Spinal schwannoma and ependymoma: a diagnosis that shouldn't be missed in SAH - literature review and case report.

Background: The incidence of subarachnoid hemorrhage (SAH) is around 9/100 000 people annually, with 15-37% having no identifiable vascular source on angiography. This study aimed to define criteria to identify patients with a possible spinal origin of SAH. We present a literature review and a case of a 61-year-old patient with SAH due to lumbar spinal schwannoma.

Methods: A literature search and review were conducted according to the PRISMA-P 2020 guidelines. We performed a restricted search using the keywords "SAH" and "Spinal Schwannoma"; "SAH" and "Ependymoma".

Results: Out of 297 articles, 32 were included between 1951 and 2023 for a total of 44 cases with SAH of spinal origin. Fourteen schwannomas (31.8%) and 30 ependymomas (68.2%) were included in the review. Men represented 77% of the schwannoma and 64% of the ependymoma cohort. The median age was 45 years in the schwannoma vs 29 years in the ependymoma group. Ependymomas were predominantly located in the lumbar spine (85%). Localised spinal symptoms were present in 65% of schwannoma cases, encompassing radicular pain (28%), motor deficit (22%), and incontinence (14.5%). This was 93% in ependymomas, with symptoms being radicular pain (40%), motor deficit (20%), and incontinence (17%). Lumbar punctures diagnosed 86.5% of SAHs, while only 18.2% had subarachnoid bleeding found on a cerebral CT or MRI.

Conclusion: In SAH patients lacking a vascular bleeding source, any spinal symptom must prompt a complete examination of the spinal axis (i.e. MRI). Without spinal symptoms, SAH associated with spinal tumors will likely be missed.