Electrodiagnostic features of true neurogenic thoracic outlet syndrome.

[thoracic outlet syndrome]

We report the electrodiagnostic (EDX ) features of 32 patients with surgically verified true neurogenic thoracic outlet syndrome (TN -TOS ).Retrospective record review .We found uniform EDX evidence of a chronic axon loss process that affected the lower portion of the brachial plexus and disproportionately involved the T 1 more than the C 8 sensory and motor fibers . Because of this relationship , the medial antebrachial cutaneous sensory nerve (T 1 ) and median motor (T 1 > C 8 ) study combination was abnormal in 89 %, whereas response combinations that primarily assessed the C 8 fibers were less frequently affected .The characteristic EDX features of TN -TOS are T 1 > C 8 nerve fiber involvement . A comprehensive EDX examination of the lower plexus with contralateral comparison studies is imperative to diagnose this disorder accurately .