Nerve Compression Health Article

Definition

Nerve compression is the restriction in the space around a nerve that can occur due to several reasons. Functioning of the nerve is compromised.

Description

There are a variety of circumstances that cause nerve compression. Despite this variety, the resulting damage to the nerve produces a similar diminished functioning of the nerve.

Demographics

The incidence of brachial plexus palsy, usually a result of birth injury to the nerves that conduct signals from the spine to the shoulder and resulting in a limp or paralyzed arm, is low, on the order of one to two births out of every 1,000. Brachial plexus palsy is associated with a difficult labor, especially compression on the baby's shoulders. Intervention or assistance during labor can lessen the chance of the physical trauma that causes the nerve damage. However, the condition cannot be totally eliminated, especially in times where an emergency response is needed to speed the birth of a fetus in distress.

Meralgia parasthetica, a condition involving compression of the lateral femoral cutaneous nerve, results in paresthesia, or tingling, numbness, and burning pain in the outer side of the thigh. Meraglia paresthetica has traditionally affected men more than women. The condition is not rare, but its overall prevalence is unknown. Meralgia paresthetica may occur after abdominal surgery or significant weight gain, in military members who often march, soccer players, or for no apparent reason in the general population. Other nerve compression maladies such as carpal tunnel syndrome can be quite common.

Causes and symptoms

There are a variety of conditions that lead to nerve compression, according to the affected nerve.

Carpal tunnel syndrome

In carpal tunnel syndrome, the nerves that pass through the wrist are pinched due to the enlargement of local tendons and ligaments. The enlargement occurs due to inflammation, which can be associated with the strain of performing a repetitive task such as typing. Carpal tunnel syndrome is also associated with maladies like diabetes, and with the restricted space that can develop in the wrist as weight is gained during pregnancy or in someone who is obese. The enlargement of the tendons and ligaments restricts the space available for the nerves that reach to the finger and also for the muscle that connects to the base of the thumb. As a consequence, the ability of the nerve to properly transmit impulses to the muscles in the fingers and thumb is affected.

The initial symptoms of carpal tunnel syndrome tend to be felt at night because the hand is at rest. The symptoms can be a burning or a tingling numbness in the fingers, in particular the thumb, along with the index and middle fingers. As well, the reduced transmission of nerve impulses to the muscles decrease muscle strength. It can become difficult to grip an object or make a fist.

Thoracic outlet syndrome

In thoracic outlet syndrome, nerve compression can occur as a result of stresses on the neck and shoulders that cause these areas to impinge on local nerves. While the underlying cause of the syndrome is not clear, there seems to be an association between thoracic outlet syndrome and physical labor, in particular the repeated lifting of heavy objects onto the shoulders, causing the shoulders to pull back and down. Reaching for objects that are positioned above shoulder level can also be irritating to muscles in the shoulders and the upper arms. Swelling and inflammation of the muscles can compress nerves between the neck and shoulders.

The symptoms of thoracic outlet syndrome include weakness of the arms, pain, and numbness of the arms and fingers. In more extreme cases, the sense of touch and ability to sense temperature changes can be lost in the fingers.