Predictors of persistent neuropathic pain after carpal tunnel decompression: Prevalence, psychological and physical risk factors, and neurophysiological correlates.

OBJECTIVE

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy, yet determinants of postoperative dissatisfaction remain poorly understood, particularly the relative roles of psychological and neurophysiological factors. This study aimed to identify the prevalence and determinants of dissatisfaction following open carpal tunnel release (OCTR).

METHODS

In this prospective cohort, 100 adults with CTS (81 women, 19 men; age 18-75 years, median 40) undergoing OCTR were assessed by demographics, the Boston Carpal Tunnel Questionnaire (BCTQ), Douleur Neuropathique-4 (DN4), psychological instruments (Five-Factor Personality Inventory; Symptom Checklist-90-Revised), and nerve conduction studies, before surgery and at 3 months, then classified as satisfied (Group A) or dissatisfied (Group B) by DN4.

RESULTS

Twenty-three percent were dissatisfied. Compared with satisfied patients, they were older, more frequently diabetic, with longer disease duration and higher inflammatory markers, and showed persistent pain, numbness, proximal spread, and minimal BCTQ improvement. Neurophysiologically, they had more severe baseline impairment and limited recovery, significant improvement occurring only in the satisfied group, alongside higher depression, anxiety, and phobic anxiety. On multivariate analysis, elevated white blood cell count, lower improvement in median SNAP amplitude and ulnar distal motor latency, and higher depression independently predicted limited DN4 improvement (depression B = -1.049, P = 0.004; SNAP amplitude B = 0.113, P = 0.008; ulnar distal motor latency B = 0.615, P = 0.011; white blood cell count B = -0.188, P = 0.027).

CONCLUSIONS

Persistent neuropathic pain 3 months after OCTR is multifactorial. Preoperative depression, systemic inflammation, and severe baseline neurophysiological impairment each predicted residual pain.