The clinical relevance of Tarlov cysts

The sacral perineural cyst was first described by Tarlov in 1938 as an incidental finding at autopsy. There are very few data in the literature regarding the role of Tarlov cysts in causing symptoms, however. Most studies report low numbers, and consequently, the recommendations for treatment are vague. Our aim, therefore, is to present further detail regarding the clinical relevance of Tarlov cysts and to identify whether or not they are a cause of lumbosacral spinal canal stenosis symptoms.

Over a 5-year period, 3535 patients underwent magnetic resonance imaging (MRI) scan for lumbosacral symptoms. Fifty-four patients were identified as having Tarlov cysts, and their clinical picture was correlated with the findings on MRI.

The majority of Tarlov cysts (n = 38) cannot be held responsible for patients' symptoms and are clinically unimportant. However, we encountered several patients in whom Tarlov cysts (n = 9) occurred at the same level as another pathology. In these cases, the cyst itself did not require any specific therapy; treatment was directed at the other pathology, and uneventful symptom resolution occurred. A smaller subgroup of cysts (n = 7) are the main cause of patients' symptoms and may require specific treatment to facilitate local decompression.

The majority of Tarlov cysts are incidental findings on MRI. Where confusion exists as to the clinical relevance of a Tarlov cyst, treatment of the primary pathology (ie, non-Tarlov lesion) is usually sufficient. Tarlov cysts may, however, be responsible for a patient's symptoms; possible mechanisms by which this may occur and treatment strategies are discussed.