Touch is one of the most important of our five senses. When we touch something, sensory organs in our skin where the tactile information is processed and interpreted, giving us our sense of touch. When a nerve supplying an area of skin becomes damaged, numbness can occur. Different individuals may experience this differently and might describe is as a “tingling”, “pins and needles”, “shooting pains”, “ants crawling”, “wooden”, “stiff”, or even “my hand has fallen asleep”. Sensory disturbances manifesting as hand numbness are most commonly a result of direct injury to the nerves fibres that supply the hand, but may also result from damage in the central nervous system (spinal cord and brain damage).
If you have numbness of the hands, it is important to find out the underlying cause of the symptoms. Accurate diagnosis is important to guide successful treatment and recovery, as there is no single common treatment that addresses all causes of hand numbness. Most commonly, numbness in the hand is causes by the damage to the median nerve or the ulnar nerve. Both the median and ulnar nerves are part of the brachial plexus, branching out from a set of common nerve roots in the axilla. The median nerve supplies the skin over the palmer surface of the thumb, index, middle and half of the ring finger. The other half of the ring finger and the little finger are innervated by the ulnar nerve. An injury to either nerve will present as numbness to their respective ‘territory’.
Cause of hand numbness
Carpal Tunnel Syndrome is a common condition that causes injury to the median nerve. The carpal tunnel is a passageway in the wrist formed by the bones and connective tissue through which the median nerve and finger tendons pass. Wrist trauma, arthritis, medical conditions such as pregnancy, as well as inflammation of the tendons caused by repetitive activity can narrow the canal and cause compression of the median nerve resulting in symptoms such as numbness, thumb weakness and clumsiness when handling small objects (e.g. buttons, coins and keys).
The ulnar nerve, on the other hand, is sometimes injured in a condition called Cubital Tunnel Syndrome. This nerve travels in a groove behind the medial epicondyle of the humerus (‘the funny bone’), and is vulnerable to injury from direct trauma to the elbow, and repetitive or prolonged elbow flexion activities (e.g. holding the phone, sleeping with elbow bent or gym exercises). Symptoms include weakness, loss of grip and pinch power and numbness over the little and ring fingers.
Other causes of hand numbness include neck arthritis (Cervical Spondylosis), thyroid disease, diabetic neuropathy, peripheral vascular disease or cerebrovascular events (strokes). Some of these conditions can be potentially life threatening and early assessment to exclude these conditions may be necessary.
Treatments for Carpal and Cubital Tunnel Syndrome may include medications, exercises, ergonomic modifications, splinting and therapy for early cases. Surgery may be required if the nerve compression in severe or prolonged. Timely and appropriate treatment of hand numbness will prevent further deterioration and allow complete recovery and restoration of function. Delays in treatment can lead to irreversible damage to the nerves that result in permanent numbness and loss of muscle function. Minimally invasive (endoscopic) approaches for decompression of the median ulnar nerve are now available, and these options can improve patient safety and comfort, while shortening their recovery times.
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