Foraminal vs. Paracentral vs. Central Disc Herniations

Name: Foraminal vs. Paracentral vs. Central Disc Herniations
Creator: Ifije Ohiorhenuan, MD, PhD

Written by Ifije Ohiorhenuan, MD, PhD — Board-Certified Spine Surgeon. Last updated 2026-06-20.

A paracentral disc herniation is a disc herniation — disc material pushed out of its normal space — that sits slightly off-center in the spinal canal, where it may irritate or compress a nearby nerve root depending on its size, level, and relationship to the nerves.

If your MRI report says “central,” “paracentral,” or “foraminal,” it is describing location. It is not automatically saying how serious the finding is.

MRI means magnetic resonance imaging. It is a scan that shows soft tissues like discs, nerves, and the spinal cord.

In my practice, I explain these words as map terms. They tell us where the disc material is sitting. Then we have to ask the more important question: does that finding match your symptoms?

What Does “Paracentral Disc Herniation” Mean?

“Para” means beside or next to. “Central” means the middle.

A paracentral disc herniation sits just to the right or left of the center of the spinal canal. The spinal canal is the main tunnel in the spine where the spinal cord and nerve roots travel.

Your report may say:

Right paracentral disc herniation
Left paracentral disc herniation
Broad-based paracentral protrusion
Paracentral disc extrusion

A right paracentral herniation sits off-center to the right. A left paracentral herniation sits off-center to the left.

A paracentral disc herniation can affect nearby nerve roots. A nerve root is a nerve branch that leaves the spine and travels toward the arm or leg. But the disc must contact, irritate, or compress the nerve for it to matter clinically.

A paracentral disc herniation is not a diagnosis of severity by itself. It tells us where the disc material is sitting.

In my practice, I explain “paracentral” as a location word. It tells me where the disc is sitting, not whether it is automatically dangerous.

The Basic Anatomy: Canal, Nerve Roots, and Foramen

To understand the MRI words, it helps to picture the spine from above, like a cross-section.

The spinal canal is the central tunnel in the spine.

In the neck and upper back, the spinal canal contains the spinal cord, which is the main nerve cable between the brain and body.

In the lower back, the spinal cord has already ended. The canal contains the cauda equina, which means “horse’s tail.” This is a bundle of nerve roots that travels down the lower spine.

The nerve roots branch off from the spinal canal. They travel to the arms or legs.

The neural foramen is the side opening where a nerve root exits the spine. “Foramen” means opening.

A simple way to think about it:

The spinal canal is the main hallway.
The neural foramen is a side doorway.
A central herniation bulges into the hallway.
A foraminal herniation crowds the doorway.
A paracentral herniation sits between the center hallway and the side doorway.

Disc herniations are described by their position near these structures.

Location words include:

Central
Paracentral
Foraminal
Far-lateral
Extraforaminal

These words are different from shape words. For example, “bulge,” “protrusion,” “extrusion,” and “sequestration” describe the shape or type of disc herniation.

You can read more about those terms here: Disc Bulge vs. Protrusion vs. Extrusion vs. Sequestration.

Central vs. Paracentral vs. Foraminal Disc Herniation

Central Disc Herniation

A central disc herniation is located in the midline. That means it points toward the middle of the spinal canal.

A central herniation may narrow the central canal. The central canal is the main space where the spinal cord or nerve roots travel.

Not every central disc herniation is dangerous. A small central protrusion can be an incidental finding. Incidental means it is seen on MRI but may not be causing symptoms.

Severity depends on:

How large the herniation is
How much room is in your spinal canal
Whether the disc contacts or compresses nerves
Whether your symptoms match the finding
What your neurologic exam shows

A neurologic exam checks nerve function. It may include strength, feeling, reflexes, walking, and balance.

In the neck, a large central herniation can matter more if it presses on the spinal cord. Pressure on the spinal cord can cause myelopathy, which means spinal cord dysfunction. Myelopathy can cause balance trouble, hand clumsiness, weakness, numbness, or walking changes.

