From the Research
Diagnosing Parsonage-Turner syndrome requires a combination of clinical evaluation, patient history, and diagnostic tests, with a focus on recognizing the characteristic presentation of sudden, severe shoulder and upper arm pain that typically evolves into weakness and muscle wasting, as noted in the most recent study 1. The diagnosis begins with a thorough neurological examination, focusing on muscle strength, reflexes, and sensory function in the affected limb.
- Electromyography (EMG) and nerve conduction studies are essential diagnostic tools, typically showing denervation in affected muscles and abnormal nerve conduction, as seen in studies 2, 3.
- MRI of the brachial plexus may help rule out other conditions and sometimes shows inflammation or edema in the affected nerves.
- Blood tests should be ordered to exclude other conditions and identify potential triggers, including complete blood count, inflammatory markers, and tests for autoimmune disorders. A detailed patient history is crucial to identify potential triggers such as recent infections, vaccinations, or surgeries, as highlighted in 4, 5. The diagnosis is often clinical, as there is no single definitive test, and it may take time to establish, particularly in the early stages when symptoms can mimic other conditions like rotator cuff injuries or cervical radiculopathy. Key considerations include:
- Differentiating Parsonage-Turner syndrome from cervical radiculopathy, as emphasized in 5
- Utilizing quantitative muscle MRI (qMRI) to quantify serratus anterior muscle neurogenic changes, as discussed in 1
- Recognizing the importance of early diagnosis and treatment to improve outcomes, as noted in 3.