Moving toes and myoclonus associated with hereditary neuropathy with liability to pressure palsy (HNPP).

A 22-year-old male awoke with right foot drop and numbness. Nerve conduction studies, sural nerve biopsy, and molecular genetic analysis were consistent with hereditary neuropathy with liability to pressure palsy (HNPP). Two months later he developed involuntary flexion/extension movements of the right toes with associated intermittent dystonic flexion of the right foot. Over the next 2 months these movements spread to the left foot and hand and myoclonus of the left trapezius and rhomboid appeared. This is the first case report of moving toes syndrome and segmental myoclonus in association with HNPP. The temporal and topographic patterns of spread of the abnormal movements suggest a central mechanism probably induced by peripheral pathology.