[Differential diagnosis and common pathology between Alzheimer's disease and vascular dementia]

Dementia due to both Alzheimer's disease (AD) and cerebrovascular disease (CVD) is designated as mixed dementia, or alternatively, AD with CVD. Cerebral amyloid angiopathy almost always accompanies AD, and causes lobar microbleeds, cortical subarachnoid hemorrhage and cortical microinfarctions. Dementia exclusively with cerebral amyloid angiopathy is a form of vascular dementia, while it is classified to AD when significant Alzheimer's pathology coexists. Between AD and vascular dementia there are common and overlapping pathologies, which is important for differential diagnosis of these diseases.

Vascular risk factors and cardiovascular outcomes in the Alzheimer's disease neuroimaging initiative

BACKGROUND

Vascular disease and medical factors are associated with cognitive decline and cardiovascular events. We examined the association between vascular risk factors and events in the Alzheimer's Disease Neuroimaging Initiative cohort.

METHODS

The association between vascular risk factors and cardiovascular events in a cohort of 810 participants, including 400 with mild cognitive impairment, 184 with Alzheimer's, and 226 controls was investigated using a longitudinal hazard model.

RESULTS

There were 31 events including 11 strokes, 7 myocardial infarctions, 5 revascularizations, and 8 deaths during an average follow-up of 31 months. Longitudinal cardiovascular event rates were low and similar between diagnostic groups.

CONCLUSIONS

All baseline vascular risk factors that were expected to be associated with longitudinal cardiovascular events were, or were trending toward, associating with cardiovascular events except atrial fibrillation, depression, and apolipoprotein E genotype. Despite differences in baseline vascular risk factors, longitudinal cardiovascular event rates were similar between diagnostic groups.

[Diffusion characteristics of subcortical structures in patients with subcortical ischemic vascular disease and its correlation to cognitive function]

OBJECTIVE

To explore the diffusion-tensor imaging (DTI) characteristics of normal-appearing white matter (NAWM) and normal-appearing gray matter (NAGM) on conventional magnetic resonance imaging (MRI) in patients with subcortical ischemic vascular disease (SIVD) and examine the relation of such features with the general cognitive function of the patients.

METHODS

DTI was performed in 46 SIVD patients and 34 age-matched control subjects with normal MRI findings. The apprarent diffusion coeeficient (ADC) and fractional anisotropy (FA) were measured within the regions of white matter lesions (WMLs), NAWM and NAGM. All the subjects were examined by neurologists with MMSE and clinical neurologic examination.

RESULTS

Compared with normal controls, SIVD subjects showed increased ADC values in the subcortical NAGM and NAWM in anterior periventricular and centrum semiovale, with decreased FA values in the caudate nucleus, thalamus and centrum semiovale. An increased severity of the WMLs was associated with increased ADC and decreased FA in the NAWM of SIVD patients. After controlling for age, the ADC in the NAWM of the posterior periventricular, NAWM and WMLs in the centrum semiovale, caudate nucleus and thalamus showed significant inverse correlations to MMSE; FA values in NAWM of the anterior periventricular and WMLs of the centrum semiovale were positively correlated to MMSE.

CONCLUSION

In SIVD patients, the NAWM and NAGM regions shown by MRI contain diffusion abnormalities, and these abnormalities shown by DTI are significantly correlated to the general cognitive function of the patients.

Vascular contributions to cognitive impairment and dementia: a statement for healthcare professionals from the american heart association/american stroke association

BACKGROUND AND PURPOSE

This scientific statement provides an overview of the evidence on vascular contributions to cognitive impairment and dementia. Vascular contributions to cognitive impairment and dementia of later life are common. Definitions of vascular cognitive impairment (VCI), neuropathology, basic science and pathophysiological aspects, role of neuroimaging and vascular and other associated risk factors, and potential opportunities for prevention and treatment are reviewed. This statement serves as an overall guide for practitioners to gain a better understanding of VCI and dementia, prevention, and treatment.

