Develop. Med. Child Neurol. 1975, 17, 749-756
‘Dilapidated’ Speech: Developmental Verbal Dyspraxia Peggg C. Ferrly Sglvia M. Hall Jeffreg L. Hicks
Introduction “In some cases of defect of speech the patient seems to huve lost much of his pow’er to do mything he is toll to do, even with those muscles that are not paralysett. Thus, a patient will be unuble to put out his tongue when we ask him, although he will use it well it1 semi-involuntary actionsfor example, eating and swallowing. He will not make the purticsrlar grimace he i s told to do, even when we make one for him to imitate. There is power in his muscles und in the centres for coordinution oj‘muscxiur groups, but he-the whole man, or the ‘will ’-cannot set them agoitrg .” Thus, in his classic paper published in 1866, Jackson first described verbal and lingual dyspraxia in adults with acquired brain disease. Only recently has verbal dyspraxia been described in childhood (Morley 1965). Verbal dyspraxia is a neurological disorder of speech manifest by impaired ability-in the absence of overt motor or sensory paralysis-to carry out purposeful movements of the organs of articulation. Synonyms in the literature include : articulatory apraxia, apraxia of speech, apraxic dysarthria, and cortical dysarthria. Because the condition in children and
young adults appears to be present from infancy, typically produces poorly intelligible speech rather than mutism, and may occur in the absence of oral dyspraxia, the term ‘developmental verbal dyspraxia’ (DVD) most clearly describes the clinical features. Critchley recently characterised children with this disorder as having ‘dilapidated‘ speech (Edwards 1973). The purpose of the present communication is to describe the clinical features and results of a neurological investigation of 60 patients with developmental verbal dyspraxia.
Methods Forty of the 60 patients were referred to the University of Oregon Health Sciences Center because of ‘delayed speech’ ( N = 26) or poor response to speech therapy ( N = 14). The other 20 patients were identified in a study of ambulatory, non-verbal residents at a state institution for mentally retarded persons. Ages of patients ranged from four years to 30 years, the great majority (42) being between four and 10 years of age. There were 40 male and 20 female patients. All the patients received physical
Correspondence fo Peggy C . Ferry, M.D., Division of Child Development, Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232. D
749
DEVELOPMENTAL MEDICINE AND CHILD NEUROLOGY.
1975, 17,
infants were born by caesarean section, one was born following a prolonged labor, and one was said to have suffered ‘mild asphyxia’ a t birth. The great majority, however, appeared to have had normal births. Of interest was a positive family history of ‘speech or articulation problem’, not specified further, noted in 17 cases, usually in a male relative (father or brother). Two sets of brothers (not twins) with almost identical dyspraxic speech are included in this survey. Because of the presenting symptom of ‘delayed speech’, many of the patients initially were considered to be mentally retarded. However, it was found that 29 of the 60 patients had IQS over 90 (Table I).
and neurological examinations, psychometric testing, and a detailed audiological, speech and language evaluation-including assessment of auditory comprehension, conversational and expository speech, verbal and non-verbal oral agility, visual naming, and symbol and word recognition and discrimination. In the institutionalised patients, supplementary non-language tests (including tests for bucco-facial and limb apraxia) were done following the format of the Boston Diagnostic Aphasia Tests (Goodglass and Kaplan 1972). Psychometric evaluation was performed by psychologists and included tests of nonverbal intelligence such as the Ammons and Ammons Full Range Vocabulary Test and Raven Progressive Matrices. Electroencephalograms were done on the institutionalised patients. Audiometric testing (air conduction 512 and 4000Hz)was done using earphones. The diagnosis of developmental verbal dyspraxia was based on the following criteria. 1. A significant (at least one year) delay in speech development. 2. Normal hearing. 3. A normal or disproportionately high receptive language level. 4. Inconsistent omissions, substitutions and distortions of speech sounds. 5. Increasing articulation difficulty with more complex phonetic combinations. 6 . Groping and struggling to achieve correct positioning of the muscles of articulation. 7. An elaborate gestural system. 8. Slow or limited progress in conventional speech therapy.
Neurological Findings Associated developmental and neurological problems are given in Table 11. All patients were ambulatory, capable of self-care, and free of major neurological deficits such as frank cerebral palsy; none had seizures. Two of the institutionalised TABLE I IQs of patients in study Intelligence levels 11c120 100-109 9c99 80-89 70-79 60-69 40-60
No. of patients
12
TABLE I1 Associated neurological problems Findings
Findings The majority of the patients in the study had been of normal birthweight, with the exception of five who weighed between 1.8kg and 2.3kg. Birth records showed no definite evidence of perinatal injury; four
Orofacial dyspraxia Mild spastic diplegia Mild motor retardation Hand tremor Hemiplegia Choreiform movements
750
No. of patients 36 13 10
2 1 1
PEGGY C. FERRY
SYLVIA hl. HALL
residents had Down’s syndrome. No abnormal gag, pharyngeal, or jaw-jerk reflexes were found in any patient. There was no lingual atrophy. Of striking significance, however, is the high percentage of patients with associated signs of oral and/or facial dyspraxia. This was often the first sign of neurological dysfunction and was evidenced by persistent and excessive drooling and difficulty with chewing, licking and sucking movements. Parents frequently commented that as infants the patients sucked poorly and took excessive time to nurse, and that as the patients grew older mealtimes were laborious and lengthy.
