ABSTRACT
Objective:
To determine the impact of postpolio-syndrome on quality of life in polio survivors.
Methods:
Forty polio survivors were included in the study. Twenty-one patients fulfilling the Halstead's postpolio-syndrome criteria participated in postpolio-syndrome group. The remaining nineteen patients formed non-postpolio-syndrome group. Control group was composed of forty healthy subjects. Quality of life was evaluated by Nottingham Health Profile, depression by Beck Depression Scale and fatigue by Fatigue Symptom Inventory. Isometric muscle strength was measured by manual muscle testing.
Results:
Total manual muscle testing score was 26.19 ± 13.24 (median: 29) in postpolio-syndrome group and 30.08 ± 8.9 (median: 32) in non-postpolio-syndrome group. Total manual muscle testing scores of non-postpolio-syndrome group were significantly higher than that of postpolio-syndrome group. Patients with postpolio-syndrome reported significantly higher levels of fatigue and reduced quality of life in terms of physical mobility, pain and energy when compared with patients without postpolio-syndrome and control group. It was not reported a statistically significant difference in social and emotional functioning and sleep quality between postpolio-syndrome, non-postpolio-syndrome and control groups. Also it was not found any statistically significant difference in Beck Depression Scale scores among the groups.
Conclusions:
Postpolio-syndrome has a negative impact on quality of life in terms of functional status, severity of pain and energy. The identification, early recognition and rehabilitation of postpolio-syndrome patients may result in an improvement in their quality of life.
Keywords:
Postpolio-syndrome (PPS); Quality of life; Fatigue; Rehabilitation
RESUMO
Objetivo:
Determinar o impacto da síndrome pós-pólio na qualidade de vida nos sobreviventes da pólio.
Métodos:
Quarenta sobreviventes da pólio foram incluídos no estudo. Participaram do grupo de síndrome pós-pólio 21 pacientes que atenderam aos critérios de síndrome pós-pólio de Halstead. Os 19 restantes formaram o grupo não síndrome pós-pólio. O grupo controle foi composto por 40 indivíduos saudáveis. A qualidade de vida foi avaliada pelo Nottingham Health Profile, a depressão pela Escala de Depressão de Beck e a fadiga pelo Inventário de Sintomas de Fadiga. A força muscular isométrica foi medida por teste muscular manual.
Resultados:
O escore total do teste muscular manual foi 26,19 ± 13,24 (mediana: 29) no grupo de síndrome pós-pólio e 30,08 ± 8,9 (mediana: 32) no grupo não síndrome pós-pólio. Escores totais de teste muscular manual de grupo não síndrome pós-pólio foram significativamente maiores do que os do grupo de síndrome pós-pólio. Os pacientes com síndrome pós-pólio relataram níveis significativamente maiores de fadiga e qualidade de vida reduzida em termos de mobilidade física, dor e energia quando comparados com pacientes sem síndrome pós-pólio e grupo controle. Não se relatou uma diferença estatisticamente significativa no funcionamento social e emocional e na qualidade do sono entre grupos de síndrome pós-pólio, não síndrome pós-pólio e controle. Além disso, não se encontrou diferença estatisticamente significativa nos escores da Escala de Depressão de Beck entre os grupos.
Conclusões:
A síndrome pós-pólio tem um impacto negativo na qualidade de vida em termos de estado funcional, gravidade da dor e energia. A identificação, o reconhecimento precoce e a reabilitação dos pacientes com síndrome pós-pólio podem resultar em uma melhoria da qualidade de vida.
Palavras-chave:
Síndrome pós-pólio; Qualidade de vida; Fadiga; Reabilitação
Introduction
Postpolio-syndrome (PPS) is a neurologic disorder characterized by a collection of late manifestations occurring many years after the initial poliomyelitis infection. New or increased muscle weakness is the hallmark. The other clinical features are fatigue, pain in joints, bones and muscles, cold intolerance and bulbar symptoms (swallow, speech, respiratory symptoms). Fatigue has been described as the most common symptom. PPS symptoms affect the ability to perform the activities of daily living, mobility, upper limb function, and respiratory capacity. PPS has a negative effect on quality of life (QoL).11 Khan F. Rehabilitation for postpolio sequelae. Aust Fam Physician. 2004;33:621-4.–33 Östlund G, Wahlin Å, Sunnerhagen KS, Borg K. Post polio syndrome: fatigued patients a specific subgroup? J Rehabil Med. 2011;43:39-45.
