Carpal Tunnel Syndrome
The carpal tunnel is a narrow passageway found between the bones of the base of the hand, specifically the pisiform, semi-lunate, pyramid and scaphoid, containing tendons and the median nerve in its proximal aspect, while distally it is formed by the trapezium, trapezoid, capitate and hamate. It is in this space where the median nerve can become trapped, resulting in peripheral neuropathy. This entrapment can be produced by the presence of fluid, inflammation of one of the tendons or any process that reduces space in the tunnel.
Guyon’s canal syndrome.
Guyon’s canal is formed by the transverse carpal ligament, the carpal ligaments and the opponens pollicis muscle of the 5th finger, with the volar carpal ligament and the palmar brevis muscle forming its roof. The ulnar nerve, which divides at this point into its superficial and deep branches, can become trapped or compressed as it passes through the canal, resulting in a neurological syndrome affecting the sensitivity of the 5th finger and part of the 4th, as well as the motor function of the hand muscles, leading to problems in bringing the fingers together and separating them.
A sensation of heat, numbness in the middle and index fingers, and especially the thumb. As it worsens, the patient experiences cramps and has difficulty making a fist, picking up objects and performing manual tasks. Loss of sensitivity is evident in some cases and pain is present in the upper area of the hand and wrist. Symptoms increase with activity, but can subside with massage and relaxation.
Guyon’s canal syndrome.
Atrophy of the hypothenar eminence and the interosseous muscles with weakness in closure movements and/or ulnar flexion of the wrist. Paresis, hypoesthesia and paresthesia in the area innervated by the ulnar affecting the flexors of the 4th and 5th fingers and the intrinsic musculature.
Rehabilitation treatment, including the use of moist warm compresses, paraffin and other techniques such as laser or electrotherapy, as well as preventative treatments like wrist mobility exercises during rest periods, in conjunction with the use of unloading splints that enable immobilisation of the wrist, hand and finger joints, as in the case of Guyon’s syndrome, are very useful for keeping the joints at rest during day and nighttime use, and preventing postural attitudes during sleep like those in which the wrists are in flexion.