Obstructive hydrocephalus secondary to brainstem sagging in recurrent cerebrospinal fluid-venous fistulas: a diagnostic and therapeutic challenge. Illustrative case.

BACKGROUND: The association of idiopathic intracranial hypertension (IIH) with spontaneous skull base CSF leaks is well known; however, its role in spinal CSF leaks is poorly established. CSF-venous fistula (CVFs) are a recognized subtype of spinal CSF leaks, but they rarely recur after successful treatment. Brainstem sagging is a known consequence of spontaneous intracranial hypotension with variable clinical sequelae. Brainstem sagging has not previously been demonstrated to cause obstructive hydrocephalus.

OBSERVATIONS: The authors describe the case of a female in her early 5th decade with presumed IIH-induced recurrent spinal CVFs. They detail the recurrent nature of her CVFs despite successful transvenous embolization, the advanced imaging techniques required for diagnosis, and the consequences of untreated intracranial hypotension, including bulbar dysfunction and obstructive hydrocephalus requiring external ventricular drainage. The placement of a ventriculoperitoneal shunt to prevent further spinal CVF recurrence is also described.

LESSONS: This illustrative case highlights the complexity of treatment in recurrent spinal CVFs and intracranial hypotension. The authors detail the extreme consequences of untreated intracranial hypotension, including obstructive hydrocephalus and progressive bulbar dysfunction. In this context, the necessity of external ventricular drainage in order to equalize transtentorial pressure differentials and restore consciousness is demonstrated. https://thejns.org/doi/10.3171/CASE25680.