Thoracic outlet syndrome

Question 1

Neurogenic thoracic outlet syndrome typically presents with?

Answer 1

muscle wasting of the hands, numbness and tingling and possibly autonomic symptoms

Question 2

Jane is a 40-year-old woman who presents with weakness and numbness of her hand. The symptoms get worse when she raises her hands above her head. The numbness is generalised and not confined to any particular dermatome. She is also complaining of a painful neck and generalised headache. She is a keen tennis player and is upset as she cannot even grip her racket properly. She also describes her fingers turning white in the cold. On examination there is wasting in her thenar eminence. No other focal neurology is found.

Answer 2

Thoracic outlet syndrome

Question 3

Thoracic outlet syndrome (TOS) is a disorder involving compression of?

Answer 3

brachial plexus, subclavian artery or vein at the site of the thoracic outlet. TOS can be neurogenic or vascular; the former accounts for 90% of the cases.

Question 4

Epidemiology of thoracic outlet syndrome?

Answer 4

given the lack of widely agreed diagnostic criteria, the epidemiology of TOS is not well documented
patients are typically young thin women possessing long neck and drooping shoulders
peak onset occurs in the 4th decade

Question 5

Aetiology of TOS?

Answer 5

TOS develops when neck trauma occurs to individuals with anatomical predispositions

neck trauma can either be a single acute incident or repeated stresses

anatomical anomalies can either be in the form of soft tissue (70%) or osseous structures (30%)

a well-known osseous anomaly is the presence of cervical rib

examples of soft tissue causes are scalene muscle hypertrophy and anomalous bands

there is usually a history of neck trauma preceding TOS

Question 6

Clinical presentation of neurogenic TOS

Answer 6

painless muscle wasting of hand muscles, with patients complaining of hand weakness e.g. grasping

sensory symptoms such as numbness and tingling may be present

if autonomic nerves are involved, the patient may experience cold hands, blanching or swelling

Question 7

Clinical presentation of vascular TOS:

Answer 7

subclavian vein compression leads to painful diffuse arm swelling with distended veins

subclavian artery compression leads to painful arm claudication and in severe cases, ulceration and gangrene

Question 8

Examinations of TOS

Answer 8

neurological examination and musculoskeletal examination are necessary

stress manoeuvres such as Adson’s manoeuvres may be attempted although they have limited utility

careful examinations should aim to rule out other pathologies of the cervical spine, the shoulder or peripheral nerves. For instance, cervical radiculopathy, shoulder injuries and carpal tunnel syndrome

Question 9

Investigations for TOS

Answer 9

chest and cervical spine plain radiographs to check for any obvious osseous abnormalities e.g. cervical ribs, exclude malignant tumours or

other differentials e.g. cervical spine degenerative changes
other imaging modalities may be helpful e.g. CT or MRI to rule out cervical root lesions

venography or angiography may be helpful in vascular TOS

an anterior scalene block may be used to confirm neurogenic TOS and check the likelihood of successful surgical treatment

Question 10

Treatment:

Answer 10

there is a limited evidence base

conservative management with education, rehabilitation, physiotherapy, or taping is typically the first-line management for neurogenic TOS

surgical decompression is warranted where conservative management has failed especially if there is a physical anomaly. Early intervention may prevent brachial plexus degeneration

in vascular TOS, surgical treatment may be preferred

other therapies being investigated include botox injection