair. However, we wonder whether similar evidence for apparent intentional production of symptoms would be seen in most diagnosed Conversion Disorder patients during weeks of careful scrutiny in an inpatient rehabilitation setting. Miller has also addressed the difficulty in distinguishing between Conversion and Factitious Disorder [22]. ' .. .it is extremely difficult to find any way of discriminating between the behaviour of those with hysterical symptoms and the behaviour (actual or anticipated) of those who might be deliberately dissimulating ... Those with hysterical
R. W. Teasel!, A.P. Shapiro / NeuroRehabi/itation 8 (1997) 163-174 symptoms could still behave like those deliberately simulating in every possible way, yet the same behaviour could still represent a common end point resulting from two entirely different internal processes. While it is impossible to prove finally that any patient with a hysterical symptom is faking, it is equally impossible to prove that he is not, and the available evidence is consistent with the notion that hysterical symptoms might be nothing more than dissimulation. For those who wish to develop an empirically verifiable explanation of hysteria, basing the definition of the phenomenon itself on a criterion that cannot be reliably shown to be present or absent is, at best, highly unsatisfactory.' (p. 276)
Indeed, Miller has argued that the criterion of whether patients are consciously aware of producing their symptoms should be dropped from the definition of Conversion Disorder [22]. This would eliminate the distinction between Conversion and Factitious Disorder, at least for those patients whose symptoms are more specific to voluntary motor and sensory function (as opposed to selfinflicted organic conditions). Our experience with patients with conversion disorders in an inpatient rehabilitation setting also leads us to question the usefulness of this distinction. 7. Summary
Neurorehabilitation specialists often encounter chronic Conversion Disorders involving unexplained symptoms or deficits that mimic neurological disorders and affect voluntary motor and sensory functions. Historically, conversion symptoms were thought to reflect painful, intrapsychic conflict which was removed from awareness by converting it into a physical complaint. More recent behavioural theories view conversion disorders as a learned response to stressful circumstances and emphasize the influence of 'secondary gain' and particularly avoidance of noxious circumstances and positive environmental reinforcement in maintaining the condition. Historically, misdiagnosis was common with a significant number of patients initially diagnosed as suffering from Conversion Disorder later found to have an organic condition to account for their original symptoms. Although misdiagnosis can still occur, it is less likely given the availability of more sophisticated diagnostic instruments.
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Nonetheless, DSM IV cautions that the diagnosis of Conversion Disorder should be viewed as provisional because understanding of anatomical and physiological mechanisms is incomplete and there are inherent limitations in available methods for objective assessment [1]. Accurate diagnosis of Conversion Dis'order is facilitated by close observation of patients in an inpatient rehabilitation setting which usually reveals dramatic inconsistencies in symptom presentation, especially between that demonstrated during formal examination versus unobtrusive observations when the patient is engaged in distracting activities and/or is unaware of being observed. Traditional 'positive' signs of hysteria have not been validated and reliance on these signs especially in non-stoic female patients with a history of psychological difficulties will often result in a misdiagnosis of hysteria. Psychological and behavioural factors may affect the course of almost every major category of disease and in the majority of these cases, the correct diagnosis is Psychological Factors Affecting a Medical Condition, not Conversion or Somatoform Disorder. There are no definitive criteria that allow one to differentiate between intentional versus unconscious production of symptoms thus calling into question the distinction between Conversion and Factitious Disorders. References [1]
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[6]
Diagnostic and Statistical Manual of Mental Disorders (DSM IV). Washington: American Psychiatric Association, 1994. Merskey H. The Analysis of Hysteria. London: Royal College of Psychiatrists, 1995. Mai FM. 'Hysteria' in clinical neurology. Can J Neurol Sci 1995;22: 101-11 O. Shapiro AP, Teasell RW. Misdiagnosis of chronic pain as hysterical. NeuroRehabilitation 1997;8:201···222. Treischman RB, Stolov WC, Montgomery ED. An approach to the treatment of abnormal ambulation resulting from conversion reaction. Arch Phys Med Rehabil 1970. Sullivan MJL, Buchanan DC. The treatment of conversion disorder in a rehabilitation setting. Can J Rehabilitation 1989;2:175-180.
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Shapiro AP, Teasell RW. Strategic behavioural intervention in the inpatient rehabilitation of non-organic (factitious/conversion) motor disorders. NeuroRehabilitation 1997;8:183-192. [8] MacKinnon J. Physical therapy treatment of a patient with a conversion reaction: A case report. Physical Ther 1984;64: 1687. [9] Lazare A. Conversion symptoms. New Engl J Med 1981;305:745-748. [lO] Weintraub MI. Hysterical Conversion Reactions. A Clinical Guide to Diagnosis and Treatment. New York: Spectrum Publications, 1983. [11] Waddell G, McCulloch JA, Kummell E. Venner RM. Non-organic physical signs in low back pain. Spine 1980; 5: 117-125. [12] Gould R. Miller BL, Goldberg MA, Benson DF. The validity of hysterical signs and symptoms. J Nervous Mental Dis 1986; 174:593-597. [13] Slater E. Diagnosis of 'hysteria'. Br Med J 1965;i:1395-1399. [14] Slater E, Glithero E. A follow-up of patients diagnosed as suffering from hysteria. J Psychosom Res 1965;9:9-13.
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Gatfield PD, Guze PB. Prognosis and differential diagnosis of conversion reactions: a follow-up study. Dis Nerv Syst 1962;23:623-631. Raskin M, Talbott JA, Meyerson AT. Diagnosed conversion reactions: predictive value of psychiatric criteria. J Am Med Assoc 1966; 197: 150-154. Stefansson JG, Messina JA, Meyerowitz S. Hysterical neurosis, conversion type: clinical and epidemiological considerations. Acta Psychiatr Scan 1976;53:119-138. Watson CG, Burenen C. The frequency and identification of false positive conversion reactions. J Nerv Ment Dis 1979;167:243-247. Teasell RW, Sue-A-Quan G, Wolfe B. Osteomalacia as a cause of chronic pain: a case study. Pain Res Manag 1996;1 :69-72. Miller BL, Benson DB, Goldberg MA, Gould R. Misdiagnosis of hysteria. Am Fam Phys 1986;34:157-160. Teasell RW, Shapiro AP. Rehabilitation of chronic motor conversion disorders. Crit Rev Phys Rehab Med 1993;5:1-13. Miller E. Defining hysterical symptoms. Psycholog Med 1988;18:275-277.
