Extended endoscopic endonasal transplanum-transtuberculum surgery for optic pathway-hypothalamic glioma presenting with tonsillar herniation and syringomyelia: illustrative case.

OPHG can cause Chiari-like pathophysiology by obstructing CSF pathways at the suprasellar and basal cistern levels. Extended endoscopic endonasal surgery provides a safe, minimally invasive route for direct ventral decompression, restoration of CSF dynamics, and effective management of selected OPHG with posterior fossa manifestations. https://thejns.org/doi/10.3171/CASE2623.