Common peroneal nerve dysfunction

Answer 1

Definition

Common peroneal nerve dysfunction is damage to the peroneal nerve leading to loss of movement or sensation in the foot and leg.

Alternative Names

Neuropathy - common peroneal nerve; Peroneal nerve injury; Peroneal nerve palsy

Causes, incidence, and risk factors

The peroneal nerve is a branch of the sciatic nerve, which supplies movement and sensation to the lower leg, foot and toes. Common peroneal nerve dysfunction is a type of peripheral neuropathy(damage to nerves outside the brain or spinal cord). This condition can affect people of any age.

Dysfunction of a single nerve, such as the common peroneal nerve, is called a mononeuropathy. Mononeuropathy implies there is a local cause of the nerve damage, although certain bodywide conditions may also cause isolated nerve injuries.

Damage to the nerve destroys the covering of the nerve cells (the myelin sheath) or causes degeneration of the entire nerve cell. There is a loss of sensation, muscle control, 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 the following:

• Trauma or injury to the knee
• Fracture of the fibula (a bone of the lower leg)
• Use of a tight plaster cast (or other long-term constriction) of the lower leg
• Habitual leg crossing
• Regularly wearing high boots
• Pressure to the knee from positions during deep sleep or coma
• Injury during knee surgery.

People who are extremely thin or emaciated (for example, from anorexia nervosa) have a higher-than-normal risk of common peroneal nerve injury. Conditions such as diabetic neuropathy or polyarteritis nodosa, as well as exposure to certain toxins, can also 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.

Symptoms

• Decreased sensation, numbness or tingling in the top of the foot or the outer part of the upper or lower leg
• Weakness of the ankles or feet
• Walking abnormalities
• "Slapping" gait (walking pattern in which each step taken makes a slapping noise)
• Foot drop (unable to hold foot horizontal)
• Toes drag while walking

Signs and tests

Examination of the legs may show a loss of muscle control over the legs (usually the lower legs) and feet. The foot or leg muscles may atrophy (lose mass). There is difficulty with dorsiflexion (lifting up the foot and toes) and with eversion (toe-out movements).

Muscle biopsy or a nerve biopsy may confirm the disorder, but they are rarely necessary.

Tests of nerve activity include:

• EMG(electromyography, a test of electrical activity in muscles)
• Nerve conduction tests
• MRI to look for compressive lesion along nerve

Other tests are determined by the suspected cause of the nerve dysfunction, based on the person's history, symptoms, and pattern of symptom development. They may include various blood tests, x-rays, scans, or other tests and procedures.

Treatment

Treatment is aimed at maximizing mobility and independence. Any illness or other source of inflammation that is causing the neuropathy should be treated.

If there is no history of trauma to the area, the condition developed suddenly with minimal sensation changes and no difficulty in movement, and there is no test evidence of nerve axon degeneration, then a conservative treatment plan will probably be recommended.

Corticosteroids injected into the area may reduce swelling and pressure on the nerve in some cases.

Surgery may be required if the disorder is persistent or symptoms are worsening, if there is difficulty with movement, or if there is evidence on testing that the nerve axon is degenerating. Surgical decompression of the area may reduce symptoms if the disorder is caused by pressure on the nerve. Surgical removal of tumors or other conditions that press on the nerve may be of benefit.

CONTROLLING SYMPTOMS

Over-the-counter or prescription analgesics may be needed to control pain. Other medications may be used to reduce the stabbing pains that some people experience, including gabapentin, carbamazepine, or tricyclic antidepressants such as amitriptyline. Whenever possible, medication use should be avoided or minimized to reduce the risk of side effects.

If pain is severe, a pain specialist should be consulted so that all options for pain treatment are explored.

Physical therapy exercises may be appropriate for some people to maintain muscle strength.

Orthopedic assistance may maximize the ability to walk and prevents contractures. This may include use of braces, splints, orthopedic shoes, or other equipment.

Vocational counseling, occupational therapy, or similar intervention may be recommended to help maximize mobility and independence.

Expectations (prognosis)

The outcome depends on the underlying cause. Successful treatment of the underlying cause may resolve the dysfunction, although it may take several months for the nerve to grow back.

Alternately, if nerve damage is severe, disability may be permanent. The nerve pain may be quite uncomfortable. This disorder does NOT usually shorten the person's expected life span.