JEFFREY L. HICKS
had temper tantrums and outbursts of rage, 14 suffered depression and were withdrawn, and four were ‘autistic’. Aggressive rage or temper outbursts often occurred in direct relation to the child’s frustration at being unable to communicate with those around him. Experienced clinicians likened the behavior to that of deaf children who are unable to make themselves understood. A variety of behavior and medical therapies had been tried, including behavior modification, tonsillectomy, clipping of the lingual frenuluni, and patterning therapy. In one particularly cruel instance, a mother was told to ignore her young son when he pointed or gestured to indicate what he wanted, for in doing so she was “inappropriately reinforcing his gestural behavior”. Other diagnostic and therapeutic recommendations had included referral for complete neurological examination (including skull x-ray, EEG, brain scan, and spinal tap), psychological testing (to look for an ‘emotional block’), orthodontic treatment, and psychiatric evaluation of ‘the child’s lack of motivation to talk‘. Electroencephalograms done on the 20 institutionalised patients were mildly and non-specifically abnormal in all cases, with mild, generalised slowing and occasional sharp wave activity. No localised abnormalities were seen.
Speech Characteristics The dyspraxic speech varied from nonexistent to partially intelligible or intelligible only to those who knew the patient well. Because of the wide range of ages involved, no specific correlations could be made between the severity of the articulation problem and other clinical features. The patients presented a strikingly uniform clinical picture of normal or near-normal auditory and visual receptive ability with paradoxically poor speech. Even the youngest had developed delightfully ingenious gestures and pantomimes in a valiant attempt to communicate with those around them. Patients had spent from one to 1 1 years in speech therapy, with painfully slow or minimal improvement. One therapist commented : “Progress in speech therapy has been slow and frustrating to both patient and therapist”. In these patients, useful speech was unlikely to develop after the age of six years if it had not done so already.
Discussion Two-thirds of all children have difficulty with articulation in early stages of speech development, but by the age of five years only 14 per cent have persisting articulation deficits. However, the great ma-jority of children referred to school speech therapists are seen for defects in articulation (Morley 1969). Many of these youngsters improve spontaneously, but in the large group of ‘functional articulation problems’, cases of developmental verbal
Associated Psychiatric Problenis Almost all the patients had significant behavioral or emotional problzms: 32 75 1
DEVELOPMENTAL MEDICINE AND CHILL) NEUROLOGY.
1975, 17
immensely complex and imperfectly understood. Whole books have been devoted to lingual muscle spindle activity, found in both intrinsic and extrinsic muscles (Bowman 1971). Differential, three-dimensional, interdigitated orientation of the tongue muscle-fibers is linked with at least 10 possible responses to a single movement or stretch. Sussman (1972) has shown that each lingual unit is associated with a discrete receptive field on the dorsal surface of the tongue. Through the hypoglossal nerve, afferent and efferent fibers are thought to form a short-latency, rapidly-acting feedback system from the lingual-muscle spindle to and from the motor cortex. As was concluded in a recent monograph devoted to the anatomy and physiology of speech, “we know that to accomplish the phenomenon of speech, a superb and complex mechanism must formulate and unify and monitor the process. But precisely where this ultimate speech control center resides and how it accomplishes its task is still not known to us.” (Sheets 1973). The cause of developmental verbal dyspraxia is completely unknown. The majority of afflicted children are free of other major neurological deficits. The predominance in males and familial tendency suggest a genetic component, the exact nature of which is unknown. No specific prenatal injury, birth trauma, or postnatal etiological factors have been identified. The condition bears many similarities to congenital suprabulbar paresis. WorsterDrought (1974) described the congenital, spastic weakness of muscles of the soft palate, pharynx and tongue, usually associated with exaggerated jaw jerks, hyperactive gag or snout reflexes, or wasting of the tongue. The distinction may be one of degree, and there are many overlapping features. Worster-Drought suggested that suprabulbar palsy is due
dyspraxia (DvD) undoubtedly are more common than have been recognised. Few of these children have careful neurological examinations of their speech and orofacial structures, and most clinicians or physicians do not appreciate the neurological significance of the presenting abnormalities, so that the dyspraxia is not recognised.
Historical Aspects Morley (1965) included a chapter on ‘developmental articulatory apraxia’ in her review of speech defects in children of one thousand families in Newcastle-uponTyne. She described 12 children with delayed speech not due to mental retardation or hearing loss who had dyspraxic articulation. In 1969 her observations were extended in a paper on articulation disorders. Similar but brief references were made to apraxic speech disturbances in association with ‘developmental aphasia’ by Critchley (1952) and Beiiton (1964). At the convention of the American Speech and Hearing Association, Darley (1968) presented a review of acquired ‘apraxis of speech’ in adults and mentioned that a childhood form of the condition had been recognised. But it remained for Rosenbek and Wertz (1972) to publish the first series of 50 cases in children. These authors noted a preponderance of males and made a plea for separating apraxic speech from so-called ‘functional’ articulation disorders. They noted that developmental apraxia of speech may be the only sign of cerebral dysfunction, especially in younger children. In 1973 Edwards reviewed the characteristics of developmental verbal dyspraxia and described theories of proprioception and perception in relation to etiology. Etiology The anatomical and physiological substrates of speech sound production are
752
PEGGY C. FERRY
SYLVIA M. HALL
to a developmental defect of the motor tract running from the lower part of the motor (Rolandic) area of the cortex to the tenth and twelfth cranial nerve nuclei- i.e. “a relative agenesis or hypogenesis of the motor tract” (Worster-Drought 1974). Edwards (1973) has observed that some children with DVD speak more clearly when outside sound-stimuli are masked hy earphones. She suggests that dyspraxic children are unable to handle the barrage of multi-sensory inputs and to integrate and organise them so that the necessary productive action of the tongue muscles can be initiated. Geshwind (1964) has postulated that the disorder could represent some developmental disruption in the cerebral association pathways, such as the arcuate fasciculus running from the parietal operculum to the motor cortex. Since no autopsy studies have been performed, the exact basis for this puzzling, highly selective speech disorder remains elusive.
