Correlation between clinical outcome and nerve conduction studies before and after surgery in patients with carpal tunnel syndrome

Objectives: In this study, we aimed to establish the correlation between clinical outcomes using a self-administered Boston carpal tunnel questionnaire (BCTQ) and nerve conduction studies (NCSs) before and after carpal tunnel release (CTR) operation in moderate, severe and extreme groups of patients. In prevalent literature, we found conflicting reports regarding the correlation, so we undertook this study to get a clear concept of the correlation between BCTQ and NCS. Materials and Methods: Thirty-two patients (39 hands) of carpal tunnel syndrome (CTS) were subdivided into three categories: Group I is moderate CTS ( n = 9 hands), Group II is severe CTS ( n = 14 hands) and Group III is extreme CTS ( n = 16 hands). We evaluated electrophysiological parameters using both conventional motor parameters such as distal motor latency (DML), forearm conduction velocity (FMCV) and short-segment NCS parameter – transcarpal motor conduction velocity (TMCV) in pre-surgical and 6- and 9-month’s post-operative patients. The correlation between BCTQ consisting of symptom severity scale (SSS), functional status scale (FSS), and NCSs before and after CTR was assessed using Spearman rank correlation coefficients to establish the importance of CTR as the most effective treatment modality for CTS patients. Results: We found a significant correlation between BCTQ parameters – SSS and FSS and motor NCS parameters – DML, FMCV and TMCV in all three groups of CTS patients preoperatively, but the Spearman correlation coefficient value decreased and became statistically non-significant after 6 and 9 months of CTR operation. The BCTQ parameters SSS and FSS are influenced by the subjective information provided by the patients, whereas NCS is the objective and quantitative method to evaluate the condition of the median nerve. Moreover, NCS should be included in the post-operative follow-up to eliminate the possibility of recurrence, inadequate release of transverse ligament compressing the median nerve, and presence of other similar pathology or post-CTR complications. Conclusion: We can, therefore, conclude that clinicians should use BCTQ and NCS together to ascertain the success of CTR operation.