The extent of using mobility assistive devices can partly explain fatigue among persons with late effects of polio

I. Santos Tavares Silva

  • Email author
  • K. S. Sunnerhagen
  • C. Willén and 
  • I. Ottenvall Hammar
BMC NeurologyBMC series – open, inclusive and trusted201616:230
DOI: 10.1186/s12883-016-0753-6
Received: 29 June 2016
Accepted: 10 November 2016
Published: 18 November 2016



Fatigue is reported as one of the most disabling symptoms and is common among persons living with late effects of polio. Although fatigue has been studied in the context of people living with late effects of polio, there is a lack of knowledge concerning the association of fatigue and variables of importance for participation in daily life. Therefore, the aim of this study was to explore possible factors associated with fatigue among persons with late effects of polio in Sweden.


This retrospective registry study consisted of 89 persons with late effects of polio living in Sweden. Fatigue was measured with the Multidimensional Fatigue Inventory (MFI-20) scale, Swedish version. Pearson’s correlation coefficient was used to analyse the correlation between the factors and fatigue, and a multiple linear regression was carried out to explore factors for fatigue.


Fatigue statistically significantly correlated with age (r = 0.234, p < 0.05) and the use of mobility assistive devices (r = 0.255, p < 0.05). The multiple linear regression model showed that the factors age (β = 0.304, p < 0.019) and mobility assistive devices (β = 0.262, p < 0.017) were associated with fatigue among persons living with late effects of polio, and the model partly explained 14% of the variation of fatigue.


Fatigue could partly be explained by the extent of using mobility assistive devices and age. Healthcare professionals should provide and demonstrate the importance of assistive devices to ensure management of fatigue in persons living with late effects of polio.


Post poliomyelitis syndrome Occupational therapy Multidimensional fatigue inventory (MFI-20) scale Cross-sectional studies


Fatigue is a common symptom reported among persons living with late effects of polio [123]. There are ambiguously definitions of fatigue in the literature [4567]. It can be assessed in different ways [5], and is seen as a complex phenomenon with a large number of conceptualizations [6]. Fatigue can be defined as an overwhelming sense of tiredness, a lack of energy, and feeling of exhaustion, that can be associated with impaired physical and/or cognitive function [6]. In this study, fatigue is defined as an overwhelming sense of tiredness, a lack of energy and a feeling of exhaustion that may be associated with the impaired physical and/or cognitive function [6]. Fatigue may be either peripheral or central depending on where in the nervous system it originates [8], and there are several types of fatigue, such as general, physical or muscle fatigue [3].
About 60–85% of persons living with late effects of polio face recurrence of the original polio related manifestations as well as new symptoms, suggesting new health problems [9]. This state is usually named post-polio syndrome (PPS). People may experience late effects of polio without being diagnosed with PPS [3]. Several terms have been used to describe the symptoms followed by polio, such as ‘the late effects of polio’ and ‘post-polio sequelae’ [10]. In this study the term ‘the late effects of polio’ is used. According to Gawne and Halstead [10], the specific criteria for PPS are: a prior episode of paralysis confirmed by history, physical exam, and findings on an electromyogram (EMG); a period of neurological recovery followed by an extended interval of neurological and functional stability, usually lasting 20 years or more; and a gradual or abrupt onset of new neurogenic, non-disuse weakness in previously affected and/or unaffected muscles. These symptoms may or may not be accompanied by other new health problems, such as excessive fatigue, muscle pain, joint pain, decreased endurance, decreased function, and atrophy. Other neurologic, medical and orthopaedic conditions that might cause the health problems mentioned above must be excluded [10].
Persons living with late effects of polio may face restrictions on participating in different areas of life [1112]. Restrictions have been identified in occupations related to their family role, work and education, and to autonomy outdoors [11]. Dependence in occupations such as cleaning, transportation, and shopping has also been associated with restrictions in daily life activities [12]. Fatigue has been pointed out as an invisible disabling symptom affecting a person’s ability to perform occupations and limiting mastery of daily occupations [13]. It has also been reported that persons living with late effects of polio act at close to maximum of their capacity, and fatigue has been found to be related to muscle overuse [1415]. The perceived fatigue can remain for days after fatiguing exercise but without reduction. This phenomenon called low frequency fatigue can be described as persisting for prolonged periods of time before full capacity has returned [1617].
Earlier research [1112131819] has identified various factors as important when exploring fatigue in everyday life among persons living with late effects of polio. The explanatory power of these factors in relation to fatigue has not yet been captured. In this study we explored fatigue in relation to the factors age, gender, country of birth, occupational/employment level and, the use of mobility assistive devices. Research has shown that there are inequities in health status associated with country of birth [1819]. The level of occupation/employment has been shown to be associated with fatigue [20]. Studies [2122] have shown that persons living with late effects of polio experience tiredness which restricts participation at work. These limitations resulted in both physical and psychosocial distress created by an internal conflict between what the person want to do and what they are able to do [2122]. Moreover, another factor of importance for fatigue is the use of assistive devices, which has shown to positively affect ability and reduce perceived difficulties [12]. Research [23] has shown that persons living with late effects of polio could experience pain and fatigue when they hesitated to start using assistive devices, in particularly mobility devices. To get a better understanding of factors associated with fatigue, the objective was to explore possible factors associated with fatigue among persons with late effects of polio in Sweden.