In the lower back, a large central herniation may affect several nerve roots. It may also contribute to central canal stenosis. Stenosis means narrowing.

You can read more here: Central Canal Stenosis Grading: Mild, Moderate, Severe.

Paracentral Disc Herniation

A paracentral disc herniation is located just off the center line.

It is often described as right-sided or left-sided.

In the lumbar spine, which is the lower back, a paracentral herniation commonly affects the traversing nerve root. The traversing nerve root is the nerve root that is traveling downward past that disc level before it exits lower down.

This is different from the exiting nerve root, which is the nerve root leaving the spine through the foramen at that same level.

Examples:

At L4-L5, a paracentral herniation often affects the L5 nerve root.
At L5-S1, a paracentral herniation often affects the S1 nerve root.

These are common patterns, not guarantees. The MRI still has to match your symptoms and exam.

Symptoms can include:

Pain traveling into the leg
Numbness
Tingling
Weakness
Reflex changes

These symptoms matter more when they follow a nerve-root pattern on the same side as the herniation.

Foraminal Disc Herniation

A foraminal disc herniation is located in the neural foramen. This is the side opening where the nerve exits the spine.

A foraminal herniation is more likely to affect the exiting nerve root at that level.

For example:

At L4-L5, a foraminal herniation may affect the L4 nerve root.

Foraminal herniations can be painful when they compress the exiting nerve root. This is because the nerve is in a tight doorway.

But a foraminal herniation is not automatically severe. Some are mild. Some do not match symptoms.

You can read more about the nerve exit opening here: Neural Foraminal Narrowing: What Mild, Moderate, and Severe Mean.

Far-Lateral or Extraforaminal Disc Herniation

Some MRI reports use the words far-lateral or extraforaminal.

Far-lateral means farther out to the side.

Extraforaminal means outside the foramen.

These herniations sit even farther to the side than foraminal herniations. They may affect the exiting nerve root after it has left the foramen.

These terms can sound alarming. They are still location words. They do not automatically decide severity or treatment.

Why the Location Matters

Location matters because it helps predict which nerve might be irritated.

But location alone does not prove the pain source.

What I look for on MRI is not just the word “herniation,” but whether the disc is actually contacting or compressing a nerve that matches the patient’s symptoms.

Several details matter.

Side matters.
A right-sided herniation is more likely to match right-sided symptoms. A left-sided herniation is more likely to match left-sided symptoms.

Level matters.
Each nerve root travels to a different area of the arm or leg. A finding at L4-L5 does not mean the same thing as a finding at L5-S1.

The nerve relationship matters.
A disc that barely touches a nerve may not act the same as a disc that clearly compresses it.

Size matters, but not by itself.
Some large-looking herniations cause surprisingly few symptoms. Some smaller foraminal herniations can be very painful if they press directly on a nerve in a tight space.

The finding matters most when the location of the herniation matches the side and pattern of your pain, numbness, tingling, or weakness.

How Disc Herniation Location Can Relate to Symptoms

Lumbar Spine Symptoms

The lumbar spine is the lower back.

Low back pain may or may not come from a disc herniation. Back pain alone can come from many structures, including joints, muscles, ligaments, and discs.

Leg symptoms are different.

Leg pain, numbness, tingling, or weakness may suggest nerve root irritation, which means a nerve root is inflamed or being compressed.

Sciatica usually means nerve pain traveling down the leg. It is often related to irritation of a lumbar nerve root, but not all leg pain is sciatica.

A lumbar paracentral herniation can cause leg symptoms if it affects a traversing nerve root.

For example, an L4-L5 paracentral herniation may irritate the L5 nerve root. An L5-S1 paracentral herniation may irritate the S1 nerve root. The side and symptom pattern still have to match.

Helpful related guides:

Cervical Spine Symptoms

The cervical spine is the neck.

