Perineural Cysts: Symptoms, Treatment, and More

If you’ve ever had an MRI for stubborn low back or tailbone pain and then read the report thinking,
“What on earth is a perineural cyst and should I be panicking?”, you’re not alone. These fluid-filled
sacs, often called Tarlov cysts, sound dramatic but are usually much less scary than their
name suggests. Still, they can be confusing and in a small percentage of people, they can be genuinely
life-disrupting.

This guide walks through what perineural cysts are, which symptoms you should watch for, how doctors diagnose
them, and what treatment options exist from “do nothing and just keep an eye on it” to surgery. It’s based
on up-to-date medical references and expert opinion, but it’s still general information, not personal medical
advice. If you think you might have a perineural cyst, talk with a qualified healthcare professional for a
diagnosis and a treatment plan tailored to you.

What Are Perineural (Tarlov) Cysts?

Perineural cysts, more commonly known as Tarlov cysts, are small, fluid-filled pouches that
form around the spinal nerve roots, most often in the sacral region at the base of the spine. They are filled
with cerebrospinal fluid (CSF) the same liquid that cushions your brain and spinal cord.

These cysts tend to form in the protective covering of the nerve root (the nerve root sheath). In many people,
they are found incidentally on imaging done for something else and never cause symptoms. Estimates suggest that
a few percent of people may have Tarlov cysts, but only a minority develop symptoms.

You might also see them called by other names, including:

• Perineurial cysts
• Sacral nerve root cysts
• Nerve root sheath cysts
• Meningeal cysts (a broader category that includes Tarlov cysts)

Regardless of the label, the basic idea is the same: a pocket of fluid forms in or around the nerve root,
usually in the lower spine.

How Common Are Perineural Cysts?

Because many perineural cysts don’t cause symptoms and are never imaged, it’s hard to know the exact numbers.
A large meta-analysis suggests that about 4% of people may have Tarlov cysts on imaging, with a smaller
fraction actually experiencing symptoms.

These cysts:

• Are more often found in adults than in children
• Appear more frequently in women than in men
• Most commonly occur in the sacral region (S1–S5), but can occur higher up the spine

Symptoms: When a Quiet Cyst Speaks Up

Most perineural cysts are quiet roommates they’re there, but you’d never know. Problems start when a cyst
becomes large enough or is positioned in such a way that it compresses nearby nerve roots or bone structures.
When that happens, symptoms can range from mildly annoying to seriously disabling.

Common Symptoms of Symptomatic Perineural Cysts

Depending on the size and location of the cyst, people may report:

• Dull or sharp pain in the lower back, sacrum (tailbone), or buttocks
• Pain that radiates into the hips, thighs, or legs (sciatica-like pain)
• Numbness, tingling, or “pins and needles” sensations in the legs or feet
• Weakness or heaviness in the legs
• Increased pain when sitting, standing, bending, coughing, or sneezing
• Difficulty sitting for long periods or needing cushions/special chairs

Because the sacral nerve roots also help control the bladder, bowel, and sexual function, some people develop:

• Bladder urgency, frequency, retention, or incontinence
• Constipation, difficulty with bowel movements, or bowel incontinence
• Pelvic or perineal pain (pain between the legs)
• Sexual dysfunction, such as pain with intercourse or erectile dysfunction

Symptoms can fluctuate. Many people notice they feel worse after long car rides, sitting at a desk, or standing
in one place basically anything that stresses the lower back and sacrum.

What Causes Perineural Cysts?

The exact cause of perineural cysts is still being studied, and there’s probably more than one pathway that
leads to their formation. Several theories have been proposed:

• Weak spots in the nerve sheath. Small congenital (present at birth) weaknesses in the
  coverings of the nerve root may slowly stretch over time and fill with cerebrospinal fluid.
• Pressure “one-way valve” effect. In some cysts, CSF may enter the sac more easily than it
  can leave, acting like a one-way valve. Over time, that pressure can cause the cyst to enlarge.
• Trauma or stress to the spine. A fall, heavy lifting, repetitive spinal stress, or prior
  spine surgery may contribute in some people, although not everyone has a clear trigger.
• Connective tissue differences. Some researchers have suggested that people with certain
  connective tissue disorders might be more prone to developing meningeal cysts, including Tarlov cysts.

Importantly, most people with perineural cysts did not “cause” them by something they did wrong. They are not
related to lifestyle choices in the way that, say, smoking is related to lung disease.