Sampling and participants

This retrospective registry study used patient data from a clinical database with persons with late effects of polio from the Polio Clinic, Sahlgrenska University Hospital, Gothenburg, Sweden. The clinic has encountered more than 900 persons with polio since the clinic opened 1994, and since that time different questionnaires have been used [24]. In the present study, data from persons that responded to a questionnaire concerning fatigue were identified from the clinical database. The following inclusion criteria were used: (i) persons aged 18 years or older, and (ii) with late effects of polio. In a total, 89 persons were included in the study; those who had answered the fatigue questionnaire. Due to internal dropouts on different items the calculations were based on slightly different sample size (see notes in Tables 234, and 5).


Data were collected between 2008 and 2011. The dependent variable of fatigue was explored and analysed in relation to the following factors; gender, age, country of birth, occupation/employment level, and the use of mobility assistive devices.

Dependent variable

Fatigue was assessed using the Swedish version of the Multidimensional Fatigue Inventory (MFI-20) [5], which is a self-administered questionnaire with a total of 20 items. The MFI-20 assesses a person’s self-rated fatigue in the following five subscales: General Fatigue (GF), Physical Fatigue (PF), Mental Fatigue (MF), Reduced Motivation (RM), and Reduced Activity (RA). The subscales and the 20 items are presented in Table 1. The level of fatigue can be scored with a minimum of 4 points to a maximum of 20 points on the 5-point Likert scale (1 = yes, that is true, 2–4 = no verbal specification, and 5 = no, that is not true). A total fatigue score ranging from 20 to 100 can be calculated as the sum of the five subscales scores. A higher score represents higher levels of fatigue. The Swedish version of the MFI-20 has been psychometrically tested, showing good psychometrically properties in different settings (persons with post-polio, cancer, fibromyalgia, chronic widespread pain and in a healthy population) [52526].
Table 1
Subscales and items within the MFI-20
MFI-20 Subscales
Item nr
General fatigue
I feel fit
I feel tired
I am rested
I tire easily
Physical fatigue
Physically I feel only able to do a little
Physically I can take on a lot
Physically I feel I am in a bad condition
Physically I feel I am in an excellent condition
Mental fatigue
When I am doing something, I can keep my thought on it
I can concentrate well
It takes a lot of effort to concentrate on things
My thoughts easily wander
Reduced activity
I feel very active
I think I do a lot in a day
I think I do very little in a day
I get little done
Reduced motivation
I feel like doing all sorts of nice things
I dread having to do things
I have a lot of plans
I don’t feel like doing anything
In this study, fatigue was dichotomized into no reported fatigue (level one to two on the scale), and reported fatigue (level three to five on the scale) only on a sub-scale level when analysing the percentage distribution of participants rating fatigue. To simplify the dichotomization into no reported fatigue and reported fatigue some of the items scale (items 2, 5, 9, 10, 13, 14, 16, 17, 18 and 19) were converted to the reverse. In contrast, the total original score for fatigue was used in the correlation analysis and in the regression model.


