THE DETERMINATION OF BIOMARKERS OF CEREBROSPINAL FLUID OF IDIOPATHIC NORMAL PRESSURE HYDRO- CEPHALUS AND ITS COMBINATION WITH ALZHEIMER'S DISEASE

The idiopathic normal pressure hydrocephalus (Hakim-Adams syndrome) is characterized by the expansion of liquor-containing cavities, which is clinically manifested by a triad of symptoms: impaired gait, cognitive impairment, and impaired urination. One of the most common diseases associated with iNPH is Alzheimer's disease. Both diseases are found in the same age group with similar complaints of memory impairment. In clinical practice, their differential diagnosis is based on the identification of the Hakim-Adams triad. However, the determination of the combination of these two states, which is observed with a frequency of up to 75%, is a difficult task. In the study, the concentrations of biomarker proteins of amyloidosis and neurodegeneration in cerebrospinal fluid were determined. A total of 47 patients were examined (14 with a diagnosis of idiopathic normotensive hydrocephalus, 25 with Alzheimer's disease, 8 with their combination). The level of proteins in the cerebrospinal fluid was assessed using enzyme-linked immunosorbent assay (ELISA). Tablets for 96 samples were used to determine each of the evaluated indicators: the content of beta-amyloid (Aβ-42), tau protein (tau) and 218-phosphorylated tau protein (ftau). The neurodegeneration coefficients were calculated (ftau/Aβ-42, tau/Aβ-42). Specific cerebrospinal fluid changes in patients with idiopathic normotensive hydrocephalus were found to have higher levels of amyloid beta, a decrease in the content of tau and phosphorylated tau protein compared with patients with Alzheimer's disease. In the case of a combination of diseases (“comorbidity”), the presence of “intermediate” results by liquorological indicators is characteristic. A higher level of amyloid beta compared with Hakim-Adams syndrome indicates amyloidogenesis. We also revealed patterns of transformation of moderate cognitive impairment into dementia (according to the ratio of tau / Aβ-42 and ftau / Aβ-42).

idiopathic normal pressure hydrocephalus, Alzheimer's disease, «AD-iNPH» syndrome, amyloid beta, tau protein, phosphorylated tau protein, neurodegeneration coefficients