How Perineural Cysts Are Diagnosed

Perineural cysts are usually picked up on imaging done for low back or sacral pain, or for neurological
symptoms in the legs or pelvis. Here’s how the diagnostic process often works:

1. Medical History and Physical Exam

A clinician will ask about your symptoms, including:

• Where the pain is located
• What makes it better or worse (for example, sitting vs. standing)
• Any bowel, bladder, or sexual function changes
• Past injuries, surgeries, or spine problems

During the exam, they may check:

• Muscle strength in the legs
• Reflexes
• Sensation to light touch or pinprick
• Gait and balance

2. Imaging Tests

The main tool for spotting perineural cysts is:

• MRI (magnetic resonance imaging). MRI can show fluid-filled cysts around the nerve roots and
  can help distinguish them from other spinal abnormalities, such as disk herniations or tumors.

In more complex cases, especially when surgery is being considered, additional studies may include:

• CT myelography. Contrast dye is injected into the spinal canal and CT images are taken to
  see whether the cyst communicates with the CSF space and how it affects nearby structures.
• Standard CT or X-rays. These don’t show the cyst itself as well as MRI but may reveal bone
  erosion or other structural changes.

A key point: just because an imaging report mentions a perineural cyst does not automatically mean it explains
your symptoms. The radiology findings have to match the clinical picture.

Treatment Options for Perineural Cysts

Treatment depends on two big questions:

1. Is the cyst actually causing your symptoms?
2. How much are those symptoms affecting your daily life?

Many cysts need no treatment at all. Others may respond to conservative care, and a smaller group may be
candidates for interventional procedures or surgery.

Conservative (Non-Surgical) Management

For mild to moderate symptoms, doctors often start with conservative strategies such as:

• Pain-relief medications. Over-the-counter options like acetaminophen or nonsteroidal
  anti-inflammatory drugs (NSAIDs) may help. Some people benefit from prescription medications such as certain
  antidepressants or anti-seizure medications that calm nerve pain.
• Physical therapy. Gentle strengthening, stretching, posture work, and core stabilization may
  reduce mechanical stress on the lower spine and help manage pain.
• Activity modification. Using cushions, avoiding long periods of sitting, taking standing or
  walking breaks, and adjusting workstations can all make a meaningful difference.
• Supportive devices. Some people feel better with a sacral cushion, ergonomic chair, or
  sit-stand desk.

Conservative management doesn’t “remove” the cyst, but for many people it keeps symptoms manageable enough to
avoid more invasive procedures.

Interventional Procedures

When conservative care isn’t enough and the cyst clearly lines up with the pain pattern, doctors may discuss
image-guided procedures such as:

• Epidural steroid injections. These injections deliver anti-inflammatory medication near the
  affected nerve roots, which may reduce inflammation and pain temporarily.
• CT-guided cyst aspiration and fibrin glue injection. Under imaging guidance, a needle is
  inserted into the cyst to drain its fluid, and a fibrin sealant may be injected to help prevent it from
  refilling. Some studies report symptom improvement in many patients, although recurrence can occur.

These procedures have potential benefits but also risks, including infection, bleeding, or nerve irritation.
They’re typically done by specialists experienced with spinal interventions.

Surgical Options

Surgery is generally reserved for people with:

• Severe, persistent pain that hasn’t responded to conservative care
• Progressive neurological deficits (such as worsening weakness)
• Significant bowel, bladder, or sexual dysfunction clearly linked to the cyst

Surgical techniques may include:

• Microsurgical fenestration or excision. The surgeon opens the area around the cyst, drains
  it, and either partially removes or reshapes the cyst wall while trying to preserve the nerve fibers.
• Imbrication and reinforcement. In some procedures, the cyst wall is folded and sutured to
  reduce its size and then reinforced with patches or adhesives.
• Decompression with laminectomy. Removing part of the bone over the sacral canal can relieve
  pressure on the cyst and nerves.

Because nerve fibers often run in the wall of the cyst, surgery must be done with extreme care to avoid
additional nerve damage. Even in expert hands, there are real risks, and outcomes can be mixed which is why
careful patient selection and detailed discussion of pros and cons are essential.

Possible Complications

Not everyone with a perineural cyst experiences complications, but potential issues include:

• Chronic pain in the lower back, sacrum, or legs
• Radiculopathy (nerve pain radiating along the path of a nerve)
• Weakness or muscle wasting over time
• Changes in bowel or bladder function
• Bone erosion or structural changes in the sacrum in large cysts
• Complications from surgery or procedures, such as CSF leaks or infection

When to See a Doctor (And When to Go Quickly)

Make an appointment with a healthcare professional if you have:

• Persistent low back, sacral, or buttock pain lasting more than a few weeks
• Numbness, tingling, or weakness in the legs
• Pain that clearly worsens when sitting or standing for long periods

Seek urgent medical care or emergency evaluation if you notice:

• Sudden or rapidly worsening weakness or numbness in the legs
• New or worsening trouble controlling your bladder or bowels (for example, incontinence or inability to urinate)
• Numbness in the groin, inner thighs, or around the anus (often called “saddle anesthesia”)

These symptoms can signal serious nerve compression and require fast assessment.

