True Neurogenic Thoracic Outlet Syndrome Following Hyperabduction during Sleep - A Case Report -

Abstract

True neurogenic thoracic outlet syndrome (TOS) is an uncommon disease and is difficult to diagnose at the early stage and then completely cure. We experienced a case of true neurogenic TOS with typical clinical symptoms and electrophysiologic findings as a result of repetitive habitual sleep posture. A 31-year-old woman who had complained of progressive tingling sensation on the 4th and 5th fingers with shoulder pain was diagnosed of brachial plexopathy at the lower trunk level by electrodiagnostic studies. There was no other cause of brachial plexopathy except her habit of hyperabduction of shoulder during sleep. This case demonstrated that the habitual abnormal posture can be the only major cause of neurogenic TOS. It is of importance to consider TOS with the habitual cause because simple correction of the posture could stabilize or even reverse disease progress.

True Neurogenic Thoracic Outlet Syndrome with Elongated C7 Transverse Processes in a Hemiplegic Patient: A Case Report

“…In order to exclude other possibilities from the differential diagnosis and confirm true NTOS, an electrodiagnostic study is essential [3]. In nerve conduction studies, reduced median CMAP, ulnar and MABC SNAP amplitudes, and normal median SNAP and ulnar CMAP amplitudes indicate chronic axonal loss at the lower trunk level of the brachial plexus [6,9]. On needle electromyography, denervation potentials in C8-and T1-inner- vated muscles (dominant T1), including the APB, ADM, FDI, and other hand intrinsic muscles, are typical findings of true NTOS [6,9].…”

“…In nerve conduction studies, reduced median CMAP, ulnar and MABC SNAP amplitudes, and normal median SNAP and ulnar CMAP amplitudes indicate chronic axonal loss at the lower trunk level of the brachial plexus [6,9]. On needle electromyography, denervation potentials in C8-and T1-inner- vated muscles (dominant T1), including the APB, ADM, FDI, and other hand intrinsic muscles, are typical findings of true NTOS [6,9]. Abnormal MABC SNAP (sensitivity, 95%) and abnormalities in the APB (sensitivity, 97%) on needle EMG are highly sensitive for true NTOS [7,10].…”