Numbness in the hands – symptoms of a tunnel syndrome

31-05-2015

Several things could cause the weakness and numbness of the hands and the arms, from spinal disorders through vascular lesions to overdose. However, only a few people have heard about a common cause of these symptoms, the tunnel syndrome. Learn more about the causes, symptoms and possible treatments of tunnel syndrome.

What is a tunnel syndrome?

Tunnel syndrome is a condition caused by a pinched nerve, running through the bony tunnels of the body. This pressure causes numbness or pain in the affected extremity.

Tunnel syndrome most commonly forms at the wrist (carpal tunnel syndrome), but it could occur in the elbow (cubital tunnel syndrome), in the groin area, under the knee, or on the dorsum of the foot.

What could cause a tunnel syndrome?

Tunnel syndrome can be associated with any condition that exerts pressure on the nerve. This pressure usually caused by the swelling of the lining of the flexor tendons, fractures, injuries, joint dislocation, inflammation, hematoma, tumor, or a developmental anomaly.

In case of a carpal tunnel syndrome, the tendons, running through the carpal tunnel, might swell and exert pressure on the median nerve. The median nerve is running from the cervical spine through the shoulder and the elbow to the hands and fingers. It is responsible for the feeling and sensation of the thumb, index finger, long finger, and half of the ring finger.

In case of a cubital tunnel syndrome, the ulnar nerve becomes compressed at the elbow by the surrounding tissues. The nerve is very vulnerable here, as it is running through a narrow space from the upper arm to the forearm and the permanent stretching and bending of the elbow could irritate the nerve.

Some diseases, like thyroid conditions, autoimmune diseases (diabetes), or rheumatoid arthritis, increase the risk of a tunnel syndrome.

How do I know, if I have a carpal or a cubital tunnel syndrome?

Three nerves are responsible for the innervation of the hand. The median nerve (nervus medianus), which serves the thumb, index and middle fingers on the palm side of the hand, and their distal phalanges on both sides, the ulnar nerve (nervus ulnaris) which provides innervation for the ring and small fingers, and the radial nerve which supplies the dorsal part of the hand. If any of these nerves is pressed by the surrounding tissues, various neurological complaints could occur on its supplied area.

If the median nerve becomes compressed in the carpal tunnel, diverse neurological symptoms occur in the served area.

The median nerve supplies the muscles at the base of the thumb that allows it to abduct, move away from the other four fingers, as well as move out of the plane of the palm.

Usually, numbness, tingling, pain, weak grip, clumsiness is felt in the thumb, index finger and middle finger. The symptoms are usually felt during the night, and later also during the daily activities.

The wrist is usually swollen, sensitive for pressure, moving is painful, which radiates to the forearm, shoulder or neck.

If the condition remains untreated, the muscles will not receive sufficient nerve stimulation, why weakness and atrophy of the thumb muscle may occur.

Usually, the dominant hand is affected.

The symptoms of the cubital tunnel syndrome can be separated into two groups. As the ulnar nerve contains both sensory and motor nerves, the first group of symptoms is sensory symptoms, like numbness, loss of sensation, pain in the ring and small finger. The other group of symptoms are motor deficits: difficulty with finger coordination, the weakening of the grip, and in an advanced stage, muscle wasting in the hand could occur.

The elbow is usually swollen, pressure-sensitive, especially along the ulnar nerve, and its range of motion is decreased.

At an early stage, symptoms are felt by night, but later also during the daily activities, when the elbow is bent for a long time, like while holding a phone.

As other diseases, like spinal disorders, or vascular lesion could cause similar complaints as well, it is recommended to visit an orthopedic specialist to detect the cause of the symptoms.

What are the treatments for the cubital tunnel syndrome?

If tunnel syndrome is diagnosed, the treatment starts with conservative (non-surgical) methods. The treatment might consist of splinting of the wrist or the elbow, which helps to reduce the pressure on the nerve. Steroid injections to the carpal or cubital tunnel could contribute to reducing the swelling around the nerve.

However, if the conservative treatment didn’t take effect or the decrease of the nerve conduction velocity is lower than the average, surgical intervention is recommended. Both for carpal and cubital tunnel syndromes, the tunnel release is performed by a hand surgeon specialist.