Electromyography and A Review of the Literature Provide Insights into the Role of Sacral Perineural Cysts in Unexplained Chronic Pelvic, Perineal and Leg Pain Syndromes
Tarlov cysts (TCs), or perineural cysts, are spinal meningeal cysts that contain nerve root fibers. They originate from dilations of the nerve root sheath at the dorsal root ganglion and are most frequently identified in the sacrum [1,2]. In 1938, when Isadore Tarlov discovered sacral cysts, he first believed that they were benign incidental findings. However, he later reported that they could be a source of radicular pain [3,4]. Unfortunately, this first erroneous assumption perpetuated, resulting in a worldwide consensus regarding their clinical insignificance [5]. There are also few clinical diagnostic characteristics that can be used to link these cysts to specific symptoms. Hence, it is almost always concluded that a patients’ pain originates from other coexisting conditions, primarily degenerative disorders that are observed on imaging [6]. Many physicians are therefore unaware that “sacral symptomatic Tarlov cysts” (STCs) are a well-defined clinical entity that includes debilitating
pelvic, perineal and leg pain and urogenital and bowel disturbances. STCs are easily identified when a comprehensive history is obtained [2,5,7,8].