Neck pain may or may not come from a cervical disc herniation. The neck has discs, joints, muscles, ligaments, nerve roots, and the spinal cord.

Arm pain, numbness, tingling, or weakness may suggest cervical radiculopathy. Radiculopathy means symptoms caused by irritation or compression of a nerve root.

A foraminal or paracentral cervical disc herniation may affect a nerve root going to the arm.

A central cervical herniation matters more when it compresses the spinal cord or causes signs of myelopathy. Myelopathy means the spinal cord is not working normally.

Possible warning signs include:

Trouble walking
Loss of balance
Hand clumsiness
Worsening arm or hand weakness
Numbness in both hands
Changes in coordination

Helpful related guides:

Does a Paracentral Disc Herniation Mean I Need Surgery?

No, not automatically.

A paracentral herniation is a location description. The treatment decision depends on how that finding matches your symptoms and neurologic exam.

Many disc herniations are treated without surgery. Symptoms can improve as nerve inflammation calms down. Some herniations can also decrease in size over time. But improvement cannot be guaranteed for one person.

Treatment decisions depend on several things:

Symptom severity
How long symptoms have been present
Pain pattern
Numbness or tingling pattern
Weakness
Reflex changes
Function and daily limits
Whether non-surgical care has helped
Whether the MRI finding matches the symptoms and exam

Surgery may be considered in selected cases. This is more likely when there is persistent nerve pain, progressive weakness, severe compression that matches symptoms, or urgent neurologic concerns.

I do not recommend treatment based on the word “paracentral” alone. I want to know what the patient feels, what the exam shows, and whether the MRI explains it.

Common MRI Report Phrases and What They Mean

MRI reports can use technical language. The table below gives plain-language meanings.

For a broader guide, see How to Read Your Spine MRI Report.

MRI phrase	Plain-language meaning	Why it may matter
Right paracentral disc protrusion	Disc material is off-center to the right	May matter if symptoms are right-sided and match that nerve level
Left paracentral disc extrusion	Larger herniation off-center to the left	May irritate a left-sided nerve root
Central disc protrusion	Disc material is in the middle of the canal	May narrow the canal depending on size
Foraminal disc herniation	Disc material is in the nerve exit opening	May affect the exiting nerve root
Disc contacts the nerve root	The disc touches the nerve	Touching does not always mean symptomatic compression
Disc compresses the nerve root	The disc pushes on the nerve	More likely clinically relevant if symptoms match

A protrusion is a type of herniation where disc material pushes out but remains relatively contained.

An extrusion is a larger type of herniation where disc material extends farther out from the disc.

Those words describe shape or type. Central, paracentral, and foraminal describe location.

You can compare these terms here: Disc Bulge vs. Protrusion vs. Extrusion vs. Sequestration.

What I look for on MRI is whether the disc is simply present, touching a nerve, or actually compressing a nerve in a way that matches the patient’s symptoms.

When the MRI Finding and Symptoms Do Not Match

A radiology report describes anatomy. It does not always identify the pain generator. The pain generator is the structure most likely causing the pain.

Many people have disc bulges or herniations on MRI without pain.

A left-sided herniation does not usually explain right-sided symptoms unless there are other findings. A right-sided herniation is more likely to match right-sided symptoms.

Back pain alone can also be hard to match to one MRI finding. It may come from several structures, not just the disc.

The MRI is a map. Your symptoms and exam tell us whether the finding on the map is the likely source of the problem.

One of the most common things I see is an MRI finding that sounds dramatic but does not actually match the patient’s symptoms.

This does not mean the MRI is useless. It means the MRI has to be interpreted in context.

Clinical correlation is essential. That means the MRI finding should match:

The side of symptoms
The level of symptoms
The nerve pattern
Strength testing
Sensation testing
Reflexes
Walking and balance findings when relevant

When to Seek Urgent Medical Care

Most disc herniations are not emergencies. However, seek urgent medical care if you develop new bowel or bladder control problems, numbness in the groin or saddle area, rapidly worsening weakness, trouble walking, new hand clumsiness or balance problems, fever with spine pain, unexplained weight loss, history of cancer, or severe pain after trauma.

