Cognitive impairment of vascular origin: neuropathology of cognitive impairment of vascular origin.
[sneddon syndrome]
The term cognitive impairment of vascular origin is used to designate global cognitive deficits as well as focal neurological deficits such as aphasia, apraxia and agnosia of vascular/circulatory origin. It has been useful for identifying early clinical and neuroradiological alterations that might permit therapeutic strategies geared to curbing the progression of cerebrovascular disease. Multi-infarct encephalopathy, infarcts in strategic areas, lacunae and lacunar status, Binswanger's encephalopathy, hippocampal sclerosis, cortical granular atrophy and watershed infarcts are common lesions. Hypertension and vascular diseases such as arteriosclerosis, small blood vessel disease, inflammatory diseases of the blood vessels, Sneddon syndrome, cerebral amyloid angiopathies, cerebral autosomic dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), and Maeda's syndrome are causative of cognitive impairment of vascular origin. Other less common causes are hereditary endotheliopathy with retinopathy, neuropathy and strokes (HERNS), cerebro-retinian vasculopathy (CRV), hereditary vascular retinopathy (HVR) (all three linked to 3p21.1-p21.3), hereditary infantile hemiparesis with arteriolar retinopathy and leukoencephalopathy (HIHRATL) (not linked to 3p21), fibromuscular dysplasia, and moya-moya disease. Lack of uniformity of clinical manifestations, the variety of vascular diseases and circulatory factors, the diverse, but often convergent, neuropathological substrates, and the common association with unrelated neurodegenerative diseases in the elderly, make it hard to assume a single clinical approach in the diagnosis and treatment of cognitive impairment of vascular origin. Rather, environmental and genetic risk factors, underlying vascular diseases, associated systemic, metabolic and neurodegenerative diseases and identification of extent and distribution of lesions with morphological and functional neuroimaging methods should be applied in every individual patient.