Complications

• Decreased ability to walk
• Permanent decrease in sensation in the legs or feet
• Permanent weakness or paralysis in the legs or feet
• Side effects of medication

Calling your health care provider

Call your health care provider if you have symptoms that indicate common peroneal nerve dysfunction.

Prevention

Avoid prolonged pressure to the back or side of the knee. Injuries to the leg or knee should be treated promptly.

If a cast, splint, dressing, or other possible constriction of the lower leg causes a tight feeling or numbness, notify your health care provider.

References

King JC. Peroneal neuropathy. In: Frontera WR, Silver JK, Rizzo TD, eds. Essentials of Physical Medicine and Rehabilitation: Musculoskeletal disoders, pain and rehabilitation.. 2nd ed. Philadelphia, Pa: Saunders Elsevier; 2008: chap 66.

Answer 2

Definition

Tibial nerve dysfunction is a loss of movement or sensation in the lower leg, caused by damage to the tibial nerve.

Alternative Names

Neuropathy - tibial nerve

Causes, incidence, and risk factors

Tibial nerve dysfunction is a form of peripheral neuropathy. It occurs when there is damage to the tibial nerve, one of the branches of the sciatic nerve of the leg. The tibial nerve supplies movement and sensation to the calf and foot muscles.

Dysfunction of a single nerve group, such as the tibial nerve, is called mononeuropathy. Mononeuropathy implies a local cause of the nerve damage, although occasionally systemic disorders may cause isolated nerve damage (such as occurs with mononeuritis multiplex).

The usual causes are direct trauma, prolonged pressure on the nerve, and compression of the nerve from nearby body structures. Entrapment involves pressure on the nerve where it passes through a narrow structure.

The damage may include destruction of the myelin sheath of the nerve (the insulation around the nerve) or destruction of part of the nerve cell (the axon). Damage to either part slows or prevents conduction of impulses through the nerve.

The tibial nerve is commonly injured by fractures or other injury to the back of the knee or the lower leg. It may be affected by systemic diseases causing polyneuropathy (damage to multiple nerves) such as diabetes. It may be damaged by pressure from lesions such as tumor, abscess, or bleeding into the knee.

In some cases, no cause can be identified.

Symptoms

• Sensation changes on the bottom of the foot
  • Numbness, tingling, or other abnormal sensations
  • Burning sensation
  • Pain
• Weakness of the knee or foot, difficulty with walking

Signs and tests

Neuromuscular examination of the legs shows tibial nerve dysfunction. There may be weakness or inability to push the foot downward (plantar flexion). Severe cases may cause wasting of the foot muscles and foot deformity.

Tests that reveal tibial nerve dysfunction may include:

• EMG (a recording of electrical activity in muscles)
• Nerve conduction tests (recording of electrical activity along the nerve)
• Nerve biopsy

Tests are done based on the suspected cause of the dysfunction suggested by the patient's history, symptoms, and pattern of symptom development. They may include various blood tests, x-rays, scans, or other tests.

Treatment

Treatment is aimed at increasing mobility and independent self-care. In some cases, no treatment is required and recovery is spontaneous.

Surgical removal of lesions that press on the nerve may benefit some people.

Over-the-counter analgesics or prescription medications may be needed to control pain (neuralgia). Various other medications (phenytoin, carbamazepine, gabapentin or tricyclic antidepressants such as nortriptyline) may reduce the stabbing pains that some people experience. Whenever possible, medication use should be avoided or reduced to lessen the risk of side effects.

Physical therapy exercises may help some people maintain muscle strength. Orthopedic assistance may aid the ability to walk. This may include use of braces, splints, orthopedic shoes, or other appliances.

Vocational counseling, occupational therapy, job changes or retraining, or similar interventions may be recommended.

Expectations (prognosis)

If the cause of the tibial nerve dysfunction can be identified and successfully treated, there is a possibility of full recovery. The extent of disability varies, with partial or complete loss of movement or sensation. Nerve pain may be quite uncomfortable and persist for a prolonged period of time.

Complications

• Partial or complete loss of foot movement
• Partial or complete loss of sensation in the foot
• Recurrent or unnoticed injury to the leg
• Deformity of the foot (mild to severe)

Calling your health care provider

Call for an appointment with your health care provider if symptoms of tibial nerve dysfunction are present. Early diagnosis and treatment increases the likelihood that symptoms can be controlled.

Prevention

Prevention is variable depending on the cause of the nerve damage.

References

Feske S, Cochrane T. Degenerative and compressive structural disorders. In: Goetz, CG, ed. Textbook of Clinical Neurology. 3rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 29.

