A Study on Relative Severity of Involvement of Digital Sensory Branches of Median Nerve in Carpal Tunnel Syndrome

J Korean Assoc EMG Electrodiagn Med 1999;1(1):26-30.
Published online January 1, 1999.

Abstract

Objects : The purpose of this study is to improve the diagnostic accuracy and preoperative evaluation in carpal tunnel syndrome(CTS) with digital branch evaluation technique. And we want understand the relationship of symptom duration with the severity of nerve conduction study. Methods : Each digital branch of the median nerve was stimulated in 19 patients with CTS. The amplitude and coduction velocity of the sensory nerve action potentials(SNAP) recorded with orthodromic and antidromic cethods were compared with the corresponding calues of asymptomatic neurologically normal, age matched group. Results : Duration of symptoms was poorly correlated with sensory latency. Sensory conduction velocity or SNAP amplitude were abnormal in all digital nerves studied in CTS. But the differences were greater in ring finger(7th branch) and thumb(1st, 2nd branches). Conclusion : We conclude that selective digital nerve study is a sensitive technique in the diagnosis of CTS. Duration of symptom is not correlated with severity of injury.

Key Words: Carpal tunnel syndrome, Duration of symtom, Digital branches of median nerve