Basic demographics of the participants were explored with gender and age, where age was divided into four following age groups: 18–29 years, 30–49 years, 50–69 years, equal and over 70 years. Country of birththe participants was divided in the two groups: persons born in Nordic countries (Sweden, Denmark, Finland and Norway), and persons born outside the Nordic countries (Afghanistan, Bolivia, Chile, Ethiopia, countries of the former Yugoslavia, Kosovo, Macedonia, the Philippines, Gambia, Iraq, Iran, Lebanon, Nigeria, Peru, Sierra Leone, Somalia, Syria, Tunisia, and Turkey). Occupation/employment level of the persons was explored by forming the two groups: working (working fulltime, working halftime or less), and not working ((unemployed, early retirement (pension before 65 years of age) and retired (pension at 65 years of age, or older)). The use of mobility assistive devices was divided into two following groups: not using mobility assistive devices and using mobility assistive devices (crutches, cane and/or walker, wheelchair occasionally, and wheelchair).

Statistical analysis

Descriptive statistics were carried out on the participants’ characteristics and fatigue. Pearson’s correlation coefficient was used to analyse the strength in correlation between variables. A multiple linear regression was used to explore explanatory factors for fatigue. Prior to analyzing the multiple linear regression, the criteria of this method was reviewed for the nature of the underlying relationships and residuals. Data were analysed using the IBM SPSS Statistics, version 22.0 (IBM Corp., Armonk, NY, 2013).


Characteristics of the participants

The mean age of the participants was 61 years (age range 19–93). Approximately half of the sample was female (54%), and the majority had PPS (99%). The occupation/employment level varied from unemployed (7%), working part time (6%), working full time (31%), early retirement (8%), and retired (48%). More than half of the participants used no mobility walking devices (66%), and among the participants who used mobility assistive devices, the use of assistive devices ranged from walking with crutches, cane and/or walker to using a wheelchair (Table 2).
Table 2
Characteristics of participants (n = 89)
n (%)
48 (54)
Age (years)
19–93 years
5 (6)
12 (13)
40 (45)
  70 ≥
32 (36)
Country of birth
 Nordic countries
65 (73)
 Outside the Nordic countries
24 (27)
Post-polio syndrome (PPS)
88 (99)
Occupation/employment level
6 (7)
 Working ≤50%
5 (6)
 Working 100%
28 (31)
 Early retirement
7 (8)
43 (48)
Use of assistive devices
 No walking devices
59 (66)
 Crutches, cane and/or walker
20 (22)
 Wheelchair occasionally
5 (6)
5 (6)


Overall, participants rated a high grade of fatigue in three of the five sub-scales of the MFI-20. The majority reported physical fatigue (90%), general fatigue (89%) and reduced activity (84%). Moreover, half of the sample reported mental fatigue and reduced motivation (Table 3).
Table 3
Percentage distribution and number of participants rating fatigue
MFI-20 Subscales
n (%)
General fatigue (4 items) (n = 89)
79 (89)
Physical fatigue (4 items) (n = 89)
80 (90)
Mental fatigue (4 items) (n = 88)
45 (51)
Reduced activity (4 items) (n = 87)
73 (84)
Reduced motivation (4 items) (n = 87)
45 (52)

Correlation between fatigue and the factors

Fatigue positively and weakly correlated with age (r = 0.234, p < 0.05) and using mobility assistive devices (r = 0.255, p < 0.05), meaning that the older participants reported more fatigue than the younger and that the participants using mobility assistive devices reported less fatigue. The use of mobility assistive devices also correlated positively and weakly with occupational employment level (r = 0.238, p < 0.05) meaning that participants not working used mobility assistive devices to a lesser extent. Finally, there was a weak and positive correlation between country of birth and occupational/employment level (r = 0.278, p < 0.01) indicating that persons born in the Nordic countries were older and so thereby more often retired (Table 4).
Table 4
Correlation between fatigue and the factors (n = 85)
Country of birth
Occupation/employment level
Country of birth
Occupation/employment level
Mobility assistive devices
*p < 0.05, **p < 0.01

