If brachial neuritis is suspected, it is important to get an accurate diagnosis in order to begin a treatment plan that offers effective pain relief, education about the condition, and emotional support for what could be a long recovery period. The process of diagnosing brachial neuritis typically involves a patient history and physical exam. More complicated cases may also require imaging studies and electrodiagnostic tests.
Patient History and Exam
The first two steps to diagnosing the cause of shoulder and/or arm pain include:
- Patient history. Information is collected about the patient’s medical history, family history, known conditions, recent illnesses or accidents, lifestyle, how/when symptoms started, and how symptoms feel now.
- Physical exam. The doctor may palpate (feel along) the neck, shoulder, and arm for any abnormalities, as well as check range of motion, strength, and reflexes.
If the patient history and physical exam suggest that the problem may be brachial neuritis or another condition that involves the nerves, imaging studies and diagnostic tests may be required for further evaluation.
A magnetic resonance imaging (MRI) scan gives an especially good view of the soft tissues, such as nerves, discs, ligaments, and muscles. While an MRI cannot diagnose brachial neuritis, it can help rule out other possibilities. For example, an MRI might show a herniated disc that corresponds to the patient’s symptoms, which would mean that the symptoms are more likely to be cervical radiculopathy than brachial neuritis.
Some patients may not be able to have an MRI due to medical reasons or lack access to one, in which case a CT scan with myelography might be ordered instead. A CT scan with myelography gives a better view of bones but may not be quite as detailed at showing the nerves and other soft tissues.
Two electrodiagnostic tests that are typically performed together to check for brachial neuritis and other nerve conditions include:
- Nerve conduction study. This test measures how fast an electrical signal travels through a nerve. If an abnormal reading is found, it may help pinpoint more specifically where the nerve damage has occurred.
- Electromyography (EMG). This test can help determine how nerves perform in the actual muscle. This test may be especially important for diagnosing brachial neuritis because it may show an abnormality in the muscle that is not detected by a nerve conduction study.
Electrodiagnostic testing for brachial neuritis is typically performed at least 3 weeks after the onset of symptoms in order to obtain more reliable results. Performing electrodiagnostic testing too soon after symptom onset may give results that do not fully encompass the nerve damage process.