Thoracic Outlet Syndrome (TOS)
- VTOS- Venous TOS- While more common than ATOS, Venous TOS is still seen much less clinically than NTOS. Occlusion of the subclavian vein by way of the scalenes, 1st rib/anomalous rib, or intra-venous blockage causes clinical VTOS.
- ATOS- Arterial TOS comprises <1% of all TOS cases and is rarely seen. When present, true ATOS is the result of emboli produced by stenosing or aneurysm in the subclavian artery.
- NTOS- Neurogenic TOS represents over 90% of all TOS cases. Scarring of the scalenes secondary to whiplash is the most common culprit for compression of the brachial plexus (Sanders, Hammond et al. 2007).
Demographics:
- More common in women ages 20-50 (Huang and Zager 2004).
- > 90% are NTOS
Clinical Presentation:
NTOS
- Parasthesias of the hands and arm
- Weakness of the hands and arm
- Head, neck, shoulder, or axillary pain
- Pain radiating down the upper extremities
- Cold intolerance
- Headache(Brooke and Freischlag 2010)
VTOS
- Pain in arm associated with activity
- Arm swelling
- Blue discoloration of arm or hand
ATOS
- Pain in arm or hand
- Claudication of arm
- Pallor of arm or hand
- Decreased pulse
- Poikilothermia (Brooke and Freischlag 2010)
Differential Diagnosis:
NTOS
Special tests-
- Increased symptoms with cervical side bending to the contralateral side
- Palpatory tenderness to the scalenes
- Increased symptoms with cervical rotation to contralateral side.
- Increased symptoms with modified ULTT (bilateral, active in sitting)
- Increased symptoms with abd. and 90 deg. ER
NTOS can mimic the following clinical pathologies:
- CTS
- RTC/biceps tendonitis
- Cervical spine disease
- Pectoralis minor syndrome
- Fibromyalgia
- TMJ dysfunction
- Stretch injury to the brachial plexus (Brooke and Freischlag 2010).
VTOS- Easily diagnosed by presence of swelling, cyanosis and distinctly visible superficial veins in the shoulder and chest wall (Sanders, Hammond et al. 2007).
ATOS- Most of the symptoms of ATOS reside in the hand and lower arm
Clinical Bottom Line: Treat and refer
- NTOS should be treated with conservative PT. If no progress is made a referral for surgery may be necessary.
- If a cluster of signs and symptoms pointing to ATOS is collected a referral is necessary, as the patient may have a peripheral thrombus.
- If signs and symptoms point toward a VTOS conservative treatment can be provide for that session but a referral afterwards should be made for diagnostic vascular imaging to screen for peripheral venous thrombi
References: Please refer to the "Thoracic Outlet Syndrome" section of the reference list.