Hereditary neuropathy with liability to pressure palsies masquerading as slowly progressive polyneuropathy

Hereditary neuropathy with liability to pressure palsies (HNLPP) is a peripheral nerve disorder in which recurrent pressure palsies are associated with pathological swelling ('tomacula') of myelinated nerve internodes. We report a patient with a slowly progressive polyneuropathy associated with substantial slowing of conduction velocities initially suggestive of an acquired or hereditary demyelinating polyneuropathy. However, repeat electrodiagnostic studies demonstrated that conduction slowing and partial conduction block were localized primarily to common sites of nerve compression and entrapment. Sural nerve biopsy revealed multiple tomacula consistent with the diagnosis of HNLPP.