The present study aimed to investigate QoL in polio survivors in Turkey, to assess the impact of PPS on various QoL domains in terms of functional status, severity of pain, social and emotional functioning.
Material and methods
The study included a total of 40 polio survivors (21 men, 19 women) who were followed at the outpatient clinic of physical medicine and rehabilitation department of a training and research Hospital which is a major referral center under Ministry of Health, located in Ankara, capital city of Turkey, between December 2012 and September 2013. Study was conducted in accordance with the principles set forth in the Helsinki Declaration 2008.
67.5% of polio survivors (21 patients) fulfilling the Halstead's PPS criteria44 Halstead LS, Rossi CD. New problems in old polio patients: results of a survey of 539 polio survivors. Orthopedics. 1985;8:845-50. participated in PPS group, and the remaining 19 polio survivors without PPS formed non-PPS group. Halstead's PPS criteria are: (1) a confirmed history of acute poliomyelitis affecting lower limbs; (2) partial or complete neurological and functional recovery after acute poliomyelitis; (3) new symptoms (extensive fatigue, muscle pain and/or joint pain, new muscle weakness in the muscles previously affected or unaffected) after a stable period of at least 15 years; (4) exclusion of other medical conditions that may explain these symptoms.44 Halstead LS, Rossi CD. New problems in old polio patients: results of a survey of 539 polio survivors. Orthopedics. 1985;8:845-50.
Isometric muscle strength was measured by manual muscle testing (MMT) according to Medical Research Council (MRC) Scale.55 Medical Research Council. Aids to the examination of the peripheral nervous system. London: HMSO; 1981. p. 1. Hip flexors, knee extensors, knee flexors, ankle dorsal flexor and ankle plantar flexors were evaluated bilaterally, then total score was obtained (maximum score: 50).
Control group consisted of 40 age and sex matched healthy subjects (20 men, 20 women) whose total MMT scores were 50. Inclusion criteria for all subjects were no other disorders including fibromyalgia, hypertension, diabetes mellitus, hepatic and renal diseases, inflammatory arthritis, other neurological or psychiatric disorders that may cause fatigue.
Symptoms including muscle pain, fatigue, joint pain, sleep disorders, respiratory disorders and dysphagia were analyzed in PPS and non-PPS groups. QoL was assessed by Nottingham Health Profile (NHP)66 Kucukdeveci AA, McKenna SP, Kutlay S, Gursel Y, Whalley D, Arasil T. The development and psychometric assessment of Turkish version of Nottingham Health Profile. Int J Rehabil Res. 2000;23:31-8. and depression by using Beck Depression Scale (BDS).77 Beck AT, Ward CH, Mendelson M, Mock J, Erbaugh J. An inventory for measuring depression. Arch Gen Psychiatry. 1961;4:561-71.
Fatigue was evaluated by using Turkish version of Fatigue Symptom Inventory (FSI).88 Oksuz E, Malhan S, Tulunay FC. Reliability and validity of the Fatigue Symptom Inventory. Moving and improving concepts and evidence for health care decisions. Ispor 11th Annual European Congress 2008 Nov 8–11; Athens, Greece. Value Health. 2008;11:A426. FSI, first published in 1998, is a 14-item self-report measure designed to assess fatigue intensity (four items), duration (two items), its interference with quality of life (7 items), and the daily pattern of fatigue. Intensity is measured on separate 11-point scales (0 = not at all fatigued; 10 = extreme fatigue) that assess most, least, current fatigue and average fatigue in the previous week. Each of these is scored as an individual item. The interference items assess the extent to which fatigue interfered with a respondent's general activity level, ability to bathe and dress, work activity, ability to concentrate, relations with others, enjoyment of life and mood during the previous week using an 11 point rating scale (0 = no interference and 10 = extreme interference). These 7 items are averaged to obtain an interference scale score. Duration items (number of days fatigued, amount of time fatigued) assess fatigue frequency. It is measured as the number of the days (from 0 to 7 days) in the past week that respondents felt fatigued and the amount of each day on average respondents felt fatigued (0 = none of the day, 10 = the entire day). Each of these is scored as an individual item. The final item asks respondents to indicate their daily pattern of fatigue and so provides descriptive information about possible diurnal variation in the daily experience of fatigue (0 = not at all fatigued, 1 = worse in the morning, 2 = worse in the afternoon, 3 = worse in the evening, 4 = no consistent daily pattern of fatigue). Final item provides information only and is not intended to be used as a quantitative scale.99 Donovan KA, Jacobsen PB. The Fatigue Symptom Inventory: a systematic review of its psychometric properties. Support Care Cancer. 