CSF biomarkers in the evaluation of idiopathic normal pressure hydrocephalus

Background - To evaluate cerebrospinal fluid (CSF) markers for neuronal degeneration and demyelination in idiopathic normal pressure hydrocephalus (INPH), subcortical arteriosclerotic encephalopathy (SAE), and neurologically healthy subjects. Methods - Lumbar CSF concentrations of sulfatide, neurofilament protein light (NFL), total-tau (T-tau), hyperphosphorylated tau (P-tau), and beta-amyloid(1-42) (A beta 42) were analyzed in 62 INPH patients, 26 SAE patients, and 23 neurologically healthy controls. In INPH patients, samples before and after shunt surgery were analysed. Results - The CSF concentration of NFL was elevated in INPH and SAE compared with the controls, and levels of T-tau, P-tau, and A beta 42 were lower in INPH compared with SAE and controls. No difference was seen for sulfatide. All markers except A beta 42 were significantly elevated after shunt surgery. Conclusions - The most striking finding was the power of the combined pattern of NFL, P-tau, and A beta 42 in distinguishing between the clinical diagnoses of INPH, SAE, and neurologically healthy elderly.