Brachial plexus neuropathy (BPN) occurs when nerves in your upper should area become damaged and cause severe pain in your shoulders or arms. BPN may also limit movement and cause decreased sensation in these areas.
The pain associated with BPN generally occurs suddenly and may be followed by weakness in a specific muscle of the arm or shoulder. Its presentation may be misleading, so BPN can sometimes be misdiagnosed as cervical disc herniation. In addition, BPN is an uncommon condition.
Causes of BPN
BPN is a type of peripheral neuropathy, which refers to damage to a single nerve or a set of nerves. With BPN, it is the brachial plexus—an area where nerves from the spinal cord branch into the arm nerves—that is damaged. The nerves of the brachial plexus run from you lower neck through your upper shoulders.
Damage to the brachial plexus usually results from direct injury. Birth trauma and other stretching injuries, pressure from tumors, and damage from radiation therapy are common culprits.
Brachial plexus neuropathy may be associated with:
- birth defects
- exposure to toxins
- inflammatory conditions
- immune system issues
There are also numerous cases in which no direct cause can be identified.
BPN Risk Factors
There are no specific risk factors associated with BPN. However, young men are more likely than women and older men to develop a rare brachial plexus condition known as Parsonage-Turner syndrome, which can cause shoulder paralysis.
Symptoms of BPN
BPN can cause numbness in your shoulder, arm, and hand. Severe cases can cause complete loss of sensation. This numbness can cause additional complications related to recurring injury to the affected areas. These complications could go unnoticed due to an inability to detect pain.
Sometimes BPN can cause abnormal sensations such as tingling and burning on or near nerves related to the brachial plexus. These types of sensations generally occur in your arm and hand.
A decreased ability to lift your wrist or extend it backward is a common way for BPN to manifest. Weakness in your hands may also indicate BPN.
Horner syndrome is rare, but it can indicate BPN. Horner syndrome results from an interruption in the nerve signals that control regions of the facial area. It is usually caused by an injury to the nerves of the brachial plexus. Symptoms of Horner syndrome are:
- constriction of the pupil (it becomes very small)
- eyelid drooping
- inability to sweat (affected facial area)
Your doctor will examine your arm, hand, and wrist to diagnose nerve issues involving the brachial plexus. Some signs of these issues may include:
- arm deformities
- hand deformities
- diminished reflexes in the arm
- muscle wasting or atrophy (decreased size or strength)
- inability to flex the hand
- difficulty in moving the arm, shoulder, hand, and fingers
Your physician will also focus on obtaining a detailed medical history to determine the cause of BPN.
Your doctor may order certain tests to diagnose the condition. These tests may include:
- blood tests
- chest X-rays
- electromyogram (to test the function of muscles and related nerves)
- magnetic resonance imaging (MRI) of the head, shoulder, or neck
- nerve biopsy (a piece of a nerve is removed for analysis)
- nerve conduction tests (to determine how impulses are traveling through a nerve)
BPN treatment is focused on correcting any underlying causes and allowing for optimum range of motion. In many cases, no treatment is needed due to spontaneous recovery.
Taking over-the-counter medications generally controls the pain. Your doctor may also prescribe anticonvulsants, tricyclic antidepressants, and other medications.
Your doctor might recommend physical therapy to help you maintain muscle strength. Orthopedic assistance may also increase range of motion. This type of therapy usually involves using braces, splints, or other similar aids.
If nerve compression is causing your symptoms, surgery may be necessary. Underlying medical conditions such as diabetes and kidney disease may also need to be treated as these diseases can adversely affect nerves.
BPN and the Workplace
Sometimes the injury that causes BPN happens on the job. To get back to work and prevent further nerve damage, vocational counseling, occupational therapy, retraining, or vocational changes might be recommended.
Your outcome largely depends on the cause of your BPN. A positive recovery is possible if the cause is identified and treated properly. Sometimes there can be partial or complete loss of sensation. Range of motion can also be permanently limited. Nerve pain could be severe and persist for a long period of time.
Prevention methods are varied, according to the condition that caused brachial plexus neuropathy.