Linear regression model

The multiple linear regression model showed that the factors age (β = 0.304, p < 0.019) and the use of mobility assistive devices (β = 0.262, p < 0.017) partially explained fatigue among persons living with late effects of polio. This result indicated that both high age and people not using mobility assistive devices reported more fatigue. There remaining two factors did not significantly explain fatigue in the final model. The regression model explained 14% of the variation in self-rated fatigue (Table 5).
Table 5
Multiple linear regression for fatigue and the factors (n =85)
Independent variables
95% CI
Occupation/employment level
Mobility assistive devices
R 2 = 14%


The aim of the present study was to explore possible factors associated with fatigue among persons with late effects of polio in Sweden. The main results were that persons not using mobility assistive devices and with high age reported more fatigue. However, the variation in fatigue could only be explained by 14% of the factors within the regression model.
In the present study, one of the factors that partly could explain the dependent variable of fatigue was the use of mobility assistive devices. A possible explanation for this could be that persons using mobility assistive devices stored their energy by simply using their mobility assistive devices, which in turn had a positive effect on the people’s self-rated fatigue. Also, persons not using mobility assistive devices might consume more energy when moving around, which may have resulted in an increased subjective feeling of fatigue. This finding of the importance of using mobility assistive devices is in line with a previous study [23], which showed that pain and fatigue could be associated with a lack of using mobility assistive devices among persons living with late effects of polio. On the other hand, another possible explanation could be that the persons with less fatigue did not need to use mobility assistive devices in a larger extent. Thus, the degree of fatigue did not lead to a need of using mobility assistive devices.
The findings from the present study indicated that age could contribute to explain fatigue among persons living with late effect of polio. This result may not only represent persons living with late effects of polio, it could also be transferred to people living with disability where fatigue is one of the symptoms. Moreover, gender and occupation/employment level could not significantly explain fatigue in the multiple regression model. This is in contrast to what has been shown in the general population, where females had higher mean values in all MFI-20 subscales compared to males [27]. One reason could be due to the small sample size. Concerning the occupation/employment level, the characteristics of the sample where more than half of the participants were not working (unemployed, early retirement, and retired) may explain this factor’s inability to explain the fatigue experienced.
Participation in many life areas might be restricted by increased fatigue. In the present study, mobility assistive devices have partly shown to have an association with fatigue, which implies that it is important to consider the access to mobility assistive devices in the healthcare system. Fatigue is a complex phenomenon [6], and therefore a number of factors that might be important for the understanding of fatigue should be included in the management of fatigue in this population. With this in mind, there is a need to consider the intersection of dimensions such as gender, age, cultural background, and occupational level.
In this retrospective registry study, fatigue was explored in relation to a set of factors that was taken from a clinical database. One limitation of using a clinical database was that it comprised predetermined variables, which restricted the choice of other factors of importance for the present study. Earlier qualitative studies [2122] have shown that life conditions related to conditions for daily occupations, social support, social network and municipal service were important for immigrants living with late effects of polio. These aspects could not be captured in the present study due to the use of predetermined variables.
Fatigue was assessed with the MFI-20 [5]. There are several questionnaires to measure fatigue [6252829], but fatigue is a widely experienced symptom [5], that might vary rapidly [30]. The MFI-20 is valid and reliable for measuring fatigue in persons with PPS [25], and was therefore a suitable questionnaire to capture fatigue. Furthermore, a limited number of factors were explored in relation to fatigue in the present study due to the small sample size which is a limitation. Therefore, further research is needed to explore other relevant explanatory factors.


Persons not using mobility assistive devices and high age reported more fatigue. Therefore, fatigue could partly be explained by the extent of using mobility assistive devices and the people’s age. These two factors are important, but to understand the complex nature of fatigue, additional factors must be considered. Healthcare professionals should provide and demonstrate the importance of assistive devices to ensure management of fatigue in persons living with late effects of polio. This knowledge contributes with an additional piece in the puzzle to better understand fatigue among persons living with late effects of polio.