Seek urgent medical care now — or emergency care if symptoms are severe or rapidly worsening — if you have:

New loss of bladder or bowel control
Numbness in the groin or saddle area
Rapidly worsening leg weakness
Severe weakness in the arm or hand
Trouble walking, loss of balance, or hand clumsiness that is new or worsening
Fever, unexplained weight loss, history of cancer, or recent serious infection along with spine pain
Severe pain after a fall, accident, or trauma

A very large central lumbar disc herniation can rarely compress multiple nerve roots and contribute to cauda equina syndrome. Cauda equina syndrome is a spine emergency that can affect bladder, bowel, sexual, and leg nerve function.

SpineClarity’s written MRI/case review is not emergency care. If you have red-flag symptoms, seek urgent in-person evaluation.

A written MRI review is not appropriate for emergency symptoms.

When a Written MRI/Case Review Can Help

If your MRI report says “central,” “paracentral,” or “foraminal” disc herniation and you are not sure whether it matches your symptoms, a written MRI/case review can help you understand the finding in plain language.

SpineClarity offers a written MRI/case review from a board-certified spine surgeon.

You upload:

Your symptoms
Your MRI report
Relevant records

You receive:

A plain-language written interpretation
An explanation of the MRI terms
A discussion of whether the imaging appears to match the symptom pattern you provided
A suggested next-step category

This is not emergency care. It is not a substitute for an in-person physician relationship. It does not provide a definitive diagnosis or treatment plan.

FAQ

Is a paracentral disc herniation serious?

Not automatically.

A paracentral disc herniation is a location description. It means the disc material sits slightly off-center.

How serious it is depends on size, nerve compression, symptoms, neurologic findings, and spinal level.

Many are managed without surgery. But red-flag symptoms need urgent care.

What is the difference between central and paracentral disc herniation?

A central disc herniation sits in the midline of the spinal canal.

A paracentral disc herniation sits slightly off to one side.

Paracentral findings may affect one side more than the other, depending on whether they contact or compress a nerve root.

What is the difference between paracentral and foraminal disc herniation?

A paracentral herniation is near the center of the spinal canal.

A foraminal herniation is in the neural foramen, which is the side opening where a nerve exits.

They may affect different nerve roots depending on the spinal level.

Can a paracentral disc herniation cause sciatica?

Yes, it can.

A lumbar paracentral disc herniation can cause sciatica if it irritates or compresses a nerve root that contributes to leg pain.

But the sciatica symptoms must match the MRI level and side.

Does a foraminal disc herniation always cause nerve pain?

No.

A foraminal disc herniation may cause symptoms if it compresses or irritates the exiting nerve root.

Some foraminal findings are mild or incidental.

Does the side of the herniation matter?

Yes, often.

A right-sided herniation is more likely to match right-sided symptoms. A left-sided herniation is more likely to match left-sided symptoms.

Mismatches can happen, but they require careful review.

Can a disc herniation shrink or improve over time?

Some disc herniations can decrease in size over time.

Symptoms can also improve as inflammation around the nerve calms down.

This cannot be guaranteed for an individual person.

How do I know if my MRI finding explains my symptoms?

The MRI finding should match the side, level, and pattern of your symptoms.

A clinician also considers exam findings such as strength, sensation, reflexes, walking, and balance.

A written review may help clarify the relationship between the MRI and symptoms. It does not replace in-person care.

Image / Diagram Suggestions

Where Disc Herniations Sit: Central vs. Paracentral vs. Foraminal

Create a simple axial, or cross-section, diagram of a vertebra and disc.

Show:

Spinal canal labeled
Nerve roots labeled
Neural foramen labeled
Central herniation in the middle
Paracentral herniation slightly off-center
Foraminal herniation in the side nerve-exit opening
Optional far-lateral or extraforaminal herniation outside the foramen

Use color coding:

Blue: nerves
Gray: bone and disc
Red/orange: herniated disc material

Caption:

These terms describe the location of the herniation, not automatically how serious it is.

