What is Thoracic Outlet Syndrome (TOS)?

From the Guidelines

Thoracic outlet syndrome (TOS) should be managed with a multidisciplinary approach, prioritizing physical therapy and lifestyle modifications, with surgical decompression considered for severe cases unresponsive to conservative treatment. TOS is a condition where blood vessels or nerves in the space between the collarbone and first rib become compressed, causing pain in the shoulders and neck and numbness in the fingers 1. The condition occurs in three main types: neurogenic (most common, affecting nerves), venous (affecting veins), and arterial (affecting arteries), each with distinct symptoms and treatment approaches.

Key Considerations

• Symptoms of TOS vary by type but commonly include arm pain, numbness, weakness, discoloration, or swelling 1.
• Early diagnosis and treatment are crucial as chronic compression can lead to permanent nerve damage or vascular complications.
• Treatment typically begins with physical therapy to strengthen chest muscles and improve posture, along with pain management using NSAIDs like ibuprofen or naproxen 1.
• Lifestyle modifications are essential, including avoiding activities that worsen symptoms, taking frequent breaks from repetitive tasks, and maintaining good posture.

Diagnostic Approach

• Understanding the various anatomic spaces and causes of narrowing is important in choosing and interpreting radiological imaging to help diagnose TOS and plan for intervention 1.
• Consultation with a radiologist may be useful at the time of examination ordering to optimize the study for the prevailing clinical symptom.

Treatment Options

• Surgical decompression may be necessary for severe cases unresponsive to conservative treatment, with the goal of relieving compression on the affected nerves or blood vessels 1.
• The choice of treatment should be individualized based on the patient's specific symptoms, medical history, and response to initial therapies.

From the Research

Definition and Classification of Thoracic Outlet Syndrome

• Thoracic outlet syndrome (TOS) is a rare condition caused by neurovascular compression at the thoracic outlet, presenting with arm pain and swelling, arm fatigue, paresthesias, weakness, and discoloration of the hand 2.
• TOS can be classified as neurogenic, arterial, or venous based on the compressed structure(s) 2.

Causes and Risk Factors

• Patients develop TOS secondary to congenital abnormalities such as cervical ribs or fibrous bands originating from a cervical rib leading to an objectively verifiable form of TOS 2.
• Neck trauma or repeated work stress can cause scalene muscle scaring or dislodging of a congenital cervical rib that can compress the brachial plexus 2.

Diagnosis

• The diagnosis of TOS is often made in the presence of symptoms with physical examination findings (disputed TOS) 2.
• Diagnosis of TOS can be established through history, physical examination maneuvers, and imaging in patients with an identifiable narrowing of the thoracic outlet and/or symptoms with a high probability of thoracic outlet neurovascular compression 2.

Treatment Options

• Nonsurgical treatment includes anti-inflammatory medication, weight loss, physical therapy/strengthening exercises, and botulinum toxin injections 2.
• The most common surgical treatments include brachial plexus decompression, neurolysis, and scalenotomy with or without first rib resection 2.
• Conservative management is generally recommended as the first stage treatment in favor of surgical intervention 3, 4, 5, 6.
• Conservative treatment seems to be effective at reducing symptoms, improving function, and facilitating return to work, also when compared to surgery 6.

Rehabilitation and Management

• The main component of the rehabilitation program is the graded restoration of scapula control, movement, and positioning at rest and through movement 3.
• Adjunctive strategies include restoration of humeral head control, isolated strengthening of weak shoulder muscles, taping, and other manual therapy techniques 3.
• Patient education, compliance to an exercise program, and behavioral modification at home and work are critical to successful conservative management 4.
• Normalized grip strength and Tinel's sign predicted patient satisfaction and return to work 5.