Sympathetic skin responses in hereditary sensory and autonomic neuropathy and familial amyloid neuropathy are different

We compared the clinical and electrophysiological findings in seven patient s with familiar amyloid polyneuropathy (FAP) and six with hereditary sensor y and autonomic neuropathy type I (HSAN). Both groups had progressive loss of pain and temperature appreciation, beginning distally in the feet. In HS AN, the median sensory nerve action potentials (SNAP) were lost early, but the sympathetic skin responses (SSR) were always preserved. In FAP, the SSR were lost at an early stage. The SSR may thus help to distinguish between these two causes of small-fiber neuropathy early in the course of the disor der. (C) 1999 John Wiley & Sons, Inc.