What is Parsonage-Turner Syndrome

Parsonage-Turner Syndrome, also known as Neuralgic Amyotrophy, is a rare neurological disorder characterized by the sudden onset of severe shoulder or arm pain followed by muscle weakness and atrophy. While the initial pain typically resolves within a few weeks, the resulting nerve damage and muscle wasting can persist for months or even years as the affected nerves slowly regenerate.

What is Parsonage-Turner Syndrome and how does it affect the body?

Parsonage-Turner Syndrome primarily affects the brachial plexus, a complex network of nerves that sends signals from the spinal cord to the shoulder, arm, and hand. The condition typically follows a distinct two-phase clinical course: an acute phase marked by intense, often debilitating pain, followed by a secondary phase of progressive muscle weakness, sensory loss, and muscle wasting (atrophy) in the upper extremities. Because the nerves controlling the shoulder girdle are most commonly involved, patients often experience difficulty lifting their arm or performing routine tasks like brushing their hair or reaching overhead.

Who is typically affected by Parsonage-Turner Syndrome?

The estimated incidence of Parsonage-Turner Syndrome is approximately 1 to 3 per 100,000 individuals, though it is likely underdiagnosed. It can affect people of all ages, but clinical data suggests it most commonly presents in adults between the ages of 30 and 50. There is a noted gender disparity, with men being affected approximately 2 to 4 times more often than women. Currently, there are 160 individuals in the DiseaseMaps.org community who have shared their experiences with this condition, highlighting the importance of peer support for those navigating this rare diagnosis.

What causes this condition and is it hereditary?

While the exact cause of Parsonage-Turner Syndrome remains a subject of ongoing research, it is widely considered an immune-mediated disorder. In many cases, it is triggered by an antecedent event, such as a viral infection, immunization, surgery, or strenuous physical activity. This trigger is believed to cause the body's immune system to mistakenly attack the nerves of the brachial plexus. While most cases are sporadic, a rare hereditary form known as Hereditary Neuralgic Amyotrophy (HNA) exists, which is linked to mutations in the SEPT9 gene.

Key facts that differentiate Parsonage-Turner Syndrome from other conditions

Distinguishing Parsonage-Turner Syndrome from other musculoskeletal or neurological issues is vital for proper management. Key features that help clinicians differentiate it include:

• Sudden Onset: The pain usually begins abruptly, often at night, and is disproportionate to any physical activity.


• Localized Weakness: Unlike a pinched nerve in the neck (cervical radiculopathy), the weakness in Parsonage-Turner Syndrome is often patchy and involves multiple nerves in the shoulder girdle.


• Pain Resolution: A hallmark of the condition is that the severe, sharp pain typically subsides just as the muscle weakness and atrophy become most apparent.


• Diagnostic Imaging: High-resolution MRI of the brachial plexus can often reveal characteristic nerve swelling (hyperintensity) that is specific to this condition.

Next steps

• Consult a neurologist or a physiatrist (physical medicine and rehabilitation specialist) to confirm your diagnosis via electromyography (EMG) or nerve conduction studies.


• Focus on physical therapy to maintain range of motion in the affected joints while the nerves heal.


• Connect with the 160 members of the DiseaseMaps.org community to share coping strategies and insights.


• Keep a detailed symptom diary to track the progression of pain and muscle recovery to share with your clinical team.

Medical disclaimer: This content is for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment; always seek the advice of your physician with any questions regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Neuralgic Amyotrophy.


• Orphanet: Parsonage-Turner syndrome (ORPHA:2634).


• OMIM (Online Mendelian Inheritance in Man): Neuralgic Amyotrophy, Hereditary (Entry #162100).


• National Institute of Neurological Disorders and Stroke (NINDS): Brachial Plexus Injuries Information Page.