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Muscle biopsy from right gastrocnemius revealed myopathic features with prominent myophagocytosis (arrow, A) and regeneration. Note presence of eosinophils in the infiltrate. In addition, neurogenic features with atrophic fibres with clumped myonuclei (arrow, B) and adipose tissue infiltration is also noted. (a: H and E, ×120, b: H and E, ×40)
Source publication
We report an unusual case of unilateral limb pseudo hypertrophy in a 21-year-old lady who developed progressive enlargement of the right calf followed by thigh in association with chronic leg pain. Magnetic resonance imaging (MRI) of the affected limb confirmed enlargement of various muscles. Electromyography revealed neurogenic features consistent...
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Unilateral enlargement of the calf in a 57-year-old man with S1 radiculopathy is described in this case report. Short tau inversion recovery-weighted imaging provided evidence of selective hypertrophy and a high signal intensity of the gastrocnemius and soleus. Histopathological analysis of the gastrocnemius revealed an endomysial inflammatory infi...
Background: Single-fiber electromyography (SFEMG) has been suggested as a quantitative method for supporting chronic partial denervation in amyotrophic lateral sclerosis (ALS) by the revised EI Escorial criteria. Although concentric needle (CN) electrodes have been used to assess jitter in myasthenia gravis patients and healthy controls, there are...
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Objectives
Neurogenic muscle hypertrophy (NMH) is a rare condition characterized by focal muscle hypertrophy caused by chronic partial nervous injury. Given its infrequency, underlying mechanisms remain poorly understood. Inspired by two clinical cases, we conducted a systematic review to gain insights into the different aspects of NMH.
Methods
We systematically searched online databases up until May 30, 2023, for reports of muscle hypertrophy attributed to acquired neurogenic factors. We conducted an exploratory analysis to identify commonly associated features. We also report two representative clinical cases.
Results
Our search identified 63 reports, describing 93 NMH cases, to which we added our two cases. NMH predominantly affects patients with compressive radiculopathy (68.4%), negligible muscular weakness (93.3%), and a chronic increase in muscle bulk. A striking finding in most neurophysiological studies (60.0%) is profuse spontaneous discharges, often hindering the analysis of voluntary traces. Some patients exhibited features consistent with more significant muscle damage, including higher creatine phosphokinase levels, muscle pain, and inflammatory muscle infiltration. These patients are sometimes referred to in literature as “focal myositis.” Treatment encompassed corticosteroid, Botulinum Toxin A, decompressive surgery, antiepileptic medications, and nerve blocks, demonstrating varying degrees of efficacy. Botulinum Toxin A yielded the most favorable response in terms of reducing spontaneous discharges.
Interpretation
This systematic review aims to provide a clear description and categorization of this uncommon presentation of an often‐overlooked neurological disorder. Though questions remain about the underlying mechanism, evidence suggests that aberrant fiber overstimulation along with increased workload that promotes focal damage may result in muscle hypertrophy. This may serve as a guide for therapeutic interventions.
Background:
Diverse adipose lesions can affect peripheral nerves, including an intrinsic disorder known as lipomatosis of nerve (LN). This condition leads to massive nerve enlargement and has often been associated with nerve territory overgrowth. Although LN has been well documented as a peripheral lesion, it is uncertain whether LN can occur or extend intradurally.
Methods:
In the present 2-part study, we searched our institutional database and the world literature to identify any case of LN occurring or extending intradurally. Strict pathognomonic imaging and histopathologic features of LN were required to be present.
Results:
We did not identify any case of LN that had occurred or extended intradurally in our institution. Specifically, in our database, we found no case of intradural LN, and an evaluation of the imaging studies of proximal examples of LN did not show any extension proximal to the spinal foramen. Our literature search identified 208 reports of potential interest, of which only 3 had reported on spinal LN. Although 2 of the 3 cases showed some similarities to LN, none had demonstrated features diagnostic for LN and none had demonstrated nerve territory overgrowth. A review of 16 cases of LN in proximal locations summarized in a recently reported systematic review did not reveal any cases with LN proximal to the foramen or in an intradural location.
Conclusion:
A review of our institutional cases and reported cases did not show any example of LN extending or occurring intradurally. It appears that LN is a benign tumor-like nerve lesion that is without a central location, unlike more well-known tumors such as schwannomas.
Calf pseudohypertrophy due to radiculopathy is an exceptional phenomenon rarely described. We report a 67 year old woman with a previous history of lumbar disc surgery consulting by progressive increase for more than a year of evolution painless right calf associated loss of strength. Electromyographic findings showed chronic S1 radiculopathy and radiologically was appreciated in the medial gastrocnemius and soleus rights substitution of normal muscle tissue by adipose tissue without evidence of myopathy or sarcomatous degeneration.
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