Concordance of CSF AD biomarkers between intraventricular and lumbar CSF in iNPH

The core Alzheimer’s Disease cerebrospinal fluid (CSF) biomarkers, amyloid β 1‐42 (Aβ42), total tau (T‐tau) and phosphorylated tau 181 (P‐tau181), have presented added value for differential diagnostics in the field of neurodegenerative diseases. Moreover, the concentration gradient of these biomarkers between intraventricular (V‐CSF) and lumbar region CSF (L‐CSF) has been partly established for idiopathic normal pressure hydrocephalus (iNPH) patients. In this study, we aim to provide conversion factors between V‐CSF and L‐CSF.