Definition of Distal median nerve dysfunction:

Distal median nerve dysfunction is a form of peripheral neuropathy that affects the movement of or sensation in the hands. Peripheral means further out from the spinal cord.

A common type of distal median nerve dysfunction is carpal tunnel syndrome.

Causes, incidence, and risk factors:

Dysfunction of one nerve group, such as the distal median nerve, is called a mononeuropathy. Mononeuropathy means there is a local cause of the nerve damage, although occasionally body-wide ( systemic) disorders may cause isolated nerve damage. An example is mononeuritis multiplex, where several nerve bundles are affected.

Distal median nerve dysfunction occurs when the nerve is inflamed, trapped, or injured by trauma. Perhaps the most common reason is trapping (entrapment), which puts pressure on the nerve where it passes through a narrow area. Wrist fractures may injure the median nerve directly or may increase the risk for trapping a nerve later on.

Inflammation of the tendons ( tendonitis) or joints ( arthritis) can also cause nerve compression.

Conditions that affect connective tissue or cause deposits to form in tissue can block blood flow and lead to nerve compression. Such conditions include:

• Acromegaly
• Hypothyroidism
• Multiple myeloma
• Pregnancy

In some cases, no cause can be identified.