Outlook: Can You Live a Normal Life With a Perineural Cyst?

For many people, the answer is yes. Most perineural cysts stay small and silent. Even when symptoms occur,
they may respond well to conservative treatment and lifestyle adjustments.

When symptoms are more severe, the path forward may involve experimenting with several approaches physical
therapy, medications, injections, and in select cases, surgery. There is no “one size fits all” solution, and
working with a team familiar with Tarlov cysts can be especially helpful.

Because research is still evolving, people with symptomatic perineural cysts may also want to follow updates
from major neurosurgical centers and patient organizations focused on Tarlov cysts, which periodically share
new data on treatment outcomes.

Real-Life Experiences: What Living With a Perineural Cyst Can Feel Like

Reading a list of symptoms and treatment options is one thing; living with a perineural cyst is another. While
everyone’s experience is unique, certain themes tend to show up in patient stories and support groups.

Many people describe the early phase as confusing. They may have had years of vague low back or pelvic pain
and bounced between diagnoses: “maybe it’s a disk,” “maybe it’s arthritis,” “maybe it’s stress.” When an MRI
finally comes back with “perineural (Tarlov) cysts” in the report, there’s often a mixture of relief (“aha,
there’s something there!”) and anxiety (“what does this mean?”).

Some describe the pain as sitting on a rock or a marble that never quite moves out of the way. Sitting through
a movie, a meeting, or a long commute can feel like a marathon event. People become experts in cushions,
seat-wedge angles, and which restaurants have chairs that don’t make things worse.

On harder days, symptoms extend beyond pain. Numbness or tingling may creep down the backs of the thighs or
into the feet. A few people find that after standing in line at the grocery store, their legs feel weak or
shaky. Others discover that their bladder suddenly seems to have two modes: “I’m fine” and “you need a bathroom
right now.” That can make planning travel, social events, or workdays feel more complicated than it used to.

Emotional reactions are just as real as the physical ones. It’s common to feel dismissed if early doctors said
the cysts were “nothing” while the symptoms clearly weren’t. Finding a clinician who listens, takes symptoms
seriously, and is willing to discuss options including when not to operate can be a turning point.

People who do well over time tend to build a toolkit, not rely on a single “magic fix.” That toolkit might
include:

• Regular, gentle movement like walking or swimming instead of long sedentary stretches
• Physical therapy to strengthen core muscles and improve posture, combined with at-home exercises that are
  actually sustainable
• Pain-management strategies such as heat, ice, stretching routines, or relaxation exercises
• Practical hacks like sit-stand desks, using voice-to-text to reduce time at the computer, or setting a timer
  to stand and walk every 30–45 minutes
• Emotional support from therapy, online forums, or patient organizations devoted to Tarlov cysts

For people who undergo interventional procedures or surgery, recovery often involves a period of intense
patience. Improvement can be gradual rather than dramatic overnight. Some notice better pain control fairly
early; others measure success in small wins, like being able to drive longer distances, sit at a family dinner
without constantly shifting, or walk through a store without needing to lean on the cart.

Not everyone achieves perfect symptom relief, and some continue to have chronic pain even after aggressive
treatment. That doesn’t mean their symptoms “don’t count” it simply underscores how complex this condition
can be. In these cases, multidisciplinary care (pain specialists, physical therapists, mental health
professionals, and surgeons all communicating with each other) often provides the best chance of improving
quality of life.

The common thread in many experiences is this: understanding what a perineural cyst is, having realistic
expectations about treatment, and learning how to adapt daily routines can transform the condition from a total
mystery into something that, while challenging, is at least manageable.

The Bottom Line

Perineural (Tarlov) cysts are fluid-filled sacs that form around spinal nerve roots, most often in the sacrum.
Most never cause trouble and are simply watched over time. When they do cause symptoms, those problems typically
stem from pressure on nearby nerves and structures, leading to pain, numbness, and sometimes bladder, bowel, or
sexual function changes.

Treatment ranges from conservative approaches like medications and physical therapy to image-guided procedures
and, in select cases, surgery. There’s no universal best option the right plan depends on your symptoms,
imaging findings, other health conditions, and personal goals.

If a perineural cyst shows up on your MRI, the next step isn’t panic; it’s a thoughtful conversation with a
knowledgeable clinician. With the right information and support, many people find ways to keep moving, keep
working, and keep enjoying their lives cyst and all.