Introduction to Thoracic Outlet Syndrome

Clinical Presentation of Thoracic Outlet Syndrome

The clinical signs and symptoms of thoracic outlet syndrome (TOS) are related to the compression of either the blood vessels and/or nerves in the thoracic outlet. For example, symptoms such as pain in the neck/shoulder/arms and a sense of numbness or tingling suggest a compression of the nerves of the brachial plexus (neurogenic TOS). Other symptoms including weakness, swelling, or coldness in the arm/hand may be caused by compression of the subclavian blood vessels resulting in decreased blood flow to the area (vascular TOS).

Patients with neurogenic TOS typically complain of:

• Pain in the scapular (shoulder blades), subscapular, and cervical area
• Headaches which radiate up the back of the head
• Paresthesia or numbness in their hands
• Exacerbation of pain, heaviness, weakness, or fatigue in their arm(s) when it is maintained in an elevated position.

For many patients, symptoms are not only neurological (e.g., numbness) but are also muscular (e.g., aching in the arm, weakness, or muscle fatigue). The theory is that abnormal posture is a contributing factor to the pain of TOS and is related to the nerve compression. Many of these patients can be shown to suffer from nerve compression associated with muscle imbalance of the upper back, shoulder, and neck. Continued poor posture causes a progression of nerve compression which results in further muscle imbalance.