[A case of hereditary sensory autonomic neuropathy type II with late onset]

We reported a 22-year-old man with hereditary sensory autonomic neuropathy (HSAN) type II. His initial neurological symptom at the age of 18 years was hypoesthesia on the feet and legs. In spite of late onset and absence of multilating acropathy, we diagnosed this case as HSAN type II because of an absence of sensory nerve action potentials with normal motor nerve conduction velocities and of a total loss of myelinated fibers with a decrease of unmyelinated fibers in the sural nerve. The sweating induced by iontophoretic pilocarpine stimulation was decreased on the dorsum of the foot. In addition, the morphometric analysis of sudomotor nerves around sweat glands showed a decrease of nerve terminals and unmyelinated axons. Because decrease or loss of sweating is one of the cardinal signs in HSAN type II, the quantitative sweating test and morphometric evaluation of the innervation of sweat glands are important for the proof of the autonomic signs.