2010;19:169-85.–1111 Hann DM, Jacobsen PB, Azzarello LM, Martin SC, Curran SL, Fields KK, et al. Measurement of fatigue in cancer patients: development and validation of the Fatigue Symptom Inventory. Qual Life Res. 1998;7:301-10. The items included in the FSI are shown in Appendix 1 Appendix 1 The Fatigue Symptom Inventory (FSI) 1-Rate your level of fatigue on the day you felt most fatigued during the past week. 0 1 2 3 4 5 6 7 8 9 10 Not at all fatigued Extreme fatigue 2-Rate your level of fatigue on the day you felt least fatig ued during the past week. 0 1 2 3 4 5 6 7 8 9 10 Not at all fatigued Extreme fatigue 3- Rate your level of fatigue on the average during th e last week. 0 1 2 3 4 5 6 7 8 9 10 Not at all fatigued Extreme fatigue 4- Rate your level of fatigue right now. 0 1 2 3 4 5 6 7 8 9 10 Not at all fatigued Extreme fatigue 5-Rate how much in the past week, fatigue interfered with your level of activity. 0 1 2 3 4 5 6 7 8 9 10 No interference Extreme in terference 6-Rate how much, in the past week fatigue interfered with your ability to bathe and dress yourself. 0 1 2 3 4 5 6 7 8 9 10 No interference Extreme in terference 7- Rate how much, in the past week fatigue interfered with your normal activity (includes both work outside the home and housework). 0 1 2 3 4 5 6 7 8 9 10 No interference Extreme in terference 8-Rate how much, in the past week fatigue interfered with your ability to concentrate. 0 1 2 3 4 5 6 7 8 9 10 No interference Extreme in terference 9- Rate how much, in the past week fatigue interfered with your relations with other people. 0 1 2 3 4 5 6 7 8 9 10 No interference Extreme in terference 10- Rate how much, in the past week fatigue interfered with your enjoyment of life . 0 1 2 3 4 5 6 7 8 9 10 No interference Extreme in terference 11- Rate how much, in the past week fatigue interfered with your mood. 0 1 2 3 4 5 6 7 8 9 10 No interference Extreme in terference 12-Indicate how many days, in the past week , you felt fatigued for any part of the day. 0 1 2 3 4 5 6 7 days 13- Rate how much of the day, on average, you felt fatigued in the past week. 0 1 2 3 4 5 6 7 8 9 10 None of the day The entire day 14-Indicate which of the following best describes the daily pattern of your fatigue in the past week 0 1 2 3 4 0 = not at all fatigued, 1 = worse in the morning, 2 = worse in the afternoon, 3 = worse in the evening, 4 = no consistent daily pattern of fatigue. .
Statistical analyses
Data were presented by descriptive analysis with means ± standard deviation (SD) and median scores. Because variables were not normally distributed, Kruskal–Wallis and Mann–Whitney U tests were performed to assess statistically significant differences in MMT, BDS, FSI and NHP scores of the groups. Categorical variables were evaluated by Chi-square test. A value of p < 0.05 was considered statistically significant. All analyses were performed using Statistical Package for the Social Sciences – 13.0 (SPSS-13.0) software.
Results
Demographic and clinical characteristics of the patients and control subjects are summarized in Table 1. Mean age was 38.15 ± 7.17 in PPS group, 37 ± 4.86 in non-PPS group and 35 ± 8.42 in the control group. At the time of acute polio, polio survivors were 19.2 ± 12.23 months old on average (3 months to 4 years, median: 18 months).
Of the patients in PPS group, 12 had paralyses of one limb, 5 had paralyses of two limbs, 2 had paralyses of three limbs, and 2 had paralyses of four limbs. One of them reported that the disease affected the respiratory system. Of the patients in non-PPS group, 15 had paralyses of one limb, 3 had paralyses of two limbs, and 1 had paralyses of three limbs. None of them had paralyses of four limbs. Also none of them reported that the respiratory system was affected (Table 1).
The most common symptoms were fatigue (16 patients, 76.2%), and muscle pain (15 patients, 71.4%) in PPS group. These were followed by sleep disorders (12 patients, 57.14%) and joint pain (11 patients, 52.38%), respectively. Dysphagia and respiratory disorders were noted in one patient (4.76%). In non-PPS group, the most frequent symptoms were muscle pain, fatigue, sleep disorders and joint pain, which were reported in 42.1%, 36.8%, 31.58%, 15.79% of the patients, respectively. Fatigue, joint pain and muscle pain were significantly higher in PPS group (p < 0.05). Total MMT score was 26.19 ± 13.24 (median: 29) in PPS group and 30.08 ± 8.9 (median: 32) in non-PPS group. According to the Mann–Whitney U test, total MMT scores of non-PPS group were significantly higher than that of PPS group (p < 0.05) (Table 2).
