Peripheral neuropathy in myotonic dystrophy. Relation to glucose intolerance.

Motor nerve conduction velocity (MNCV) was measured in three peripheral nerves in each of 24 patients with myotonic dystrophy having various degress of associated glucose intolerance and was compared with results in a control group. Both groups had similar glucose tolerance and were matched for age and adiposity. The mean MNCV in the ulnar, median, and peroneal nerves in the myotonic dystrophy group were all significantly slowed (P less than .01). This peripheral nerve dysfunction, usually subclinical, is yet another manifestation of this multisystem disease and is unrelated to the associated glucose intolerance.