What does it feel like?
Most patients describe numbness and tingling that involves the thumb, index, middle and a side of the ring finger. This is often intermittent, but can be constant in long-standing cases. Many people find that this can affect their sleep, waking often through the night with the urge to ‘shake the hand out’. Activities like gripping a steering wheel or holding a phone, can bring on the pins-and-needles discomfort. Sometimes patients describe clumsiness or weakness, partly from being unable to accurately gauge their grip strength, but also from losing strength in some of the small muscles in the hand.
What is it?
It is a nerve compression syndrome. Examples of times you may have compressed a nerve include crossing your legs for a prolonged period and finding that your leg has “gone to sleep”. In this case, one of the three main nerves to the hand, the median nerve, is compressed as it passes through a tunnel, known as the carpal tunnel, in the lower half of your hand.
This results in typical nerve compression symptoms, much like a leg that has “gone to sleep” – paraesthesia (pins-and-needles), anaesthesia (numbness) or dysaesthesia (altered sensation). If this is long-standing, the nervous supply to muscles in the hand, particularly of the thumb, is diminished, and as a result, weakness may ensue.
What causes it?
Many things can cause compression of the median nerve within the carpal tunnel. In normal life, certain actions like gripping and flexing your wrist downwards, increases the pressure within the carpal tunnel. Space-occupying lesions, like ganglions, or swelling of the linings of the tendons that also run in the carpal tunnel, can also encroach on the available space and compress the nerve. Medical conditions that cause tissue swelling (e.g. thyroid problems) or pregnancy can also potentiate carpal tunnel syndrome.
What are my treatment options?
Early or mild carpal tunnel syndrome may respond well to a change in posture of the hand. A splint may assist with this, and particularly is helpful at night, when most people have no conscious control over how they position their wrists. Avoiding excessive gripping, and wrist flexion, may alleviate symptoms. A hand therapist may also be able to provide you with exercises (as well as a splint) that encourage nerve gliding without exacerbating the symptoms of carpal tunnel.
If non-operative measures don’t work, surgery is likely to be your next best option. Discuss this with your doctor, and arrange to see a hand surgeon for review. This is usually performed as a day procedure, and aims to prevent further deterioration in function as well as improve sensation and night symptoms.