Kruskal–Wallis test revealed that differences among groups were significant in all FSI subgroups (p < 0.05). According to the Mann–Whitney U test, FSI scores of PPS group were significantly higher than that of both non-PPS group and the control group (p < 0.05) (Table 3). It was not found any statistically significant difference in BDS scores between PPS, non-PPS and control groups (p > 0.05). Median values of BDS and FSI in patients and the control group are given in Table 3.
Kruskal–Wallis test showed that differences among groups were significant in all NHP subgroups except social isolation, emotional reaction and sleep (p < 0.05). According to the Mann–Whitney U test, PPS group scored significantly higher in pain, physical mobility and energy subgroups of NHP than non-PPS and the control group (p < 0.05). It was not reported a statistically significant difference in social isolation, emotional reaction and sleep subgroups. Also non-PPS group reported poorer levels in all NHP groups except social isolation, emotional reaction and sleep subgroups, when compared to the control group (Table 4). Median values of NHP scores in patients and the control group are given in Table 4.
Discussion
The aim of this study was to investigate QoL in polio survivors in Turkey in order to assess the impact of PPS on QoL in terms of functional status, severity of pain, social and emotional functioning.
The results showed that PPS impaired QoL including physical mobility, pain and energy, but did not affect emotional and social health. Furthermore it was not found any statistically significant difference in BDS scores between PPS, non-PPS and control groups. This finding confirmed that PPS did not have a negative impact on emotional status. Our results support the previous studies in the literature. It was reported lower scores in physical functioning in 38 post-polio patients in the study of McNaughton et al. where QoL was measured by using Short Form-36 (SF-36).1212 McNaughton H, McPherson K, Falkner E, Taylor W. Impairment, disability, handicap, and participation in post-poliomyelitis subjects. Int J Rehabil Res. 2001;24:133-6. Similarly, Jacob investigated QoL in 101 polio survivors from two post-polio clinics in Israel and reported low physical scores and normal mental scores including emotional and social functioning in post-polio patients.1313 Jacob T, Shapira A. Quality of life and health conditions reported from two post-polio clinics in Israel. J Rehabil Med. 2010;42:377-9. Tate et al. confirmed that polio survivors did not differ from the general population in levels of depression.1414 Tate DG, Forchheimer M, Kirsch N, Maynard F, Roller A. Prevalence and associated features of depression and psychological distress in polio survivors. Arch Phys Med Rehabil. 1993;74:1056-60. By contrast, Schanke,1515 Schanke AK, Stanghelle JK. Fatigue in polio survivors. Spinal Cord. 2000;39:243-51. Conrady1616 Conrady LJ, Wish JR, Agre JC, Rodriquez AA, Sperling KB. Psychologic characteristics of polio survivors: a preliminary report. Arch Phys Med Rehabil. 1989;70:458-63. and Hazendonk1717 Hazendonk KM, Crowe SF. A neuropsychological study of the postpolio syndrome: support for depression without neuropsychological impairment. Neuropsychiatry Neuropsychol Behav Neurol. 2000;13:112-8. reported that PPS patients had higher levels of depressive symptoms as compared to control groups. Also On et al. found lower physical, social and emotional scores in PPS group where QoL was evaluated by using NHP.1818 On AY, Oncu J, Atamaz F, Durmaz B. Impact of post-polio-related fatigue on quality of life. J Rehabil Med. 2006;38:329-32.