METHODS

Writing group members were nominated by the writing group co-chairs on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council Scientific Statement Oversight Committee, the Council on Epidemiology and Prevention, and the Manuscript Oversight Committee. The writing group used systematic literature reviews (primarily covering publications from 1990 to May 1, 2010), previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and, when appropriate, formulate recommendations using standard American Heart Association criteria. All members of the writing group had the opportunity to comment on the recommendations and approved the final version of this document. After peer review by the American Heart Association, as well as review by the Stroke Council leadership, Council on Epidemiology and Prevention Council, and Scientific Statements Oversight Committee, the statement was approved by the American Heart Association Science Advisory and Coordinating Committee.

RESULTS

The construct of VCI has been introduced to capture the entire spectrum of cognitive disorders associated with all forms of cerebral vascular brain injury-not solely stroke-ranging from mild cognitive impairment through fully developed dementia. Dysfunction of the neurovascular unit and mechanisms regulating cerebral blood flow are likely to be important components of the pathophysiological processes underlying VCI. Cerebral amyloid angiopathy is emerging as an important marker of risk for Alzheimer disease, microinfarction, microhemorrhage and macrohemorrhage of the brain, and VCI. The neuropathology of cognitive impairment in later life is often a mixture of Alzheimer disease and microvascular brain damage, which may overlap and synergize to heighten the risk of cognitive impairment. In this regard, magnetic resonance imaging and other neuroimaging techniques play an important role in the definition and detection of VCI and provide evidence that subcortical forms of VCI with white matter hyperintensities and small deep infarcts are common. In many cases, risk markers for VCI are the same as traditional risk factors for stroke. These risks may include but are not limited to atrial fibrillation, hypertension, diabetes mellitus, and hypercholesterolemia. Furthermore, these same vascular risk factors may be risk markers for Alzheimer disease. Carotid intimal-medial thickness and arterial stiffness are emerging as markers of arterial aging and may serve as risk markers for VCI. Currently, no specific treatments for VCI have been approved by the US Food and Drug Administration. However, detection and control of the traditional risk factors for stroke and cardiovascular disease may be effective in the prevention of VCI, even in older people.

CONCLUSIONS

Vascular contributions to cognitive impairment and dementia are important. Understanding of VCI has evolved substantially in recent years, based on preclinical, neuropathologic, neuroimaging, physiological, and epidemiological studies. Transdisciplinary, translational, and transactional approaches are recommended to further our understanding of this entity and to better characterize its neuropsychological profile. There is a need for prospective, quantitative, clinical-pathological-neuroimaging studies to improve knowledge of the pathological basis of neuroimaging change and the complex interplay between vascular and Alzheimer disease pathologies in the evolution of clinical VCI and Alzheimer disease. Long-term vascular risk marker interventional studies beginning as early as midlife may be required to prevent or postpone the onset of VCI and Alzheimer disease. Studies of intensive reduction of vascular risk factors in high-risk groups are another important avenue of research.

Vascular contributions to cognitive impairment and dementia: a statement for healthcare professionals from the american heart association/american stroke association

BACKGROUND AND PURPOSE

This scientific statement provides an overview of the evidence on vascular contributions to cognitive impairment and dementia. Vascular contributions to cognitive impairment and dementia of later life are common. Definitions of vascular cognitive impairment (VCI), neuropathology, basic science and pathophysiological aspects, role of neuroimaging and vascular and other associated risk factors, and potential opportunities for prevention and treatment are reviewed. This statement serves as an overall guide for practitioners to gain a better understanding of VCI and dementia, prevention, and treatment.

METHODS

Writing group members were nominated by the writing group co-chairs on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council Scientific Statement Oversight Committee, the Council on Epidemiology and Prevention, and the Manuscript Oversight Committee. The writing group used systematic literature reviews (primarily covering publications from 1990 to May 1, 2010), previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and, when appropriate, formulate recommendations using standard American Heart Association criteria. All members of the writing group had the opportunity to comment on the recommendations and approved the final version of this document. After peer review by the American Heart Association, as well as review by the Stroke Council leadership, Council on Epidemiology and Prevention Council, and Scientific Statements Oversight Committee, the statement was approved by the American Heart Association Science Advisory and Coordinating Committee.

