Is the left/right judgment task performance altered in unilateral carpal tunnel syndrome: And associated with symptom severity?

Background: Left/right judgment task performance (LRJT) is impaired in severe neuropathic pain conditions. However, comparison of LRJT performance in patients with carpal tunnel syndrome (CTS) with a control group with similar cognitive functions has not been investigated.

Objective: The aim of the study was to compare the LRJT performance of CTS patients with healthy controls and the unaffected side.

Methods: Seventy-five CTS patients with dominant, right-hand involvement and 75 control subjects were included in the study. The Recognize® tablet application was used for LRJT performance. Tactile acuity (Two-point discrimination) and handgrip strength; pain severity (Visual Analog Scale) and neuropathic component of pain (Pain Detect Questionnaire); symptom severity and functional impact of CTS (Boston CTS Assessment Test) were evaluated. Mixed-design ANOVAs and correlation analyses were used for data analysis.

Design: Cross-sectional study.

Results: Analysis of variance showed that there was no significant effect of side (affected versus unaffected) or group (CTS versus control group) on recognition accuracy or time. Significant group*site interactions were found for the two-point discrimination F (1,148) = 6.388, p = 0.013; and for handgrip strength F (1,148) = 17.552, p < 0.01. A statistically significant negative correlation was found between recognition accuracy and symptom duration and a significant positive correlation was found between recognition accuracy and handgrip strength in CTS patients (r = -0.267, p = 0.020; r = 0.290, p = 0.012).

Conclusion: CTS patients recognize the affected side as accurately and quickly as the unaffected side and control group. Further research is needed to clarify the relationship between LRJT performance in the severely affected CTS group.

Gov Registration Number: NCT04967144 CLINICALTRIALS.

Gov Registration Date: 19 July 2021.