JEFFREY L. HICKS
myotonic dystrophy, and the syndrome of acquired language disorder with convulsive disorder and EEG abnormality (Gascon et a/. 1973). Careful history and neurological examination will provide the correct diagnosis. Excessive drooling, early feeding difficulties and ‘delayed speech’ are characteristic of both Moebius syndrome and myotonic dystrophy, but in these disorders the speech itself is dysarthric, not dyspraxic, in character. The bilateral peripheral facial weakness, genetic aspects, and associated neurological findings make the distinctions clear. The syndrome of acquired aphasia, seizures, and abnormal EEG presents in childhood. It may he associated with facial apraxia but includes receptive as well as expressive language difficulties; the major distinction from DVD is that it occurs in a previously healthy child, rather than being present from birth (Gascon et 01. 1973). Treatment Chappell (1973) reviewed the wide variety of treatment programs that have been used in DVD, including the audiroryvisual stimulation approach, verbal instruction, behavior modification of key articulation gestures, and the motokinetic approach. Since the natural history of the disorder varies widely, no one therapeutic regime has been shown to be unequivocally superior. No controlled studies have been done to show the benefit of treatment over waiting for spontaneous improvement with maturation. Our experience with the severe form suggests that, as with other congenital organic disorders of speech, if useful speech has not developed by the age of six years it is unlikely to d o so thereafter. Many children with DVD spend futile, frustrating and expensive months or years in speech therapy. Far more rational is the current policy of reconimending a trial of intensive (daily) speech therapy by an experienced clinician for
Djferential Diagnosis Neurologists examining children with ‘poor’ or ‘delayed speech’ or ‘dysarthria’ must become proficient with examination techniques specifically designed to evaluate disordered speech and language. The evaluation should provide assessment of receptive language and of expressive speech, including phonology, morphology, syntax, semantics, orofacial movements and pertinent oropharygeal reflexes. Assessment of non-verbal IQ and hearing acuity are essential. I n addition, special tests for orofacial dyspraxia such as described by Goodglass and Kaplan (1972) are helpful. Children who are reluctant or unable to talk will often partake eagerly in the ‘whistling, blowing, clicking, sucking, and chewing’ games of oral dyspraxia testing. Besides suprabulbar paresis, other neurological disorders which may be confused with DVD include Moebius syndrome,
753
DEVELOPMENTAL MEDICINE AND CHILD NEUROLOGY.
six months; if significant improvement has not occurred, consideration is then given to alternative forms of therapy. Recent studies of deaf children have shown that nulestones in acquiring signlanguage parallel those of spoken language (Schlesinger and Meadow 1972) : children at 12 months of age can begin to learn sign-language and its use does not interfere with speech acquisition. Increasingly, experienced clinicians are recommending total communication therapy-(using all available means of communication : gesturing, manual sign-language, finger-spelling, pantomime, language boards, special typewriters or electronic communication devices)-far treatment of severe articulation disorders (Larson 1971). Kleffner (1973) stated: “If motor impairment is severe and intelligible speech an impracticality, the11 other means for expressive communication should be devised for the child”. Preliminary observations with our patients suggest that they learn sign-
1975, 17
language as readily as completely verbal children of similar intelligence levels. In doing so, many of the aggressive behavioral outbursts disappear. In 1958, DuBrul said the following: “It is quite true that in speaking, the lungs, diaphragm, and muscles of the belly wall and larynx twitter, but all animals have these parts and only one of them can spesk . . . I suspect that the difficulty in discovering the source of speech has been in not knowing where to look”. Perhaps children with developmental verbal dyspraxia, an intriguing neurological disorder of speech, will help show us where to look. AUTHORS’ APPOINTMENTS Peggy C. Ferry, M.D., Associate Professor of Pediatrics and Neurology; Head, Division of Child Development; Vanderbilt University School of Medicine, Nashville, Tennessee 37232. Sylvia M. Hall, M.A., Head, Communications Disorders Section; Jeffrey L. Hicks. Ph.D., Department of Psychology; Fairview Hospital and Training Center, Salem, Oregon 97310.
