Carpal Tunnel Syndrome

Definition:
Carpal tunnel syndrome (CTS) is a compression neuropathy caused by constriction
of the median nerve where it passes beneath the flexor retinaculum of the wrist. It is
a common condition. The crude incidence rate in the UK of about one per thousand
person-years in hospital-diagnosed patients and twice that in primary care.

Clinical Features:

1. Tingling (paraesthesia), numbness, or discomfort in the thumb, index and
   middle fingers. Distressing tingling is often prominent by night, and the patient
   may need to exercise the fingers or shake the hand in attempt to gain relief.


2. Weakness and/or clumsiness of the hand, particularly in carrying out fine
   movements such as those concerned in writing, typing, sewing and other tasks
   necessitating pinch grip.


3. There is often forearm or elbow pain, aching in nature, poorly localised and
   exacerbated by activity. Some patients have shoulder pain. In advanced cases
   of median nerve entrapment, there is impaired sensation and thenar atrophy.

Aetiology:

Carpal tunnel syndrome usually presents as an isolated phenomenon but it is often
associated with other conditions especially where there is fluid retention or
inflammation. These include, diabetes mellitus (where it may be due to diabetic
mono-neuropathy rather than compression), the prolonged use of oral
contraceptives, pregnancy, Colles' or scaphoid fractures, other direct trauma, electric
shock, tenosynovitis, rheumatoid disease, osteoarthritis and gout. Obesity and short
stature are independent risk factors.