News Flash: Sciatica isn’t caused by disc herniations. In this article, we explore three compelling reasons why sciatica is attributed to disc gel, which comes from disc tears, and not pinched nerves as previously believed.
Shifting Paradigms: From Pinched Nerves to Leaking Discs
Long ago, doctors thought sciatica resulted from pinched nerves caused by disc herniations. Today, we know those doctors were close but wrong. Today we know that sciatica is not triggered by pinched nerves; instead, it’s linked to leaking discs. Here are three reasons supporting this paradigm shift.
Here are 3 reasons confirming Sciatica is caused by leaking gel and not pinched nerves.
Variable Symptoms: A Clue to the Real Culprit
(1) Symptoms come and go. Sciatica symptoms increase and decrease in severity instead of being constant. This variability can only be explained because liquid gel from the disc flows at different rates onto the adjacent spinal nerves, causing variable sciatica symptoms. If it was instead a pinched nerve from a disc herniation or bone spur, symptoms would be constant. They’re not constant.
Changing symptoms only makes sense recognizing it’s liquid gel flowing. Symptoms are variable; severe when gel leakage is severe, and unnoticeable when gel leakage is little. Sometimes it’s severe pain, spasms, and weakness, while other times it’s mild numbness or pins and needles.
The Mechanism Behind Sciatica Symptoms
Here’s why sciatica symptoms occur: When discs tear (known as annular tears) they cause gel (nucleus pulposus) to leak from inside discs and outwards onto adjacent spinal nerves.
The gel causes inflammation because it’s perceived as a foreign substance by the human body, causing the human body to mount the foreign body response against the gel, which is inflammation.
Because every disc herniation is caused by annular tears, these tears often leak gel. This leaked gel causes sciatica symptoms, and symptoms aren’t caused by the disc herniation incidentally observed on MRI.
Seeing Beyond the Surface: Surgeons’ Misconception
It’s easy to understand why surgeons long ago wrongly thought disc herniations caused sciatica instead of the gel. It’s because surgeons easily saw herniations on MRIs, but couldn’t see the leaked liquid gel causing sciatica inflammation on Spinal nerves.
The outer layers of a disc look like the Annular rings of a tree, so disc rings are called “Annulus Fibrosis” and their tears are called “Annular tears.” There are 17 annular layers.
The Role of Steroids: Temporary Relief, Revealing the Truth
(2) Epidural Steroids or anti-inflammatories provide temporary relief. The only thing steroids can do is stop inflammation. When you feel short-term relief after steroids or an epidural injection, you’ve proved it’s not a pinched nerve or disc herniation, because steroids cannot “unpinch” a pinched nerve or remove a herniated disc. After steroids leave the area of the leaking disc and spinal nerve, symptoms return. This proves sciatica isn’t caused by a pinched nerve.
Landmark Study: Debunking the Disc Herniation Myth
(3) The majority of people with no sciatica or low back pain have disc herniations and pinched nerves. In a landmark study in the New England Journal of Medicine, a large group of adults who never had sciatica or low back pain were all given MRIs. Over 60% of the people had large disc herniations or pinched nerves (New England Journal of Medicine, July, 1994). This proved disc herniations don’t cause the symptoms.
This paper won the “Outstanding Paper of the Year” I believe because it was so eloquently simple. Sometimes, the best things in life are simple.
Empowering Patients: Advocacy and Education
Whenever I teach, whether it’s at Harvard, Stanford, or my alma mater Penn, I bring a stack of these papers and I’m shocked to learn most surgeons are unfamiliar with this landmark study defining the value of the MRIs they use every day.
If your family doctor tells you that you have a pinched nerve causing symptoms, politely:
- Teach them about leaking discs from tears causing varying symptoms.
- Teach them what it means when steroids provide temporary relief.
- Teach them about the “Outstanding Paper” in the New England Journal of Medicine.
…because you are your best advocate.