Tarlov cysts are fluid filled sacs in the spinal cord region along the nerve, usually close to where it enters the region to leave the spinal canal. The cysts are usually small, and not in a position that would cause symptoms. They became better known once we developed advanced imaging like MRI and CT scans. Their cause is not known, and usually they do not need to be treated, although occasionally they have been associated with connective tissue disorders including Marfans and Ehlers-Danlos syndrome.

Symptoms and Diagnosis

Tarlov cysts are sometimes larger than 0.5 inches in diameter, and at that size they may become symptomatic. The larger size may cause them to put pressure on a nerve root or even the spinal cord. Symptoms are related to the location; most likely in the sacrum. Problems include tailbone pain, pain in the groin region, sexual dysfunction, bladder dysfunction, and lower extremity numbness and weakness. Over time, without treatment, they do have a tendency to enlarge, meaning the cysts may start without symptoms and later develop into problems.

The diagnosis now is usually made by MRI scan, but may also be noted on CT scan. Tarlov cysts are usually found incidentally when scans are done looking for causes of back pain symptoms. Since most of these cysts are small, they usually are not correlated to symptoms being investigated.

Causes and Treatments

The cause of Tarlov cysts is unknown. There are many theories, but none appear to be definitively correlated to their development. Since there is no known cause, there is no known method to prevent their formation.

Treatment of Tarlov cysts is only necessary if they are definitely linked to symptoms or bone/neurologic compromise. Depending on the exact location, sometimes they can be ruptured by a radiologically guided needle under CT scan. Otherwise, they may need surgical management to drain. Unfortunately, they do have a propensity to re-occur and may need retreatment.

In summary, most Tarlov cysts are found by accident on an MRI scan for another issue. They are often small and usually cause no problems.  If they are large, sometimes they do need treatment and your physician can help determine possible options that would relieve the problems.