TARLOV CYST

What is a Tarlov Cyst (Perineural Cyst)? Symptoms and Treatment

In medical literature, Tarlov Cysts, also known as Perineural Cysts, are fluid-filled sacs that form on the nerve root sheaths, most commonly found in the sacrum (the base of the spine/tailbone). These cysts are filled with Cerebrospinal Fluid (CSF).

They are often detected incidentally during MRI scans for other issues. The prevalence in the general population is estimated to be between 4% and 9%. Most of the time, they are "silent" (asymptomatic) and do not require treatment. However, when a cyst grows and the internal fluid pressure increases, it compresses adjacent nerve fibers and bone structures, leading to a condition known as Symptomatic Tarlov Cyst. This can significantly reduce a patient's quality of life.

Symptoms of Tarlov Cysts: Often Mistaken for Herniated Discs

Because of their location, Tarlov cysts can mimic the symptoms of a herniated disc. However, one of the most distinguishing features is that pain changes with position.

Symptoms of an active cyst include:

• Mechanical Pain: The most typical symptom is pain in the tailbone, buttocks, or lower back that worsens when sitting on hard surfaces and improves when lying down. Standing or walking may also trigger pain.
• Sciatica-like Pain: Sharp, electric-shock-like pain radiating from the buttocks down the legs and into the feet due to compression of the sciatic nerve.
• Sensory Loss: Numbness, tingling (paresthesia), or reduced sensation in the legs, feet, or genital area.
• Muscle Weakness: Loss of strength in the legs (leg weakness) or fatigue.
• Pelvic and Sexual Dysfunction: In advanced cases, bowel or bladder dysfunction (incontinence, urinary frequency, constipation) and sexual dysfunction (painful intercourse, erectile dysfunction) may occur due to compression of the sacral nerves.

How is it Diagnosed?

Since symptoms are often confused with lumbar disc herniation, the diagnosis process can be prolonged. The "Gold Standard" for definitive diagnosis is a Sacral MRI (Magnetic Resonance Imaging). An MRI clearly shows the size of the cyst, its relationship with the nerves, and whether it has caused any erosion (wear) on the sacral bone.

Treatment of Tarlov Cysts and Surgery Decision

The treatment approach for Tarlov cysts is based on the principle of "first, do no harm." The mere presence of a cyst on an MRI does not necessitate surgery. The treatment plan follows these steps:

1. Conservative (Non-Surgical) Treatments

The first goal is to manage pain.

• Medication: Analgesics (painkillers), anti-inflammatory drugs, and medications specifically for nerve pain (neuropathic pain).
• Physical Therapy: Pelvic floor exercises and physical therapy modalities are used to alleviate symptoms caused by nerve compression.

2. Interventional Methods

Before considering major surgery, CT-guided cyst aspiration (draining the fluid with a needle) may be performed for both diagnostic confirmation and temporary relief. Sometimes, techniques like injecting "fibrin glue" to prevent the cyst from refilling are attempted, though the long-term effectiveness of these methods is debated.

3. Tarlov Cyst Surgery

Surgical intervention is the last resort for Tarlov cysts. However, surgery becomes unavoidable if the patient's pain prevents daily functioning, if bladder/bowel issues have developed, or if the cyst has grown large enough to erode the bone.

• Surgical Process: Using microsurgical techniques, the cyst wall may be fenestrated (opened), reduced, or the connection allowing fluid entry may be closed (ligated) to relieve pressure on the nerve.
• Risk and Success: Because the area is extremely sensitive, surgery requires high expertise. Due to risks such as cyst recurrence or nerve damage (CSF leak), the decision to operate must be made very carefully, weighing the risks against the benefits.

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