Parkinsonism and Related Disorders 20 (2014) 1311e1312
Contents lists available at ScienceDirect
Parkinsonism and Related Disorders journal homepage: www.elsevier.com/locate/parkreldis
Letter to the Editor
Tremor severity is a poor predictor of social disability in patients with essential tremor Keywords: Essential tremor Quality of life Social Narrative medicine
Although it is well established that essential tremor (ET) can be a disabling condition, the severity of tremor does not always correlate with the degree of disability [1]. This discrepancy may be related to non-motor features of ET including sleep disturbances, fatigue, pain, anxiety, depression and reduced morale. Essential tremor has also been found to affect quality of life (QoL). The Quality of Life in Essential Tremor (QUEST) [2] questionnaire has been developed as a disease-specific outcome measure of QoL. In a recent trial of DBS for ET, a discrepancy was noted between improvement in tremor severity and only modest improvement in QoL as measured by the QUEST [3]. In light of this a more individualized approach than that offered by QoL scales may be necessary to capture the degree of disability in ET patients. To explore this further we used a narrative based approach to assess how ET affects QoL as well as quantitatively examining the relationship between QoL and tremor severity using the QUEST questionnaire in an outpatient cohort of ET patients. Thirty-eight patients who met the criteria for definite ET (1998 Movement Disorders Society) were included for analysis. The study was carried out with the approval of Galway University Hospital's ethics committee; written informed consent was obtained from subjects prior to participation. Face-to-face interviews consisted of four parts as follows: (i) Collection of demographic details, alcohol responsiveness and family history of tremor; (ii) Supervised completion of the QUEST questionnaire consisting of 30 items with 5 subscales examining different QoL domains (Physical, Psychosocial, Communication, Hobbies/Leisure, Work/Finance) as well as to the total or summary index (SI) score, representing the mean of the five domain scores; a higher score indicates greater disability/dissatisfaction. (iii) Measurement of tremor severity using the FahneTolosaeMarin tremor rating scale (FTMRS) [4]. This scale consists of 21-items divided into three parts: Part A measures tremor amplitude at rest, posture and action; Part B assesses patient performance on tasks. Part C assesses functional disability as perceived by the patient. As the questions in Part C overlap considerably with those of the Physical domain of QUEST Part C was excluded from our analysis. (iv) Using a largely unformatted, narrative-based approach, each patient was invited (with openended questions) to describe in their own words how their tremor affects them. Spearman's rho coefficient (rs) was used to perform http://dx.doi.org/10.1016/j.parkreldis.2014.09.006 1353-8020/© 2014 Elsevier Ltd. All rights reserved.
correlations between variables. Thematic analysis of the narrative information was performed with post hoc themes and subthemes being drawn up based on the issues raised by the participants. Patient demographics are summarized in Table 1. Tremor severity measured by FTMRS was significantly correlated with the QUEST physical domain [rs ¼ .660], and the QUEST summary index, [rs ¼ .528; (p < .001)] (Fig. 1). The strength of the correlation was stronger for part B (writing, drawing and pouring tasks) of FTMRS. However, there were no significant correlations between tremor severity and any of the other QUEST domains (i.e. psychosocial, communications, hobbies/leisure, work/finance) (Fig. 1). Moreover, there was no significant relationship between patient age or age at onset and QoL. Several qualitative issues were raised during the unformatted patient interview. Embarrassment was the commonest problem with a third of patients avoiding social situations because of their tremor. Difficulty with eating (36%) and drinking (47%) and anxiety (32%) were commonly reported. The presence of anxiety also appears to drive tremor severity with 39% noting intensification in the severity of the tremor when they feel anxious. However, despite the diverse range of issues raised by patients, nearly a quarter of those interviewed feel that they cope well with their tremor. In agreement with recent studies of QoL in ET patients [5], we found a significant correlation between tremor severity and the overall impact of ET on QoL. However, in contrast to the Chandran
Table 1 Demographics of participating cohort (n ¼ 38). Variable
Mean/%
Age (years) Female gender Right handed Age of tremor onset (years) Tremor duration (years) Positive family history Alcohol responsive Takes regular ET medication Tremor severity e mFTMRS Facial tremor Tongue tremor Vocal tremor Head tremor Lower limb tremor QUEST physical QUEST psychosocial QUEST communication QUEST hobbies/leisure QUEST work/finance QUEST summary index
61 ± 17 42.1% 92.1% 39 ± 21 21.43 ± 18.83 78.9% 50% 28.9% 22.97 ± 10.08 21.1% 34.2% 5.3% 26.3% 21.1% 33.55 ± 24.65 19.88 ± 14.83 6.36 ± 12.77 7.46 ± 20.39 4.17 ± 9.64 14.28 ± 10.34
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Letter to the Editor / Parkinsonism and Related Disorders 20 (2014) 1311e1312
Fig. 1. Tremor severity (mFTMRS) versus QUEST-physical and -psychosocial domains. The scatter graph in panel a depicts a positive correlation between the physical domain of QUEST and tremor severity (rs ¼ .660, p < .001) while in panel b the graph shows no significant correlation between the psychosocial domain of QUEST and tremor severity (rs ¼ .095, p ¼ .568).
