Orthostatic headache and aseptic cerebrospinal fluid pleocytosis from an intrasacral meningocele

We present a rare case of a giant intrasacral meningocele with a unique presentation, discuss diagnostic challenges, and describe surgical management. Although intrasacral meningoceles are often incidentally found, they can cause debilitating pain and other severe neurological symptoms. A 48-year-old woman initially presented with severe orthostatic headaches, nausea, and vomiting. Cranial and cervical spine imaging was unremarkable, and CSF analysis showed lymphocytic pleocytosis, leading to a diagnosis of aseptic meningitis. Symptoms partially improved with conservative management but recurred 2.5 years later after a fall onto the sacrum, now with sacral pain and left-sided radiculopathy in addition to prior symptoms. Whole-spine MRI revealed a large intrasacral cyst with dural ectasia and possible spinal cord tethering. Surgical intervention included cyst resection, detethering of the spinal cord, closure of the cyst ostium, and reconstruction of the sacrum. Genetic testing for connective tissue disorders was also performed. The presence of a giant intrasacral meningocele compressing the sacral nerve roots with an associated tethered cord was confirmed intraoperatively. Postoperatively, orthostatic headaches and radiculopathy resolved. Genetic testing identified a variant of uncertain significance in the SKI gene, raising concern for a possible mild connective tissue phenotype. This case highlights the importance of considering spinal meningeal pathology in the differential diagnosis of patients with unexplained orthostatic headaches, even in the presence of CSF pleocytosis. Surgical management of symptomatic intrasacral meningoceles can lead to rapid and sustained improvements in neurological function and quality of life.