Objective: To evaluate the utility of somatosensory and motor evoked potentials in the diagnosis of neurogenic thoracic outlet syndrome (TOS).
Materials and methods: In a female patient with progressive weakness and sensory disturbance, ulnar nerve somatosensory evoked potentials (SSEP), and intraoperative motor evoked potential (MEP) were performed.
Results: The SSEPs demonstrated no significant change in latency of major peaks at rest and after abduction of the shoulder. Diminishment of amplitude was noted after dynamic position of the arm. The MEPs demonstrated no significant change in latency after dynamic position. Diminishment of amplitude was noted after the dynamic position. The amplitude returned to normal after repositioning the arm.
Conclusions: Electrophysiologic study is helpful in the diagnosis of neurogenic TOS. Reduced amplitude of cortical SSEP and myogenic MEP is expected during dynamic position of the affected arm.