General fatigue
Mental fatigue
Multidimensional fatigue inventory
Physical fatigue
Post-polio syndrome
Reduced activity
Reduced motivation



This study was supported by grants from the local Research and Development Council of Gothenburg and southern Bohuslän, and the Swedish Research Council for Health, and Working and Welfare (AGECAP 2013-2300). The authors are grateful to the polio team for gathering data and all the patients that have responded to the questionnaires. The authors are also grateful to Professor Synneve Dahlin-Ivanoff and PhD Anna-Lisa Thorén-Jönsson for valuable comments, and to Oscar Hammar, PhD Mathematical Statistics, for statistical consultation.

Availability of data and materials

Data will not be shared, because it is part of a clinical database.

Authors’ contributions

ISTS, KSS, and IOH conceived and designed the study. ISTS and IOH performed all the analyses. All authors read and approved the final manuscript.

Competing interests

The authors declare that they have no competing interests.

Consent for publication

Not applicable, the manuscript doesn’t contain any individual person’s data.

Ethics approval and consent to participate

The written informed patient consent has been approved by the Regional Ethical Review Board in Gothenburg, Sweden (Dnr 123-09). All participants signed an informed consent form, and received written and verbal information before participating in the clinical database.
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.


  1. On AY, Oncu J, Atamaz F, Durmaz B. Impact of post-polio-related fatigue on quality of life. J Rehabil Med. 2006;38(5):329–32.View ArticlePubMedGoogle Scholar
  2. Schanke AK, Stanghelle JK. Fatigue in polio survivors. Spinal Cord. 2001;39(5):243–51.View ArticlePubMedGoogle Scholar
  3. Trojan DA, Cashman NR. Post-poliomyelitis syndrome. Muscle Nerve. 2005;31(1):6–19.View ArticlePubMedGoogle Scholar
  4. Jason LA, Evans M, Brown M, Porter N. What is Fatigue? Pathological and Nonpathological Fatigue. PMR. 2010;2(5):327–31.View ArticleGoogle Scholar
  5. Lundh Hagelin C, Wengström Y, Runesdotter S, Johan FC. The psychometric properties of the Swedish Multidimensional Fatigue Inventory MFI-20 in four different populations. Acta Oncol. 2007;46(1):97–104.View ArticleGoogle Scholar
  6. Shen J, Barbera J, Shapiro CM. Distinguishing sleepiness and fatigue: focus on definition and measurement. Sleep Med Rev. 2006;10(1):63–76.View ArticlePubMedGoogle Scholar
  7. Westbrook MT. A survey of post-poliomyelitis sequelae: Manifestations, effects on people’s lives and responses to treatment. Aust J Physiother. 1991;37(2):89–102.View ArticlePubMedGoogle Scholar
  8. Davis MP, Walsh D. Mechanisms of fatigue. J Support Oncol. 2010;8(4):164–74.PubMedGoogle Scholar
  9. Fartu ERT, Gilhus NE. Post-polio syndrome an total health status in a perspective hospital study. Eur J Neurol. 2003;10:407–13.View ArticleGoogle Scholar
  10. Gawne ACHL. Post-polio syndrome: Pathophysiology and clinical management. Phys Rehabil Med. 1995;7:147–88.Google Scholar
  11. Lund ML, Lexell J. Perceived participation in life situations in persons with late effects of polio. J Rehabil Med. 2008;40(8):659–64.View ArticlePubMedGoogle Scholar
  12. Thoren-Jonsson AL, Grimby G. Ability and perceived difficulty in daily activities in people with poliomyelitis sequelae. J Rehabil Med. 2001;33(1):4–11.View ArticlePubMedGoogle Scholar
