Two women suffered from a similar, slowly progressive illness characterized by upper and lower motor neuron involvement, sensory disturbances, and neurogenic bladder. Radiographic examinations showed cerebral atrophy and, in one, changes on computerized tomography suggesting leukodystrophy. Sural nerve biopsies revealed axonal neuropathy associated with a large number of polyglucosan bodies accumulating predominantly but not exclusively in myelinated axons.