Classically, the positive fi ndings that suggest NTOS include a history of tingling, deadness, or weakness in the upper extremity which are exacerbated by maneuvers that compromise the thoracic outlet (arms overhead) or stretch the plexus (dangling). Similar findings may be elicited by bedside maneuvers that simulate a patient’s experience. Pulse obliteration with arm abduction may be found to suggest combined neural and vascular compromise through the thoracic outlet. Actual muscle atrophy may occur on rare occasion. Sensitivity to palpation of the neural elements may be found in the supraclavicular fossa or over the pectoralis tendon insertion.
Neurological symptoms affected by position
The presence of a history of positional paresthesias with reaching overhead, although suggestive of NTOS, is nonspecific. Nocturnal numbness, which is often reported by NTOS patients, is also a common complaint in patients with carpal tunnel syndrome and ulnar compression neuropathy. Patients with NTOS may also report worsening of symptoms with dangling of the arm when walking.
Pulse obliteration with arm hyperabduction
Pulse obliteration may be observed with arm hyperabduction in patients with NTOS, although this finding alone is very common in normal individuals.
Stress maneuver reproduction of symptoms
Stress maneuvers have been described to reproduce those positional and effort related activities that may produce a sensory experience that is historically familiar to the patient.
Elevated Arm Stress Test (EAST)
Although a 3 min test was classically described by Roos, a 1 min stress test (1 min EAST) may be considered because many patients with NTOS will have marked symptoms within a few seconds.
The Adson maneuver is performed by having the patient turn their head toward the pathologic side as the patient inhales with the arm extended; classically described to look for pulse changes, many use it to assess whether neurologic symptoms are exacerbated.