Anterior intradural CSF collection causing postoperative neurological deterioration after intramedullary tumor resection and associated syringomyelia: illustrative case.

BACKGROUND: CSF-related complications such as CSF leakage and meningitis are well recognized after intramedullary spinal cord tumor surgery. In contrast, postoperative localized ventral intradural CSF collection causing acute spinal cord compression has not been well described.

OBSERVATIONS: A 62-year-old man with an intramedullary spinal cord tumor extending from C6 to T2 and associated extensive syringomyelia underwent tumor resection with posterior decompression and fusion. Gross-total resection was achieved under intraoperative neurophysiological monitoring without immediate neurological deterioration. Approximately 5 hours postoperatively, the patient developed acute paraplegia. Emergency MRI demonstrated a ventral intradural fluid collection with dorsal displacement of the spinal cord. Emergency reoperation demonstrated no evidence of hematoma, and intraoperative ultrasound confirmed a localized ventral intradural CSF accumulation. A markedly thinned segment of the spinal cord with a pinhole-like communication to the ventral intradural space was identified, suggesting a check-valve-like mechanism resulting in a compressive CSF collection. Expansive duraplasty was performed, after which neurological function improved.

LESSONS: Localized ventral intradural CSF collection can cause acute neurological deterioration after intramedullary spinal cord tumor surgery, particularly in cases with tumor-associated syringomyelia. Although extremely rare, this condition may be reversible with early recognition and prompt surgical decompression, including expansive duraplasty. https://thejns.org/doi/10.3171/CASE26123.