References

Amin, R. M., Andrade, N. S., & Neuman, B. J. (2017). Lumbar disc herniation. Current Reviews in Musculoskeletal Medicine, 10(4), 507–516. https://doi.org/10.1007/s12178-017-9441-4

ACR Expert Panel on Neurological Imaging. (2021). ACR Appropriateness Criteria® Low Back Pain. Journal of the American College of Radiology, 18(11S), S361–S379. https://doi.org/10.1016/j.jacr.2021.08.002

ACR Expert Panel on Neurological Imaging. (2019). ACR Appropriateness Criteria® Cervical Neck Pain or Cervical Radiculopathy. Journal of the American College of Radiology, 16(5S), S57–S76. https://doi.org/10.1016/j.jacr.2019.02.023

Brinjikji, W., Luetmer, P. H., Comstock, B., et al. (2015). Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. AJNR American Journal of Neuroradiology, 36(4), 811–816. https://doi.org/10.3174/ajnr.A4173

Chiu, C. C., Chuang, T. Y., Chang, K. H., Wu, C. H., Lin, P. W., & Hsu, W. Y. (2015). The probability of spontaneous regression of lumbar herniated disc: A systematic review. Clinical Rehabilitation, 29(2), 184–195. https://doi.org/10.1177/0269215514540919

Fardon, D. F., Williams, A. L., Dohring, E. J., Murtagh, F. R., Gabriel Rothman, S. L., & Sze, G. K. (2014). Lumbar disc nomenclature: Version 2.0: Recommendations of the combined task forces of the North American Spine Society, American Society of Spine Radiology and American Society of Neuroradiology. The Spine Journal, 14(11), 2525–2545. https://doi.org/10.1016/j.spinee.2014.04.022

Fehlings, M. G., Tetreault, L. A., Riew, K. D., et al. (2017). A clinical practice guideline for the management of patients with degenerative cervical myelopathy. Global Spine Journal, 7(3 Suppl), 21S–27S. https://doi.org/10.1177/2192568217701914

Jensen, M. C., Brant-Zawadzki, M. N., Obuchowski, N., Modic, M. T., Malkasian, D., & Ross, J. S. (1994). Magnetic resonance imaging of the lumbar spine in people without back pain. New England Journal of Medicine, 331(2), 69–73. https://doi.org/10.1056/NEJM199407143310201

Kreiner, D. S., Hwang, S. W., Easa, J. E., et al. (2014). An evidence-based clinical guideline for the diagnosis and treatment of lumbar disc herniation with radiculopathy. The Spine Journal, 14(1), 180–191. https://doi.org/10.1016/j.spinee.2013.08.003

NCBI Bookshelf. (Updated periodically). Cauda Equina and Conus Medullaris Syndromes. In StatPearls. Treasure Island, FL: StatPearls Publishing.

NCBI Bookshelf. (Updated periodically). Lumbar Disc Herniation. In StatPearls. Treasure Island, FL: StatPearls Publishing.

Ropper, A. H., & Zafonte, R. D. (2015). Sciatica. New England Journal of Medicine, 372(13), 1240–1248. https://doi.org/10.1056/NEJMra1410151

Weinstein, J. N., Tosteson, T. D., Lurie, J. D., et al. (2006). Surgical vs nonoperative treatment for lumbar disk herniation: The Spine Patient Outcomes Research Trial, a randomized trial. JAMA, 296(20), 2441–2450. https://doi.org/10.1001/jama.296.20.2441

Zhong, M., Liu, J. T., Jiang, H., Mo, W., Yu, P. F., Li, X. C., & Xue, R. R. (2017). Incidence of spontaneous resorption of lumbar disc herniation: A meta-analysis. Pain Physician, 20(1), E45–E52.