The underdiagnosis of the vascular contribution to dementia.
ABSTRACT The existence of vascular dementia (VaD) was first identified by Marie, who described the etat lacunaire, and by Binswanger, who identified white matter lesions in the brain subcortical areas. Alois Alzheimer, when defining the disease now bearing his name, did so in a patient with a presenile onset. The majority of demented elderly people were then believed to have cerebral arteriosclerosis underlying their cognitive decline. The role of cortical vascular lesions, while clear to clinicians, was highlighted only later, by the pathological studies of Tomlinson et al. and the clinical demonstrations of Hachinski et al. who have defined multi-infarct dementia. Lately, the emphasis shifted to pathogenic mechanisms for vascular brain disease with the identification of a multitude of processes, such as lipohyalinosis, cardiac dysfunction and genetic causes, to name only a few. Epidemiologic studies have demonstrated the high frequency of vascular lesions in brains of demented individuals, as well as the fact that vascular factors can contribute to Alzheimer's disease (AD). Moreover, many factors, which were identified as contributing to cerebrovascular disease in general and VaD in particular, are frequently suspected as predisposing to AD as well. All these considerations converge to the realization that vascular components are extremely important in the pathogenesis of old-age dementia and that prevention and perhaps treatment of dementia are within reach. These surprising findings highlight the importance of mixed vascular-degenerative dementia as a disorder that has to be properly defined.
Article: Vascular Dementia[Show abstract] [Hide abstract]
ABSTRACT: The purpose of this review is to highlight existing literature on the epidemiology, pathophysiology, and novel risk factors for vascular dementia. We further examine the evidence linking chronic brain hypoperfusion induced by a variety of cardiovascular diseases to the development of vascular dementia. In the elderly, in whom cerebral perfusion is diminished by the aging process, additional reduction in cerebral blood flow stemming from exposure to potentially modifiable vascular risk factors increases the probability of developing vascular dementia. Finally, we discuss the association between obstructive sleep apnea, an underrecognized risk factor for stroke, and vascular dementia. Obstructive sleep apnea is linked to cerebrovascular disease through many intermediary vascular risk factors and may directly cause cerebrovascular damage through microvacular disease. Insight into how cardiovascular risk factors induce vascular dementia offers an enhanced understanding of the multifactorial pathophysiology by this disorder and ways of preventing and managing the cerebrovascular precursors of vascular dementia. Many vital questions about the relation of obstructive sleep apnea with stroke and vascular dementia are still unanswered and await future well-designed studies.09/2013; 2(3). DOI:10.1007/s13670-013-0054-5
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ABSTRACT: Alzheimer's disease (AD) is closely linked to cardiovascular risk factors.Clinical Interventions in Aging 01/2014; 9:1115-21. DOI:10.2147/CIA.S63337 · 2.65 Impact Factor
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ABSTRACT: Although selective neurodegeneration of nigro-striatal dopaminergic neurons is widely accepted as a cause of Parkinson's disease (PD), the role of vascular components in the brain in PD pathology is not well understood. However, the neurodegeneration seen in PD is known to be associated with neuroinflammatory-like changes that can affect or be associated with brain vascular function. Thus, dysfunction of the capillary endothelial cell component of neurovascular units present in the brain may contribute to the damage to dopaminergic neurons that occurs in PD. An animal model of PD employing acute, sub-acute and chronic exposures of mice to methyl-phenyl-tetrahydropyridine (MPTP) was used to determine the extent to which brain vasculature may be damaged in PD. Fluoro-Turquoise gelatin labeling of microvessels and endothelial cells was used to determine the extent of vascular damage produced by MPTP. In addition, tyrosine hydroxylase (TH) and NeuN were employed to detect and quantify dopaminergic neuron damage in the striatum (CPu) and substantia nigra (SNc). Gliosis was evaluated through GFAP immunohistochemistry. MPTP treatment drastically reduced TH immunoreactive neurons in the SNc (20.68±2.83 in acute; 22.98±2.14 in sub-acute; 10.20 ±2.24 in chronic vs 34.88 ±2.91in controls; p<0.001). Similarly, TH immunoreactive terminals were dramatically reduced in the CPu of MPTP treated mice. Additionally, all three MPTP exposures resulted in a decrease in the intensity, length, and number of vessels in both CPu and SNc. Degenerative vascular changes such as endothelial cell 'clusters' were also observed after MPTP suggesting that vasculature damage may be modifying the availability of nutrients and exposing blood cells and/or toxic substances to neurons and glia. In summary, vascular damage and degeneration could be an additional exacerbating factor in the progression of PD, and therapeutics that protect and insure vascular integrity may be novel treatments for PD.Current neurovascular research 11/2013; 11(1). DOI:10.2174/1567202610666131124234506 · 3.23 Impact Factor