EC Orthopaedics

Tarlov cysts, also known as sacral perineural cysts, are cerebrospinal fluid-filled dilatations that arise between the endoneurium and perineurium of the posterior nerve root sheath, most commonly at the S2 and S3 levels. First described by Isadore Tarlov in 1938 as incidental autopsy findings, they are now recognised on magnetic resonance imaging (MRI) in roughly 4 - 9% of the population undergoing lumbosacral imaging, although only about 1% of those harbouring cysts become symptomatic. When symptomatic, Tarlov cysts may present with sacrococcygeal or radicular pain, sensory disturbance, bladder, bowel, or sexual dysfunction and, rarely, acute cauda equina syndrome following cyst haemorrhage or rupture. Their pathogenesis remains incompletely understood, but a one-way valve mechanism permitting cerebrospinal fluid ingress without egress, congenital dural wall weakness, and an association with heritable connective tissue disorders such as Ehlers-Danlos and Marfan syndromes have all been implicated. MRI is the diagnostic investigation of choice, with CT myelography reserved for confirming communication with the thecal sac before intervention. Management is graded according to symptom severity: asymptomatic and mildly symptomatic cysts are observed; moderately symptomatic cysts may respond to CT-guided percutaneous aspiration with fibrin sealant injection; and cysts causing progressive neurological deficit or refractory pain are considered for microsurgical treatment, most often cyst fenestration with imbrication of the redundant nerve root sheath and fibrin glue reinforcement. This review synthesises the anatomy, classification, epidemiology, clinical features, imaging characteristics, differential diagnosis, and current conservative, percutaneous, and surgical management strategies for spinal Tarlov cysts, with attention to outcomes and complications reported in the contemporary literature.

 Keywords: Tarlov Cyst; Perineural Cyst; Sacral Meningeal Cyst; Spinal Arachnoid Cyst; Cauda Equina; Cyst Fenestration; Fibrin Glue

1. Tarlov IM. “Perineural cysts of the spinal nerve roots”. Archives of Neurology and Psychiatry 6 (1938): 1067-1074.
2. Tarlov IM. “Cysts (perineurial) of the sacral roots”. Journal of the American Medical Association 10 (1948): 740-744.
3. Tarlov IM. “Sacral nerve-root cysts: Another cause of the sciatica or cauda equina syndrome”. Springfield, IL: Charles C Thomas (1953).
4. Tarlov IM. “Spinal perineurial and meningeal cysts”. Journal of Neurology, Neurosurgery and Psychiatry 6 (1970): 833-843.
5. Nabors MW., et al. “Updated assessment and current classification of spinal meningeal cysts”. Journal of Neurosurgery3 (1988): 366-377.
6. Voyadzis JM., et al. “Tarlov cysts: a study of 10 cases with review of the literature”. Journal of Neurosurgery1 (2001): 25-32.
7. Caspar W., et al. “Microsurgical excision of symptomatic sacral perineural cysts: a study of 15 cases”. Surgical Neurology 2 (2003): 101-105.
8. Wilkins RH. “Intraspinal cysts”. In: Wilkins RH, Rengachary SS, eds. Neurosurgery. New York: McGraw-Hill (1996): 2061-2070.
9. Langdown AJ., et al. “The clinical relevance of Tarlov cysts”. Journal of Spinal Disorders and Techniques 1 (2005): 29-33.
10. Lucantoni C., et al. “Tarlov cysts: a controversial lesion of the sacral spine”. Neurosurgery Focus6 (2011): E14.
11. Prashad B., et al. “Tarlov cyst: case report and review of literature”. Indian Journal of Orthopaedics 4 (2007): 401-403.
12. Henderson FC Sr., et al. “Neurological and spinal manifestations of the Ehlers-Danlos syndromes”. American Journal of Medical Genetics Part C: Seminars in Medical Genetics 1 (2017): 195-211.
13. Isono M., et al. “Ehlers-Danlos syndrome associated with multiple spinal meningeal cysts - case report”. Neurologia Medico-Chirurgica (Tokyo) 5 (1999): 380-383.
14. Paterakis K., et al. “A giant Tarlov cyst presenting with hydronephrosis in a patient with Marfan syndrome: a case report and review of the literature”. World Neurosurgery 126 (2019): 581-587.
15. Medani K., et al. “Surgical management of symptomatic Tarlov cysts: cyst fenestration and nerve root imbrication - a single institutional experience”. Journal of Spine Surgery 4 (2019): 496-503.
16. Soon WC., et al. “Haemorrhagic Tarlov cyst: a rare complication of anticoagulation therapy”. Oxford Medical Case Reports 8 (2021): omab063.
17. Paulsen RD., et al. “Prevalence and percutaneous drainage of cysts of the sacral nerve root sheath (Tarlov cysts)”. American Journal of Neuroradiology 2 (1994): 293-297.
18. Rodziewicz GS., et al. “Diagnosis of sacral perineural cysts by nuclear magnetic resonance”. Surgical Neurology 1 (1984): 452-456.
19. Burke JF., et al. “Microsurgical treatment of sacral perineural (Tarlov) cysts: case series and review of the literature”. Journal of Neurosurgery: Spine 5 (2016): 700-707.
20. Patel MR., et al. “Percutaneous fibrin glue therapy of meningeal cysts of the sacral spine”. American Journal of Roentgenology 2 (1997): 367-370.
21. Zhang T., et al. “Percutaneous fibrin glue therapy for meningeal cysts of the sacral spine with or without aspiration of the cerebrospinal fluid”. Journal of Neurosurgery: Spine 2 (2007): 145-150.
22. Shao Z., et al. “CT-guided percutaneous injection of fibrin glue for the therapy of symptomatic arachnoid cysts”. American Journal of Neuroradiology 8 (2011): 1469-1473.
23. Schnupp S., et al. “Two-needle technique for the treatment of symptomatic Tarlov cysts”. Journal of Vascular and Interventional Radiology 5 (2008): 771-773.
24. Murphy K., et al. “Treatment of 213 patients with symptomatic Tarlov cysts by CT-guided percutaneous injection of fibrin sealant”. American Journal of Neuroradiology 2 (2016): 373-379.
25. Tracz J., et al. “Interventional approaches to symptomatic Tarlov cysts: a 15-year institutional experience”. Journal of NeuroInterventional Surgery 7 (2024): 737-741.
26. Yucesoy K., et al. “A novel surgical technique for treatment of symptomatic Tarlov cysts”. British Journal of Neurosurgery 2 (2023): 188-192.
27. Kameda-Smith MM., et al. “A systematic review of the efficacy of surgical intervention in the management of symptomatic Tarlov cysts: a meta-analysis”. British Journal of Neurosurgery 1 (2024): 49-60.
28. Acosta FL Jr., et al. “Diagnosis and management of sacral Tarlov cysts. Case report and review of the literature”. Neurosurgery Focus2 (2003): E15.
29. Yoshioka F., et al. “Elimination of the check-valve mechanism of the sacral Tarlov cyst using a rotation flap technique in a pediatric patient: technical note”. Child's Nervous System 5 (2021): 1741-1745.
30. Kuzucu S and Akdulum I. “A rare cause of urinary incontinence in a child: a case of Tarlov cyst and a review of literature”. Cureus 8 (2024): e67712.