Postpoliomyelitis muscle pseudohypertrophy

Accuracy of Resting Energy Expenditure Estimation Equations in Polio Survivors

OBJECTIVE

To evaluate the accuracy of 4 equations validated for the general population to determine resting energy expenditure (REE) in polio survivors.

DESIGN

A descriptive, ambispective, single-center observational cohort study of minimal risk care.

SETTING

Tertiary university care hospital.

PARTICIPANTS

DATAPOL database of polio survivors followed up in a specialist department (N=298).

INTERVENTIONS

None.

MAIN OUTCOMES MEASURES

REE measurement by indirect calorimetry and estimated REE using 4 equations and comparing the values with indirect calorimetry. Analysis of correlations between measured REE and weight, height, and body mass index (BMI) and indicators of severity of polio sequelae.

RESULTS

Of the 298 polio cases in the database between January 2014 and May 2017, 41 were included (19 men and 22 women). Mean±SD BMI was 26.0±5.6 kg/m² (56.1% below 25). Measured REE correlated significantly and positively with weight and weaker with BMI. Correlations between measured and estimated REE were strong (between 0.49 and 0.59); correlations were strongest for the simplified World Health Organization and the Harris and Benedict equations. However, the equations systematically overestimated REE by more than 20%, especially in men. We calculated a correction factor for the World Health Organization scale: -340.3 kcal/d for women and -618.8 kcal/d for men.

CONCLUSION

Analysis of REE is important for polio survivors; The use of estimation equations could lead to the prescription of a nonadapted diet. We determined a correction factor that should be validated in prospective studies.

Prevalence and Effect of Obesity on Mobility According to Different Criteria in Polio Survivors

OBJECTIVE

Obesity is a major and functionally important problem in polio survivors. The aim of this study was to investigate the prevalence of obesity using body mass index and percentage body fat in polio survivors and to analyze the relationship between obesity and mobility.

DESIGN

Eighty-four polio survivors were included. Anthropometric parameters, knee extensor strength, and the Short Physical Performance Battery were evaluated. A questionnaire was used to explore the late effects of poliomyelitis. Obesity was determined using both body mass index and percentage body fat.

RESULTS

The prevalence of obesity in polio survivors was 39.3% and 81.5% using the body mass index and percentage body fat criteria, respectively. The Short Physical Performance Battery scores were significantly different between the obese and nonobese groups as determined by percentage body fat (P < 0.05). Only percentage body fat was significantly associated with mobility after controlling for the confounding variables in obese polio survivors (P < 0.05).

CONCLUSIONS

Obesity in polio survivors was underestimated when the body mass index criteria were used. Percentage body fat was a significantly associated factor for mobility in obese polio survivors. Obesity determined by percentage body fat criteria is useful to address obesity-related problems in polio survivors.

Isolated spinal accessory mononeuropathy associated with neurogenic muscle hypertrophy: restricted neuralgic amyotrophy or stretch-palsy? A case report

A 55-year-old man developed transient bi-brachial paresthesias followed by severe pain over his left shoulder ridge and periscapular region within 8 hours of rigorous hand-over-hand hoisting of a 33.8-kg (75-lb) object. He experienced weakness in shoulder abduction followed several weeks later by focal hypertrophy of the left trapezius. Electrophysiologic studies showed significant spontaneous motor activity in the form of denervation potentials, fasciculations, and complex repetitive discharges. The 2 major diagnostic considerations were restricted neuralgic amyotrophy versus stretch palsy of the spinal accessory nerve. The clinical similarities and differences between restricted forms of neuralgic amyotrophy and stretch palsies are discussed.

Muscle hypertrophy with complex repetitive discharges in C-6 radiculopathy

OBJECTIVE

To report on a case of post-denervation muscle hypertrophy in an unusual distribution.

CASE REPORT

A 52-year-old patient with severe flaccid paraparesis after polio developed unilateral C-6 radiculopathy that resolved with conservative treatment. Within 2 years marked hypertrophy, stiffness and pain in the muscles in the affected myotome developed. EMG discovered abundant complex repetitive discharges (CRD) within hypertrophic muscles. On biopsy, true hypertrophy of muscle fibers and some group atrophy was found. Steroid treatment relieved the symptoms and significantly suppressed the CRD. The possible causative role of CRD for hypertrophy in partially denervated muscle is discussed.

Hypertrophie musculaire neurogène : à propos de trois cas, imagerie et revue de la littérature

OBJECTIVE

To review the literature on well-documented cases of neurogenic muscle hypertrophy in order to define significant features of this disease.

PATIENTS AND METHODS

The PUBMED and SCIENCE DIRECT web-sites were used to conduct an inventory of all reported cases of this disease. We entered the key-words "hypertrophy", "muscle" and "neurogenic", and found 48 articles, describing 129 cases. Our criteria of inclusion included hypertrophy of one or several muscles of a lower limb, previous realization of at least one imaging study (CT or MRI) and electromyography of lower limbs; criterion of exclusion was hypertrophy related to hereditary or acquired polyneuropathies. Twenty-five cases were retained for investigation along with 3 recent cases observed in our department.

