Median Versus Ulnar Sensory and Motor Latency Difference in Early Diagnosis of Carpal Tunnel Syndrome

This study proposed to detect sensitivity of different electrophysiological techniques in early diagnosis of Carpal Tunnel Syndrome (CTS) compared to the standard technique as Median Sensory Latency. 

The present study included 70 hands (40 hands with clinical evidence of idiopathic CTS and 30 hands as control group). The following tests were done for both groups: 1- Sensory

median nerve, ulnar nerve, median versus ulnar latency difference between second and fifth digits, median versus ulnar latency difference (ring finger)  2- Motor nerve conduction study: median nerve, ulnar nerve, median versus ulnar motor latency difference.

The most sensitive (92%) two tests were median-ulnar sensory latency difference recorded from second and fifth digits and median-ulnar sensory latency difference recorded from fourth digit, while median-ulnar motor latency difference and median motor latency showed lowest sensitivity  (61, 53%) respectively. 

Median-ulnar sensory latency difference recorded from digit two and digit five and that recorded from digit 4 have highest sensitivity for early detection of CTS.