RESULTS

The construct of VCI has been introduced to capture the entire spectrum of cognitive disorders associated with all forms of cerebral vascular brain injury-not solely stroke-ranging from mild cognitive impairment through fully developed dementia. Dysfunction of the neurovascular unit and mechanisms regulating cerebral blood flow are likely to be important components of the pathophysiological processes underlying VCI. Cerebral amyloid angiopathy is emerging as an important marker of risk for Alzheimer disease, microinfarction, microhemorrhage and macrohemorrhage of the brain, and VCI. The neuropathology of cognitive impairment in later life is often a mixture of Alzheimer disease and microvascular brain damage, which may overlap and synergize to heighten the risk of cognitive impairment. In this regard, magnetic resonance imaging and other neuroimaging techniques play an important role in the definition and detection of VCI and provide evidence that subcortical forms of VCI with white matter hyperintensities and small deep infarcts are common. In many cases, risk markers for VCI are the same as traditional risk factors for stroke. These risks may include but are not limited to atrial fibrillation, hypertension, diabetes mellitus, and hypercholesterolemia. Furthermore, these same vascular risk factors may be risk markers for Alzheimer disease. Carotid intimal-medial thickness and arterial stiffness are emerging as markers of arterial aging and may serve as risk markers for VCI. Currently, no specific treatments for VCI have been approved by the US Food and Drug Administration. However, detection and control of the traditional risk factors for stroke and cardiovascular disease may be effective in the prevention of VCI, even in older people.

CONCLUSIONS

Vascular contributions to cognitive impairment and dementia are important. Understanding of VCI has evolved substantially in recent years, based on preclinical, neuropathologic, neuroimaging, physiological, and epidemiological studies. Transdisciplinary, translational, and transactional approaches are recommended to further our understanding of this entity and to better characterize its neuropsychological profile. There is a need for prospective, quantitative, clinical-pathological-neuroimaging studies to improve knowledge of the pathological basis of neuroimaging change and the complex interplay between vascular and Alzheimer disease pathologies in the evolution of clinical VCI and Alzheimer disease. Long-term vascular risk marker interventional studies beginning as early as midlife may be required to prevent or postpone the onset of VCI and Alzheimer disease. Studies of intensive reduction of vascular risk factors in high-risk groups are another important avenue of research.

Ecology of the aging human brain

BACKGROUND

Alzheimer disease, cerebral vascular brain injury, and isocortical Lewy body disease (LBD) are the major contributors to dementia in community- and population-based studies.

OBJECTIVE

To estimate the prevalence of clinically silent forms of these diseases in cognitively normal (CN) adults.

DESIGN

Autopsy study.

SETTING

Community- and population based.

PARTICIPANTS

A total of 1672 brain autopsies from the Adult Changes in Thought study, Honolulu-Asia Aging Study, Nun Study, and Oregon Brain Aging Study, of which 424 met the criteria for CN.

MAIN OUTCOME MEASURES

Of these, 336 cases had a comprehensive neuropathologic examination of neuritic plaque density, Braak stage for neurofibrillary tangles, LB distribution, and number of cerebral microinfarcts.

RESULTS

Forty-seven percent of CN cases had moderate or frequent neuritic plaque density; of these, 6% also had Braak stage V or VI for neurofibrillary tangles. Fifteen percent of CN cases had medullary LBD; 8% also had nigral and 4% isocortical LBD. The presence of any cerebral microinfarcts was identified in 33% and of high-level cerebral microinfarcts in 10% of CN individuals. Overall, the burden of lesions in each individual and their comorbidity varied widely within each study but were similar across studies.

CONCLUSIONS

These data show an individually varying complex convergence of subclinical diseases in the brain of older CN adults. Appreciating this ecology should help guide future biomarker and neuroimaging studies and clinical trials that focus on community- and population-based cohorts.

