Spinal arachnoid cysts. A case series and review of literature with subgroup comparison of intradural and extradural arachnoid cysts.

Objectives: Spinal arachnoid cysts (SAC) are rare lesions. There are many uncertainties regarding details about Intradural and Extradural SAC. We present a series of 12 cases of SAC along with a comprehensive review of the literature. In this review, we discussed the differences between Intradural and Extradural SAC pertaining to demography, pathogenesis, surgical procedures and outcomes. Methods: We retrospectively collected the data of 12 patients of SAC treated at our Institute from 2012 to 2023. The age, gender, clinical, radiological, surgical data and outcome were noted. An extensive review of the literature was done to analyse and note the differences between Intradural and extradural SAC and their surgical management. Results: In our series of 12 patients, 7 had Extradural SAC(58.3%), 3 had Intradural SAC(25%) and 2 had Intramedullary SAC(16.7%). . Of the 12 patients, 4 were males and 8 were females (1:2). Age range was 9 to 64 years and the mean age was 34.42 ± 17.71 years. There were four paediatric patients in the series. The most common symptoms reported at presentation are weakness of limbs(81.9%),back pain(36.4%), sensory symptoms(36.4%), radicular pain (18.2%), and bladder disturbances(9.1%). Out of the 12 patients, surgery was done in 11 patients and one patient was managed conservatively. Conclusions: From the review of the literature, intradural SAC was twice as common as extradural SAC. Ventrally located SACs are more common in Intradural locations as compared to Extradural. The intradural SACs were more commonly located in the thoracic and cervical regions when compared to extradural SACs which were located commonly in the thoracolumbar, thoracic and lumbar regions. Extradural SACs were mostly Primary and the mainstay of treatment is complete or partial excision of the cyst with identification and ligation of the communicating pedicle. Selective laminectomy, partial excision of the cyst and wide fenestration to sustain CSF flow is the recommended treatment in Intradural SAC. [ABSTRACT FROM AUTHOR]