Median nerve distal sensory onset latency measurement on the electrodıagnosıs of carpal tunnel syndrome [Karpal tünel sendromunun elektrofizyolojik tanısında median sinir duyusal başlangıç latansı ölçümü]

Objective: we aim to analyze the effects of gender and age on antidromic median nerve distal sensory onset latency (mdsol) and action potential (msnap) amplitude over wrist-to- second finger segment,and also searches whether the usage of a stratified cut off points chart reduces the misdiagnosis rate on mdsol measurements on carpal tunnel syndrome (cts) or not. methods: recordings of the patients referred to our laboratory for the upper extremity nerve conduction studies (ncss) were analyzed retrospectively. sensory ncss were done with standard antidromic supramaximal stimulation technique. the numbers of false positive and negative diagnoses were detected in case of a single cut off point usage for dsol,and of a stratified chart usage (eight subgroups: males/females; 16-35,36-45,46-55,and over 56 years old),separately. results: the study enrolled the 261 normal and 279 extremities with cts. analyses of normal hands showed significant mdsol elongation and msnap amplitude reduction with increasing age. mean mdsol was shorter,and msnap amplitude was greater in females. the best cut off point for mdsol was 2.66 msec for whole study population with a misdiagnosis rate of 12.4%. when we used a stratified chart,the rate of misdiagnosis decreased to 8.3%. (p=0.036) conclusions: the gender and age have prominent effects on mdsol and msnap amplitude values. this study revealed that electroneuromyography laboratories,rather than use of a single best cut off point,should use their own cut off points chart stratified by gender and age to utilize dsol as a main electrodiagnostic parameter for cts. © 2016,ege university press. all right reserved.