The role of arterial and venous blood flow and cerebrospinal fluid flow disturbances in the development of cognitive impairments in cerebral microangiopathy

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Cerebral microangiopathy (CMA) is the main cause of vascular cognitive disorders, the leading cause of mixed dementia, and the main modifiable risk factor in Alzheimer’s disease. Study objective. To investigate the role of arterial and venous blood flow and cerebrospinal fluid flow, as well as their interrelation in the development of cognitive disorders in patients with CMA. Materials and methods. Ninety-six patients (32 men and 64 women, mean age 60.6±6.3 years) with cognitive complaints and CMA, diagnosed according to the STRIVE international MRI criteria, were examined. The severity of cognitive disturbance was assessed based on the overall cognitive level (MoCA scale and independence in daily life), the results of memory tests (10 words memory test) and executive brain function tests (TMT B-A). Phase contrast MRI was used to measure blood flow in the internal carotid and vertebral arteries (total arterial blood flow), the internal jugular veins and the straight and superior sagittal sinuses, as well as the aqueductal cerebrospinal fluid flow. Arterial pulsation and intracranial compliance indices were calculated. Results. Dementia and severe memory impairment were statistically significantly associated with an increase in the arterial pulsation index, intracranial compliance index and the aqueductal CSF stroke volume. Significant disturbances in brain executive function were also associated with a decrease in the total arterial blood flow, as well as the venous blood flow in the straight and superior sagittal sinuses. The characteristics of blood flow and cerebrospinal fluid are closely related, and the arterial pulsation index affects all the studied parameters. Conclusion. The severity of cognitive disturbance in CMA is determined by an increase in the arterial pulsation index, the intracranial compliance index and the aqueductal CSF stroke volume, while the severity of dysregulation disorders is determined by a concurrent decrease in the total arterial blood flow and venous blood flow in the straight and superior sagittal sinuses. The specific changes in blood flow and CSF flow and their interrelation in patients with cognitive impairment due to CMA suggest the pathogenetic importance of cerebral hydrodynamic disturbances in the aetiology of brain damage and the development of cognitive impairment in CMA.