Median Nerve Damage

Median nerve damage or median nerve entrapment occurs due to trauma or injury to the parts of the body the median nerve runs through, which are the forearm, arm, and hand. When this nerve is damaged it loses the ability to send sensory and motor messages to the brain.

Overview

The median nerve is one of three main nerves in the forearm, arm, and hand. It stems from the neck at brachial plexus and runs along the center of the arm and forearm then enters the hand through the carpal tunnel. This nerve also extends to the inner side of the joint at the elbow.

The median nerve plays an important role in the functioning of the upper limb and controls muscles in the hand (including the palm) and forearm. It also sends sensation and movement messages to the brain. Movements of the wrist and fingers (except the pinky finger) are controlled by this nerve.

Injury or damage to the median nerve can occur due to trauma at the elbow, wrist, arm, or forearm. Furthermore, any damage to the median nerve at the elbow, however slight, can result in symptoms that affect the hand, wrist, and forearm.

Carpal tunnel syndrome is one of the most common forms of median nerve damage. The type of median nerve damage depends on the cause. Symptoms and treatment may differ depending on the cause and location of the damage.

Types of Median Nerve Damage

  • Carpal tunnel syndrome
  • Pronator teres syndrome
  • Anterior interosseous nerve syndrome

Carpal Tunnel Syndrome

Carpel tunnel syndrome results from entrapment (pressure and squeezing) of the median nerve in the hand. It can affect one or both hands but typically affects the dominant hand. Usually, the soft tissues or tendons in the carpal tunnel get irritated or swollen, causing compression of the nerve. Adults between the ages of 30 and 60 are more likely to develop this syndrome, and women are said to be more affected by it than men. Pain caused by carpal tunnel syndrome is felt mostly at night and may occur after activities, such as prolong typing on a computer keyboard or driving. Carpal tunnel symptoms commonly recur.

Pronator Teres Syndrome

Unlike with carpal tunnel syndrome, patients with pronator teres syndrome feel pain and weakness when turning the palm of the hand down (pronation). Repetitive or prolonged grasping with the hand in a forceful manner accompanied by twisting of the wrist primarily causes pronator teres syndrome. Weight lifting, rowing, and playing racket sports are common activities that trigger this syndrome. Trauma to the forearm may also cause this condition, which affects women more than men.

Anterior Interosseous Nerve Syndrome

Anterior interosseous nerve syndrome, also known as Kiloh-Nevin syndrome, is another type of median nerve damage that occurs when there is an injury or damage to the anterior interosseous nerveā€”a branch of the median nerve. It affects the forearm when one or more structures within the forearm cause compression of the nerve. These include enlarged biceps and tendon bursa. Direct injury or trauma to the forearm such as a fracture or dislocation can also cause compression. People with gouty arthritis and rheumatoid disease are more at risk of developing this type of median nerve damage.

Symptoms of Median Nerve Damage

The symptoms of the three types of median nerve damage or injury are mostly similar in nature, with a slight variance. Symptoms may be constant or intermittent depending on the severity of the injury.

Symptoms of Carpal Tunnel Syndrome

  • Difficulty or inability flexing the wrist downward
  • Muscle wasting at the base of the thumb
  • Difficulty or inability turning the hand over
  • Unable to move the thumb across the palm
  • Hand muscles too weak to grip
  • Pain in the wrist (especially at night)
  • Numbness or tingling in the forearm, thumb, and fingers (except the pinky finger)
  • Dull ache in the forearm or wrist which radiates to the thumb and three adjacent fingers

Symptoms of Pronator Teres Syndrome

  • Tenderness when the pronator teres muscle in the arm is pressed
  • Difficulty or inability to bend the wrist
  • Difficulty or inability to turn the forearm
  • Loss of strength in the thumb

Symptoms of Anterior Interosseous Nerve Syndrome

  • Weakness in the thumb and index finger
  • Dull ache in the forearm
  • Loss of pinch (inability to hold something between the thumb and index finger)
  • Inability to write due to loss of pinch
  • No sensory loss

Causes of Median Nerve Damage

Median nerve damage occurs due to some other type of injury that mainly cause a compression of the nerve. One or more of the following factors may lead to damage of the median nerve:

