When 'Piriformis Syndrome' Was Actually a Massive Disc Herniation: A Case Study

It was a Sunday evening when my phone rang. A friend from the US was on the line, and I could hear the concern in his voice before he even explained why he was calling. His partner was in agony, barely able to stand, and their local medical team had discussed a potential diagnosis of piriformis syndrome. As someone who’s navigated seven spine surgeries myself and spent over two decades in rehabilitation, I’ve learned that severe sciatic pain rarely tell a simple story.

“Can you just take a look at her over Zoom?” he asked.

What unfolded over the next 48 hours would become a masterclass in why patient advocacy matters, why the right imaging is crucial, and why sometimes the obvious diagnosis isn’t the right one.

The Patient: Active, Healthy, and Suddenly Debilitated

The woman on my screen that Sunday evening didn’t fit the typical profile of someone heading for spine surgery. She was physically active—a regular at yoga, devoted to her Peloton, and consistent with light resistance training. Just a week earlier, she’d returned from a city break where she and her partner had walked for miles over four or five days, exploring and enjoying themselves.

It started innocently enough: a sensation of tightness in her left buttock and hamstring. Like any health-conscious person, she booked a session with her physical therapist. The tightness felt muscular, the kind you might get after an intense workout. Stretching should help, they reasoned. Massage should relieve it.

But over four or five days of treatment, nothing improved. In their final session, the physical therapist offered what seemed like a logical diagnosis: piriformis syndrome. The theory made sense—the piriformis was tight, compressing the sciatic nerve as it traverses past the muscle. It’s a common diagnosis for active people with sciatica, buttock and leg pain.

There was just one problem: the pain was getting dramatically worse.

The Zoom Consultation That Changed Everything

When I saw her on video that Sunday evening, she wasn’t dealing with muscle tightness anymore. She was experiencing severe left leg pain that made standing and walking nearly impossible. Sitting provided brief relief before the pain would surge back, even worse than before.

I asked her to perform a simple neural glide test—she sat down, straightened her knee, and raised her toes toward her shin. This movement doesn’t just stretch the hamstring and calf; it mobilizes the sciatic nerve itself.

Her reaction was immediate and telling. “The pain from her buttock right down the leg was unbearable,” she managed to say through gritted teeth.

This wasn’t piriformis syndrome.

“You need to go to the hospital and you need to request an MRI scan—it’s the only way to see if there’s nerve compression from your lumbar spine.”

The Emergency Room Runaround

Twenty-four hours later, my phone rang again. They’d been to the emergency room, where she’d received an X-ray. Her husband read me the radiologist’s report: no vertebral fractures, no suspicious lesions, spine “relatively unremarkable.”

I took a breath before responding. “An X-ray isn’t the correct scan for her symptoms,” I explained. She hadn’t fallen. She had no history of cancer. She wasn’t in an accident. An X-ray shows bone, not the soft tissue structures that compress nerves.

“You need to go back and request an MRI,” I said.

To his credit, the husband was persistent. The radiology department agreed to the MRI. An hour later, another phone call. Another report being read to me over the phone. This time it was an MRI report, but the conclusion was eerily similar: “relatively unremarkable spine” with some age-appropriate arthritic changes at L4-5 and L5-S1. Most crucially, the report stated there was “nothing on radiology that correlates with her clinical symptoms.”

“They’ve missed something!”

Let me be absolutely clear—this wasn’t a dismissal of the radiologist’s skill. I have enormous respect for radiologists and the critical work they do. But I also understood the reality of a busy emergency department. The radiologist was likely overwhelmed, scanning for red flags that would require immediate surgical intervention. They were looking for the obvious emergencies, not necessarily correlating every finding with specific symptoms.

“I need to see the actual images,” I said.

Within thirty minutes, through the modern miracle of digital medical records and patient consent, I had access to the MRI scans. We reconvened on Zoom, and I began walking through the images with them.

The Late-Night Discovery

At first glance, I could see why the radiologist had written what they did. Most of the spine looked remarkably good for someone her age. The central canal was clear, the disc heights were maintained, and there were no obvious compressions in the usual places.

Mid central image of her spine - all looks pretty normal

Left side of her spine, L4/L5 disc very mild bulging - no nerve compression

But I had something the emergency radiologist didn’t have: time. It was late Sunday night for me, and I wasn’t managing twenty other emergency cases. I could look carefully, slice by slice, examining not just the obvious areas but the subtle zones where problems can hide.

And then I found it.

“There,” I said, sharing my screen to show them. “Do you see this?”

What I was pointing to was an extremely large L4-5 extra-foraminal disc herniation on the left side. It wasn’t in the central canal where most herniations occur. It was positioned laterally, outside the main highway of the spine, in a location that’s notoriously easy to miss if you’re not specifically looking for it.