SUMMARY
A clinical and neurological review of 60 patients with developmental verbal dyspraxia is reported. The condition is more common in males and characteristically presents with delayed or imperfect speech in association with a normal or surprisingly high receptive language level. Speech is absent or poorly intelligible and becomes worse with increasingly complex phonetic combinations. Patients may show signs of associated oral dyspraxia. Conventional speech therapy is unsuccessful, although some improvement may occur with time. If intelligible speech has not developed by the age of six years, it is unlikely to develop. Total communication therapy started at the earliest possible age is the treatment of choice. The etiology of developmental verbal dyspraxia is unknown. RESUME
Langage ‘dilapide“: dyspraxie verbule de dth~eloppernentdans l’enfunce Les auteurs rapportent une revue clinique et neurologique de 60 sujets presentant une dyspraxie verbale de dkveloppement. Cette condition est plus frkquente chez le garCon et associe de facon caracteristique un langage retarde ou imparfait avec un niveau de comprehension de langage normal ou Ctonnamment Clevt. La parole est absente ou pauvrement comprehensible et empire progressivenient avec ]’acquisition des complexes phonktiques. Les patients peuvtnt montrer des signes associts de dyspraxie bucco-faciale. Les therapeutiques conventionnelles de langage sont inactives mais quelques progrbs peuvent survenir avec la maturation. Si un langage intelligible ne s’est pas dCveloppC A l’fige de six ans, il a peu de chance de se dkvelopper plus tard. Une therapeutique de communication 754
PEGGY C. FERRY
SYLVIA M. HALL
JEFFREY L. HICKS
totale a l’rige le plus prtcoce possible est le traitement de choix. L‘etiologie de la dyspraxie verbale de dtveloppernent est inconnue. ZUSAMMEN FASSUNG
‘Verwahrloste’ Sprache: Dyspraxie der Wortentwicklung im Kindesalter Es wird eine klinische und neurologische Ubersicht von 60 Patienten rnit Dyspraxie der Wortentwicklung gegeben. Dieser Befund ist haufiger beim mannlichen Geschlecht und prasentiert sich charakteriscischenveise als verlangsamte oder unvollkommene Sprache in Verbindung mit einem normalen oder uberraschend hohen Grad an sprachlicher Ernpfanglichkeit. Die Sprache ist nicht oder schwer veistandlich und verschlechtert sich rnit zunehmender Komplexitat phonetischer Kombinationen. Die Patienten konnen dazu auch Zeichen oraler Dyspraxie bieten. Eine konventionelle Sprachtherapie iot erfolglos, obgleich einige Besserung mit zunehmender Reife auftreten kann. Wenn bis zum 6. Lebensjahr keine verstandliche Sprache entwickelt wurde, ist es unwahrscheinlich, dal3 sie sich spater noch entwickelt. Eine totale Kornmunikationstherapie zum fruhest moglichen Zeitpunkt ist die Behandlung der Wahl. Die Atiologie der Dyspraxie der Wortentwicklung ist unbekannt. RESUMEN
Lenguaje ‘dilapidado’: riisprasia verbal de desarrollo en la infancia Se aporta una revision clinica y neurologica de 60 pacientes con dispraxia verbal de desarrollo. El problema es mis corriente en varones y, caracteristicamente, se presenta con lenguaje retrasado o imperfect0 en asociacion con un nivel receptivo de lenguaje normal o sorprendenternente alto. La logopedia convencional fracasa, aunque puede darse alguna mejoria con la maduracih. Si a 10s seis aiios de edad no se ha desarrollado un lenguaje inteligible, no es facil que se desarrolle mas tarde. El tratarniento de eleccion es una terapia de comunicacion total iniciada lo m8s precozrnente posible. Se desconoce la etiologia de la dispraxia verbal de desarrollo. REFERENCES Benton, A. L. (1964) ‘Developmental aphasia and brain damage.’ Cortex, 1, 40. Bowman, J. P. (1 97 I ) The Muscle Spindle and Neural Controlofthe Tongue. Springfield Ill. : Charles C Thomas. Chappell, G. (1973) ’Childhood verbal aprariia and its treatment.’ Journal of Speech arid Hearing Disorders, 38, 362. Critchley, M. (1957) ‘Articulatory defects in aphasia.’ Jourml of Laryngologj~arid Otologj., 66, 1. Darley, F. L. (1968) ‘Apraxia of speech: 107 years of terminological confusion.’ Presented at the American Speech and Hearing Association Convention, Denver, Colorado, November 1968. DuBrul, E. L. (1958) Evolution of the Speech Apparatus. Springfield, 111.: Charles C Thomas. Edwards, M. ( 1973) ‘Developmental verbal dyspraxia.’ British Journal of Disorders ofConimu/iication, 8,64. Gascon, G., Victor, D., Lombroso, C. T. (1973) ‘Language disorder, convulsive disorder, and electroencephalographic abnormality. Acquired syndrome in children.’ Archives of Nriirologj, 28, 156. Geschwind, N. (1964) ‘The clinical syndromes of the cortical connections.’ D7 Williams, D. (Ed.) Modern Trends in Neurology, No. 5 . London: Whitefriars Press, chap. 2. Goodglass, H., Kaplan, E. (1 972) The Assesswrrrt of Aphasia at7d Related Disorders. Philadelphia: Lea and Febiger. Jackson, H. ( I 866) ‘Remarks on those cases of disease of the nervous system in which defect of expression is the most striking symptom.’ Medical Tinws a d Gazette, 659. Kleffner, F. R. (1973) Language Disorders iu Children. Bobbs-Merrill Studies in Communicative Disorders. Indianapolis: Bobbs-Merrill Co. Larson, T. (1971) ‘Communication for the nonverbal child.’ Acadeniic Therap),, 6, 305. Morley, M. E. (1965) The Development arid Disorders of Speech i/7 Childhood, 2nd Edn. Baltimore: Williams and Wilkins, p. 237. - ( I 969) ‘Disorders of articulation : theory and therapy.’ British Journal of Disorders of Cotnmunication, 4 151.
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DEVELOPMENTAL MEDICINE AND CHILD NEUROLOGY.
1975, 17
Rosenbek, J. C., Wertz, R. T. (1972) ‘A review of fifty cases of developmental apraxia of speech.’Langunge, Speech and Hearing Services in Schools, 3, 23. Schlesinger, H. S., Meadow, K. P. (1972) Sound arid Sign. Childhood Deafness and M e n t d Health. Berkeley: University of California Press. Sheets, B. V. ( I 973) Anatomy and Physiology of rhe Speech Mechanism. Bobbs-Merrill Studies in Cornmunicative Disorders. Indianapolis: Bobbs-Merrill Co. Sussman. H. M. (1972) ‘What the tongue tells the brain.’ Psychological Bulletin, 77, 262. Worster-Drought. C. (1 974) Suprabulbar Paresis. Devrlopmenral Medicine and Child Neurology, 16, suppl. 30.