et al., study, we found no correlation between the psychosocial domain of QUEST and tremor severity. Indeed our study suggests that the severity of the tremor itself is a poor predictor of the social disability experienced by patients with ET. Importantly however, we identified a significant number of patients who had low tremor severity scores but exhibited high levels of psychosocial distress based on the narrative information. The converse is also true and in these instances patient personality and coping strategies are important factors. The qualitative, narrative-based research approach differs from that of the structured questionnaire in that the former offers patients not only the chance to highlight an issue and how frequently it occurs but also allows the patient to identify which issues are most distressing. It is also less restrictive than a questionnaire approach. Indeed, while the QUEST scale includes many relevant questions, it does not offer the patient the opportunity to weight those issues causing most distress. For instance a patient may indicate that their tremor always interferes with their ability to write and always causes them embarrassment but this offers little insight into which of these is more distressing. While useful for assessing functional disability, measures of tremor severity may not always give an accurate indication of the psychosocial distress experienced by patients with ET. These observations highlight the complex problem presented by QoL measurement in this group of patients.
€ster AI, Pahwa R, Fields JA, Tanner CM, Lyons KE. Quality of life in essential [2] Tro tremor questionnaire (QUEST): development and initial validation. Parkinsonism Relat Disord 2005;11:367e73. [3] Sandvik U, Hariz G-M, Blomstedt P. Quality of life following DBS in the caudal zona incerta in patients with essential tremor. Acta Neurochir 2012;154:495e9. [4] Fahn S, Tolosa E, Marin C. Clinical rating scale for tremor. In: Jankovic J, Tolosa E, editors. Parkinson's disease and movement disorders. Baltimore: Williams & Wilkins; 1993. p. 271e80. [5] Chandran V, Kumar P. Quality of life and its determinants in essential tremor. Parkinsonism Relat Disord 2012;19:62e5.
Patrick W. Cullinane School of Medicine, National University of Ireland Galway, Galway, Ireland Patrick J. Browne School of Medicine, National University of Ireland Galway, Galway, Ireland Department of Neurology, Galway University Hospital, Galway, Ireland Teresa K. Leahy, Eavan M. McGovern Department of Neurology, Galway University Hospital, Galway, Ireland Timothy J. Counihan* School of Medicine, National University of Ireland Galway, Galway, Ireland Department of Neurology, Galway University Hospital, Galway, Ireland
Acknowledgments Supported by a Research Support Fund grant from the National University of Ireland Galway. References roux ME, Parisi SL, Larocerie-Salgado J, Norman KE. Upper-extremity [1] He disability in essential tremor. Arch Phys Med Rehabil 2006;87:661e70.
