INVESTIGATION OF NONSPECIFIC NEUROGENIC THORACIC OUTLET SYNDROME

Objective. To determine the value of investigations for nonspecific neurogenic thoracic outlet syndrome (NNTOS) and formulate a rational diagnostic approach. Design. Retrospective review. Setting. Thoracic surgery clinic. Patients. Fifty-six patients referred with a presumptive diagnosis of NNTOS. Patients with arterial, venous, or true (classic) neurogenic TOS were excluded. interventions, All patients underwent careful history and examination. Fifty-three had cervical spine radiographs, 45 had electrophysiologic testing, and 30 patients had arterial doppler studies. Main outcome measures. The value of investigations that documented a diagnosis other than NNTOS could be assessed but objective evaluation of investigations that appeared to support a diagnosis of NNTOS was not possible. No standard diagnostic criteria exist for NNTOS. Results. Forty (71%) patients were female. Thirty-four (61%) patients had a pulse deficit with provocative maneuvers. Cervical spine radiographs showed cervical ribs in 10 patients and degenerative disease in 11 patients. Electrophysiologic testing demonstrated carpal tunnel syndrome in II patients. Arterial Doppler studies were strongly positive for TOS in 10 patients. Thirty-six (64%) patients were diagnosed with conditions other than NNTOS. The diagnosis of NNTOS was accepted in 20 (36%) patients. All 20 patients were initially treated conservatively but 3 (5%) eventually underwent surgery. Conclusions. NNTOS is a diagnosis of exclusion. Two thirds of patients referred to a thoracic surgery clinic were eventually diagnosed with conditions other than NNTOS. Objective evaluation of investigations that may support a diagnosis of NNTOS is not currently possible.