Peripheral immunity changes are associated with neurodegeneration and worse clinical outcome in idiopathic normal pressure hydrocephalus

Background and purpose Idiopathic normal pressure hydrocephalus (iNPH) pathogenesis is multifactorial. Systemic inflammation might have a role in gathering clinical–pathological trajectories. We aimed to shape the peripheral immune profile of iNPH and establish correlations with cerebrospinal fluid (CSF) markers, ventricular enlargement, and clinical outcomes. Methods We conducted a single‐center retrospective–longitudinal study, including 38 iNPH patients and 38 controls. Baseline iNPH Grading Scale and modified Rankin Scale (mRS) scores were collected with peripheral blood cell count, CSF amyloid‐β42 (Aβ42), total tau (t‐tau), phosphorylated‐181‐tau, and Evans index. Depending on 5‐year outcome, iNPH patients were grouped into “poor outcome” (PO; mRS ≥ 5) and “favorable outcome” (FO; mRS