SCHWARTZ-JAMPEL-SYNDROME - EVIDENCE OF CENTRAL-NERVOUS-SYSTEM DYSFUNCTION

We report four patients with Schwartz-Jampel syndrome showing evidence of central conduction impairment documented by somatosensory evoked p otentials. Median nerve somatosensory evoked potential showed normal l atencies to Erb's point and N13 in all patients. Interpeak latencies b etween N13 and N19 were prolonged in five nerves, with complete block in three nerves. Posterior tibial nerve somatosensory evoked potential s were performed in three patients. Peripheral latencies were normal i n all patients. Interpeak latencies between lumbar and cervical potent ials were prolonged in two patients, with conduction delay between cer vical and cortical potentials in five of the six nerves tested. Visual ly evoked potentials, brainstem auditory evoked potentials, electromyo graphy, and nerve conduction velocity studies were normal in all patie nts. Parents' median nerve and posterior tibial nerve somatosensory ev oked potentials were normal.