756
‘Dilapidated’ Speech: Developmental Verbal Dyspraxia Peggg C. Ferrly Sglvia M. Hall Jeffreg L. Hicks
Introduction “In some cases of defect of speech the patient seems to huve lost much of his pow’er to do mything he is toll to do, even with those muscles that are not paralysett. Thus, a patient will be unuble to put out his tongue when we ask him, although he will use it well it1 semi-involuntary actionsfor example, eating and swallowing. He will not make the purticsrlar grimace he i s told to do, even when we make one for him to imitate. There is power in his muscles und in the centres for coordinution oj‘muscxiur groups, but he-the whole man, or the ‘will ’-cannot set them agoitrg .” Thus, in his classic paper published in 1866, Jackson first described verbal and lingual dyspraxia in adults with acquired brain disease. Only recently has verbal dyspraxia been described in childhood (Morley 1965). Verbal dyspraxia is a neurological disorder of speech manifest by impaired ability-in the absence of overt motor or sensory paralysis-to carry out purposeful movements of the organs of articulation. Synonyms in the literature include : articulatory apraxia, apraxia of speech, apraxic dysarthria, and cortical dysarthria. Because the condition in children and
young adults appears to be present from infancy, typically produces poorly intelligible speech rather than mutism, and may occur in the absence of oral dyspraxia, the term ‘developmental verbal dyspraxia’ (DVD) most clearly describes the clinical features. Critchley recently characterised children with this disorder as having ‘dilapidated‘ speech (Edwards 1973). The purpose of the present communication is to describe the clinical features and results of a neurological investigation of 60 patients with developmental verbal dyspraxia.
Methods Forty of the 60 patients were referred to the University of Oregon Health Sciences Center because of ‘delayed speech’ ( N = 26) or poor response to speech therapy ( N = 14). The other 20 patients were identified in a study of ambulatory, non-verbal residents at a state institution for mentally retarded persons. Ages of patients ranged from four years to 30 years, the great majority (42) being between four and 10 years of age. There were 40 male and 20 female patients. All the patients received physical
Correspondence fo Peggy C . Ferry, M.D., Division of Child Development, Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232. D
749
DEVELOPMENTAL MEDICINE AND CHILD NEUROLOGY.
1975, 17,
infants were born by caesarean section, one was born following a prolonged labor, and one was said to have suffered ‘mild asphyxia’ a t birth. The great majority, however, appeared to have had normal births. Of interest was a positive family history of ‘speech or articulation problem’, not specified further, noted in 17 cases, usually in a male relative (father or brother). Two sets of brothers (not twins) with almost identical dyspraxic speech are included in this survey. Because of the presenting symptom of ‘delayed speech’, many of the patients initially were considered to be mentally retarded. However, it was found that 29 of the 60 patients had IQS over 90 (Table I).
and neurological examinations, psychometric testing, and a detailed audiological, speech and language evaluation-including assessment of auditory comprehension, conversational and expository speech, verbal and non-verbal oral agility, visual naming, and symbol and word recognition and discrimination. In the institutionalised patients, supplementary non-language tests (including tests for bucco-facial and limb apraxia) were done following the format of the Boston Diagnostic Aphasia Tests (Goodglass and Kaplan 1972). Psychometric evaluation was performed by psychologists and included tests of nonverbal intelligence such as the Ammons and Ammons Full Range Vocabulary Test and Raven Progressive Matrices. Electroencephalograms were done on the institutionalised patients. Audiometric testing (air conduction 512 and 4000Hz)was done using earphones. The diagnosis of developmental verbal dyspraxia was based on the following criteria. 1. A significant (at least one year) delay in speech development. 2. Normal hearing. 3. A normal or disproportionately high receptive language level. 4. Inconsistent omissions, substitutions and distortions of speech sounds. 5. Increasing articulation difficulty with more complex phonetic combinations. 6 . Groping and struggling to achieve correct positioning of the muscles of articulation. 7. An elaborate gestural system. 8. Slow or limited progress in conventional speech therapy.
Neurological Findings Associated developmental and neurological problems are given in Table 11. All patients were ambulatory, capable of self-care, and free of major neurological deficits such as frank cerebral palsy; none had seizures. Two of the institutionalised TABLE I IQs of patients in study Intelligence levels 11c120 100-109 9c99 80-89 70-79 60-69 40-60
No. of patients
12
TABLE I1 Associated neurological problems Findings
Findings The majority of the patients in the study had been of normal birthweight, with the exception of five who weighed between 1.8kg and 2.3kg. Birth records showed no definite evidence of perinatal injury; four
Orofacial dyspraxia Mild spastic diplegia Mild motor retardation Hand tremor Hemiplegia Choreiform movements
750
No. of patients 36 13 10
2 1 1
PEGGY C. FERRY
SYLVIA hl. HALL
residents had Down’s syndrome. No abnormal gag, pharyngeal, or jaw-jerk reflexes were found in any patient. There was no lingual atrophy. Of striking significance, however, is the high percentage of patients with associated signs of oral and/or facial dyspraxia. This was often the first sign of neurological dysfunction and was evidenced by persistent and excessive drooling and difficulty with chewing, licking and sucking movements. Parents frequently commented that as infants the patients sucked poorly and took excessive time to nurse, and that as the patients grew older mealtimes were laborious and lengthy.