Answer 3

Definition

Common peroneal nerve dysfunction is damage to the peroneal nerve leading to loss of movement or sensation in the foot and leg.

Alternative Names

Neuropathy - common peroneal nerve; Peroneal nerve injury; Peroneal nerve palsy

Causes, incidence, and risk factors

The peroneal nerve is a branch of the sciatic nerve, which supplies movement and sensation to the lower leg, foot and toes. Common peroneal nerve dysfunction is a type of peripheral neuropathy(damage to nerves outside the brain or spinal cord). This condition can affect people of any age.

Dysfunction of a single nerve, such as the common peroneal nerve, is called a mononeuropathy. Mononeuropathy means the nerve damage occurred in one area. However, certain bodywide conditions may also cause single nerve injuries.

Damage to the nerve destroys the myelin sheath that covers the axon (branch of the nerve cell). Or it may destroy the whole nerve cell. There is a loss of feeling, muscle control, muscle tone, and eventual loss of muscle mass because the nerves aren't stimulating the muscles.

Common causes of damage to the peroneal nerve include the following:

• Trauma or injury to the knee
• Fracture of the fibula (a bone of the lower leg)
• Use of a tight plaster cast (or other long-term constriction) of the lower leg
• Crossing the legs regularly
• Regularly wearing high boots
• Pressure to the knee from positions during deep sleep or coma
• Injury during knee surgery or from being placed in an awkward position during anesthesia

Common perineal nerve injury is more common in people:

• Who are very thin (for example, from anorexia nervosa)
• Who have conditions such as diabetic neuropathy or polyarteritis nodosa
• Who are exposed to certain toxins that can damage the common peroneal nerve

Charcot-Marie-Tooth disease is an inherited disorder that affects all of the nerves. Perineal nerve dysfunction occurs early in this disorder.

Symptoms

• Decreased sensation, numbness, or tingling in the top of the foot or the outer part of the upper or lower leg
• Foot that drops (unable to hold the foot straight across)
• "Slapping" gait (walking pattern in which each step makes a slapping noise)
• Toes drag while walking
• Walking problems
• Weakness of the ankles or feet

Signs and tests

Examination of the legs may show:

• Loss of muscle control in the legs (usually the lower legs) and feet
• Atrophy of the foot or leg muscles
• Difficulty lifting up the foot and toes and making toe-out movements

Muscle biopsy or a nerve biopsy may confirm the disorder, but they are rarely needed.

Tests of nerve activity include:

• Electromyography (EMG, a test of electrical activity in muscles)
• Nerve conduction tests
• MRI

What other tests are done depend on the suspected cause of nerve dysfunction, and the person's symptoms and how they developed. Tests may include blood tests, x-rays and scans.

Treatment

Treatment aims to improve mobility and independence. Any illness or other cause of the neuropathy should be treated.

Corticosteroids injected into the area may reduce swelling and pressure on the nerve in some cases.

You may need surgery if:

• The disorder does not go away
• You have problems with movement
• There is evidence that the nerve axon is damaged

Surgery to relieve pressure on the nerve may reduce symptoms if the disorder is caused by pressure on the nerve. Surgery to remove tumors on the nerve may also help.

CONTROLLING SYMPTOMS

You may need over-the-counter or prescription pain relievers to control pain. Other medications may be used to reduce pain include gabapentin, carbamazepine, or tricyclic antidepressants such as amitriptyline. Whenever possible, avoid or limit the use of medication to reduce the risk of side effects.

If your pain is severe, a pain specialist can help you explore all options for pain relief.

Physical therapy exercises may help you maintain muscle strength.

Orthopedic devices may improve your ability to walk and prevent contractures. These may include braces, splints, orthopedic shoes, or other equipment.

Vocational counseling, occupational therapy, or similar programs may help you maximize your mobility and independence.

Expectations (prognosis)

The outcome depends on the cause of the problem. Successfully treating the cause may relieve the dysfunction, although it may take several months for the nerve to grow back.

However, if nerve damage is severe, disability may be permanent. The nerve pain may be very uncomfortable. This disorder does NOT usually shorten a person's expected lifespan.

Complications

• Decreased ability to walk
• Permanent decrease in sensation in the legs or feet
• Permanent weakness or paralysis in the legs or feet
• Side effects of medication

Calling your health care provider

Call your health care provider if you have symptoms of common peroneal nerve dysfunction.