*
Corresponding author. School of Medicine, National University of Ireland Galway, Galway, Ireland. Tel.: þ353 91 544251. E-mail address: [email protected] (T.J. Counihan). 26 May 2014
Contents lists available at ScienceDirect
Parkinsonism and Related Disorders journal homepage: www.elsevier.com/locate/parkreldis
Letter to the Editor
Tremor severity is a poor predictor of social disability in patients with essential tremor Keywords: Essential tremor Quality of life Social Narrative medicine
Although it is well established that essential tremor (ET) can be a disabling condition, the severity of tremor does not always correlate with the degree of disability [1]. This discrepancy may be related to non-motor features of ET including sleep disturbances, fatigue, pain, anxiety, depression and reduced morale. Essential tremor has also been found to affect quality of life (QoL). The Quality of Life in Essential Tremor (QUEST) [2] questionnaire has been developed as a disease-specific outcome measure of QoL. In a recent trial of DBS for ET, a discrepancy was noted between improvement in tremor severity and only modest improvement in QoL as measured by the QUEST [3]. In light of this a more individualized approach than that offered by QoL scales may be necessary to capture the degree of disability in ET patients. To explore this further we used a narrative based approach to assess how ET affects QoL as well as quantitatively examining the relationship between QoL and tremor severity using the QUEST questionnaire in an outpatient cohort of ET patients. Thirty-eight patients who met the criteria for definite ET (1998 Movement Disorders Society) were included for analysis. The study was carried out with the approval of Galway University Hospital's ethics committee; written informed consent was obtained from subjects prior to participation. Face-to-face interviews consisted of four parts as follows: (i) Collection of demographic details, alcohol responsiveness and family history of tremor; (ii) Supervised completion of the QUEST questionnaire consisting of 30 items with 5 subscales examining different QoL domains (Physical, Psychosocial, Communication, Hobbies/Leisure, Work/Finance) as well as to the total or summary index (SI) score, representing the mean of the five domain scores; a higher score indicates greater disability/dissatisfaction. (iii) Measurement of tremor severity using the FahneTolosaeMarin tremor rating scale (FTMRS) [4]. This scale consists of 21-items divided into three parts: Part A measures tremor amplitude at rest, posture and action; Part B assesses patient performance on tasks. Part C assesses functional disability as perceived by the patient. As the questions in Part C overlap considerably with those of the Physical domain of QUEST Part C was excluded from our analysis. (iv) Using a largely unformatted, narrative-based approach, each patient was invited (with openended questions) to describe in their own words how their tremor affects them. Spearman's rho coefficient (rs) was used to perform http://dx.doi.org/10.1016/j.parkreldis.2014.09.006 1353-8020/© 2014 Elsevier Ltd. All rights reserved.
correlations between variables. Thematic analysis of the narrative information was performed with post hoc themes and subthemes being drawn up based on the issues raised by the participants. Patient demographics are summarized in Table 1. Tremor severity measured by FTMRS was significantly correlated with the QUEST physical domain [rs ¼ .660], and the QUEST summary index, [rs ¼ .528; (p < .001)] (Fig. 1). The strength of the correlation was stronger for part B (writing, drawing and pouring tasks) of FTMRS. However, there were no significant correlations between tremor severity and any of the other QUEST domains (i.e. psychosocial, communications, hobbies/leisure, work/finance) (Fig. 1). Moreover, there was no significant relationship between patient age or age at onset and QoL. Several qualitative issues were raised during the unformatted patient interview. Embarrassment was the commonest problem with a third of patients avoiding social situations because of their tremor. Difficulty with eating (36%) and drinking (47%) and anxiety (32%) were commonly reported. The presence of anxiety also appears to drive tremor severity with 39% noting intensification in the severity of the tremor when they feel anxious. However, despite the diverse range of issues raised by patients, nearly a quarter of those interviewed feel that they cope well with their tremor. In agreement with recent studies of QoL in ET patients [5], we found a significant correlation between tremor severity and the overall impact of ET on QoL. However, in contrast to the Chandran
Table 1 Demographics of participating cohort (n ¼ 38). Variable
Mean/%
Age (years) Female gender Right handed Age of tremor onset (years) Tremor duration (years) Positive family history Alcohol responsive Takes regular ET medication Tremor severity e mFTMRS Facial tremor Tongue tremor Vocal tremor Head tremor Lower limb tremor QUEST physical QUEST psychosocial QUEST communication QUEST hobbies/leisure QUEST work/finance QUEST summary index
61 ± 17 42.1% 92.1% 39 ± 21 21.43 ± 18.83 78.9% 50% 28.9% 22.97 ± 10.08 21.1% 34.2% 5.3% 26.3% 21.1% 33.55 ± 24.65 19.88 ± 14.83 6.36 ± 12.77 7.46 ± 20.39 4.17 ± 9.64 14.28 ± 10.34
1312
Letter to the Editor / Parkinsonism and Related Disorders 20 (2014) 1311e1312
Fig. 1. Tremor severity (mFTMRS) versus QUEST-physical and -psychosocial domains. The scatter graph in panel a depicts a positive correlation between the physical domain of QUEST and tremor severity (rs ¼ .660, p < .001) while in panel b the graph shows no significant correlation between the psychosocial domain of QUEST and tremor severity (rs ¼ .095, p ¼ .568).
