Study of the SSEP for the Diagnosis of the Throracic Outlet Syndrome

SSEPs have recently applied to 15 cases suspected of having thoracic outlet syndrome and to 21 normal cases depending on the absence of neurological sign. SSEPs have been recorded while stimulating the median and ulnar nerves at the wrist.On stimulating the ulnar nerve, the SSEPs of the N9 at the Erb's point in the groups with thoracic outlet syndrome recorded an increase in N9 conduction time and a low amplitude of N9 potential. In the analysis of the N9 at the Erb's point, N91 is located in the peak of the first positive wave and N92 is located in the peak of the first negative wave. N9 (1-2) conduction time was 1.59±0.22 msec in the group of the thoracic outlet syndrome and was 1.40±0.17 msec in the normal group.N9 (1-2) amplitude was 3.54±1.62μV in the normal group of the thoracic outlet syndrome and was 4.96±2.42μV in the normal group. These studies suggest that N9 (1-2) conduction time and N9 (1-2) amplitude provide useful information of the diagnosis in thoracic outlet syndrome.