The presentation of the thoracic outlet syndrome varies with the underlying cause.
Presentation associated with a structural abnormality:
- gradual onset of sensory +/- motor +/- vascular features
- sensory - most common; usually pain, referred to the ulnar border of the hand and distal half of the forearm; may be associated with numbness, tingling or paraesthesia; often aggravated by exercise especially with the arm raised; may involve the ring finger
- motor - weakness and wasting, corresponding to the part of the plexus affected; frequently of thenar muscles, occasionally of interossei
- vascular - unilateral Raynaud's phenomenon; radial pulse weaker on affected side with positive Adson's sign; brittle trophic nails; limb pallor on elevation; susceptible to subclavian venous thrombosis
- cervical rib may be visible or palpable as a bony swelling in the neck - pressure on this exacerbates sensory features
Presentation not associated with a structural abnormality:
- usually less severe than with structural abnormality
- often, mostly sensory and subjective
- may be entirely nocturnal developing after lying down for a long period; or may develop during the day after carrying a heavy object
- more common in women
- often due to a low shoulder girdle