Dorsal root entry zone fenestration for intramedullary ependymal cyst: illustrative case

BACKGROUND Intramedullary ependymal cysts are rare and difficult to distinguish from syringomyelia and neuroenteric cysts. Almost all cases in the literature have been case reports and have been performed with the traditional posterior median sulcus incision, which is difficult to identify accurately during spinal rotation. Approximately 40% of cases have transient neurological deterioration. The dorsal root entry zone has been proven to be an effective incision area in the treatment of intramedullary lesions, but so far, its utilization in intramedullary ependymal cysts has been rarely reported. OBSERVATIONS This study is the first to report on six cases of intramedullary ependymal cysts treated with an 8-mm incision in the dorsal root entry zone to fully establish the communication between the cyst and the subarachnoid space. Imaging changes and neurological improvement were analyzed in all cases before and after surgery and were followed up for 49.7 months. LESSONS The utilization of dorsal root entry zone fenestration in intramedullary ependymal cyst has demonstrated feasibility and effectiveness, ensuring the functional integrity of the posterior column.