Neurogenic thoracic outlet syndrome (nTOS) is caused by brachial plexus compression in the thoracic outlet. It accounts for 85%-95% of thoracic outlet syndrome (TOS) cases, which may also be caused by compression of the subclavian artery and vein. Compression occurs in the interscalene triangle, costoclavicular space or subpectoralis minor space, with congenital anomalies and repetitive overhead activities as contributing factors. Diagnosis is challenging due to overlapping symptoms with other conditions. Patients commonly report pain, numbness, tingling and weakness in the neck, shoulder and arm, exacerbated by arm elevation. Symptoms related to nTOS may manifest in the distribution of the upper (C5-C6), middle (C7) and lower plexus (C8-T1). Although widely used, provocative tests have varying degrees of sensitivity and specificity and may have high false-positive rates, complicating the diagnosis. Patterns on electrodiagnostic studies provide key diagnostic clues, such as reduced sensory response in the medial antebrachial cutaneous nerve and low compound motor action potential in the median nerve. Imaging techniques like magnetic resonance imaging (MRI), alongside procedures like diagnostic and therapeutic anterior scalene blocks, assist in identifying anatomical abnormalities and predicting surgical outcomes. Management of nTOS involves lifestyle changes, physical therapy, medication and botulinum toxin injections for symptomatic relief. Surgical options may include supraclavicular, transaxillary and infraclavicular approaches, each offering specific benefits based on patient anatomy and surgeon expertise. Minimally invasive techniques, such as video-assisted thoracoscopic surgery (VATS) and robotic surgery, enhance exposure and dexterity, leading to better outcomes. Future research should focus on developing precise diagnostic tools, understanding nTOS pathophysiology, standardising diagnostic criteria and surgical approaches, comparing long-term treatment outcomes and exploring preventive measures to improve patient care and quality of life. Level of Evidence: Level V (Therapeutic).
Keywords: Brachial plexus; Compression neuropathy; Hand surgery; Neurogenic thoracic outlet syndrome; Peripheral nerve.