Prevention

Avoid putting long-term pressure ono the back or side of the knee. Treat injuries to the leg or knee right away.

If a cast, splint, dressing, or other pressure on the lower leg causes a tight feeling or numbness, call your health care provider.

References

King JC. Peroneal neuropathy. In: Frontera WR, Silver JK, Rizzo TD, eds. Essentials of Physical Medicine and Rehabilitation: Musculoskeletal disorders, pain and rehabilitation.. 2nd ed. Philadelphia, Pa: Saunders Elsevier; 2008:chap 66.

Reviewed By

Review Date: 09/26/2011

David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by Luc Jasmin, MD, PhD, Departments of Anatomy and Neurological Surgery, University of California, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

Answer 4

Definition

Tibial nerve dysfunction is a loss of movement or sensation in the foot from damage to the tibial nerve.

Alternative Names

Neuropathy - posterior tibial nerve; Tarsal tunnel syndrome

Causes, incidence, and risk factors

Tibial nerve dysfunction is an unusual form of peripheral neuropathy. It occurs when there is damage to the tibial nerve, one of the lower branches of the sciatic nerve of the leg. The tibial nerve supplies movement and sensation to the calf and foot muscles.

A problem in function with a single nerve group, such as the tibial nerve, is called mononeuropathy. The usual causes are:

• Direct trauma
• Pressure on the nerve for a long period of time
• Pressure on the nerve from nearby body structures

Entrapment createes pressure on the nerve where it passes through a narrow structure.

The damage may destroy the myelin sheath that protects and insulates the nerve, or part of the nerve cell (the axon). This damage reduces or prevents the movement of impulses through the nerve.

The tibial nerve is often injured by pressure from a ligament on the inner part of the ankle. Injury or disease of structures near the knee may also damage the tibial nerve. The tibial nerve may also be affected by diseases that damage many nerves, such as diabetes.

In some cases, no cause can be found.

Symptoms

• Sensation changes in the bottom of the foot and toes
  • Burning sensation
  • Numbness, tingling, or other abnormal sensations
  • Pain
• Weakness of foot muscles
• Weakness of the toes or ankle

Signs and tests

An examination of the legs will be done to diagnose tibial nerve dysfunction. The health care provider will also take a medical history.

Signs include:

• Inability to curl the toes, push the foot down, or twist the ankle inward
• Weakness

In severe cases, the foot muscles may become very weak and the foot may be deformed.

Tests for tibial nerve dysfunction may include:

• EMG (a recording of electrical activity in muscles)
• Nerve biopsy
• Nerve conduction tests (recording of electrical activity along the nerve)

Tests may also include blood tests, x-rays, or scans.

Treatment

Treatment is aimed at restoring feeling and strength to the foot and toes. In some cases, no treatment is needed, and patients will recover on their own. Severe loss of sensation may lead to toe or foot sores (ulcers) and infections.

Surgery to enlarge the tarsal tunnel will reduce pressure on the tibial nerve and may benefit some people.

Over-the-counter analgesics may be helpful for mild pain (neuralgia). Other medicines include:

• Phenytoin, carbamazepine, gabapentin, pregabalin, duloxetine, or tricyclic antidepressants such as nortriptyline may reduce the stabbing pains that some people experience.
• Opiate pain relievers, such as morphine or fentanyl, may be needed to control severe pain.

Whenever possible, medication should be avoided or reduced to lessen the risk of side effects.

Physical therapy exercises may help some people maintain muscle strength.

Job counseling, therapy, changes, or retraining may be recommended.

Expectations (prognosis)

If the cause of the tibial nerve dysfunction can be found and successfully treated, patients can recover fully. Some people may have a partial or complete loss of movement or sensation. Nerve pain may be uncomfortable and last for a long period of time.

Complications

• Deformity of the foot (mild to severe)
• Movement loss in the toes (partial or complete)
• Repeated or unnoticed injury to the leg
• Sensation loss in the toes or foot (partial or complete)

Calling your health care provider

Call for an appointment with your health care provider if symptoms of tibial nerve dysfunction are present. Early diagnosis and treatment increases the likelihood that symptoms can be controlled.

Prevention

Prevention is variable depending on the cause of the nerve damage.

References

Harati Y, Bosch EP. Disorders of peripheral nerves. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Bradley: Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth-Heinemann Elsevier; 2008:chap 80.

Reviewed By

Review Date: 02/05/2011

David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by Josh V. Campellone, MD, Division of Neurology, Cooper University Hospital, Camden, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.