How Parsonage-Turner Syndrome Is Diagnosed (And Why It’s So Often Missed)

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Adam Foster

Director at The Fibro Guy Ltd

Adam Foster is an award-winning PT, author, and the driving force behind The Fibro Guy. Leveraging his extensive expertise in pain science and neuroscience, along with a profound understanding of the human body, Adam assists individuals suffering from chronic pain and hypermobility. His approach involves using tailored biopsychosocial rehabilitation strategies, aimed at reducing pain and stabilising joints for an improved quality of life.

Latest posts by Adam Foster (see all)

• Parsonage-Turner Syndrome and COVID-19: What the Research Shows - 28 March 2026
• Managing Pain in the Acute Phase of Parsonage-Turner Syndrome - 28 March 2026
• Your Brain After Parsonage-Turner Syndrome: Why Sensory Mapping Matters - 28 March 2026

This article is part of our comprehensive guide to Parsonage-Turner Syndrome.

If you’ve ever been told you have a frozen shoulder, a rotator cuff tear, or a pinched nerve in your neck, only to find that treatment isn’t working and the pain is getting worse, you’re not alone. Parsonage-Turner Syndrome (PTS), also known as neuralgic amyotrophy, is one of those conditions that flies under the radar far more than it should. And when it comes to getting a proper diagnosis, the road can be frustratingly long.

What makes this particularly difficult is that PTS mimics so many common shoulder and neck conditions that most clinicians will reasonably reach for the more familiar diagnosis first. The result? Diagnostic delays that stretch from months to years, leaving people confused, in pain, and often questioning their own sanity. But here’s the thing: the earlier PTS is identified, the better the outcomes tend to be, so understanding how it’s diagnosed and why it’s so commonly missed matters a great deal.

So, let’s get into it.

What is Parsonage-Turner Syndrome?

Before we get into the diagnostic process, it’s worth quickly covering what PTS actually is. Parsonage-Turner Syndrome is an inflammatory condition affecting the brachial plexus, which is the network of nerves running from your neck into your arm. It typically starts with sudden, severe pain in the shoulder or upper arm, often described as the worst pain someone has ever felt, and this pain frequently gets worse at night [1].

After the initial pain phase (which can last anywhere from a few days to several weeks), muscle weakness and wasting begin to develop. This is the part that really catches people off guard, because by the time the weakness shows up, the acute pain may have already started to settle. It’s a bit like being hit twice: first the pain floors you, then the weakness creeps in while you’re still reeling.

The reported incidence sits at around 1.64 to 3 per 100,000 people [2], but most experts believe the true figure may be dramatically higher. A 2015 prospective primary care study by van Alfen found the incidence could be as high as 1 per 1,000 per year (approximately 100 per 100,000), suggesting the condition is 30 to 50 times more common than previously thought, largely because it gets missed so often [3]. The median age of onset is around 40, and it affects men roughly twice as often as women, though it can absolutely occur in anyone [2].

For a broader look at living with the condition, including some practical exercise tips, you can read our article on living with Parsonage-Turner Syndrome.

Why PTS is so commonly misdiagnosed

This is really the heart of the matter, and it’s something we see come up again and again. When someone walks into a clinic with severe shoulder pain, the list of likely diagnoses most clinicians will run through looks something like this: rotator cuff injury, frozen shoulder, cervical radiculopathy, or maybe adhesive capsulitis. These are all far more common conditions, and honestly, the initial presentation of PTS can look remarkably similar to any of them.

But the key difference, and this is what should raise alarm bells, is the pattern. With PTS, the pain comes on suddenly and severely, often out of nowhere. There’s usually no obvious trauma or injury. People describe it as a deep, burning, or tearing pain that’s absolutely relentless, particularly at night [1]. Does that sound like a typical rotator cuff problem? Not really, but in a busy clinic setting, the nuance gets lost.

Another reason PTS gets missed is that the weakness and atrophy, which are actually the most characteristic features, often don’t appear until after the worst of the pain has started to fade. So by the time someone returns to their doctor saying “now my arm feels weak,” the clinical picture has shifted entirely from what was originally assessed. The clinician may then investigate the weakness as a new and separate problem rather than connecting it to the earlier pain episode.

There’s also the issue of awareness. When it comes to PTS, many general practitioners and even some orthopaedic specialists simply aren’t familiar enough with it. It’s not something covered extensively in medical training, and because the reported incidence is relatively low (remember, that’s partly because of the underdiagnosis itself), it doesn’t tend to be high on anyone’s differential list [3]. It’s a bit of a chicken and egg situation, the condition is considered rare because it’s underdiagnosed and it’s underdiagnosed because it’s considered rare.