Large left L4/5 extra foraminal disc herniation, compressing the exiting L4 nerve root and dorsal root ganglion

But here’s what made it particularly severe: the herniation was compressing the dorsal root ganglion of the exiting L4 nerve root. The dorsal root ganglion houses all the sensory components of the nerve—it’s essentially the nerve’s pain center. When you compress this structure, you don’t just get pain; you get excruciating, intractable, life-altering pain.

This explained everything: why her pain was so severe, why no position provided relief, why stretching made it worse, and why it was rapidly progressing. The disc material was crushing one of the most sensitive structures in the human nervous system.

Vindication and Next Steps

Armed with my findings and explanation, she took this information to a spine surgeon the next day. The surgeon’s response was unequivocal: The radiologist had indeed missed it, and she needed surgery.

She was scheduled for a left-sided L4-L5 endoscopic discectomy¹⁾ within the week. The surgeon chose this minimally invasive approach specifically because of the herniation’s location—being extra-foraminal meant he could approach from an angle with minimal muscle disruption.

They had tried one last conservative measure—a transforaminal steroid epidural injection—but it provided no relief. The mechanical compression was simply too severe for anti-inflammatories to overcome.

Lessons from a Misdiagnosis

This case highlights several crucial lessons that every spine pain patient should understand. Studies show²⁾ that extra-foraminal disc herniations are frequently overlooked due to insufficiently detailed radiological examinations:

1. Severe, progressively worsening leg pain needs proper imaging. If you have neural symptoms—pain, numbness, or tingling running down your leg—an MRI is the gold standard for diagnosis. An X-ray cannot show disc herniations, nerve compression, or soft tissue problems.

2. Reports can be wrong. Radiologists are highly skilled professionals working under tremendous pressure. But in busy emergency departments, subtle findings can be missed. If your symptoms don’t match the report, it’s worth getting a second opinion on the actual images, not just the report.

3. Extra-foraminal herniations are the hidden enemy. These lateral herniations occur in only about 7-12% of all disc herniations, but they cause disproportionate pain because of their location. They’re harder to see on MRI, harder to treat conservatively, and often missed on initial readings.

4. Trust your body’s signals. When pain is intractable—meaning no position provides relief—and progressively worsening despite treatment, something structural is likely wrong. This isn’t the time for more stretching or massage; it’s time for proper investigation.

5. Advocacy matters. Without her partner’s persistence in requesting an MRI, without their willingness to seek a second opinion, and without pushing back on the initial reports, she might have spent weeks or months in unnecessary agony, trying failed treatments for the wrong condition.

The Difference Between Piriformis Syndrome and Disc Herniation

For those wondering how to tell the difference, here are key distinctions:

Piriformis syndrome typically:

• Usually worsens with sitting, especially on hard surfaces
• Improves with certain positions or movements
• May respond to targeted stretching and massage over time
• Causes buttock pain that may or may not extend down the leg

Disc herniation with nerve compression typically:

• Causes pain that runs along specific nerve pathways (mostly)
• Worsens with spinal movements (bending, twisting, etc)
• Doesn’t always respond well to conservative treatment
• Creates neuropathic symptoms (numbness, tingling, weakness)
• Pain may be intractable with no position providing complete relief

Moving Forward: The Role of Proper Guidance

The surgeon was refreshingly honest about the recovery. Despite being “minimally invasive,” endoscopic surgery carries risks. He imposed a strict six-week protocol: no bending, lifting, or twisting. He wanted to prevent re-herniation and give the disc time to heal properly.

A Final Thought on Patient Empowerment

This case began with a friend’s worried phone call and ended with a correct diagnosis and appropriate treatment plan. But it required persistence, advocacy, and access to expertise. Not everyone has a friend with spine expertise they can call on a Sunday evening.

As I told her husband that night:

Sometimes the obvious diagnosis—piriformis syndrome—isn’t the right one. Sometimes it takes a late-night Zoom call, a persistent advocate, and a careful second look to find the truth hiding in plain sight on an MRI scan.

The patient has already had surgery and with proper surgical treatment and guided recovery, her prognosis for full recovery is excellent—a far cry from the weeks or months of unnecessary suffering that might have resulted from treating the wrong condition.

For more information about recovery from endoscopic discectomy and other spine procedures, visit Vertera Health or join our waitlist for comprehensive, expert-guided recovery protocols.

References

1. Bergamaschi JPM, Teixeira KO, Soares TQ, et al. Extraforaminal Full-Endoscopic Approach for the Treatment of Lateral Compressive Diseases of the Lumbar Spine. J Pers Med. 2023;13(3):453. https://pmc.ncbi.nlm.nih.gov/articles/PMC10058867/

2. Berra LV, Di Rita A, Longhitano F, et al. Far lateral lumbar disc herniation part 1: Imaging, neurophysiology and clinical features. World J Orthop. 2021;12(12):961-969. https://pmc.ncbi.nlm.nih.gov/articles/PMC8696601/