Neurogenic Muscle Hypertrophy Research Articles

Neurogenic muscle hypertrophy as an uncommon case of the calf enlargement — a case report and literature review

Unilateral limb edema is a common diagnostic problem. Apart from the most common pathologies, i.e. chronic venous insufficiency and lymphedema, differential diagnosis should include unusual causes of asymmetric extremity edema. We presented a case of 41-year-old man with suspicion of lymphedema of the left calf, who reported to a lymphology clinic. We discuss subsequent steps of the diagnostic procedure in case of the calf edema. In our patient, neurogenic muscle hypertrophy was found to be the cause of the calf enlargement. The diagnosis was confirmed by results of ultrasound, magnetic resonance, computed tomography, lymphoscintigraphy and electromyography examinations. Neurogenic muscle hypertrophy is a very rare and unusual cause of the calf enlargement. Nevertheless, it should be taken into account in the differential diagnosis.

Pathological mechanism of lumbar disc herniation resulting in neurogenic muscle hypertrophy

We present a 33-year-old man with 5-year history of low back pain who presented with an enlarging right calf. The patient underwent an extensive workup including biopsy without diagnosis. The patient’s examination was significant for diminished pinprick sensation in the right L5/S1 dermatome. Reflexes were absent in the right ankle. The circumference of the right calf (58 cm) was twice that of the left. MRI revealed a herniated lumbar disc at the L5/S1 level. He then underwent a L5/S1 microdiscectomy. Following this surgery, the patient noted complete resolution of all sensory deficits in his lower extremity. His calf circumference had decreased by 5 cm at 4 months and by a total of 8 cm at his 2-year post-operative visit. Histological examination of the affected muscle demonstrated severe grouped atrophy of both type I and type II fibers. There was also evidence of compensatory fiber hypertrophy as well as fiber splitting. We concluded that the patient suffered from a herniated lumbar disc causing radiculopathy with calf hypertrophy (neurogenic hypertrophy). To our knowledge this is the first report of both grouped atrophy and compensatory hypertrophy of both muscle fiber types seen in this phenomenon.

Neurogenic muscle hypertrophy in Type III spinal muscular atrophy

Neurogenic muscle hypertrophy is very unusual and has been rarely described. We described a 25-year-old woman presented with proximal muscle weakness with calf muscle hypertrophy. Limb magnetic resonance imaging scans showed increased muscle bulk without fatty changes, and a muscle biopsy revealed prominent hypertrophic type II muscle fibers. A mutation in SMN1 was found in a genetic analysis. This is the first report of neurogenic muscle hypertrophy seen in genetically confirmed spinal muscular atrophy III.

Neurogenic muscle hypertrophy

We report the case of a 48-year-old man who presented with left calf hypertrophy 6 years after an episode of left S1 sciatica related to a herniated disk. Magnetic resonance imaging disclosed muscle hypertrophy. Electromyography showed left S1 radiculopathy with abnormal spontaneous muscle activity. Neurogenic muscle hypertrophy is a rare phenomenon that is chiefly seen when denervation occurs slowly and gradually. The typical patient is a middle-aged man who has a history of S1 radiculopathy. The soleus muscle is the main site of involvement. The pathophysiology is unclear but may involve type I fiber hypertrophy in response to the complex repetitive discharges recorded by electromyography. The natural history of neurogenic muscle hypertrophy is incompletely understood.

Isolated Spinal Accessory Mononeuropathy Associated With Neurogenic Muscle Hypertrophy: Restricted Neuralgic Amyotrophy or Stretch-Palsy? A Case Report

Baker SK. 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.

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.

Congenital monomelic neurogenic disorder with calf muscle hypertrophy

An 8-year-old girl had hypertrophy of the right calf muscle since birth, with progressive ankle contracture and mild muscle weakness. Her right leg was 3 cm shorter than her left. Electromyography and biopsy of the affected muscle showed neurogenic changes. She also had neurogenic bladder and spina bifida occulta at the S1 level. We believe that the spina bifida was responsible for the neurogenic changes in her right calf, but could not find definite evidence for this association. Although cases with neurogenic muscle hypertrophy, especially calf muscle hypertrophy, have been reported, none of them was congenital or associated with spina bifida occulta.

Segmental neurogenic muscle hypertrophy associated with radiation injury

A 48-year-old man presented with painless left trapezius hypertrophy 20 years after radiotherapy for nasopharyngeal carcinoma. EMG sampling showed myokymic discharges, reduced polyphasic motor unit recruitment and no signs of active denervation. The relationship between radiotherapy, brachial plexopathy and neurogenic muscle hypertrophy is discussed.

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.