Patients with PPS experienced significantly higher levels of fatigue when compared to non-PPS and control group. This finding supports the previous studies.1818 On AY, Oncu J, Atamaz F, Durmaz B. Impact of post-polio-related fatigue on quality of life. J Rehabil Med. 2006;38:329-32.–2020 Packer TL, Sauriol A, Brouwer B. Fatigue secondary to chronic illness: postpolio syndrome, chronic fatigue syndrome, and multiple sclerosis. Arch Phys Med Rehabil. 1994;75:1122-6. To our knowledge, this is the first study to evaluate fatigue in polio survivors by using FSI. Fatigue is a complex symptom and it must be assessed by a multidimensional questionnaire which identifies different aspects of fatigue in detail. FSI deals with various characteristics of fatigue and its perceived interference with quality of life in terms of general work activities, ability to concentrate, and enjoyment of life and mood. Furthermore, it states daily patterns of Fatigue.1010 Hann DM, Denniston MM, Baker F. Measurement of fatigue in cancer patients: further validation of the Fatigue Symptom Inventory. Qual Life Res. 2000;9:847-54.,1111 Hann DM, Jacobsen PB, Azzarello LM, Martin SC, Curran SL, Fields KK, et al. Measurement of fatigue in cancer patients: development and validation of the Fatigue Symptom Inventory. Qual Life Res. 1998;7:301-10. It was suggested as a useful instrument in assessment of fatigue by the reviewers.2121 Dittner AJ, Wessely SC, Brown RG. The assessment of fatigue: a practical guide for clinicians and researchers. J Psychosom Res. 2004;56:157-70. In previous studies, no significant differences were found in total MMT scores between PPS and non-PPS groups.1818 On AY, Oncu J, Atamaz F, Durmaz B. Impact of post-polio-related fatigue on quality of life. J Rehabil Med. 2006;38:329-32.,2222 Nollet F, Beelen A, Prins MH, De Visser M, Sargeant AJ, Lankhorst GJ, et al. Disability and functional assessment in former polio patients with and without postpolio syndrome. Arch Phys Med Rehabil. 1999;80:136-43. Contrarily, in our study, total MMT scores of PPS group were significantly lower than that of non-PPS group.
In the present study, the most common symptoms were fatigue (76.2%), and muscle pain (71.4%) in PPS group. This result is in accordance with other clinical studies. In a study by Nollet on disability and functional status in Dutch patients with PPS, 78% of the patients selected fatigue as their major problem.2222 Nollet F, Beelen A, Prins MH, De Visser M, Sargeant AJ, Lankhorst GJ, et al. Disability and functional assessment in former polio patients with and without postpolio syndrome. Arch Phys Med Rehabil. 1999;80:136-43. In Conde's study, the most frequent complaints were fatigue (87.1%), muscle pain (82.4%), and joint pain (72%).2323 Conde MT, Oliveira AS, Quadros AA, Moreira GA, Silva HC, Pereira RD, et al. Post-polio syndrome: epidemiologic and prognostic aspects in Brazil. Acta Neurol Scand. 2009;120:191-7. We found that prevalence of fatigue, joint pain and muscle pain was significantly higher in PPS group than non-PPS group. Prevalence of sleep disorders was similar in both of the groups. 57% of PPS patients had sleep disorders. In the study of van Kralingen, prevalence of sleep disorders was found as 50%.2424 Van Kralingen KW, Ivanyi B, Van Keimpema AR, Venmans BJ, De Visser M, Postmus PE. Sleep complaints in postpolio syndrome. Arch Phys Med Rehabil. 1996;77:609-11. Östlund reported that post polio related fatigue had a negative effect on sleep quality.2525 Östlund G, Wahlin A, Sunnerhagen KS, Borg K. Vitality among Swedish patients with polio: a physiological phenomenon. J Rehabil Med. 2008;40:709-14. Contrarily, in our study, fatigue did not influence NHP sleep scores.
The small sample size deemed our main limitation. It is due to the exclusion of concomitant medical and psychiatric diseases that may cause fatigue.
As a conclusion, PPS has a negative impact on QoL in terms of functional status, severity of pain and energy. Thus, early recognition and complex rehabilitation in the beginning of PPS may result in an increase in QoL in polio survivors. Also identifying postpolio-related fatigue and then reducing it may be an additional strategy in improving QoL. Since FSI is a multidimensional questionnaire that presents different aspects of fatigue, it should take place in clinical practice.
-
☆
This study originated from the Department of Physical Medicine and Rehabilitation, Ankara Numune Training and Research Hospital, Ankara, Turkey.
Appendix 1 The Fatigue Symptom Inventory (FSI)
REFERENCES
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1Khan F. Rehabilitation for postpolio sequelae. Aust Fam Physician. 2004;33:621-4.
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2Silver JK, Aiello DD. What internists need to know about postpolio syndrome. Cleve Clin J Med. 2002;69:704-6, 709–12.
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3Östlund G, Wahlin Å, Sunnerhagen KS, Borg K. Post polio syndrome: fatigued patients a specific subgroup? J Rehabil Med. 2011;43:39-45.
