Parsonage-Turner syndrome — also called brachial neuritis, brachial neuralgia or neuralgic amyotrophy — is a neurological disorder that causes severe pain followed by lasting damage to the nerves and muscles. It usually affects the nerves of the brachial plexus in the shoulder, though any nerve can be involved. We think the immune system triggers it, often after a common viral infection such as a cold. So what is Parsonage-Turner syndrome, and what does it mean for someone affected? 

brachial plexus picture

Symptoms of brachial plexus neuritis 

The condition starts with severe pain in the shoulder or upper arm. Over the following days to weeks, wasting and weakening of the affected muscles follow.

Symptoms usually occur in two phases: an acute phase and a chronic phase.

The acute phase

The pain is usually one-sided, affecting the shoulder, arm, and neck. It varies — sharp, burning, or throbbing — but is almost always severe, and pins and needles or numbness sometimes accompany it. This phase lasts anywhere from hours to weeks.

The chronic phase

Once the acute pain settles, lasting damage to the muscles and nerves shows itself. People notice a gradual loss of strength and muscle wasting, ranging from a barely noticeable weakness to gross wasting of the shoulder muscles and severe loss of power.

Muscle damage and wasting around the shoulder can sometimes lead to a frozen shoulder. In more severe cases, the circulation is affected, causing swelling and discolouration of the skin, excessive sweating, and cold hands and fingers.

Causes of Parsonage-Turner syndrome

We still don’t know exactly why neuralgic amyotrophy occurs. We think various environmental factors trigger an immune response that inflames the nerves. Recognised triggers include infections, immunisations, surgery, and childbirth.

How do we diagnose brachial plexus neuritis?

We diagnose it from the clinical picture, supported by tests such as MRI and nerve conduction studies. Tests are often normal in the acute phase, before the muscle weakness and wasting begin.

It’s essential to rule out other causes of nerve pain and muscle wasting — a bulging disc in the neck, peripheral neuropathy, or other causes of nerve inflammation.

MRI in Neuralgic amyotrophy

MRI of the arm and brachial plexus helps identify the nerve damage, shows which muscles are affected, and rules out other causes of shoulder and arm pain. Occasionally, pain and muscle wasting arise from a nerve growth or tumour, which MRI helps exclude.

Nerve studies, such as EMG, identify the extent and site of nerve and muscle damage. Sometimes we add X-rays or blood tests to exclude other problems.

Brachial neuritis or radiculitis: how to tell them apart

A disc bulge in the neck often triggers radiculitis — inflammation of the nerve roots — and it presents differently. People with radiculitis usually have neck pain shooting down the arm into the hand, with weakness but no significant wasting, and neck movement typically brings on the symptoms. In Parsonage-Turner syndrome, the severe pain comes first and is followed by the striking muscle wasting that sets it apart.

Parsonage-Turner syndrome treatment

Treatment aims to relieve the acute symptoms and restore muscle function.

For the acute pain, we may use painkillers such as ibuprofen or codeine. Physiotherapy relieves pain in the muscles and joints, and hot and cold compresses and a TENS machine can help. For longer-lasting nerve pain, neuropathic medications such as amitriptyline help.

Physiotherapy for Parsonage-Turner syndrome

Intensive exercise therapy is the mainstay, stimulating nerve function and restoring muscle activity. People start with exercises to regain shoulder and arm movement, then progress to strengthening to rebuild muscle bulk. Recovery is gradual, and patience is important.

Frequently asked questions about brachial neuritis

Is there a cure for Parsonage-Turner syndrome?

There’s no specific cure, but the outlook is generally good. Most people — around 85–90% — regain strength and function over many months. That leaves about 10–15% with ongoing pain and loss of shoulder function, and in some of these cases surgery to repair affected tendons or nerves is considered.

Can Parsonage-Turner syndrome recur?

Yes. The recurrence rate is around 25%, and it often occurs on the other side or in a different limb.

Can the COVID or flu vaccine cause Parsonage-Turner syndrome?

It can act as a trigger. We suspect that immunisations, like viral infections, can set off the immune response behind the condition. It remains uncommon, and the pattern — severe shoulder pain followed by weakness — is what prompts assessment.

How long does recovery take?

Recovery is slow, usually measured in months rather than weeks, and sometimes up to two to three years for full strength to return. The acute pain settles first, then strength and muscle bulk rebuild gradually with exercise therapy.

Are there treatments to speed up healing?

There are no proven active treatments that accelerate recovery. Some doctors use immunoglobulin, with mixed results. The evidence-based mainstay remains pain control in the acute phase and progressive exercise therapy through the recovery.

How is it different from a frozen shoulder or a rotator cuff tear?

All three cause shoulder pain and restricted use. The distinguishing feature of Parsonage-Turner syndrome is the sequence — sudden, severe pain followed by muscle wasting and true weakness, rather than the stiffness of a frozen shoulder or the specific weakness of a rotator cuff tear. Nerve studies and MRI confirm it.

Final word from Sport Doctor London about brachial neuritis

Parsonage-Turner syndrome is an important cause of severe shoulder pain followed by weakness and muscle wasting. It is also called brachial neuritis or neuralgic amotrophy. Because it mimics other shoulder and neck conditions, it’s essential to see a doctor experienced in diagnosing it and excluding the alternatives. The outlook is good for most people, though recovery takes time.

If you have severe shoulder or arm pain, particularly followed by weakness, Dr Masci can assess you in London, including ultrasound in clinic. Contact the team here or call +44 (0) 203 488 0350.

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