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Distal median nerve dysfunction
Neuropathy - distal median nerve
Distal median nerve dysfunction is a form of peripheral neuropathy that affects the movement of or sensation in the hands.
Peripheral neuropathy
Peripheral nerves carry information to and from the brain. They also carry signals to and from the spinal cord to the rest of the body. Peripheral n...
A common type of distal median nerve dysfunction is carpal tunnel syndrome .
Carpal tunnel syndrome
Carpal tunnel syndrome is a condition in which there is excessive pressure on the median nerve. This is the nerve in the wrist that allows feeling a...
Causes
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. Sometimes, bodywide ( systemic ) disorders can cause isolated nerve damage.
Mononeuropathy
Mononeuropathy is damage to a single nerve, which results in loss of movement, sensation, or other function of that nerve.
Systemic
Systemic means affecting the entire body, rather than a single organ or body part. For example, systemic disorders, such as high blood pressure, or s...
This condition occurs when the nerve is inflamed, trapped, or injured by trauma. The most common reason is trapping (entrapment). Trapping puts pressure on the nerve where it passes through a narrow area. Wrist fractures may injure the median nerve directly. Or, it may increase the risk for trapping the nerve later on.
Inflammation of the tendons ( tendonitis ) or joints ( arthritis ) can also put pressure on the nerve. Some repetitive movements increase the chance of developing carpal tunnel entrapment.
Tendonitis
Tendons are the fibrous structures that join muscles to bones. When these tendons become swollen or inflamed, it is called tendinitis. In many case...
Arthritis
Arthritis is inflammation of one or more joints. A joint is the area where 2 bones meet. There are more than 100 different types of arthritis....
Problems that affect the tissue near the nerve or cause deposits to form in the tissue can block blood flow and lead to pressure on the nerve. Such conditions include:
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Too much growth hormone in the body (
acromegaly
)
Acromegaly
Acromegaly is a condition in which there is too much growth hormone in the body.
ImageRead Article Now Book Mark Article - Diabetes
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Underactive thyroid (
hypothyroidism
)
Hypothyroidism
Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone. This condition is often called underactive thyroid....
ImageRead Article Now Book Mark Article - Kidney disease
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Blood cancer called
multiple myeloma
Multiple myeloma
Multiple myeloma is a blood cancer that starts in the plasma cells in the bone marrow. Bone marrow is the soft, spongy tissue found inside most bone...
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In some cases, no cause can be found. Diabetes can make this condition worse.
Symptoms
Symptoms may include any of the following:
- Pain in the wrist or hand that may be severe and wake you up at night, and that may be felt in other areas, such as the upper arm (this is called referred pain)
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Sensation changes in the thumb, index, middle, and part of the ring fingers, such as a burning feeling,
decreased sensation
,
numbness and tingling
Decreased sensation
Numbness and tingling are abnormal sensations that can occur anywhere in your body, but they are often felt in your fingers, hands, feet, arms, or le...
ImageRead Article Now Book Mark ArticleNumbness and tingling
Numbness and tingling are abnormal sensations that can occur anywhere in your body, but they are often felt in your fingers, hands, feet, arms, or le...
ImageRead Article Now Book Mark Article - Weakness of the hand that causes you to drop things or have difficulty grasping objects or buttoning a shirt
Exams and Tests
Your health care provider will examine your wrist and ask about your medical history. Tests that may be done include:
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Electromyogram (EMG)
to check the electrical activity of the muscles
Electromyogram (EMG)
Electromyography (EMG) is a test that checks the health of the muscles and the nerves that control the muscles.
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Nerve conduction tests
to check how fast electrical signals move through a nerve
Nerve conduction tests
Nerve conduction velocity (NCV) is a test to see how fast electrical signals move through a nerve.
ImageRead Article Now Book Mark Article - Neuromuscular ultrasound to view problems with the muscles and nerves
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Nerve biopsy
in which nerve tissue is removed for examination (rarely needed)
Nerve biopsy
A nerve biopsy is the removal of a small piece of a nerve for examination.
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Treatment
Treatment is aimed at the underlying cause.
If the median nerve is affected by carpal tunnel syndrome, a wrist splint can reduce further injury to the nerve and help relieve symptoms. Wearing the splint at night rests the area and decreases inflammation. An injection into the wrist may help with symptoms, but it won't fix the underlying problem. Surgery may be needed if a splint or medicines don't help.
Surgery
Carpal tunnel release is surgery to treat carpal tunnel syndrome. Carpal tunnel syndrome is pain and weakness in the hand that is caused by pressure...
For other causes, treatment may involve any of the following:
- Medicines to control nerve pain
- Treating the medical problem causing nerve damage, such as diabetes or kidney disease
- Physical therapy to help maintain muscle strength
Outlook (Prognosis)
If the cause of the nerve dysfunction can be identified and treated, there is a good chance of full recovery. In some cases, there is some or complete loss of movement or sensation. Nerve pain may be severe and persist for a long time.
Loss of movement
Muscle function loss is when a muscle does not work or move normally. The medical term for complete loss of muscle function is paralysis.
Nerve pain
Neuralgia is a sharp, shocking pain that follows the path of a nerve and is due to irritation or damage to the nerve. Common neuralgias include:Posth...
Possible Complications
Complications may include:
- Deformity of the hand (rare)
- Partial or complete loss of hand movement
- Partial or complete loss of sensation in the fingers
- Recurrent or unnoticed injury to the hand
When to Contact a Medical Professional
Call your provider if you have symptoms of distal median nerve dysfunction. Early diagnosis and treatment increase the chance of curing or controlling symptoms.
Prevention
Prevention varies, depending on the cause. In people with diabetes, controlling blood sugar may reduce the risk of developing nerve disorders.
For people with jobs that involve repetitive wrist movements, a change in the way the job is performed may be needed. Frequent breaks in activity may also help.
References
Katirji B. Disorders of peripheral nerves. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley's Neurology in Clinical Practice . 7th ed. Philadelphia, PA: Elsevier; 2016:chap 107.
Wolfe VM, Rosenwasser MP, Tang P. Entrapment neuropathies of the arm, elbow, and forearm. In: Miller MD, Thompson SR, eds. DeLee and Drez's Orthopaedic Sports Medicine: Principles and Practice . 4th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 67.
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Central nervous system - illustration
The central nervous system is comprised of the brain and spinal cord. The peripheral nervous system includes all peripheral nerves.
Central nervous system
illustration
Review Date: 5/30/2016
Reviewed By: Amit M. Shelat, DO, FACP, Attending Neurologist and Assistant Professor of Clinical Neurology, SUNY Stony Brook, School of Medicine, Stony Brook, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