[Functional MRI and cognition assessment in subcortical ischemic vascular disease]

OBJECTIVE

To evaluate the imaging features of patients with vascular cognitive impairment (VCI) induced by Subcortical Ischemic Vascular Disease (SIVD), through magnetic resonance diffusion tensor imaging (DTI) and proton spectroscopy (MRS) technology.

METHODS

A total of 52 patients with SIVD were enrolled. After analysis of scale score, 32 patients with cognitive impairment were assigned to VCI group and 20 patients with no cognitive impairment were assigned to control group. Both group received DTI and MRS examination. The mean values of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of the bilateral temporal, frontal, parietal and occipital white matter regions as well as in the bilateral centrum semiovale were calculated. The peak value of MRS of N-acetyl aspartate (NAA), choline (Cho), creatine (Cr) and phaseomannite (mI) were calculated.

RESULTS

Compared with control group, FA decreased in the region of temporal, frontal, parietal as well as in the centrum semiovale, and ADC increased in VCI group (P < 0.05). In the frontal regions and centrum semiovale, the VCI patients had a significant FA decrease. The ADC value increased obviously in the temporal lobe. Spectrum analysis results showed, NAA/Cr was lower than control group in VCI group in the frontal lobe (1.43 ± 0.08 vs 1.53 ± 0.92), while mI/Cr was higher than control group in the temporal lobe (0.51 ± 0.06 vs 0.46 ± 0.07) (P < 0.05).

CONCLUSION

FA in the temporal and centrum semiovale regions of VCI group and NAA in the temporal white matter regions decreased obviously. DTI and MRS could provide a reference value for early diagnosis and assessment of VCI.

Endothelial progenitor cells with Alzheimer's disease

BACKGROUND

Endothelial dysfunction is thought to be critical events in the pathogenesis of Alzheimer's disease (AD). Endothelial progenitor cells (EPCs) have provided insight into maintaining and repairing endothelial function. To study the relation between EPCs and AD, we explored the number of circulating EPCs in patients with AD.

METHODS

A total of 104 patients were recruited from both the outpatients and inpatients of the geriatric neurology department at General Hospital, Tianjin Medical University. Consecutive patients with newly diagnosed AD (n = 30), patients with vascular dementia (VaD, n = 34), and healthy elderly control subjects with normal cognition (n = 40) were enrolled after matching for age, gender, body mass index, medical history, current medication and Mini Mental State Examination. Middle cerebral artery flow velocity was examined with transcranial Doppler. Endothelial function was evaluated according to the level of EPCs, and peripheral blood EPCs was counted by flow cytometry.

RESULTS

There were no significant statistical differences of clinical data in AD, VaD and control groups (P > 0.05). The patients with AD showed decreased CD34-positive (CD34(+)) or CD133-positive (CD133(+)) levels compared to the control subjects, but there were no significant statistical differences in patients with AD. The patients with AD had significantly lower CD34(+)CD133(+) EPCs (CD34 and CD133 double positive endothelial progenitor cells) than the control subjects (P < 0.05). In the patients with AD, a lower CD34(+)CD133(+) EPCs count was independently associated with a lower Mini-Mental State Examination score (r = 0.514,P = 0.004). Patients with VaD also showed a significant decrease in CD34(+)CD133(+) EPCs levels, but this was not evidently associated with the Mini-Mental State Examination score. The changes of middle cerebral artery flow velocity were similar between AD and VaD. Middle cerebral artery flow velocity was decreased in the AD and VaD groups and significantly lower than the normal control group (P < 0.01). There was no significant difference of the blood flow velocity between the AD and VaD patients (P > 0.05).

CONCLUSIONS

The results provided evidence that patients with AD have reduced circulating EPCs. Endothelial function is impaired in patients with AD and vascular factors have a role in the pathogenesis of AD. CD34(+)CD133(+) EPCs may be a novel biomarker of AD dementia.

