NERVE CONDUCTION STUDIES AND THEIR SIGNIFICANCE IN CUBITAL TUNNEL SYNDROME

Abstract

Introduction: Nerve conduction study (NCS) examination of the ulnar nerve is a diagnostic tool when investigating patients presenting with cubital tunnel syndomre (CTS). However, NCS are associated with a false negative rate. Decompressive surgery of the ulnar nerve remains the primary treatment of cubital tunnel syndrome. The aim of our study was to look at:

1. The correlation between the results of NCS and the subsequent outcome from surgery

2. Compare these results with a similar group of patients that underwent decompressive surgery without NCS.

Method: A retrospective study of 75 cases of CTS was undertaken. All patients had clinical examination with documentation of features, followed by NCS if indicated. If NCS were carried out, the results of the study was graded (negative, mild, moderate or severe). All patients had decompressive surgery of the ulnar nerve at the elbow. Operative functional outcomes was evaluated pre and post operatively using standard DASH score. A successful outcome was defined as resolution of symptoms.

Results: There were 53 men and 22 women. Patient age showed a normal distribution (range 26–84, mean 49 years). Overall, 65 patients (87%) had resolution of symptoms postoperatively and 10 patients (13%) had unresolved symptoms (5 sensory, 1 pain, 2 sensory & pain, 2 sensory & motor). Outcomes of patients that did not undergo NCS showed a resolution rate of 89% (24/27). Those that had a negative NCS, showed a resolution rate of 100% (12/12), whilst those that had a positive NCS showed a resolution rate of 81% (29/36).

Discussion: Our study highlighted that patients with electro-negative CTS can be effectively and safely treated by simple decompression. Surgical outcome can be correlated to the severity of the pre-operative NCS. There would seem no reason to refer patients for NCS prior to offering operative treatment.