ReviewPublished 12 May 2026Variability in the circulation of cerebrospinal fluid: causes and clinical implications for intraventricular drug deliveryHerbert H. Engelhard · Olivier Balédent · Matthew T. Borzage · Lydia Andrews-Jones · Thomas M. Feldsien · Didier R. LefebvreFrontiers in Drug Deliverydoi 10.3389/fddev.2026.1735474