High Prevalence of Small-Fiber Neuropathy in Patients with Tarlov Cysts: Toward a More Comprehensive Clinical Understanding
Tarlov cysts (TCs) are dilations of the nerve root sheaths that form as a result of elevated pulsatile cerebrospinal fluid pressure (CSFP). These dilations are situated at the dorsal root ganglion (DRG), where sensory and small-fiber neurons are located. TCs are primarily situated in the sacrum, where the hydrostatic pressure adds to the pathologically increased CSFP. TCs may induce radiculopathy of the nerve root on which they are located or by compressing the nearby nerve roots. Cysts causing radiculopathy with symptoms in the corresponding dermatomes or myotomes are termed “symptomatic TCs”.1,2 In a recent meta-analysis of 13,266 subjects, the incidence of TCs in Europe was estimated to be 6%, and 1 out of 6 (16%) were symptomatic TCs.3 However, while symptomatic TCs are rare, patients with symptomatic and non-symptomatic TCs often exhibit not only radicular manifestations but also symptoms that are not directly localized at the level of the affected area but are instead felt in other, seemingly unrelated, areas. These symptoms include headaches, fatigue, neuropathic pain elsewhere and autonomic dysfunction, among others.4,5