26 - Tarlov Cysts

Abstract

Tarlov cysts are common, occurring in 1% to 2% of persons undergoing spinal magnetic resonance imaging (MRI), particularly in the sacrum. Some 10% to 30% are potentially symptomatic. Sacral nerve root compression by the cyst/s can result in lower back and sacral symptoms, including S1, S2, and S3 radiculopathy, perineal and pelvic pain, and bowel, bladder, or sexual dysfunction that can be disabling to the patient. Pain is exacerbated by sitting or standing, and is generally relieved by lying down. Occasionally, patients present with isolated dyspareunia, vaginal hyperesthesia, or coccydynia. MRI is the study of choice to evaluate Tarlov cysts, while computed tomography myelography results are variable, depending upon the extent of communication of the Tarlov cyst with the spinal sac. Every Tarlov cyst indirectly communicates with the spinal sac and is filled with spinal fluid. Large Tarlov cysts should be differentiated from other types of spinal meningeal cysts, such as intrasacral meningoceles, which are typically much larger, associated with significant bone remodeling or erosion, and sometimes result in sacral insufficiency fracture. Tarlov cysts appear to occur more commonly in patients with collagen disorders, particularly Marfan and Ehlers–Danlos syndromes, and the hypermobility spectrum disorders. An image-directed diagnostic nerve block to the appropriate nerve can be helpful in confirming whether a Tarlov cyst is the source of the patient’s symptoms. Microsurgical ablation of the cyst/s is generally effective in relieving pain, depending upon the extent of preoperative injury, and is associated with 88% long-term success. Treatment with aspiration and filling with fibrin glue may give variable improvement in selected patients, but may complicate later surgical treatment.