Neurophysiology not required before surgery for typical carpal tunnel syndrome

We wished to determine whether preoperative neuropyhsiology might safely be omitted in patients who present with typical carpal tunnel syndrome (CTS). 68 patients with clinically typical CTS were included. The diagnosis was based on a typical history and Tinel's sign and Phalen's test. The patients also underwent preoperative neurophysiological investigation, but the studies were not assessed until after completion of the present trial. Open carpal tunnel release was performed. The diagnosis was considered to be confirmed when there was a prompt resolution of preoperative symptoms. The postoperative course verified the diagnosis of CTS in 63 patients. Two patients did not improve and were considered not to have CTS. Three cases had an equivocal postoperative course. Neurophysiology was reported as normal in the two patients who had wrongly been diagnosed clinically as having CTS, but also in 14 of the 63 patients with verified CTS. Knowing the results of the neurophysiological studies preoperatively would probably have saved the two wrongly diagnosed patients from operation, but might also have led to inappropriate postponement or omission of operation in more than one-fifth of cases. We conclude that neurophysiological studies contribute little in the diagnosis of typical cases of CTS and are more often confounding than of assistance.