Parsonage Turner Syndrome

WRITTEN BY: GAJURRI SRIKUMAR CLASS OF 2028

This blog addresses PTS, which is a rare neurological condition that causes pain and loss of muscle control in the shoulder or arm. Medicines and therapies help in reducing the pain and in improving the condition. It is mostly a curable syndrome where recovery can take from 1 to 3 years.

Let’s begin with a simple question, What is a syndrome? Simply, a syndrome can be defined as a group of signs and symptoms that occur together and characterize a particular abnormality or condition. Syndromes are differentiated from diseases on the basis of where, disease is a health condition having a clear reason (established condition) behind it where syndromes as mentioned above refers to a group of symptoms. In this article we’ll be looking into a rare neurological syndrome called the Parsonage Turner Syndrome.

WHAT IS PARSONAGE TURNER SYNDROME?

Parsonage Turner Syndrome, also known as Brachial neuritis is a form of peripheral neuropathy that affects the nerves going to the chest, shoulder, arm and hand. It is a neurological condition characterized by a rapid onset of severe pain in your shoulder and upper arm due to weakening of muscles. The pain can last from a few days to several months. Most people (70% to 90%) make a good recovery over two to three years. This condition is due to damaging of brachial plexus, which is a network of nerves that go from your spine through your neck, into both of your armpits and then down the arms

Parsonage Turner Syndrome mainly affects motor nerves and axons that are responsible for controlling movement and thus leading to muscle weakness. PTS is a rare condition where up to 3 people per 100,000 get PTS each year.

PHASES OF PARSONAGE TURNER SYNDROME

PTS comprises of three phases.

Phase 1: This is the acute pain phase. This phase involves severe and sudden pain that affects the shoulder. This phase can last from a few days to few weeks. Longer this phase, longer it takes to recover.

Phase 2: Once the pain starts to ease, weakening of muscles develop leading to muscle atrophy. This phase typically lasts 6 to 18 months, but can last longer too.

Phase 3: After a period, muscles regain strength and functionality.

What are the symptoms of Parsonage Turner Syndrome?

As mentioned above, sudden pain and subsequent muscle weakness happens to be the main symptoms of PTS. In 80% of cases it only affects one arm (unilateral), whereas in the remaining 20%, it affects both the arms (bilateral).PTS can also affect our lower trunk. Weakening of shoulder muscles can also affect the function of chest or diaphragm.

Although muscle pain happens to be the common symptom here, severity of symptoms can vary from one individual to another due to the specific nerves affected by this syndrome. Some of those symptoms are: Lack of muscle control in the shoulder or arm, Numbness, Swelling of hand, Red or spotted hands due to poor circulation, Partial shoulder dislocation and Shortening of muscles or tendons in the affected arm.

What causes Parsonage Turner Syndrome?

Even though the exact cause of PTS is not known yet, scientists believe that an abnormal reaction of our immune system happens to be the main cause.

The following 2 reasons were put forward by scientists for causing PTS:

1) Parasitic, bacterial or viral infections directly affecting the brachial plexus.

2) Immune system directly attacking antigens causing the damage of brachial plexus.

And also recent viral infections due to viruses like HIV, Coxsackie B virus and Parvovirus B19 can trigger PTS in human body.

Diagnosing PTS: First, a physical exam is conducted

Later on electromyography (EMG) is recommended by the doctor to the patient, if the doctor believes that the patient might be suffering from PTS. Electromyography is a test conducted to figure out the functioning of skeletal muscles and nerves supplying them. Other tests include Nerve Ultrasound, Computed tomography scan and Magnetic Resonance Imaging (MRI).

MRI is pretty much sensitive in detecting signal abnormalities in the muscles of the shoulder girdle of patients with PTS. In a study conducted between the years of 1997 and 2005, 26 patients affected by PTS were diagnosed by the help of MRI.

In the study it was concluded that brachial plexus and shoulder in patients showed intramuscular denervation changes involving one or more muscles of the shoulder girdle, with supraspinatus and infraspinatus muscles to be affected the most. And thus it was concluded that MRI could be used in accurately diagnosing the syndrome.

Risk factors for developing PTS: Risk factors for developing PTS include: Vaccines, Radiation therapy, Pregnancy, Shoulder injury, Anesthesia and Autoimmune conditions like Lupus and Polyarteritis Nodosa.

TREATMENT

Even though there is no any specific treatment for this syndrome yet, early diagnosis and care by a group of specialists including Neurologists, Physical therapists, Orthopaedists, Primary care physicians and Neuromuscular disease specialists can help in recovering from this syndrome as early as possible.

Before physical therapy is recommended to patients, doctors evaluate the pain levels, shoulder strength and nerve function of the patient. Once the above mentioned factors are accessed, a physical therapy program is designed for the patient.

Therapies for phase 1 of PTS include: Acupuncture, Oral corticosteroids (Glucocorticoids can be given to reduce inflammation of the nerve), Transcutaneous electrical nerve stimulation and immobilizing arm by limiting use of it or using a shoulder stabilizer. Pain medications (pregabalin, gabapentin), antidepressant medicines and anti-seizure medicines can be used for relief from nerve related pain.

Therapies for phase 2 and 3 of PTS include: Physical therapy and Co- analgesics.

In case of severe cases, surgical methods such as nerve grafting or tendon transfers may include.

How to prevent Parsonage Turner Syndrome?

Since the exact cause of PTS is not known, there is nothing that can be done to prevent it. Staying as healthy as possible by protecting our immune system, avoiding arm and shoulder injuries may help lower the chances of getting PTS.