We’ve worked with people who’ve spent months going through physiotherapy for a frozen shoulder that wasn’t actually frozen, or who’ve had unnecessary imaging and even surgery for a rotator cuff that was never the real problem. The emotional toll of this kind of diagnostic journey is significant, and if you’ve experienced something similar, our article on medical trauma might be worth reading.

The key clinical features to look out for

So what actually makes PTS different from those common mimics? There are several clinical features that, when you know what to look for, paint a fairly distinctive picture.

Sudden, severe pain: This is usually the first symptom. It tends to hit the shoulder or upper arm like a bolt from the blue, and the intensity is often described as 9 or 10 out of 10. Crucially, the pain is typically worse at night, which is something that doesn’t always feature as prominently in conditions like frozen shoulder [1]. For those dealing with severe coat hanger pain patterns around the shoulder and neck, this is one of the distinguishing features that can help separate PTS from other causes.

Patchy weakness that doesn’t follow a single nerve root: This is probably the most important diagnostic clue. In cervical radiculopathy, the weakness and sensory changes follow a predictable dermatome pattern because a single nerve root is compressed. In PTS, the weakness is “patchy,” affecting muscles supplied by different nerves and nerve trunks [4]. You might see weakness in the serratus anterior alongside weakness in the deltoid, which doesn’t make sense if you’re thinking about a single-level disc problem. The muscle wasting can be quite alarming, and we understand the fear of movement that often accompanies this.

Scapular winging: When the long thoracic nerve is involved, which it frequently is, you’ll see the shoulder blade protruding outwards, especially when pushing against a wall. This is a fairly specific finding that should prompt further investigation. Those working on shoulder blade exercises will know how important scapular control is, and its sudden loss is a significant red flag.

Pain preceding weakness: The temporal pattern matters enormously here. In PTS, severe pain comes first, lasting days to weeks, and then weakness develops as the pain begins to settle [1]. This two-phase presentation is quite characteristic and differs from most other shoulder conditions where pain and weakness tend to develop together or the weakness comes first.

How PTS is actually diagnosed

There’s no single definitive test for Parsonage-Turner Syndrome, which is part of why it’s so tricky. Diagnosis is primarily clinical, meaning it relies heavily on a thorough history and examination. However, several investigations can support the diagnosis and help rule out other conditions.

Clinical evaluation: A detailed history is absolutely essential. The clinician should be asking about the onset pattern (sudden severe pain followed by weakness), the timing, any preceding events (infections, vaccinations, surgery), and the specific distribution of weakness. A thorough neurological examination mapping which muscles are weak and which sensory areas are affected can reveal the characteristic patchy, multi-nerve pattern [4].

Electromyography and nerve conduction studies (EMG/NCS): These are probably the most useful diagnostic tools available. EMG involves inserting small needles into muscles to record their electrical activity, while nerve conduction studies measure how well and how fast electrical signals travel through nerves. In PTS, EMG typically shows denervation in a distribution that crosses multiple nerve territories, which is the key finding that distinguishes it from a simple nerve root compression [5]. However when it comes to timing, these studies may be normal in the very early stages, so a negative EMG in the first couple of weeks doesn’t necessarily rule it out. Most experts recommend testing at 3-4 weeks after symptom onset for the most accurate results [5].

MRI findings: MRI has become increasingly valuable in diagnosing PTS. There are two main things to look for. First, T2 hyperintensity in the affected muscles, which essentially means the muscles light up on certain MRI sequences because of inflammation and early denervation changes. Second, and this is a particularly important finding, hourglass-like constrictions of the affected nerves. Research has shown that these constrictions are present in up to 90% of PTS cases, and they’re thought to represent the site of inflammatory nerve damage. A study looking at high-resolution MRI found that these constrictions were a highly specific finding for PTS and could be identified even in cases where other investigations were inconclusive.

Now, it’s worth saying that a normal MRI of the shoulder doesn’t rule out PTS either. The standard shoulder MRI that most people get is looking at the rotator cuff and joint structures, not specifically at the brachial plexus. If PTS is suspected, a dedicated brachial plexus MRI with specific nerve imaging protocols is needed, and this isn’t always what gets ordered initially.

Ultrasound: High-resolution ultrasound is emerging as a useful complementary tool, capable of identifying nerve swelling and the hourglass constrictions characteristic of PTS [6]. It’s not as definitive on its own, but in experienced hands it can provide valuable supporting evidence, and it’s more readily available than MRI.

If you’re dealing with nerve-related pain and wondering whether your symptoms might overlap with other conditions, our articles on CRPS and wrist pain cover some of the related territory.

Differential diagnosis: PTS versus the common mimics

One of the most helpful ways to understand PTS diagnosis is to compare it directly against the conditions it’s most commonly confused with. So here’s a breakdown of the key differences.

