Cerebrospinal fluid biomarkers in idiopathic normal pressure hydrocephalus

Abstract

The diagnosis of idiopathic normal pressure hydrocephalus (iNPH) presents difficulties because of the same symptomatology in neurodegenerative diseases. The data of brain magnetic resonance imaging (MRI) and invasive techniques (tap test, external lumbar drainage, and infusion test) not always allow an accurate diagnosis of iNPH, especially when patients have comorbidity. This increases the role of cerebrospinal fluid (CSF) biomarkers in the differential diagnosis of iNPH and comorbidities at early stages. Objective : to analyze the data available in the literature on current ideas about CSF biomarkers and their role in the differential diagnosis of iNPH and neurodegenerative diseases in the brain. Material and methods . The literature data were sought in the internet resource PubMed by the keywords: normal pressure hydrocephalus, CSF biomarkers, neurodegeneration, Alzheimer's disease (AD), beta-amyloid protein, and tau protein. Fifty-three communications published in 1965 to 2018 were reviewed. Results and discussion . In accordance with the data available in the literature, the most informative CSF biomarkers for the differential diagnosis of iNPH are beta-amyloid (Aβ) proteins β42, Aβ-40, Aβ -38, sAPPβ, sAPPβ, and t-tau and p-tau. The study of CSF biomarkers opens up prospects not only for the detection of iNPH, but also for its differential diagnosis with neurodegenerative diseases, primarily with AD. The detection of biomarkers can be used in addition to brain MRI and invasive techniques to improve the accuracy of diagnosis, as well as to predict the efficiency of bypass surgery, but provided that they are comprehensively assessed. Conclusion . The analysis of the levels of specific CSF proteins holds promise for the differential diagnosis of iNPH.