Pediatric low-pressure hydrocephalus: a case series and re-analysis of a rare disease.

backgroundLow or negative pressure hydrocephalus (LPH) is a rare condition characterized by signs and symptoms of hydrocephalus in the presence of a relatively low or negative intracranial pressure (ICP). The aim of the present study was to review and analyze the clinical characteristics, management, and outcomes of pediatric patients treated for LPH at a single center.

methodsWe conducted a retrospective study of pediatric patients (≤ 18 years) diagnosed with LPH at our institution between November 2017 and December 2024. Inclusion criteria were change in ventricular size with symptoms of hydrocephalus, measured intracranial pressure (ICP) ≤ 5 cmH2O, and clinical improvement following cerebrospinal fluid (CSF) drainage. Demographics, etiology, clinical presentation, management, and patient outcomes were collected.

resultsSix patients were included. All patients exhibited symptoms of hydrocephalus with an ICP ≤ 5 cmH2O. Management involved placement of ventriculoperitoneal shunts at low-resistance settings (n = 3) or shunting into negative pressure cavities (n = 3). One illustrative case required multiple shunt revisions before clinical resolution, whereas another needed prolonged external ventricular drainage prior to definitive ventriculoatrial shunting. Prior jugular or sigmoid sinus thrombosis was observed in 1/3rd of patients (n = 2). We model the role of venous thrombosis and demonstrate how prior venous thrombosis may contribute to LPH.

conclusionsLPH in children is rare and clinically challenging, with pathogenesis possibly involving altered cerebral viscoelasticity and/or a transmantle pressure gradient. Management requires placement of low-resistance valves or shunting into negative-pressure cavities. We hypothesize that prior venous thrombosis may contribute to the development of LPH.