A Review of Thoracic Outlet Syndrome and the Possible Role of Botulinum Toxin in the Treatment of This Syndrome

The objective of this paper is to discuss the classification, diagnosis, pathophysiology and management of Thoracic outlet syndrome (TOS). Thoracic outlet syndrome (TOS) is a complex entity that is characterized by different neurovascular signs and symptoms involving the upper limb. TOS is defined as upper extremity symptoms due to compression of the neurovascular bundle in the area of the neck just above the first rib. Compression is thought to occur at one or more of the three anatomical compartments: the interscalene triangle, the costoclavicular space and the retropectoralis minor spaces. The clinical presentation can include both neurogenic and vascular symptoms. TOS can be difficult to diagnose because there is no standardized objective test that can be used and the clinician must rely on history and several positive findings on physical exam. The medial antebrachial cutaneous nerve conduction may be a sensitive way to detect pathology in the lower trunks of the brachial plexus which is promising for future research. Treatment options continue to be conservative and surgical. However, for those who have failed physical therapy there is research to suggest that botulinum toxin may help with symptom relief. However, given that there has been conflicting evidence, further research is required using randomized controlled trials.