Large- and Small-Fiber Neuropathy in Patients with Tarlov Cysts
Tarlov cysts (TCs) or perineural cysts are dilations of nerve root sheaths near the dorsal root ganglion containing nerve roots and neurons. The dilations are assumed to originate from moderately pathologically increased pulsatile cerebrospinal pressure forcing cerebrospinal fluid (CSF) into the nerve root sheaths. Nerve root dilations occur more frequently in the sacrum, where the hydrostatic pressure is the highest.1–3 The prevalence of TCs ≥ 5 mm on lumbar and sacral magnetic resonance imaging (MRI) performed for any reason is 13%.4 TCs produce symptoms more frequently than generally assumed.5 It has been estimated that approximately 25% of TCs are symptomatic and that an unknown percentage of asymptomatic TCs may become symptomatic later in life.6