Brachial plexopathy; Brachial plexus dysfunction
Brachial plexopathy is decreased movement or sensation in the arm and shoulder, caused by impaired function of the brachial plexus (a bundle of nerves that control sensation and movement of the arm).
Causes, incidence, and risk factors
Brachial plexus dysfunction (brachial plexopathy) is a form of peripheral neuropathy. It occurs when there is damage to the brachial plexus, an area where a nerve bundle from the spinal cord splits into the individual arm nerves.
Damage to the brachial plexus is usually related to direct trauma to the nerve, stretch injury, pressure from tumors in the area of the brachial plexus, or damage that results from radiation therapy (therapy for some forms of cancer, such as lung cancer).
It may be related to congenital abnormalities that cause pressure on the cervical (neck) ribs and may also sometimes be associated with exposure to toxins, chemicals, or drugs.
Rarely, it is caused by an inflammatory condition. In some cases, no cause can be identified. The mechanical factors (pressure) may be complicated by ischemia (lack of oxygen caused by decreased blood flow) in the area.
- Shoulder pain
- Numbness of the shoulder, arm, or hand
- Tingling, burning, pain, or abnormal sensations whose location varies with the part of the plexus injured
- Weakness (decreased muscle strength, independent of exercise) of the arm, hand, or wrist. o Inability to extend or lift the wrist (wrist drop) o Hand weakness
- Horner’s syndrome (eye drooping, small pupil, and decreased sweating in the face) - possibly caused by a lung tumor compressing the plexus
Signs and tests
Neuromuscular examination of the arm, hand, and wrist indicates brachial plexus dysfunction. Reflexes may be abnormal in the arm. Specific muscle losses may indicate the portion of the brachial plexus that has been damaged.
Variable deformities may develop in the arm or hand, and loss of muscle mass (atrophy) may be profound. Detailed history may be needed to determine the possible cause of the problem.
Tests that reveal brachial plexopathy may include:
- Nerve conduction test and electromyography (NCS/EMG), which is a recording of the electrical activity of nerves and muscles
- Nerve biopsy - indicating systemic diseases that may affect the brachial plexus
Tests are guided by the suspected cause of the dysfunction, as suggested by the history, symptoms, and pattern of symptom development. They may include various blood tests, x-rays, scans, or other tests and procedures.
Treatment is aimed at maximizing independence. The cause should be identified and treated as appropriate. In some cases, no treatment is required and recovery is spontaneous.
If there is no history of trauma to the area, conservative treatment may be tried for patients who experienced sudden onset of symptoms, minimal sensation changes, no movement difficulties, and no evidence of nerve fiber loss on NCS/EMG.
Potent anti-inflamatory drugs (steroids) may be recommended for cases that are caused by inflammatory lesions, such as brachial amyotrophy and brachial neuritis.
Surgery may be necessary if the disorder is long-lasting, symptoms worsen, difficulty with movement is profound, or there is evidence of nerve fiber loss. Surgical decompression (removal of lesions that press on the nerve) may help some patients.
Common painkillers, like acetaminophen, aspirin, and ibuprofen may be insufficient to control pain (neuralgia). Various other medications may be used to reduce the stabbing pains that some people experience, including antiseizure medications such as phenytoin, carbamazepine, and gabapentin. Tricyclic antidepressants, such as amitriptyline, may also provide pain relief.
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 in order to make sure all options for pain treatment are considered.
Physical therapy exercises to maintain muscle strength may be appropriate for some people. Orthopedic assistance with different aids (such as braces, splints, or other appliances) may maximize the ability to use the arm.
Vocational counseling, occupational therapy, occupational changes, job retraining, or similar interventions may be recommended in some cases.
The probable outcome is variable depending on the cause. Recovery takes several months and may be incomplete. Nerve pain may be quite uncomfortable and may persist for a prolonged period of time.
- Partial or complete arm paralysis
- Partial or complete loss of sensation in the arm, hand, or fingers
- Recurrent or unnoticed injury to the hand or arm due to diminished sensation
- Deformity of the hand or arm, mild to severe, which can lead to contractures
Calling your health care provider
Call your health care provider if you experience pain, numbness, tingling or weakness in the shoulder, arm, or hand.
Prevention is varied, depending on the cause.
by Harutyun Medina, M.D.