Hypertrophic neuropathy with diabetes mellitus.

A 52-year-old male with diabetes mellitus showed sensorimotor disturbance of symmetrical glove and stocking distribution. Electromyography demonstrated signs of denervation, and motor nerve conduction velocities could not be obtained because the muscle action potential was not evoked by the electrical stimulation of the nerves. Quantitative histologic and ultrastructual studies were performed in the sural nerve biopsy. Determination of fiber densities revealed a striking decrease of both myelinated and unmyelinated fibers and remarkable increase of the onion bulb formations. Hypertrophic changes with onion bulb formations have been observed in various clinical conditions, particularly in hereditary disorders, but uncommon in diabetic neuropathy. Our case was non-familial and may form one atypical type of diabetic neuropathy.