Common peroneal nerve dysfunction

Alternative names:

neuropathy - common peroneal nerve; peroneal nerve injury

Definition:

A disorder characterized by progressive loss of movement or sensation of the feet and legs caused by damage to the peroneal nerve.

Causes, incidence, and risk factors:

Common peroneal nerve dysfunction is a peripheral neuropathy (damage to nerves not including the brain or spinal cord). It may occur in a person of any age. The peroneal nerve is a branching of the sciatic nerve. It supplies movement and sensation to the lower leg, foot, and toes.

Involvement of a single nerve, such as the common peroneal nerve, is classed as mononeuropathy. Mononeuropathy implies a local cause of the nerve damage, although systemic conditions may cause isolated nerve injuries (such as occurs with mononeuritis multiplex). Damage to the nerve causes destruction (degeneration) of the covering of the nerve cells (myelin sheath), or degeneration of the entire nerve cell. There is a loss of muscle control, loss of muscle tone, and eventual loss of muscle mass because of lack of nervous stimulation to the muscles.

Common causes of damage to the peroneal nerve include trauma or injury to the knee, fracture of the fibula bone of the lower leg, tight plaster cast (or other long-term constriction) of the lower leg, habitual leg crossing, chronic wearing of high boots, pressure to the knee from positions during deep sleep or coma, and other conditions that place pressure on the back of the knee. The common peroneal nerve may also be injured during knee surgery. Another risk is a very thin or emaciated body build. Systemic conditions such as diabetic neuropathy or polyarteritis nodosa may cause damage to the common peroneal nerve. Charcot-Marie-Tooth disease is an inherited disorder that affects all nerves, with peroneal nerve dysfunction apparent early in the disorder.