The usefulness of latency difference test of fourth digit median- ulnar in carpal tunnel syndrome -

Objective: Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy. In this study, 4th finger median and ulnar nerve sensory latency difference test in minimal and mild carpal tunnel syndrome and the amplitude difference test between the 2nd finger median sensory response and the 5th finger ulnar sensory response were evaluated and their usefulness were discussed. Material and Method: In this study, the patients admitted to AžiAŸli Etfal Training and Research Hospital Neurology Clinic, EMG laboratory with the diagnosis of CTS were included. In addition to conventional electrophysiological methods, 4th finger median - ulnar nerve sensory latency difference test was used. Electrophysiological studies were performed using Medelec Saphire 4E EMG device. Data was evaluated with Statistical Package for Social Sciences (SPSS) for Windows 17 program and descriptive analysis was performed. Results: In 3 (17.64%) of the 17 patients who had abnormality in the 4th finger of median-ulnar sensory latency difference test, 2nd digit median nerve sensory response amplitude was found to be lower than the 5th digit ulnar nerve sensory amplitude response. Conclusion: In our study, which is a preliminary study, a small number of patients whose 4th finger median-ulnar sensory latency difference test were abnormal also revealed a relative decrease in 2nd digit median nerve sensory response amplitude. Further studies with a larger group of patients are needed. The amplitude difference test between 2nd digit median and 5th digit ulnar sensory response may be an alternative sensitive method in order to obtain faster results and to identify early cases of CTS.