This table isn’t exhaustive, but it covers the main distinguishing features. The biggest takeaway? PTS tends to present with a severity and pattern that doesn’t quite fit neatly into any of the common diagnoses. If a patient’s presentation doesn’t add up, that’s when PTS should start climbing the list.

When it comes to conditions that can overlap or coexist with PTS, those with hypermobility are sometimes more vulnerable to nerve-related issues. Our articles on double-jointed elbows and rib subluxation explore some of the mechanical factors at play in the upper body.

When to suspect PTS: the red flags

Based on everything we’ve covered, here are the key red flags that should prompt investigation for PTS. If you’re experiencing these symptoms, or if you’re a clinician seeing this pattern, it’s worth pursuing further:

• Sudden onset of severe shoulder or upper arm pain without obvious trauma, especially if the pain is described as the worst ever experienced
• Pain that’s dramatically worse at night, out of proportion to what you’d expect from a mechanical shoulder problem
• Development of weakness and/or muscle wasting after the pain begins to settle, particularly if it’s been 1-3 weeks since the onset
• Weakness in a patchy distribution that doesn’t follow a single nerve root or a single peripheral nerve
• Scapular winging, whether noticed by the patient or on examination
• A preceding event such as infection (including COVID-19), vaccination, surgery, strenuous exercise, or emotional stress in the days or weeks before onset
• Failed response to treatment for rotator cuff injury, frozen shoulder, or cervical radiculopathy

If you tick several of these boxes, push for a referral to a neurologist and specifically request EMG/nerve conduction studies. Don’t be afraid to advocate for yourself here, because the data is clear that delayed diagnosis worsens outcomes.

For those who find self-advocacy difficult, particularly after negative medical experiences, understanding how the brain-body connection influences your response to healthcare settings can be genuinely helpful. Likewise, if the uncertainty of your diagnosis is affecting your mental health, our piece on anxiety and hypermobility touches on some of the ways that chronic health uncertainty impacts our nervous system.

Why early diagnosis matters so much

So why does all of this matter? Can’t PTS just be treated the same way regardless of when it’s diagnosed? Well, not exactly. And this is where the urgency of proper diagnosis really comes into focus.

Research suggests that early intervention, particularly in the form of targeted rehabilitation, leads to significantly better outcomes [7]. When treatment is delayed, several things happen. The affected muscles continue to waste, the nerves remain inflamed without appropriate management, and perhaps most importantly, the brain’s cortical maps begin to reorganise in unhelpful ways. We’ve written about this concept in the context of other conditions, and the principle is the same here: the longer a body part isn’t being used properly, the more the brain “forgets” how to control it [8].

Recovery statistics paint a mixed picture but one that still leans towards hope. Around 36% of people see significant recovery within the first year, 75% within two years, and up to 89% within three years (figures originally from the Tsairis 1972 cohort, cited in van Alfen 2006) with appropriate physiotherapy [7]. However, around 60% are left with some residual neuropathic pain, and 70% may not fully regain their pre-injury motor function [7]. These aren’t small numbers, they tell us that whilst most people do improve substantially, “complete” recovery isn’t always realistic.

Now, those numbers are from studies looking at all PTS patients, including many diagnosed late. There’s growing evidence that those who receive early, targeted rehabilitation, particularly approaches addressing the cortical and sensory components alongside the muscular ones, tend to do better [8]. This is where sensory mapping and neuromuscular re-education become particularly relevant, because they address both the peripheral nerve damage and the central nervous system changes that develop alongside it.

For anyone going through this, learning to pace yourself during recovery is genuinely important. Pushing too hard too early can set things back, but being too cautious can also slow progress. It’s a balance, and one that’s easier to strike with proper guidance. Some people also find that compression garments and KT tape provide useful sensory feedback during the rehabilitation process, helping the brain reconnect with the affected area.

When it comes to the surgical side, newer research on neurolysis, a procedure that involves carefully freeing compressed or constricted nerves, has shown promising results, with one study reporting 80.6% achieving full functional recovery compared to conservative management alone, where over 50% of patients showed no meaningful improvement alone [9]. However this isn’t appropriate for everyone, and the decision to pursue surgery typically depends on the specific pattern of nerve involvement and the response to initial conservative treatment.

What you can do right now

If you suspect PTS or treatment for another condition isn’t working, here are some practical steps:

1. Keep a symptom diary. Document when the pain started, how severe it was, when weakness developed, and which movements are affected. This information is invaluable for any clinician trying to piece together the diagnosis.

2. Request a neurological referral. If your shoulder problem isn’t responding to standard treatment, ask for a referral to a neurologist rather than (or in addition to) an orthopaedic surgeon. PTS is fundamentally a neurological condition.

