2023 年 9 巻 p. 9-21
Cerebrovascular disorders are inherently heterogenous. They entail a variety of clinical, pathological and cognitive features. In recent years, cerebral small vessel disease (SVD) has been at the forefront mainly because it is attributed to a common cause of strokes and responsible for long-term sequalae including disability. Advances in neuroimaging, particularly magnetic resonance imaging (MRI) have expounded on the radiological definition of SVD involving white matter hyperintensities and parenchymal changes whereas it is difficult to appreciate covert pathology in intracranial arteries and arterioles. SVD pathology incorporates small cortical and subcortical infarcts, microinfarcts, microbleeds, perivascular spacing and white matter attenuation. Cerebral vessels undergo loss of smooth muscle cells and disruption of the extracellular matrix within basement membranes with consequences on interstitial fluid drainage. The distribution and quantity of SVD pathology involving both parenchymal lesions and arteriopathy vary with age, gender, vascular risk factors and genetically determined disorders. However, both types of lesions invariably correlate with progression of impairment or worsen cognitive function. SVD is part and parcel of almost all types of dementias. The incorporation of SVD as a biomarker is much warranted in the biological definition of dementia. Therapeutic interventions to reduce SVD pathology via risk control will have a major impact on the burden of dementia.
