The glymphatic system and hydrocephalus: emerging insights into pathophysiological mechanisms.

Hydrocephalus is a complex neurological disorder traditionally thought to result from excessive cerebrospinal fluid (CSF) production, obstruction of CSF outflow, or impaired absorption. However, these classical theories have limitations in explaining key phenomena observed in certain clinical subtypes, such as normal pressure hydrocephalus. Recent advances in neuro-fluid dynamics have introduced the concept of the glymphatic system, a functional network in the brain that facilitates the exchange of CSF and interstitial fluid (ISF) along perivascular pathways and mediates the clearance of metabolic waste. This new perspective offers a fresh lens for understanding CSF circulation and fluid homeostasis. This review aims to reexamine the pathogenesis of hydrocephalus from the perspective of glymphatic dysfunction and, by integrating anatomical, physiological, and imaging evidence, explore its theoretical implications and clinical relevance.