JEFFREY L. HICKS
had temper tantrums and outbursts of rage, 14 suffered depression and were withdrawn, and four were ‘autistic’. Aggressive rage or temper outbursts often occurred in direct relation to the child’s frustration at being unable to communicate with those around him. Experienced clinicians likened the behavior to that of deaf children who are unable to make themselves understood. A variety of behavior and medical therapies had been tried, including behavior modification, tonsillectomy, clipping of the lingual frenuluni, and patterning therapy. In one particularly cruel instance, a mother was told to ignore her young son when he pointed or gestured to indicate what he wanted, for in doing so she was “inappropriately reinforcing his gestural behavior”. Other diagnostic and therapeutic recommendations had included referral for complete neurological examination (including skull x-ray, EEG, brain scan, and spinal tap), psychological testing (to look for an ‘emotional block’), orthodontic treatment, and psychiatric evaluation of ‘the child’s lack of motivation to talk‘. Electroencephalograms done on the 20 institutionalised patients were mildly and non-specifically abnormal in all cases, with mild, generalised slowing and occasional sharp wave activity. No localised abnormalities were seen.
Speech Characteristics The dyspraxic speech varied from nonexistent to partially intelligible or intelligible only to those who knew the patient well. Because of the wide range of ages involved, no specific correlations could be made between the severity of the articulation problem and other clinical features. The patients presented a strikingly uniform clinical picture of normal or near-normal auditory and visual receptive ability with paradoxically poor speech. Even the youngest had developed delightfully ingenious gestures and pantomimes in a valiant attempt to communicate with those around them. Patients had spent from one to 1 1 years in speech therapy, with painfully slow or minimal improvement. One therapist commented : “Progress in speech therapy has been slow and frustrating to both patient and therapist”. In these patients, useful speech was unlikely to develop after the age of six years if it had not done so already.
Discussion Two-thirds of all children have difficulty with articulation in early stages of speech development, but by the age of five years only 14 per cent have persisting articulation deficits. However, the great ma-jority of children referred to school speech therapists are seen for defects in articulation (Morley 1969). Many of these youngsters improve spontaneously, but in the large group of ‘functional articulation problems’, cases of developmental verbal
Associated Psychiatric Problenis Almost all the patients had significant behavioral or emotional problzms: 32 75 1
DEVELOPMENTAL MEDICINE AND CHILL) NEUROLOGY.
1975, 17
immensely complex and imperfectly understood. Whole books have been devoted to lingual muscle spindle activity, found in both intrinsic and extrinsic muscles (Bowman 1971). Differential, three-dimensional, interdigitated orientation of the tongue muscle-fibers is linked with at least 10 possible responses to a single movement or stretch. Sussman (1972) has shown that each lingual unit is associated with a discrete receptive field on the dorsal surface of the tongue. Through the hypoglossal nerve, afferent and efferent fibers are thought to form a short-latency, rapidly-acting feedback system from the lingual-muscle spindle to and from the motor cortex. As was concluded in a recent monograph devoted to the anatomy and physiology of speech, “we know that to accomplish the phenomenon of speech, a superb and complex mechanism must formulate and unify and monitor the process. But precisely where this ultimate speech control center resides and how it accomplishes its task is still not known to us.” (Sheets 1973). The cause of developmental verbal dyspraxia is completely unknown. The majority of afflicted children are free of other major neurological deficits. The predominance in males and familial tendency suggest a genetic component, the exact nature of which is unknown. No specific prenatal injury, birth trauma, or postnatal etiological factors have been identified. The condition bears many similarities to congenital suprabulbar paresis. WorsterDrought (1974) described the congenital, spastic weakness of muscles of the soft palate, pharynx and tongue, usually associated with exaggerated jaw jerks, hyperactive gag or snout reflexes, or wasting of the tongue. The distinction may be one of degree, and there are many overlapping features. Worster-Drought suggested that suprabulbar palsy is due
dyspraxia (DvD) undoubtedly are more common than have been recognised. Few of these children have careful neurological examinations of their speech and orofacial structures, and most clinicians or physicians do not appreciate the neurological significance of the presenting abnormalities, so that the dyspraxia is not recognised.
Historical Aspects Morley (1965) included a chapter on ‘developmental articulatory apraxia’ in her review of speech defects in children of one thousand families in Newcastle-uponTyne. She described 12 children with delayed speech not due to mental retardation or hearing loss who had dyspraxic articulation. In 1969 her observations were extended in a paper on articulation disorders. Similar but brief references were made to apraxic speech disturbances in association with ‘developmental aphasia’ by Critchley (1952) and Beiiton (1964). At the convention of the American Speech and Hearing Association, Darley (1968) presented a review of acquired ‘apraxis of speech’ in adults and mentioned that a childhood form of the condition had been recognised. But it remained for Rosenbek and Wertz (1972) to publish the first series of 50 cases in children. These authors noted a preponderance of males and made a plea for separating apraxic speech from so-called ‘functional’ articulation disorders. They noted that developmental apraxia of speech may be the only sign of cerebral dysfunction, especially in younger children. In 1973 Edwards reviewed the characteristics of developmental verbal dyspraxia and described theories of proprioception and perception in relation to etiology. Etiology The anatomical and physiological substrates of speech sound production are
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to a developmental defect of the motor tract running from the lower part of the motor (Rolandic) area of the cortex to the tenth and twelfth cranial nerve nuclei- i.e. “a relative agenesis or hypogenesis of the motor tract” (Worster-Drought 1974). Edwards (1973) has observed that some children with DVD speak more clearly when outside sound-stimuli are masked hy earphones. She suggests that dyspraxic children are unable to handle the barrage of multi-sensory inputs and to integrate and organise them so that the necessary productive action of the tongue muscles can be initiated. Geshwind (1964) has postulated that the disorder could represent some developmental disruption in the cerebral association pathways, such as the arcuate fasciculus running from the parietal operculum to the motor cortex. Since no autopsy studies have been performed, the exact basis for this puzzling, highly selective speech disorder remains elusive.