  13. Santos Tavares Silva I. The dynamic nature of Participation - Experiences, strategies and conditions for occupations in daily life amongst persons with late effects of polio. Gothenburg: University od Gothenburg; 2016.Google Scholar
  14. Borg K, Borg J, Edström L, Grimby L. Effects of excessive use of remaining muscle fibers in prior polio and LV lesion. Muscle Nerve. 1988;11(12):1219–30.View ArticlePubMedGoogle Scholar
  15. Perry J, Barnes G, Gronley JK. The Postpolio Syndrome: An Overuse Phenomenon. Clin Orthop Relat Res. 1988;233:145–62.Google Scholar
  16. Grimby L, Tollbäck A, Müller U, Larsson L. Fatigue of chronically overused motor units in prior polio patients. Muscle Nerve. 1996;19(6):728–37.View ArticlePubMedGoogle Scholar
  17. Sunnerhagen KS, Carlsson U, Sandberg A, Stålberg E, Hedberg M, Grimby G. Electrophysiologic evaluation of muscle fatigue development and recovery in late polio. Arch Phys Med Rehabil. 2000;81(6):770–6.View ArticlePubMedGoogle Scholar
  18. Malmusi D. Immigrants’ health and health inequality by type of integration policies in European countries. Eur J Public Health. 2015;25(2):293–9.View ArticlePubMedGoogle Scholar
  19. Rechel B, Mladovsky P, Ingleby D, Mackenbach JP, McKee M. Migration and health in an increasingly diverse Europe. Lancet. 2013;381(9873):1235–45.View ArticlePubMedGoogle Scholar
  20. Ostlund G, Wahlin A, Sunnerhagen KS, Borg K. Vitality among Swedish patients with post-polio: a physiological phenomenon. J Rehabil Med. 2008;40(9):709–14.View ArticlePubMedGoogle Scholar
  21. Santos Tavares Silva I, Thorén-Jönsson A-L. Struggling to be part of Swedish society: Strategies used by immigrants with late effects of polio. Scand J Occup Ther. 2015;22(6):450–61.View ArticlePubMedGoogle Scholar
  22. Santos-Tavares I, Thorén-Jönsson A-L. Confidence in the future and hopelessness: Experiences in daily occupations of immigrants with late effects of polio. Scand J Occupl Ther. 2013;20(1):9–20.View ArticleGoogle Scholar
  23. Thorén-Jönsson A-L. Adaptation and ability in daily occupation in people with poliomyelitis sequelae. Gothenburg: University of Gothenburg; 2000.Google Scholar
  24. Vreede KS, Sunnerhagen KS. Characteristics of Patients at First Visit to a Polio Clinic in Sweden. PLoS ONE. 2016;11(3):e0150286.View ArticlePubMedPubMed CentralGoogle Scholar
  25. Dencker A, Sunnerhagen KS, Taft C, Lundgren-Nilsson Å. Multidimensional fatigue inventory and post-polio syndrome – a Rasch analysis. Health Qual Life Outcomes. 2015;13:20.View ArticlePubMedPubMed CentralGoogle Scholar
  26. Ericsson A, Mannerkorpi K. Assessment of fatigue in patients with fibromyalgia and chronic widespread pain. Reliability and validity of the Swedish version of the MFI-20. Disabil Rehabil. 2007;29(22):1665–70.View ArticlePubMedGoogle Scholar
  27. Schwarz R, Krauss O, Hinz A. Fatigue in the general population. Oncologie. 2003;26(2):140–4.Google Scholar
  28. Horemans HL, Nollet F, Beelen A, Lankhorst GJ. A comparison of 4 questionnaires to measure fatigue in postpoliomyelitis syndrome 1. Arch Phys Med Rehabil. 2004;85(3):392–8.View ArticlePubMedGoogle Scholar
  29. Smets EMA, Garssen B, Bonke B, De Haes JCJM. The multidimensional Fatigue Inventory (MFI) psychometric qualities of an instrument to assess fatigue. J Psychosom Res. 1995;39(3):315–25.View ArticlePubMedGoogle Scholar
  30. Whitehead L. The Measurement of Fatigue in Chronic Illness: A Systematic Review of Unidimensional and Multidimensional Fatigue Measures. J Pain Symptom Manage. 2009;37(1):107–28.View ArticlePubMedGoogle Scholar

