Overview
Thoracic outlet syndrome (TOS) describes the compression of neurovascular structures travelling out of the thoracic outlet. It can be neurogenic (90% of cases) or vascular. Cervical ribs can cause TOS. Many patients may be asymptomatic.
Epidemiology
- Over 90% of cases are neurogenic
- More common in women than men
Risk Factors
- Cervical rib
- Female sex
- Trauma
- Poor posture
- Motor vehicle collisions
- Obesity
- Repetitive overhead activity e.g. lifting, baseball, swimmers, weightlifters etc.
- Large breasts/implants
Presentation
Neurogenic thoracic outlet syndrome
- Painless muscle wasting of the hand
- Numbness/tingling of the upper limb
- Autonomic nerve compression signs:
- Cold hands
- Swelling
- Blanches
Arterial thoracic outlet syndrome
- Subclavian vein compression signs:
- Arm swelling
- Vein distention
- Diffuse hand/arm pain
- Subclavian artery compression signs:
- Colour changes
- Claudication
- Ulceration
- Gangrene
Investigations
- X-ray of chest and cervical spine:
- To rule out bony abnormalities e.g. cervical ribs
- EMG – if neurological TOS suspected:
- Reduced amplitudes seen
- CT angiography:
- If arterial TOS suspected
- Doppler ultrasonography:
- If venous TOS suspected
- MRI:
- Considered in neurological TOS for nerve root compression
Management
- Neurogenic TOS: rehabilitation and therapy
- Consider surgical decompression
- Vascular TOS: surgery may be performed
Complications and Prognosis
Complications
- Chronic pain
- Reduced function
- Neurological deficits
- Ischaemia
- Psychosocial problems e.g. depression/anxiety
Prognosis
- The prognosis is generally good unless the condition is severe enough to warrant having surgery