JEFFREY L. HICKS
myotonic dystrophy, and the syndrome of acquired language disorder with convulsive disorder and EEG abnormality (Gascon et a/. 1973). Careful history and neurological examination will provide the correct diagnosis. Excessive drooling, early feeding difficulties and ‘delayed speech’ are characteristic of both Moebius syndrome and myotonic dystrophy, but in these disorders the speech itself is dysarthric, not dyspraxic, in character. The bilateral peripheral facial weakness, genetic aspects, and associated neurological findings make the distinctions clear. The syndrome of acquired aphasia, seizures, and abnormal EEG presents in childhood. It may he associated with facial apraxia but includes receptive as well as expressive language difficulties; the major distinction from DVD is that it occurs in a previously healthy child, rather than being present from birth (Gascon et 01. 1973). Treatment Chappell (1973) reviewed the wide variety of treatment programs that have been used in DVD, including the audiroryvisual stimulation approach, verbal instruction, behavior modification of key articulation gestures, and the motokinetic approach. Since the natural history of the disorder varies widely, no one therapeutic regime has been shown to be unequivocally superior. No controlled studies have been done to show the benefit of treatment over waiting for spontaneous improvement with maturation. Our experience with the severe form suggests that, as with other congenital organic disorders of speech, if useful speech has not developed by the age of six years it is unlikely to d o so thereafter. Many children with DVD spend futile, frustrating and expensive months or years in speech therapy. Far more rational is the current policy of reconimending a trial of intensive (daily) speech therapy by an experienced clinician for
Djferential Diagnosis Neurologists examining children with ‘poor’ or ‘delayed speech’ or ‘dysarthria’ must become proficient with examination techniques specifically designed to evaluate disordered speech and language. The evaluation should provide assessment of receptive language and of expressive speech, including phonology, morphology, syntax, semantics, orofacial movements and pertinent oropharygeal reflexes. Assessment of non-verbal IQ and hearing acuity are essential. I n addition, special tests for orofacial dyspraxia such as described by Goodglass and Kaplan (1972) are helpful. Children who are reluctant or unable to talk will often partake eagerly in the ‘whistling, blowing, clicking, sucking, and chewing’ games of oral dyspraxia testing. Besides suprabulbar paresis, other neurological disorders which may be confused with DVD include Moebius syndrome,
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six months; if significant improvement has not occurred, consideration is then given to alternative forms of therapy. Recent studies of deaf children have shown that nulestones in acquiring signlanguage parallel those of spoken language (Schlesinger and Meadow 1972) : children at 12 months of age can begin to learn sign-language and its use does not interfere with speech acquisition. Increasingly, experienced clinicians are recommending total communication therapy-(using all available means of communication : gesturing, manual sign-language, finger-spelling, pantomime, language boards, special typewriters or electronic communication devices)-far treatment of severe articulation disorders (Larson 1971). Kleffner (1973) stated: “If motor impairment is severe and intelligible speech an impracticality, the11 other means for expressive communication should be devised for the child”. Preliminary observations with our patients suggest that they learn sign-
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language as readily as completely verbal children of similar intelligence levels. In doing so, many of the aggressive behavioral outbursts disappear. In 1958, DuBrul said the following: “It is quite true that in speaking, the lungs, diaphragm, and muscles of the belly wall and larynx twitter, but all animals have these parts and only one of them can spesk . . . I suspect that the difficulty in discovering the source of speech has been in not knowing where to look”. Perhaps children with developmental verbal dyspraxia, an intriguing neurological disorder of speech, will help show us where to look. AUTHORS’ APPOINTMENTS Peggy C. Ferry, M.D., Associate Professor of Pediatrics and Neurology; Head, Division of Child Development; Vanderbilt University School of Medicine, Nashville, Tennessee 37232. Sylvia M. Hall, M.A., Head, Communications Disorders Section; Jeffrey L. Hicks. Ph.D., Department of Psychology; Fairview Hospital and Training Center, Salem, Oregon 97310.
