How is Brachial Neuritis Diagnosed?

Jan 17, 2025

Brachial neuritis, also known as Parsonage-Turner syndrome, is a rare neurological condition characterized by sudden onset of shoulder and arm pain followed by weakness in the affected limb. The diagnosis of brachial neuritis can be complex due to its similarity to other conditions affecting the brachial plexus, a network of nerves that controls movement and sensation in the arm. This blog will explore the diagnostic process for brachial neuritis, including patient history, physical examination, imaging studies, and electrodiagnostic tests.

Understanding Brachial Neuritis

Brachial neuritis typically presents with acute pain in the shoulder or upper arm, which may last from days to weeks. Following this painful phase, patients often experience weakness or paralysis in the affected arm. While the exact cause of brachial neuritis is not fully understood, it may be associated with viral infections, vaccinations, or physical trauma. Understanding this condition's symptoms and progression is crucial for accurate diagnosis and effective treatment.

Initial Steps in Diagnosis

Patient History

The first step in diagnosing brachial neuritis involves a thorough patient history. Healthcare providers will ask about:

• Symptom Onset: When did the pain start? Was it sudden or gradual?
• Nature of Pain: Is the pain sharp, dull, constant, or intermittent?
• Medical History: Any recent illnesses, vaccinations, or injuries that might relate to nerve damage?
• Family History: Any family members with similar neurological conditions?

This information helps clinicians determine whether the symptoms align with brachial neuritis or suggest another condition.

Physical Examination

Following the patient history, a physical examination is conducted. The physician will assess:

• Range of Motion: Testing how well the patient can move their shoulder and arm.
• Strength Testing: Evaluating muscle strength in various parts of the arm.
• Reflexes: Checking reflex responses to determine nerve function.
• Palpation: Feeling for any abnormalities in the neck, shoulder, and arm areas.

This examination helps identify any signs of nerve involvement and guides further diagnostic testing.

Imaging Studies

If brachial neuritis is suspected based on history and physical exam findings, healthcare providers may recommend imaging studies to rule out other potential causes of symptoms.

Magnetic Resonance Imaging (MRI)

An MRI scan provides detailed images of soft tissues, including nerves and muscles. While an MRI cannot definitively diagnose brachial neuritis, it can reveal other issues such as:

• Herniated discs
• Tumors
• Other structural abnormalities

In cases of acute brachial neuritis, MRI may show denervation changes within days of symptom onset. High signal intensity on T2-weighted images can indicate neurogenic edema in affected muscles.

Computed Tomography (CT) Myelography

For patients unable to undergo MRI due to medical reasons or lack of access, a CT scan with myelography may be performed. This test uses contrast dye to provide images of the spinal cord and nerve roots but is less detailed than MRI regarding soft tissue evaluation.

Electrodiagnostic Tests

Electrodiagnostic tests are crucial for confirming a diagnosis of brachial neuritis. These tests measure electrical activity in nerves and muscles.

Nerve Conduction Studies (NCS)

A nerve conduction study assesses how quickly electrical signals travel through a nerve. Abnormal results can indicate where nerve damage has occurred. This test is typically performed at least three weeks after symptom onset to ensure reliable results.

Electromyography (EMG)

Electromyography involves inserting a needle electrode into muscles to measure their electrical activity during contraction and at rest. EMG can help identify muscle denervation patterns characteristic of brachial neuritis. Abnormal findings may include spontaneous fibrillations and positive waves in affected muscles. Both NCS and EMG are often performed together to provide comprehensive insights into nerve function and help differentiate brachial neuritis from other conditions like cervical radiculopathy.

Differential Diagnosis

Accurate diagnosis is critical as several conditions can mimic the symptoms of brachial neuritis. Conditions that need to be differentiated include:

• Cervical Radiculopathy: Nerve root compression often due to herniated discs.
• Rotator Cuff Injuries: Tears or strains that can cause shoulder pain.
• Peripheral Neuropathy: Damage to peripheral nerves from various causes.

A careful assessment combining patient history, physical examination findings, imaging studies, and electrodiagnostic tests helps ensure an accurate diagnosis.

Conclusion

Diagnosing brachial neuritis requires a comprehensive approach that includes gathering detailed patient history, conducting thorough physical examinations, utilizing advanced imaging techniques like MRI or CT scans, and performing electrodiagnostic tests such as EMG and NCS. Early diagnosis is vital for effective treatment planning and management of this condition.

If you are experiencing symptoms consistent with brachial neuritis or have concerns about your nerve health, it’s essential to seek professional medical advice. At Southern California Brain & Spine Surgery, our team specializes in diagnosing and treating complex neurological conditions. We provide personalized care tailored to your needs.