Hereditary motor and sensory neuropathy type II (HMSN-II) and neurogenic muscle hypertrophy: a case report and literature review.

We present two siblings affected by hereditary motor and sensory type II neuropathy (HMSN-II) with neuromyotonia, and associated with muscle hypertrophy of the thighs and calves in one. We review the literature about the association between HMSN-II, neuromyotonia and muscle hypertrophy. Muscle enlargement in HMSN-II is rare and may be sporadic or under genetic control. In our patient, muscle hypertrophy was sporadic and probably due to neuromyotonia. The relationship between muscle hypertrophy and neuromyotonia can be deduced by the fact that both conditions were reduced after diphenylhydantoin treatment (200 mg/day).