Objectives To evaluate the relationship between extramedian spreading of sensorial symptoms and median and ulnar nerve cross-sectional area in patient with carpal tunnel syndrome (CTS), to compare the ultrasonographic and electrophysiological findings in patients with CTS whose sensorial symptoms are extramedian spreading or median distribution only.

Methods Patients with CTS were divided into two groups as with and without extramedian symptoms and were assessed clinically, electrophysiologically and ultrasonographically by three blind investigators. In electrophysiological tests, median and ulnar nerve conduction studies were performed. Nerve cross-sectional areas were measured at hamatum hook, psiform bone, radio-ulnar joint, one-third distal part of forearm, and medial epicondyle for median nerve; radio-ulnar joint, psiform bone, one-third distal part of forearm, and medial epicondyle for ulnar nerve by ultrasonography.

Results The study was completed with 61 patients (108 hands). Extramedian symptoms were present in 31 patients (54 hands). Finger grip strength was lower, pain values evaluated with visual analogue scale were higher in these patients (p<0.05). There was no statistically significant difference in electrophysiological and ultrasonographic parameters between two groups.

Conclusions These results suggest that extramedian spread in CTS patients is more related to central and peripheral sensitization than peripheral causes.

Disclosure of Interest None declared