-
4Halstead LS, Rossi CD. New problems in old polio patients: results of a survey of 539 polio survivors. Orthopedics. 1985;8:845-50.
-
5Medical Research Council. Aids to the examination of the peripheral nervous system. London: HMSO; 1981. p. 1.
-
6Kucukdeveci AA, McKenna SP, Kutlay S, Gursel Y, Whalley D, Arasil T. The development and psychometric assessment of Turkish version of Nottingham Health Profile. Int J Rehabil Res. 2000;23:31-8.
-
7Beck AT, Ward CH, Mendelson M, Mock J, Erbaugh J. An inventory for measuring depression. Arch Gen Psychiatry. 1961;4:561-71.
-
8Oksuz E, Malhan S, Tulunay FC. Reliability and validity of the Fatigue Symptom Inventory. Moving and improving concepts and evidence for health care decisions. Ispor 11th Annual European Congress 2008 Nov 8–11; Athens, Greece. Value Health. 2008;11:A426.
-
9Donovan KA, Jacobsen PB. The Fatigue Symptom Inventory: a systematic review of its psychometric properties. Support Care Cancer. 2010;19:169-85.
-
10Hann DM, Denniston MM, Baker F. Measurement of fatigue in cancer patients: further validation of the Fatigue Symptom Inventory. Qual Life Res. 2000;9:847-54.
-
11Hann DM, Jacobsen PB, Azzarello LM, Martin SC, Curran SL, Fields KK, et al. Measurement of fatigue in cancer patients: development and validation of the Fatigue Symptom Inventory. Qual Life Res. 1998;7:301-10.
-
12McNaughton H, McPherson K, Falkner E, Taylor W. Impairment, disability, handicap, and participation in post-poliomyelitis subjects. Int J Rehabil Res. 2001;24:133-6.
-
13Jacob T, Shapira A. Quality of life and health conditions reported from two post-polio clinics in Israel. J Rehabil Med. 2010;42:377-9.
-
14Tate DG, Forchheimer M, Kirsch N, Maynard F, Roller A. Prevalence and associated features of depression and psychological distress in polio survivors. Arch Phys Med Rehabil. 1993;74:1056-60.
-
15Schanke AK, Stanghelle JK. Fatigue in polio survivors. Spinal Cord. 2000;39:243-51.
-
16Conrady LJ, Wish JR, Agre JC, Rodriquez AA, Sperling KB. Psychologic characteristics of polio survivors: a preliminary report. Arch Phys Med Rehabil. 1989;70:458-63.
-
17Hazendonk KM, Crowe SF. A neuropsychological study of the postpolio syndrome: support for depression without neuropsychological impairment. Neuropsychiatry Neuropsychol Behav Neurol. 2000;13:112-8.
-
18On AY, Oncu J, Atamaz F, Durmaz B. Impact of post-polio-related fatigue on quality of life. J Rehabil Med. 2006;38:329-32.
-
19Berryl MH, Strauser WW, Hall KM. Fatigue in postpolio syndrome. Arch Phys Med Rehabil. 1991;72:115-8.
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20Packer TL, Sauriol A, Brouwer B. Fatigue secondary to chronic illness: postpolio syndrome, chronic fatigue syndrome, and multiple sclerosis. Arch Phys Med Rehabil. 1994;75:1122-6.
-
21Dittner AJ, Wessely SC, Brown RG. The assessment of fatigue: a practical guide for clinicians and researchers. J Psychosom Res. 2004;56:157-70.
-
22Nollet F, Beelen A, Prins MH, De Visser M, Sargeant AJ, Lankhorst GJ, et al. Disability and functional assessment in former polio patients with and without postpolio syndrome. Arch Phys Med Rehabil. 1999;80:136-43.
-
23Conde MT, Oliveira AS, Quadros AA, Moreira GA, Silva HC, Pereira RD, et al. Post-polio syndrome: epidemiologic and prognostic aspects in Brazil. Acta Neurol Scand. 2009;120:191-7.
-
24Van Kralingen KW, Ivanyi B, Van Keimpema AR, Venmans BJ, De Visser M, Postmus PE. Sleep complaints in postpolio syndrome. Arch Phys Med Rehabil. 1996;77:609-11.
-
25Östlund G, Wahlin A, Sunnerhagen KS, Borg K. Vitality among Swedish patients with polio: a physiological phenomenon. J Rehabil Med. 2008;40:709-14.
Publication Dates
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Publication in this collection
Jan-Feb 2017
History
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Received
14 Feb 2014 -
Accepted
1 Dec 2014