This is a condition whereby the ulnar nerve (nerve that supplies sensation to the little finger and half of ring finger plus small muscles of the hand) is compressed at the level of the wrist. It is characterised by numbness and tingling affecting the little and half of the ring fingers as well as weakness affecting the small muscles of the hand. The patient may notice loss of strength and dexterity in the hand which can be truly debilitating.
This can occur fairly acutely and has been seen in patients using crutches in a prolonged fashion and also in keen cyclists. In both cases it is probably related to direct pressure effects. In cyclists, the wrist is flexed and ulnar deviated in a prolonged fashion resulting in increased pressure in the Guyon’s canal and subsequently the nerve undergoes ‘damage’ resulting in the symptoms. In occasional cases the hand can become profoundly weak and wasted.
Nerve conduction studies are obtained to confirm the diagnosis, assess severity and exclude a double crush phenomenon where the same nerve is compressed in a second location along it’spath. If the condition is refractory to non-operative treatment then surgical decompression is offered.
This is initiated with splints, hand therapy exercises to prevent clawing of the fingers and anti-inflammatories if pain is an issue. If recovery does not occur day on day then surgical release would be considered.