[Carasil]

Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is a single-gene disorder directly affecting the cerebral small blood vessels, that is caused by mutations in the HTRA1 gene encoding HtrA serine peptidase/protease 1 (HTRA1). CARASIL is the second known genetic form of ischemic, nonhypertensive, cerebral small-vessel diseases with an identified gene, following CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy). The exact prevalence of CARASIL is currently unknown, and so far about 50 patients have been reported, most of them from Japan and two from China. Genetically no founder haplotype has been identified, and so the disease is expected to be found more widely. The main clinical manifestations are ischemic stroke or stepwise deterioration in brain functions, progressive dementia, premature baldness, and attacks of severe low back pain or spondylosis deformans/disk herniation. The most characteristic brain MRI findings are homogeneously confluent white-matter changes and multiple lacunar infarctions in the basal ganglia and thalamus. Histopathologically, CARASIL is characterized by intense arteriosclerosis, mainly in the small penetrating arteries, without granular osmiophilic materials (GOM) or amyloid deposition. CARASIL is a prototype single-gene disorder of cerebral small vessels, secondary to and distinct from CADASIL. CARASIL-associated mutant HTRA1s exhibited decreased protease activity and failed to repress transforming growth factor-β (TGF-β) family signaling, indicating that the increased TGF-β signaling causes arteriopathy in CARASIL. Therefore, HTRA1 represents another new gene to be considered in future studies of the mechanisms and therapeutic strategies of cerebral small-vessel diseases, as well as alopecia and degenerative vertebral/disk diseases.

[Protective effect of valsartan or/and ligustrazine on hippocampal neuronal loss in rats with vascular dementia]

OBJECTIVE

To investigate the effect of Valsartan and Ligustrazine on hippocampal neuronal loss and the ability of learning and memory of rats with vascular dementia.

METHODS

Vascular dementia was induced in rats by blocking bilateral carotid artery repeatedly and intraperitoneal injection of sodium nitroprusside. The vacuity learning and memory of the rats were measured with Morris water maze. The plasma AVP and ANGII were determined by radio-immunity methods. The activities of SOD, GSH-Px and MDA in hippocampal tissues were detected by chemistry colorimetry. The hippocampal neuronal loss was observe with light microscope.

RESULTS

Both valsartan and ligustrazine shortened escape latency (P < 0.05), and increased the numbers of rats crossing platform and the time spent in target quadrant (P < 0.01). Valsartan decreased plasma AVP, whereas ligustrazine increased plasma AVP. Both valsartan and ligustrazine increased plasma ANGII (P < 0.01), increased the activities of SOD and GSH-PX in hippocampal tissues, and decreased MDA activities in hippocampal tissues (P < 0.05). The damages in structure, number and volume of hippocampal neuron cells were reduced by Valsartan and Ligustrazine. The combined use of Valsartan and Ligustrazine produced greater effects than either of the drugs alone in all of the indicators except for plasma AVP.

CONCLUSION

Valsartan or/and Ligustrazine have protective effect on hippocampal neuronal loss in rats with vascular dementia, possibly through inhibiting RAS activation and free radical formation induced by cerebral ischemia-reperfusion.

The clinical importance of white matter hyperintensities on brain magnetic resonance imaging: systematic review and meta-analysis

OBJECTIVES

To review the evidence for an association of white matter hyperintensities with risk of stroke, cognitive decline, dementia, and death.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed from 1966 to 23 November 2009.

STUDY SELECTION

Prospective longitudinal studies that used magnetic resonance imaging and assessed the impact of white matter hyperintensities on risk of incident stroke, cognitive decline, dementia, and death, and, for the meta-analysis, studies that provided risk estimates for a categorical measure of white matter hyperintensities, assessing the impact of these lesions on risk of stroke, dementia, and death.

DATA EXTRACTION

Population studied, duration of follow-up, method used to measure white matter hyperintensities, definition of the outcome, and measure of the association of white matter hyperintensities with the outcome.