RESULTS

Results show that neurogenic muscle hypertrophy is usually presents with painful enlargement of a calf in a male, aged 32 to 60 years, with previous history of low back pain and sciatica, 68% of the time due to disk herniation or lumbar stenosis. Other clinical findings may include radiation therapy or trauma.

CONCLUSION

The symptoms of neurogenic muscle hypertrophy may lead to MRI examination before electromyography. This disease should be included in the differential diagnosis.

Botulinum toxin a for aesthetic contouring of enlarged medial gastrocnemius muscle

BACKGROUND

Oversized, muscular calves can cause psychological stress in women. Botulinum toxin A has been used in the treatment of benign masseteric hypertrophy with correction of the squared facial appearance. It is believed that botulinum toxin might also be effective in reducing enlarged calf muscles.

OBJECTIVE

This study was performed to investigate the effect of botulinum toxin A in reducing enlarged medial gastrocnemius muscles in volunteers with muscular legs.

METHODS

Botulinum toxin A of 32, 48, or 72 U was injected in each medial head of the gastrocnemius muscle in six women. Clinical photography was taken and the leg circumferences were measured. The functional evaluations were performed by examining range of joint motion and motor and sensory examination.

RESULTS

All of the enrolled subjects showed a reduction in the medial gastrocnemius muscle after the botulinum toxin injection. The reduction in medial calf was noticed even after 1 week and the effect of was well maintained for 6 months. Leg contouring was obtained by the botulinum toxin treatment. The middle leg circumference showed a slight decrease in five subjects. No functional disabilities were observed.

CONCLUSION

Botulinum toxin A can be used to contour the aesthetic enlargement of the medial gastrocnemius muscle with slight reduction in volume. Botulinum toxin-induced atrophy of the muscle caused no functional disabilities and the clinical improvement was well maintained for 6 months after the botulinum toxin A injection.

Muscle fiber conduction velocity in situ (MFCV) in denervation, reinnervation and disuse atrophy

OBJECTIVES

Muscle fiber conduction velocity (MFCV) was performed in disuse atrophy, in denervated muscle and during reinnervation as a possible index of muscle atrophy, and to clarify the evolution of the fiber size.

MATERIAL AND METHODS

MFCV was performed in 12 patients with complete denervation of biceps brachii muscle and during various stages of reinnervation. Twenty-one patients with disuse quadriceps atrophy were also tested. Invasive MFCV was performed according to the method reported elsewhere (2).

RESULTS

MFCV decreased significantly in denervated muscles. Reduction of MFCV was found during the first weeks and was progressive. Peak frequency in histograms decreased and the normal Gaussian distribution was lost. MFCV increased progressively after reinnervation with coexistence of slow and significant increase of faster MFCV. MFCV decreased significantly also during the first weeks after immobilization and improved by rehabilitation therapy.

CONCLUSION

MFCV is a reliable method to test the muscle fiber size after denervation and immobilization, and its evolution by reinnervation and therapy.

AAEM minimonograph #46: neurogenic muscle hypertrophy

Muscle hypertrophy occurs uncommonly in several neurogenic disorders including neuropathies, radiculopathies, spinal muscular atrophy, and post-polio syndrome. Its pathogenesis varies in different circumstances. In the presence of generalized myokymia and neuromyotonia (Isaacs' syndrome), symmetrical hypertrophy appears to be the result of continuous spontaneous electrical stimulation of myofibers and, in some cases, results in type 1 myofiber preponderance. Focal hypertrophy occurring with radiculopathies and mononeuropathies was associated with complex repetitive discharges (CRDs) in approximately half the cases. CRDs may play a role in the pathogenesis of myofiber hypertrophy by continuous myofiber stimulation, but in some cases, with and without CRDs, myofiber hypertrophy may be related to mechanical events. Muscle enlargement seen in old polio appears to involve a significant degree of pseudohypertrophy, although some myofiber hypertrophy occurs. The symmetrical occurrence of hypertrophy in genetically determined disorders, such as spinal muscular atrophy, and hereditary motor and sensory neuropathy types 1 and 2 may have both a genetic and a mechanical basis in addition to pseudohypertrophy in some cases.

