June 05, 2025
A little more than 75 years ago, British neurologists Maurice Parsonage and Aldren Turner encountered 136 World War II soldiers experiencing some puzzling symptoms — rapid-onset, severe shoulder and arm pain, followed by progressive, disabling weakness and muscle atrophy. Dr. Parsonage and Dr. Turner termed the condition brachial neuralgic amyotrophy. Although they weren't the first to describe it, their detailed observations provided new insight into this painful disorder.
Today, clinicians and researchers refer to this rare condition as either Parsonage-Turner syndrome (PTS) or neuralgic amyotrophy. To mark the 75th anniversary of the original description of PTS, Mayo Clinic researchers published a review article in Mayo Clinic Proceedings in 2024. The article provides updated information about PTS and its genetic counterpart, hereditary brachial plexus neuropathy (HBPN).
Although the cause or trigger for these attacks is still unclear, some associations, including prior viral infection, surgeries, trauma, vaccination and childbirth, have been identified. According to the lead author of the review article, James B. Meiling, D.O., clinicians have significantly shifted their approach to diagnosis and management of these conditions over the past decade. Dr. Meiling is a neuromuscular physiatrist and researcher at Mayo Clinic in Rochester, Minnesota.
"While we previously thought that these conditions were a purely isolated and idiopathic injury to the brachial plexus highway of nerves just outside the neck, we are now beginning to consider that they may involve either the brachial plexus or the peripheral nerves themselves as they leave the plexus," says Dr. Meiling.
Clinical presentation
Winged scapula
A winged scapula (left) is reported in 30% to 70% of attacks. Weakness of the serratus anterior muscle can result from a long thoracic nerve injury causing scapular winging (right).
Dr. Meiling and co-authors provide a detailed description of the clinical presentation for PTS and HBPN. These conditions are virtually indistinguishable and typically include the following:
- Rapid onset of asymmetric, "severe," "sharp" or "stabbing" neuropathic shoulder and arm pain, often occurring or worsening at night, accompanied by asymmetric weakness and early muscle atrophy in the shoulder, arm or hand.
- Acute-onset dyspnea that awakens patients from sleep with orthopnea from phrenic nerve involvement.
- A winged scapula, reported in 30% to 70% of attacks, resulting from weakened and atrophic serratus anterior, trapezius or rhomboid muscle from long thoracic, spinal accessory or dorsal scapular neuropathies, respectively.
- Sensory loss, commonly in the shoulder or lateral forearm and frequently occurring in location(s) separate from the area(s) affected by muscle weakness.
- Weakened muscles, initially presenting with decreased tone or flaccidity, that can become stiff and shortened over time (contracture).
Overview of diagnostic tests
Dr. Meiling and co-authors explain that aside from screening for SEPT9 mutations for HBPN, there are currently no laboratory tests exclusively specific for PTS and HBPN. Magnetic resonance and nerve ultrasound imaging and electrodiagnostic testing can be useful and help prevent unnecessary shoulder and neck surgeries for mimicking disorders. Diaphragm ultrasound can reveal phrenic nerve involvement, which is common.
Nerve ultrasound
Dr. Meiling has published multiple articles focused on the role of nerve ultrasound in examining neuromuscular conditions. "Nerve ultrasound is what helped the medical community discover that neuralgic amyotrophy does not involve a process isolated to the brachial plexus, but rather one that can occur in the proximal portions of the terminal nerves as they leave the brachial plexus," he says.
In a 2025 publication in the Journal of Clinical Neuromuscular Disease, Dr. Meiling and co-authors described how nerve ultrasound provides evidence that in some cases only individual pieces or fascicles of the nerves are involved, rather than the entire nerve.
"The new term 'fasciculopathy' is one that we introduced into the literature to describe an injury or damaged fascicle of a nerve," says Dr. Meiling. "In neuralgic amyotrophy, these fascicles can become enlarged and entwined. This can lead to partial or complete torsion of the entire nerve or, in rare instances, to the previously described 'hourglass constrictions' of the nerve. These occurrences typically indicate a poorer prognosis for recovery. As ultrasound technology continues to improve and allow better and clearer visualization of the individual nerve fascicles, we may be able to better understand their nature and their piece of the neuralgic amyotrophy puzzle."
Recovery and management strategies
The amount of time it takes to recover from PTS and HBPN can vary. As the neuralgic pain improves over several weeks from onset, it is replaced by aching, deep, more-transient pain that typically resolves over months. However, the co-authors state that some survey data suggests that shoulder pain and fatigue may persist in many.
Management strategies
Dr. Meiling emphasizes that after the initial painful acute phase has completed and the subsequent weakness and atrophy set in, rehabilitation can play a huge role in recovery.
"Physiatrists are key members in the recovery team for individuals with neuralgic amyotrophy. We can provide a range of services, including management of superimposed musculoskeletal injuries, organization of therapies and scapular winging protocols for better stabilization of the shoulder blade."
Dr. Meiling also notes that improving patient outcomes also will require more research focused on motor recovery. "Motor recovery is imperative to sort out, as much of our research on reinnervation and recovery of peripheral nerve injuries comes from the traumatic nerve injury literature," says Dr. Meiling. "We now are pretty sure that neuralgic amyotrophy is an inflammatory immune-mediated condition that behaves differently than physical trauma to a nerve."
Because different mechanisms are involved in neuralgic amyotrophy, Dr. Meiling says that the recovery timelines and the window for reinnervation are also likely to be different from those that occur after traumatic nerve injury. "Further research about the natural progression of reinnervation and the timeline for recovery is needed," says Dr. Meiling.
For more information
Meiling JB, et al. Parsonage-Turner syndrome and hereditary brachial plexus neuropathy. Mayo Clinic Proceedings. 2024;99:124.
Zhitnitsky MD, et al. Neuromuscular ultrasound identification of musculocutaneous fasciculopathies in neuralgic amyotrophy. Journal of Clinical Neuromuscular Disease. 2025;26:119.
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