Parsonage-Turner Syndrome - Causes, Symptoms, Diagnosis, and Treatment

Introduction

PTS (Parsonage-Turner syndrome) is a rare neurological disorder characterized by a sudden onset of severe pain in the shoulder and arm. Each year, up to three people per 100,000 develop Parsonage-Turner syndrome. It affects men more than women. Young to middle-aged adults are more likely to contract it, but young children and the elderly have also been reported to have it.

What Is Parsonage-Turner Syndrome?

Parsonage-Turner syndrome, also known as brachial neuritis, is distinguished by the sudden onset of shoulder and upper arm pain, followed by significant upper arm weakness or atrophy. Individuals with the condition may present several weeks after an injury, infection, or immunization or in the absence of a clear inciting event. Symptomatic treatment may include pain relievers and physical therapy. Although affected individuals may experience paralysis of the affected areas for months or even years, the prognosis is generally favorable, with most people recovering completely within two years.

The pain is experienced along the path of a single or more nerves and is frequently unrelated to a physical cause. The brachial plexus is a complex nerve network. It begins at the spinal cord and runs down the side of the neck behind the collarbone to the arm like a braid. Brachial plexus nerves control the shoulder, arm, forearm, elbow, wrist, and hand movement and carry sensation (feeling) from the arm to the spinal cord. Damage to these nerves causes muscle weakness. Parsonage-Turner syndrome is often misdiagnosed as cervical spondylosis or cervical radiculopathy.

What Causes Parsonage-Turner Syndrome?

In most cases, the pain in the shoulder or arm comes on suddenly, often in the middle of the night. It is incisive and intense. The severe pain can last anywhere from a few hours to four weeks. The muscles in the arm on that side will become weak within 24 hours of the pain beginning or a few weeks later.

Weakness is most commonly felt in the shoulder or upper arm, but it can also occur in the forearm or hand. The shoulder blade, chest wall, and diaphragm muscles are occasionally affected. Leg and cranial (head) muscle involvement have been reported on rare occasions. In addition, muscle tissue can be lost over time when the muscles are weak. This is referred to as atrophy. Many people also lose sensation in their arms.

The exact cause of Parsonage-Turner syndrome is unknown. There are, however, several theories, including:

• Approximately 25 % of people report having a virus or infection just before developing Parsonage-Turner syndrome. It is unclear whether the virus or infection caused the syndrome. There have been a few reports of Parsonage-Turner syndrome following a COVID-19 infection.

• Approximately 15 % of cases occurred following vaccination.

• Injuries, such as a motorcycle accident or a football injury can result in shoulder trauma.

• Cancerous cells.

• Immunizations or a compromised immune system.

• Lumbar puncture (spinal tap).

• Recent surgery, childbirth, or radiotherapy.

• Infection with parasites.

• Rheumatologic and autoimmune diseases.

• Heroin use.

Parsonage-Turner syndrome could also be inherited.

What Are the Different Kinds of Parsonage-Turner Syndrome?

Parsonage-Turner syndrome occurs in two stages. The acute phase is the first. This is the worst part of the pain. The second period, known as the chronic phase, has less pain. Parsonage-Turner syndrome is caused by genetic factors in a small percentage of patients (hereditary neuralgic amyotrophy).

What Are the Signs and Symptoms of Parsonage-Turner Syndrome?

As people differ, similarly the severity, location, and the duration of pain and weakness will not be the same. The symptoms of Parsonage-Turner syndrome include;

• Sudden sharp, aching, burning, or stabbing pain (gradual in some cases).

• Pain in one shoulder (sometimes in both shoulders). Pain in the neck, arm, and hand may also be present on the same side of the affected shoulder. The ache in the legs is rare.

• The pain is worse in the evenings or at night. Pain can range from mild to unbearable and incapacitating.

• Shoulder muscle twitching (days or weeks after the initial pain). The weakness can be mild, severe, or almost paralyzing (this is rare).

• Reflex difficulties.

• Numbness or loss of sensation. Tickling, prickling, or burning sensation.

• Partial dislocation of the shoulder joint, leading to restricted movement. Winged scapula (a condition where the shoulder blade sticks out).

• Muscles or tendons are shortened.

• Breathing difficulty (rare).

• Sweating excessively.

• Red, purple, or spotted hands.

• Swelling.

How Is Parsonage-Turner Syndrome Diagnosed?

PTS is diagnosed by identifying characteristic symptoms, patient history, a thorough clinical evaluation, and many specialized tests.Certain tests, such as nerve conduction studies or electromyography, can be used to evaluate the health of muscles and the nerves that control them.

• Nerve conduction studies assess the ability of specific peripheral nervous system nerves to relay nerve impulses to the brain. During a nerve conduction study, electrodes are placed over specific nerves, such as those in the shoulders and arms. The electrodes stimulate the nerves and record the signal conduction. This test can assist in determining the location of nerve disease or injury.

• Electromyography involves inserting a tiny needle electrode through the skin into an affected muscle. The electrode records the electrical activity of the muscle. This record demonstrates how well a muscle responds to nerves and can be used to determine whether muscle weakness is because of the muscles themselves or by the nerves that control those muscles.

• Magnetic resonance imaging (MRI), a specialized imaging technique, can aid in diagnosing PTS. An MRI creates cross-sectional images of specific organs and bodily tissues using a magnetic field and radio waves. In addition, an MRI can help to rule out other potential causes of shoulder pain, demonstrate muscle atrophy, and detect signal changes caused by a lack of nerve supply (denervation).

• A traditional X-ray of the shoulder may be advised to rule out specific conditions that can impact the shoulder.

How Is Parsonage-Turner Syndrome Treated?

Experts have yet to discover a cure for Parsonage-Turner syndrome. However, some treatments that may be beneficial include:

• Painkillers are being used to alleviate the pain. When the problem first appears, the pain is excruciating. Pain medications include tricyclic antidepressants, Duloxetine, and Gabapentin. In the early stages, steroid medications such as Prednisone may be considered. As the months pass, the pain lessens.

• The doctor may recommend three to eight weeks of physical and occupational therapy. This can improve one's range of motion and help maintain strength.

• TENS (transcutaneous electrical nerve stimulation) may reduce pain by altering or blocking nerve transmissions.

• Surgery is considered after all other treatments have failed. One may need a nerve graft or a tendon transfer. A nerve graft is a procedure in which the surgeon uses nerve tissue from another part of the body to repair damaged nerves. Similarly, a tendon transfer is when a healthy tendon from another body part is removed to replace a damaged tendon, like a shoulder tendon.

Conclusion

Parsonage-Turner syndrome is characterized by severe weakness and sudden, intense pain. Both pain and weakness can have a negative impact on the quality of life. A healthcare provider must be consulted if one gets pain in the shoulder and arm to start treatment at the earliest. Parsonage-Turner syndrome is usually managed by physical and occupational therapy along with pain reliving medications, or severe cases are treated by surgical intervention.