Evolution of clinical, electrophysiological, and radiological aspects of the carpal tunnel syndrome before and after surgery

The aim of the study was to analyze the evolution of the clinical, electrophysiological, and ultrasound aspects of carpal tunnel syndrome (CTS) before and 4 and 8 weeks after surgery. A Boston Carpal Tunnel Questionnaire, an ultrasound scan, and an electrophysiological exam were performed in 14 patients the day of surgery, 4 and 8 weeks after. The nerve conduction study included: median nerve sensory conduction stimulating digit 3 and 4, median motor conduction from the abductor pollicis brevis, ulnar nerve sensory, and motor conduction. A significant improvement of the symptoms and a significant decrease of the median nerve proximal cross-sectional area on the ultrasound scan were observed 4 weeks after surgery. Distal motor latency (DML) was > 4.2 ms in six patients and decreased along the three visits. DML was ≤ 4.2 ms in the eight others and stayed stable after surgery. We observed a significant increase of the sensory median nerve amplitude response at the wrist stimulating the third digit 8 weeks after surgery. When operated patients are referred for control, we recommend to perform: (1) 4 weeks after surgery, an ultrasonography, and a measure of the DML of the median nerve; (2) 8 weeks after surgery, a measure of the sensory conduction velocity of the median nerve.