et al., study, we found no correlation between the psychosocial domain of QUEST and tremor severity. Indeed our study suggests that the severity of the tremor itself is a poor predictor of the social disability experienced by patients with ET. Importantly however, we identified a significant number of patients who had low tremor severity scores but exhibited high levels of psychosocial distress based on the narrative information. The converse is also true and in these instances patient personality and coping strategies are important factors. The qualitative, narrative-based research approach differs from that of the structured questionnaire in that the former offers patients not only the chance to highlight an issue and how frequently it occurs but also allows the patient to identify which issues are most distressing. It is also less restrictive than a questionnaire approach. Indeed, while the QUEST scale includes many relevant questions, it does not offer the patient the opportunity to weight those issues causing most distress. For instance a patient may indicate that their tremor always interferes with their ability to write and always causes them embarrassment but this offers little insight into which of these is more distressing. While useful for assessing functional disability, measures of tremor severity may not always give an accurate indication of the psychosocial distress experienced by patients with ET. These observations highlight the complex problem presented by QoL measurement in this group of patients.
€ster AI, Pahwa R, Fields JA, Tanner CM, Lyons KE. Quality of life in essential [2] Tro tremor questionnaire (QUEST): development and initial validation. Parkinsonism Relat Disord 2005;11:367e73. [3] Sandvik U, Hariz G-M, Blomstedt P. Quality of life following DBS in the caudal zona incerta in patients with essential tremor. Acta Neurochir 2012;154:495e9. [4] Fahn S, Tolosa E, Marin C. Clinical rating scale for tremor. In: Jankovic J, Tolosa E, editors. Parkinson's disease and movement disorders. Baltimore: Williams & Wilkins; 1993. p. 271e80. [5] Chandran V, Kumar P. Quality of life and its determinants in essential tremor. Parkinsonism Relat Disord 2012;19:62e5.
Patrick W. Cullinane School of Medicine, National University of Ireland Galway, Galway, Ireland Patrick J. Browne School of Medicine, National University of Ireland Galway, Galway, Ireland Department of Neurology, Galway University Hospital, Galway, Ireland Teresa K. Leahy, Eavan M. McGovern Department of Neurology, Galway University Hospital, Galway, Ireland Timothy J. Counihan* School of Medicine, National University of Ireland Galway, Galway, Ireland Department of Neurology, Galway University Hospital, Galway, Ireland
Acknowledgments Supported by a Research Support Fund grant from the National University of Ireland Galway. References roux ME, Parisi SL, Larocerie-Salgado J, Norman KE. Upper-extremity [1] He disability in essential tremor. Arch Phys Med Rehabil 2006;87:661e70.
*
Corresponding author. School of Medicine, National University of Ireland Galway, Galway, Ireland. Tel.: þ353 91 544251. E-mail address: [email protected] (T.J. Counihan). 26 May 2014
