Hereditary neuropathy with liability to pressure palsies in children.

The clinical and neurophysiologic findings of two children presenting with focal weakness and atrophy in unusual nerve distributions and no apparent antecedent injuries are reported. Patient 1 presented with a droopy left shoulder that was initially attributed to scoliosis. Patient 2 presented with right biceps brachii atrophy that was first brought to his parent's attention during a routine physical examination. In addition to documenting focal spinal accessory and musculocutaneous mononeuropathies as the cause of weakness in Patients 1 and 2, respectively, nerve conduction studies also revealed evidence of superimposed diffuse demyelinating polyneuropathy in both children. The latter findings suggested the diagnosis of hereditary neuropathy with liability to pressure palsies and led to definitive DNA diagnoses.