Endoscopic third ventriculostomy for idiopathic normal pressure hydrocephalus: association of cerebrospinal fluid flow dynamics with outcome

Introduction

Endoscopic third ventriculostomy (ETV) has been proposed for selected patients with idiopathic normal pressure hydrocephalus (iNPH), but predictors of sustained benefit are uncertain. Phase-contrast MRI (PC-MRI) may quantify cerebrospinal fluid (CSF) pulsatility and support patient selection. Research question: Is sustained clinical improvement after primary ETV associated with preoperative aqueductal CSF flow parameters measured by PC-MRI? Material and methods: In this prospective single-centre observational study, patients with iNPH underwent primary ETV after standardized diagnostic work-up. Preoperative assessment included the Kiefer scale and PC-MRI measurements at the cerebral aqueduct: peak velocity (PV), aqueductal stroke volume (ASV), and net ASV. Clinical follow-up was performed for 12 months. Sustained response was defined as an NPH recovery rate ≥3 at 3 and 12 months without secondary ventriculoperitoneal shunt implantation. Analyses were exploratory.