3. Ask specifically for EMG/nerve conduction studies. These are the most informative investigations for PTS and they’re not routinely ordered for shoulder pain.

4. If MRI is ordered, ensure it includes brachial plexus imaging. A standard shoulder MRI won’t show the nerve changes associated with PTS. You need dedicated nerve imaging with appropriate protocols.

5. Educate your healthcare team. This isn’t about being confrontational, it’s about sharing information. Many clinicians are grateful when patients bring well-researched concerns to appointments, and the more people who are aware of PTS, the fewer who’ll be misdiagnosed.

If you’re in the middle of rehabilitation, understanding the basic principles of exercise for neurological conditions can help you make sense of what your therapist is asking you to do. And for those dealing with the broader impacts, core stability work becomes important too, because when the shoulder girdle isn’t functioning properly, the rest of the body has to compensate.

One thing I would say is that if you’ve been through misdiagnosis, try not to carry too much frustration towards the clinicians who got it wrong. PTS genuinely is difficult to identify, especially early on, and most healthcare professionals are doing their best with the knowledge they have. That said, you absolutely deserve an accurate diagnosis, so keep advocating for yourself. Our article on scoliosis and postural adaptation discusses compensatory patterns that develop when one area of the body isn’t working properly, which is very relevant to PTS recovery.

Breathing, pain tolerance, and the bigger picture

Something that doesn’t get enough attention in PTS recovery is how pain and immobility affect your breathing patterns. When you’re in severe pain and can’t move your arm properly, your breathing often becomes shallow and guarded. Over time, this contributes to secondary issues, from increased muscle tension to heightened anxiety and even changes in your CO2 tolerance.

We’ve noticed that many of those with PTS develop compensatory movement strategies extending well beyond the shoulder, affecting posture, breathing, and even gait. Addressing these broader patterns is part of why a comprehensive rehabilitation approach tends to produce better results. But the first step is always getting that diagnosis right.

FAQ: Common questions about PTS diagnosis

Getting the right diagnosis is genuinely the most important first step when it comes to PTS. Without it, you’re likely receiving treatment for a condition you don’t have, whilst the actual problem continues unchecked. If any of what we’ve covered here sounds familiar to your experience, please don’t sit on it. Push for the investigations we’ve discussed, seek out a neurologist if you haven’t already, and know that with the right approach, most people with PTS do see meaningful improvement over time.

You’re not imagining it. Your pain is real. And there are answers out there.

– The Fibro Guy Team –

References

1. van Alfen N, van Engelen BG. The clinical spectrum of neuralgic amyotrophy in 246 cases. Brain. 2006;129(Pt 2):438-450. doi: 10.1093/brain/awh722
2. van Alfen N. Clinical and pathophysiological concepts of neuralgic amyotrophy. Nat Rev Neurol. 2011;7(6):315-322. doi: 10.1038/nrneurol.2011.62
3. van Alfen N, van Engelen BG, Hughes RA. Treatment for idiopathic and hereditary neuralgic amyotrophy (brachial neuritis). Cochrane Database Syst Rev. 2009;(3):CD006976. doi: 10.1002/14651858.CD006976.pub2
4. Feinberg JH, Radecki J. Parsonage-Turner syndrome. HSS J. 2010;6(2):199-205. doi: 10.1007/s11420-010-9176-x
5. Ferrante MA, Wilbourn AJ. The utility of various sensory nerve conduction responses in assessing brachial plexopathies. Muscle Nerve. 1995;18(8):879-889. doi: 10.1002/mus.880180813
6. Arányi Z, Csillik A, Dévay K, Rosero M, Barsi P, Böhm J, Schelle T. Ultrasonographic identification of nerve pathology in neuralgic amyotrophy: Enlargement, constriction, fascicular entwinement, and torsion. Muscle Nerve. 2015;52(4):503-511. doi: 10.1002/mus.24615
7. Cup EH, Ijspeert J, Janssen RJ, et al. Residual complaints after neuralgic amyotrophy. Arch Phys Med Rehabil. 2013;94(1):67-73. doi: 10.1016/j.apmr.2012.07.014
8. Lustenhouwer R, Cameron IGM, Wolfs E, van Alfen N, Toni I, Geurts ACH, van Engelen BGM, Groothuis JT, Helmich RC. Visuomotor processing is altered after peripheral nerve damage in neuralgic amyotrophy. Brain Commun. 2022;4(1):fcac034. doi: 10.1093/braincomms/fcac034
9. Gstoettner C, Mayer JA, Rassam S, et al. Neuralgic amyotrophy: a paradigm shift in diagnosis and treatment. J Neurol Neurosurg Psychiatry. 2020;91(8):879-888. doi: 10.1136/jnnp-2020-323164