  • Major or minor trauma or injury to the nerve at the elbow
  • Swelling or compression of soft tissues the nerve passes through
  • A dislocation or fracture occurring where the median nerve runs through
  • Squeezing and irritation of the nerve that reduces the space at the carpal tunnel
  • Inflammation of the nerve, e.g. due to rheumatoid arthritis
  • Prolonged flexing of the wrist
  • Forceful gripping of an object accompanied by flexion of the fingers, such as in weightlifting

Diagnosis

A physical examination can be done to diagnose the condition. Your doctor may test for feelings in your fingers and the degree of strength of your hand muscles. The doctor may test the nerve in your hand by tapping on or around the area or asking you to flex or bend your wrist. An x-ray may also be done to rule out a fracture or arthritis as the source of the symptoms. In some cases, an electromyogram (EMG) is done to test for muscle damage. Nerve conduction studies, MRI, EMG, and ultrasound imaging are methods used to diagnose anterior interosseous nerve syndrome.

Treatment for Median Nerve Damage

It is important to get treated right away to reduce the risk of chronic damage to the median nerve. The most effective treatment will depend on the extent of the injury which could be mild, severe or permanent.

Since damage to the median nerve typically manifests in closely similar symptoms for the three types of injuries discussed, treatment for each is generally the same. Median nerve damage is, in essence, a symptom in itself of an initial injury in a part of the body that houses the nerve. This could be a soft tissue injury, fracture, dislocation or even arthritis.

Therefore, treatment should target that initial injury in order to relieve the symptoms of the nerve damage. The following are common ways to treat this condition and ease the pressure on the median nerve:

Self-Care

The following self-care remedies can help a minor injury to repair itself within minutes, days, or weeks.

  • Use an ice pack to reduce swelling
  • Rest the hand for about 2 weeks
  • Massage the affected area to help relax the muscles
  • Stop or avoid activities that reinforce the injury to the hand, wrist, elbow or forearm
  • Take frequent breaks from the activity that trigger the symptoms
  • Use a wrist splint to immobilize the wrists (if necessary)
  • Compression and elevation can help reduce swelling due to soft tissue injury

Medication

Self-care remedies may not be effective in cases of long-term damage of the median nerve. While they bring some relief, the symptoms are likely to persist. As such, medical intervention would become necessary. Pain can be treated with pain relievers or anti-inflammatory medicines. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen may be prescribed.

A steroid injection such as corticosteroids may be used for severe symptoms. The doctor may inject the carpal tunnel using ultrasound to guide the needle. Corticosteroids reduce swelling and inflammation which in turn relieves pressure on the affected nerve. The oral steroid, Prednisone, relieves the symptoms but is not quite as effective as injectable steroids.

Physical Therapy

The strength of the muscle in the hand may be restored using physical therapy. This could include a sports massage to relieve muscular tension. Stretching the forearm, palm, wrist, and fingers and wrist rotation may help relax the muscles and tissues surrounding the median nerve.

Alternative Remedies

Even though its effectiveness has not been scientifically proven, it is believed that acupuncture relieves the pressure on the median nerve. Patients with carpal tunnel syndrome have used yoga to relieve pain and improve muscle strength.

Surgery

When all other treatment fails, surgery may be necessary to release the compression of the nerve. This is especially necessary for dislocations and fractures. Realigning the dislocation or fracture eliminates the pressure on the median nerve and allows it to return to the normal function of sending sensory and motor messages to the brain. In the case of carpal tunnel syndrome when there is a cut nerve or broken nerve fibers, surgery helps the nerve to heal properly.

Prevention of Median Nerve Damage

  • Frequent short breaks should be taken from repetitive hand activities.
  • Stretch the palm and fingers during the break as well as rotate the wrist to release pressure on the muscles.
  • A snug wrist splint can be worn to protect the wrist from injury or avoid future injury.
  • Avoid sleeping with your hands under your head or body.
  • Employers can redesign workplaces and use technologically advanced equipment and machines that do not require prolonged rotation and flexing of the forearm and wrist.