Foraminal narrowing means the small bony tunnel a nerve uses to exit the spine has become tighter.
In more detail
- Between each pair of vertebrae there are two openings, one on each side. They are called the neural foramina. A spinal nerve root leaves through each one.
- Several things narrow it at once. The disc loses height, so the opening gets shorter. The facet joint enlarges with arthritis. And ligaments thicken.
- It is graded mild, moderate or severe. It is described for each level and each side.
What it means for you
What matters is whether the nerve in that tunnel is really being pinched. That is a clinical question. Moderate narrowing with no symptoms needs nothing. Mild narrowing that matches numbness in the right toes exactly does matter. The exam decides, not the grade.
Remember the general rule. Findings like this one are common in people with no pain at all. They get steadily more common with age. A finding on a report is not a diagnosis until someone has matched it to your symptoms and your exam. See understanding your MRI report.
Bring your scan and report in and we will go through it with you. Call us or request an appointment.
Related: if the word itself is unclear, start with what foraminal means.
How common is it, and what does it predict?
Foraminal narrowing means the opening a nerve root exits through has gotten smaller. It usually comes from disc height loss, facet enlargement or a disc bulging out to the side. Each nerve root passes through its own foramen. So the finding only matters when the level and side match your symptoms. Narrowing at the right L5-S1 foramen fits right calf and heel symptoms. It has nothing to do with left thigh pain. The opening also changes size with position. It narrows when you bend back and when you bend toward the side with symptoms.
Common questions
Will foraminal narrowing get worse?
It tends to get worse slowly with age. But symptoms come and go, and often improve even when the imaging does not change.
What should I avoid?
Holding the back bent backward closes the foramen further. That includes repeated backward bending and overhead work with an arched back. Bending forward tends to open it.
Is surgery needed?
Only where there is significant nerve compromise (real pressure on the nerve) that has not responded to treatment. Many people have foraminal narrowing with no symptoms. Where symptoms exist, targeted injection and conditioning are usually tried first. Most foraminal narrowing is managed without surgery.
Why does bending backwards make it worse?
Bending back narrows the foramen further. Bending toward the side with symptoms does the same. That is why some people lean away without thinking.
Can this be treated without surgery?
Often. A transforaminal injection targets the affected root directly. Conditioning that lowers backward-bending load often helps you handle more.
Transforaminal Epidural Steroid Injection covers that injection.
Sources
- Fardon DF et al. Lumbar disc nomenclature: version 2.0: Recommendations of the combined task forces of the North American Spine Society, the American Society of Spine Radiology and the American Society of Neuroradiology. The spine journal : official journal of the North American Spine Society, 2014. PubMed 24768732
- Brinjikji W et al. Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. AJNR. American journal of neuroradiology, 2015. PubMed 25430861
- Katz JN et al. Diagnosis and Management of Lumbar Spinal Stenosis: A Review. JAMA, 2022. PubMed 35503342
- Williams AL et al. Lumbar disc nomenclature: version 2.0. AJNR. American journal of neuroradiology, 2014. PubMed 25339648
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