From the Guidelines
Diagnosing thoracic outlet syndrome (TOS) typically involves a combination of physical examination and imaging studies, with the most recent and highest quality study suggesting that MRI or CT scans are the most appropriate initial imaging tests for evaluating the thoracic outlet anatomy 1.
Diagnostic Tests
The diagnostic approach to TOS may include:
- Physical examination to assess for signs of neurovascular compression
- Provocative tests such as the Adson's test, elevated arm stress test, and Wright's test to reproduce symptoms
- Imaging studies including:
- Chest X-rays to check for cervical ribs
- MRI or CT scans to visualize the thoracic outlet anatomy
- Nerve conduction studies to assess neurological involvement
- Vascular studies such as ultrasound or angiography if vascular TOS is suspected
Treatment Options
Treatment for TOS begins with conservative approaches including:
- Physical therapy focused on strengthening shoulder muscles and improving posture
- Pain management using NSAIDs like ibuprofen (400-800mg three times daily) or naproxen (500mg twice daily)
- Muscle relaxants such as baclofen (5-25mg three times daily) or cyclobenzaprine (5-10mg three times daily) to reduce muscle spasms
- For more severe cases, botulinum toxin injections into the scalene muscles can provide temporary relief
Surgical Intervention
If conservative measures fail after 3-6 months, surgical intervention may be necessary, including:
- First rib resection
- Scalenectomy
- Removal of cervical ribs Surgery is particularly indicated for vascular TOS with blood clots or severe neurological symptoms.
Post-Surgical Care
Post-surgical physical therapy is essential for optimal recovery, typically starting 2-4 weeks after surgery and continuing for several months. The choice of treatment depends on the specific type of TOS (neurogenic, venous, or arterial), symptom severity, and individual patient factors 1.
From the Research
Diagnostic Tests for Thoracic Outlet Syndrome
- The Halstead maneuver, Wright's test, Cyriax Release test, and supraclavicular pressure test have good diagnostic accuracy for provoking symptoms in patients with upper extremity pathology, including thoracic outlet syndrome 2
- The Adson's test and Roos test should be discontinued for the differential diagnosis of thoracic outlet syndrome due to high false-positive rates 2
- Nerve conduction studies, F-waves, and dermatosomal and lor somatosensory evoked potential have a low level of sensitivity for Thoracic Outlet Compression Syndrome (TOCS) diagnosis 3
- The upper limb tension test (ULTT) is a useful initial provocative test to screen for TOS, and a positive ULTT should be followed up with an elevated arm stress test (EAST) to further support the diagnosis 4
- Additional diagnostic testing such as ultrasound, electromyography (EMG), or magnetic resonance imaging/magnetic resonance angiography (MRI/MRA) may be utilized to further distinguish the vascular or neurological etiologies of the symptoms 4
Treatment Options for Thoracic Outlet Syndrome
- Initial treatment for neurogenic TOS (nTOS) is often conservative, but there is no conclusive evidence that any one treatment method or combination is more effective 4
- Surgery in nTOS is considered for refractory cases only 4
- Anticoagulation and surgical decompression remain the treatment of choice for vascular versions of TOS 4
- The costoclavicular distance can be used as a standard in the radiological evaluation of thoracic outlet syndrome, and measurements below the fifth percentile may indicate a narrowed costoclavicular distance and a greater chance of developing thoracic outlet syndrome 5
Radiological Evaluation of Thoracic Outlet Syndrome
- High-resolution chest computed tomography (CT) scans can be used to measure the costoclavicular distance at neurovascular bundle crossing points (near the subclavian vein and the subclavian artery/brachial plexus branches) 5
- The costoclavicular distance can be analyzed with respect to age, sex, height, and body mass index to aid in the diagnosis and direct therapeutic indications for symptomatic patients with thoracic outlet syndrome 5