Tarlov cysts: A cause of low back pain?

It's possible. However, Tarlov cysts are an uncommon cause of back pain.

Tarlov cysts are fluid-filled sacs that most often affect nerve roots at the lower end of the spine (sacrum). Such cysts typically cause no symptoms and are found incidentally on magnetic resonance imaging (MRI) studies done for other reasons.

However, in some cases, the cysts expand, compressing or distending the affected nerve root. This irritation of the nerve root results in pain, weakness or numbness. Rarely, the cysts enlarge so much that surrounding bone is eroded, which may cause localized pain as well. The cause of Tarlov cysts isn't clear.

In most cases, Tarlov cysts require no treatment. But treatment for painful Tarlov cysts typically involves corticosteroid injections or other medications to relieve pain. Innovative surgical treatments — such as draining the cyst or amputating the affected nerve root — have not been highly successful and are usually reserved for cases in which conservative treatments have been ineffective.