[Subcortical vascular dementia: significance in the differential diagnosis of dementia].

Subcortical vascular dementia (SVD) is a subtype of vascular dementia which constitutes approximately half of vascular dementia in Japan. It is featured by hypertensive small vessel disease such as white matter lesions and lacunar infarctions. The clinical and pathological features of SVD are relatively uniform. White matter lesions may remain asymptomatic but may develop subcortical dementia and Parkinsonism, if neural network function is impaired severe enough. SVD and CAA are considered to be a subcortical and cortical counterpart of small vessel disease, respectively, and the latter is closely associated with Alzheimer's disease. Therapeutic strategy for SVD is classified to the remedies for vascular risk factors and anti-dementia treatment. Anti-choline esterase inhibitors and memantine may be beneficial for SVD patients, but are not approved as therapeutic agents for vascular dementia.