A Tarlov cyst is a collection of fluid near the spinal cord. It’s named after Isadore Tarlov, a neurosurgeon who is credited with first describing the condition in 1938.

Most Tarlov cysts are in the lower part of the spine. This is the sacral spine, where the lower spine attaches to the pelvis. The cause is unknown. It’s estimated that up to 9% of people have Tarlov cysts. But most people who have them don’t know it because these cysts don’t commonly cause symptoms.

Still, Tarlov cysts can get bigger and squeeze or irritate the nerves near or in the spinal cord. When there are symptoms, they include:

• Pain in the buttock or down the leg
• Weakness or numbness (or both) in the legs
• Difficulty sitting, standing or walking for long periods
• Incontinence (inability to control bladder or bowels)
• Problems with sexual function

The sciatic nerve is commonly affected, too. That’s because it’s location near the lower spine where Tarlov cysts form.

You want to confirm that the Tarlov cysts are the actual cause of the sciatic nerve pain (sciatica). Sciatica is common among people who do not have Tarlov cysts, so it’s possible that your pain is unrelated. And other types of cysts may be confused with Tarlov cysts. Neurologists and neurosurgeons are usually the most expert at figuring out whether these are definitely Tarlov cysts and whether one or both cysts are contributing to your symptoms.

If your doctor confirms that you have a Tarlov cyst causing the pain, review all of your treatment options. These include:

• Physical therapy.
• Anti-inflammatory and pain medicines, such as acetaminophen or ibuprofen. (Meloxicam is helpful for a few days at a time. But a different dose or a different anti-inflammatory drug might be more effective.)
• Removing the fluid in the cyst (cyst aspiration).Fluid often re-accumulates. But improvement of symptoms, even if temporary, can help confirm that the cyst is causing the symptoms.
• Surgery to drain or remove the cyst.

Surgery is usually reserved for the most severe cases, such as large cysts with significant symptoms that have not improved with other treatments. Surgery is not effective in all cases. But you may want to think about it if you’re not improving with less invasive treatments.