Hereditary motor and sensory neuropathy with calf hypertrophy is associated with 17p11.2 duplication

The demyelinating type of hereditary motor and sensory neuropathy (HMSN I) is characterized by progressive weakness and atrophy of leg muscles. Six patients (age, 25-79 yr) belonging to three generations had calf hypertrophy (6 of 6), foot drop or difficulty with heel walking (4 of 6), pes cavus (3 of 6), absent or depressed tendon jerks in the lower limbs (4 of 6), and mild distal sensory loss (3 of 6). No other family member had leg atrophy. Motor conduction velocities ranged from 20 to 40 m/sec. Sural nerve biopsy showed loss of large myelinated fibers, numerous onion bulbs, and segmental demyelination and remyelination. Computed tomographic scans of leg muscles and histological and morphometric findings in gastrocnemius revealed true muscular hypertrophy. Southern blot and fluorescence in situ hybridization documented the duplication of the entire 17p11.2 segment associated with classical HMSN IA. The pathogenesis of muscle hypertrophy in our cases is unclear. Chronic leg muscle weakness and long-standing partial denervation might cause calf enlargement by a combination of compensatory "work-induced" and "stretch-induced" fiber hypertrophy. Alternatively, that all the affected family members presented calf hypertrophy might suggest the action of a genetic factor associated with the duplication at 17p11.2.

Muscle hypertrophy secondary to the tethered cord syndrome

Segmental muscle enlargement occurs in a variety of neurogenic conditions. We present a case with calf hypertrophy, likely produced by partial denervation and continuous neuromuscular irritability, which was caused by a tethered spinal cord that was demonstrated by MRI. Muscle MRI correlated with muscle biopsy findings in which atrophy and hypertrophy were accompanied by rimmed vacuoles.

Hereditary motor and sensory neuropathy with calf muscle enlargement

We report three related patients with autosomal dominant hereditary motor and sensory neuropathy (HMSN). An unusual and characteristic feature was calf enlargement, caused by muscle fiber hypertrophy predominantly of type 1 fibers. None of the family members showed atrophy of the legs. Sural nerve pathology disclosed marked loss of myelinated fibers and numerous onion bulb formations. While cases of HMSN with calf muscle hypertrophy have been reported, the present pedigree was different from that in any of the previous cases in that no family member showed clinically apparent leg atrophy.

Clinical and morphological study of calf enlargement following S-1 radiculopathy

Calf enlargement following sciatica is a rare condition. It is reported the case of a 28-year-old woman who complained of repeated episodes of lower back pain radiating into the left buttock and foot. One year after the beginning of her symptoms, she noticed enlargement of her left calf. X-ray studies disclosed L5-S1 disk degeneration. EMG showed muscle denervation with normal motor conduction velocity. Open biopsies of the gastrocnemius muscles were performed. The left gastrocnemius muscle showed hypertrophic type 2 fibers in comparison with the right gastrocnemius. Electron microscopy showed mildly increased number of mitochondria in these fibers. A satisfactory explanation for denervation hypertrophy has yet to be provided.

Isolated muscle hypertrophy as a sign of radicular or peripheral nerve injury

Two patients with isolated neurogenic hypertrophy of the trapezius muscle due to accessory nerve injury and a patient with neurogenic hypertrophy of the anterior tibial muscle due to chronic radicular lesion L4 are described. Electromyography of the affected muscles showed dense continuing spontaneous discharges of complex potentials. Muscle biopsy performed in two patients showed abundant hypertrophic muscle fibres, identified in one case by ATP-ase reaction as being of predominantly type I. In the majority of previously reported patients with neurogenic muscle hypertrophy confined to the calf muscle, a passive stretch mechanism was suggested as a cause of the hypertrophy. It is assumed that the excessive spontaneous muscle activity gave rise to the hypertrophy in these patients. This may also be true in previously reported patients with neurogenic hypertrophy and similar spontaneous activity in electromyography.

Postpolio syndrome

The recurrence of symptoms many years after the rehabilitation of individuals who survived the acute illness, poliomyelitis, is a major concern. The purpose of this article is to provide information to the nurse practitioner (NP), who, as a primary health care provider, may be the first health professional to encounter persons with such complaints. Although no cure has been identified, diagnosis and treatment is available and is important to the psychosocial well-being of those who suffer from postpolio syndrome. This article reviews research on the syndrome including etiology, pathophysiology, symptoms and management, psychological issues, and the role of the aging process. Some areas where further research is indicated are also identified.

Calf enlargement in hereditary motor and sensory neuropathy

Six members originating from two families with hereditary motor and sensory neuropathy (hypertrophic and neuronal types) were noted to have enlarged calf muscles. Muscle computed tomography revealed that muscle enlargement in the propositus of the family with the hypertrophic type of HMSN was due to an increase in muscle and/or connective tissue. Computed tomography of the legs of the propositus of the family with the neuronal type of HMSN showed infiltration of the medial head of the gastrocnemius muscle by adipose tissue.

Neurogenic muscle hypertrophy. Report of two cases

Muscle hypertrophy is rare in denervating diseases. A patient with calf enlargement associated with L5-S1 radiculopathy and another with thenar, hypothenar, forearm and calf muscle hypertrophy in the course of chronic relapsing inflammatory demyelinating polyneuropathy are described. Gastrocnemius muscle biopsy revealed both type I and type II fibre hypertrophy in the former case and predominant type I fibre hypertrophy in the latter. Passive stretching and abnormal spontaneous muscular activity might have played a role in the origin of hypertrophy in both patients, but a satisfactory explanation for denervation hypertrophy has yet to be provided.