Long term and frequent electrophysiological observation in carpal tunnel syndrome

Carpal tunnel syndrome (CTS) is one of the most common compression neuropathies in neurology. Electromyography (EMG) including nerve conduction study (NCS) is the most useful diagnostic technique for CTS. In this study, we aim to demonstrate changes in electrophysiological parameters in different level of CTS patients by frequent EMG studies.

We prospectively followed patients with CTS regularly once every 12 weeks for 1 year. Fourteen women (28 hands) with EMG/NCS findings of CTS were observed and classified in 3 groups according to electrophysiological severity. All patients were instructed to wear the splint for 12 weeks. At the end of this period, patients were evaluated by electrophysiologic parameters. If findings were still abnormal, they were encouraged to continue wearing the splint. In severe cases, surgical release was carried out.

No statistically significant changes were noted in EMG recordings of mild cases repeated every 3 months. It was determined that significant improvements begin to occur in the moderate group in all parameters, except for the amplitude of the median sensory nerve. However, when the mean values were studied in the severe CTS group, it was observed that the preoperative motor and sensory parameters became increasingly impaired, but approached the initial values in the first evaluation in the postoperative period.

Subjects with CTS, particularly moderate as determined by electrophysiology, may benefit from conservative therapy, with improvements which continue for about one year. In severe cases the main treatment modality seems to be operation. Frequent electrophysiological follow-ups may be useful in guiding treatment.