The Polio Crusade

THE POLIO CRUSADE IN AMERICAN EXPERIENCE A GOOD VIDEO THE STORY OF THE POLIO CRUSADE pays tribute to a time when Americans banded together to conquer a terrible disease. The medical breakthrough saved countless lives and had a pervasive impact on American philanthropy that ... Continue reading..http://www.pbs.org/wgbh/americanexperience/polio/

Erradicación de La poliomielitis

Polio Tricisilla Adaptada

March Of Dimes Polio History

Dr. Bruno




A 41-year-old man developed an acute illness at the age of 9 months during which, following a viral illness with headache, he developed severe weakness and wasting of the limbs of the left side. After several months he began to recover, such that he was able to walk at the age of 2 years and later was able to run, although he was never very good at sports. He had stable function until the age of 18 when he began to notice greater than usual difficulty lifting heavy objects. By the age of 25 he was noticing progressive difficulty walking due to weakness of both legs, and he noticed that the right calf had become larger. The symptoms became more noticeable over the course of the next 10 years and ultimately both upper as well as both lower limbs had become noticeably weaker.

On examination there was wasting of the muscles of upper and lower limbs on the left, and massively hypertrophied gastrocnemius, soleus and tensor fascia late on the right. The calf circumference on the right exceeded that on the left by 10 cm (figure1). The right shoulder girdle, triceps, thenar eminence and small muscles of the hand were wasted and there was winging of both scapulae. The right quadriceps was also wasted. The wasted muscles were also weak but the hypertrophied right ankle plantar flexors had normal power. The tendon reflexes were absent in the lower limbs and present in the upper limbs, although the right triceps was reduced. The remainder of the examination was normal.

Figure 1

The patient's legs, showing massive enlargement of the right calf and wasting on the left


What is that nature of the acute illness in infancy?
What is the nature of the subsequent deterioration?
What investigations should be performed?
What is the differential diagnosis of the cause of the progressive calf hypertrophy?



An acute paralytic illness which follows symptoms of a viral infection with or without signs of meningitis is typical of poliomyelitis. Usually caused by one of the three polio viruses, it may also occur following vaccination and following infections with other enteroviruses.1 Other disorders which would cause a similar syndrome but with upper motor neurone signs would include acute vascular lesions, meningoencephalitis and acute disseminated encephalomyelitis.


A progressive functional deterioration many years after paralytic poliomyelitis is well known, although its pathogenesis is not fully understood.2 It is a diagnosis of exclusion; a careful search for alternative causes, for example, orthopaedic deformities such as osteoarthritis or worsening scoliosis, superimposed neurological disorders such as entrapment neuropathies or coincidental muscle disease or neuropathy, and general medical causes such as respiratory complications and endocrinopathies.3


Investigations revealed normal blood count and erythrocyte sedimentation rate and normal biochemistry apart from a raised creatine kinase at 330 IU/l (normal range 60–120 IU/l), which is commonly seen in cases of ongoing denervation. Electromyography showed evidence of denervation in the right APB and FDI with polyphasic motor units and complex repetitive discharges, no spontaneous activity in the left calf and large polyphasic units in the right calf consistent with chronic partial denervation. Motor and sensory conduction velocities were normal. A lumbar myelogram was normal. Magnetic resonance imaging (MRI) scan of the calves is shown in figure2.

Figure 2

Axial T1 weighted MRI scan (TR 588 ms, TE 15 ms) of the calves, showing gross muscle atrophy and replacement by adipose tissue on the left, and hypertrophy of the muscles on the right, with only minor adipose tissue deposition


The differential diagnosis of the progressive calf hypertrophy is given in the box.

Causes of calf muscle hypertrophy

Chronic partial denervation

  • radiculopathy

  • peripheral neuropathy

  • hereditary motor and sensory neuropathy

  • spinal muscular atrophy

  • following paralytic poliomyelitis

    Neuromyotonia and myokymia

  • Isaac's syndrome

  • generalised myokymia

  • neurotonia

  • continuous muscle fibre activity due to: chronic inflammatory demyelinating polyradiculopathy, Guillain Barre syndrome, myasthenia gravis, thymoma, thyrotoxicosis, thyroiditis

    Muscular dystrophies



  • tumours

  • amyloidosis

  • cysticercosis

    Link here