SUMMARY
A clinical and neurological review of 60 patients with developmental verbal dyspraxia is reported. The condition is more common in males and characteristically presents with delayed or imperfect speech in association with a normal or surprisingly high receptive language level. Speech is absent or poorly intelligible and becomes worse with increasingly complex phonetic combinations. Patients may show signs of associated oral dyspraxia. Conventional speech therapy is unsuccessful, although some improvement may occur with time. If intelligible speech has not developed by the age of six years, it is unlikely to develop. Total communication therapy started at the earliest possible age is the treatment of choice. The etiology of developmental verbal dyspraxia is unknown. RESUME
Langage ‘dilapide“: dyspraxie verbule de dth~eloppernentdans l’enfunce Les auteurs rapportent une revue clinique et neurologique de 60 sujets presentant une dyspraxie verbale de dkveloppement. Cette condition est plus frkquente chez le garCon et associe de facon caracteristique un langage retarde ou imparfait avec un niveau de comprehension de langage normal ou Ctonnamment Clevt. La parole est absente ou pauvrement comprehensible et empire progressivenient avec ]’acquisition des complexes phonktiques. Les patients peuvtnt montrer des signes associts de dyspraxie bucco-faciale. Les therapeutiques conventionnelles de langage sont inactives mais quelques progrbs peuvent survenir avec la maturation. Si un langage intelligible ne s’est pas dCveloppC A l’fige de six ans, il a peu de chance de se dkvelopper plus tard. Une therapeutique de communication 754
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totale a l’rige le plus prtcoce possible est le traitement de choix. L‘etiologie de la dyspraxie verbale de dtveloppernent est inconnue. ZUSAMMEN FASSUNG
‘Verwahrloste’ Sprache: Dyspraxie der Wortentwicklung im Kindesalter Es wird eine klinische und neurologische Ubersicht von 60 Patienten rnit Dyspraxie der Wortentwicklung gegeben. Dieser Befund ist haufiger beim mannlichen Geschlecht und prasentiert sich charakteriscischenveise als verlangsamte oder unvollkommene Sprache in Verbindung mit einem normalen oder uberraschend hohen Grad an sprachlicher Ernpfanglichkeit. Die Sprache ist nicht oder schwer veistandlich und verschlechtert sich rnit zunehmender Komplexitat phonetischer Kombinationen. Die Patienten konnen dazu auch Zeichen oraler Dyspraxie bieten. Eine konventionelle Sprachtherapie iot erfolglos, obgleich einige Besserung mit zunehmender Reife auftreten kann. Wenn bis zum 6. Lebensjahr keine verstandliche Sprache entwickelt wurde, ist es unwahrscheinlich, dal3 sie sich spater noch entwickelt. Eine totale Kornmunikationstherapie zum fruhest moglichen Zeitpunkt ist die Behandlung der Wahl. Die Atiologie der Dyspraxie der Wortentwicklung ist unbekannt. RESUMEN
Lenguaje ‘dilapidado’: riisprasia verbal de desarrollo en la infancia Se aporta una revision clinica y neurologica de 60 pacientes con dispraxia verbal de desarrollo. El problema es mis corriente en varones y, caracteristicamente, se presenta con lenguaje retrasado o imperfect0 en asociacion con un nivel receptivo de lenguaje normal o sorprendenternente alto. La logopedia convencional fracasa, aunque puede darse alguna mejoria con la maduracih. Si a 10s seis aiios de edad no se ha desarrollado un lenguaje inteligible, no es facil que se desarrolle mas tarde. El tratarniento de eleccion es una terapia de comunicacion total iniciada lo m8s precozrnente posible. Se desconoce la etiologia de la dispraxia verbal de desarrollo. REFERENCES Benton, A. L. (1964) ‘Developmental aphasia and brain damage.’ Cortex, 1, 40. Bowman, J. P. (1 97 I ) The Muscle Spindle and Neural Controlofthe Tongue. Springfield Ill. : Charles C Thomas. Chappell, G. (1973) ’Childhood verbal aprariia and its treatment.’ Journal of Speech arid Hearing Disorders, 38, 362. Critchley, M. (1957) ‘Articulatory defects in aphasia.’ Jourml of Laryngologj~arid Otologj., 66, 1. Darley, F. L. (1968) ‘Apraxia of speech: 107 years of terminological confusion.’ Presented at the American Speech and Hearing Association Convention, Denver, Colorado, November 1968. DuBrul, E. L. (1958) Evolution of the Speech Apparatus. Springfield, 111.: Charles C Thomas. Edwards, M. ( 1973) ‘Developmental verbal dyspraxia.’ British Journal of Disorders ofConimu/iication, 8,64. Gascon, G., Victor, D., Lombroso, C. T. (1973) ‘Language disorder, convulsive disorder, and electroencephalographic abnormality. Acquired syndrome in children.’ Archives of Nriirologj, 28, 156. Geschwind, N. (1964) ‘The clinical syndromes of the cortical connections.’ D7 Williams, D. (Ed.) Modern Trends in Neurology, No. 5 . London: Whitefriars Press, chap. 2. Goodglass, H., Kaplan, E. (1 972) The Assesswrrrt of Aphasia at7d Related Disorders. Philadelphia: Lea and Febiger. Jackson, H. ( I 866) ‘Remarks on those cases of disease of the nervous system in which defect of expression is the most striking symptom.’ Medical Tinws a d Gazette, 659. Kleffner, F. R. (1973) Language Disorders iu Children. Bobbs-Merrill Studies in Communicative Disorders. Indianapolis: Bobbs-Merrill Co. Larson, T. (1971) ‘Communication for the nonverbal child.’ Acadeniic Therap),, 6, 305. Morley, M. E. (1965) The Development arid Disorders of Speech i/7 Childhood, 2nd Edn. Baltimore: Williams and Wilkins, p. 237. - ( I 969) ‘Disorders of articulation : theory and therapy.’ British Journal of Disorders of Cotnmunication, 4 151.
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Rosenbek, J. C., Wertz, R. T. (1972) ‘A review of fifty cases of developmental apraxia of speech.’Langunge, Speech and Hearing Services in Schools, 3, 23. Schlesinger, H. S., Meadow, K. P. (1972) Sound arid Sign. Childhood Deafness and M e n t d Health. Berkeley: University of California Press. Sheets, B. V. ( I 973) Anatomy and Physiology of rhe Speech Mechanism. Bobbs-Merrill Studies in Cornmunicative Disorders. Indianapolis: Bobbs-Merrill Co. Sussman. H. M. (1972) ‘What the tongue tells the brain.’ Psychological Bulletin, 77, 262. Worster-Drought. C. (1 974) Suprabulbar Paresis. Devrlopmenral Medicine and Child Neurology, 16, suppl. 30.
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