Calf pseudohypertrophy in a patient with double neurogenic pathology.

A pseudohypertrophy of the calf can be rarely associated with neurogenic pathologies as S-1 radiculopathy, poliomyelitis, spinal muscular atrophy, traumatic lesions of peripheral nerves, intraspinal neurinoma. The causes of this particular phenomenon are unknown. The authors present the case of a 52-year-old man with an enlargement of the left calf suffering from a mild form of spinal paralytic poliomyelitis in the early childhood and episodes of severe left sciatica in the last four years. Electromyography demonstrated a pattern of denervation in both legs and an H-reflex absent when the left tibial nerve was stimulated. An open muscle biopsy of the left calf was performed. Light microscopic and ultrastructural examination of the muscle confirmed the presence of a pattern of "neurogenic type" pseudohypertrophy. Our results could be interesting for the understanding of the mechanism of neurogenic pseudohypertrophy. This case suggests that timing of stimulus or "dose" of denervation may be important factors in such a phenomenon.