DATA SYNTHESIS

46 longitudinal studies evaluated the association of white matter hyperintensities with risk of stroke (n=12), cognitive decline (n=19), dementia (n=17), and death (n=10). 22 studies could be included in a meta-analysis (nine of stroke, nine of dementia, eight of death). White matter hyperintensities were associated with an increased risk of stroke (hazard ratio 3.3, 95% confidence interval 2.6 to 4.4), dementia (1.9, 1.3 to 2.8), and death (2.0, 1.6 to 2.7). An association of white matter hyperintensities with a faster decline in global cognitive performance, executive function, and processing speed was also suggested.

CONCLUSION

White matter hyperintensities predict an increased risk of stroke, dementia, and death. Therefore white matter hyperintensities indicate an increased risk of cerebrovascular events when identified as part of diagnostic investigations, and support their use as an intermediate marker in a research setting. Their discovery should prompt detailed screening for risk factors of stroke and dementia.

[Effect of Shengmaisan on learning and memory abilities and hippocampal nitric oxide synthase expression and neuronal apoptosis in rats with vascular dementia]

OBJECTIVE

To observe the effect of Shengmaisan on the learning and memory abilities and the expression of nitric oxide synthase and neuron apoptosis in the hippocampus of rats with vascular dementia (VD), and explore the mechanism of Shengmaisan for treatment of VD.

METHODS

Wistar rats were divided randomly in to normal control group, sham-operated group, VD model group, high-dose Shengmaisan group, low-dose Shengmaisan group, and nimodipine group. In the latter 4 groups, bilateral common carotid artery occlusion (BCCAO) was performed to establish rat models of VD followed by intragastric administration of Shengmaisan at 10 or 30 g.kg(-1).day(-1) or nimodipine at 20 g.kg(-1).day(-1) accordingly. The rats in the control, sham-operated and model groups were given saline in the same manner. The improvement of learning and memory abilities of the rats was assessed using Morris water maze test, and NOS activity and neuronal apoptosis in the hippocampus were determined after the treatment.

RESULTS

The learning and memory ability and hippocampal NOS activity and neuronal apoptosis in low-dose Shengmaisan group and nimodipine group were significantly different from those in the VD model group (P<0.01), but no significant differences were found between high-dose Shengmaisan group and nimodipine group (P>0.05).

CONCLUSION

Shengmaisan can significantly improve the learning and memory abilities of VD rats but may not be able to totally reverse the damage. The therapeutic effect of Shengmaisan might be related to its effect in decreasing NOS activity and inhibiting neuronal apoptosis in the hippocampus.

Vascular pathology in the aged human brain

Cerebral atherosclerosis (AS), small vessel disease (SVD), and cerebral amyloid angiopathy (CAA) are the most prevalent arterial disorders in the aged brain. Pathogenetically, AS and SVD share similar mechanisms: plasma protein leakage into the vessel wall, accumulation of lipid-containing macrophages, and fibrosis of the vessel wall. CAA, on the other hand, is characterized by the deposition of the amyloid β-protein in the vessel wall. Despite these differences between CAA, AS and SVD, apolipoprotein E (apoE) is involved in all three disorders. Such a pathogenetic link may explain the correlations between AS, SVD, CAA, and Alzheimer’s disease in the brains of elderly individuals reported in the literature. In addition, AS, SVD, and CAA can lead to tissue lesions such as hemorrhage and infarction. Moreover, intracerebral SVD leads to plasma protein leakage into the damaged vessel wall and into the perivascular space resulting in a blood–brain barrier (BBB) dysfunction. This SVD-related BBB dysfunction is considered to cause white matter lesions (WMLs) and lacunar infarcts. In this review, we demonstrate the relationship between AS, SVD, and CAA as well as their contribution to the development of vascular tissue lesions and we emphasize an important role for apoE in the pathogenesis of vessel disorders and vascular tissue lesions as well as for BBB dysfunction on WML and lacunar infarct development.

[Post-stroke vascular dementia: risk factors and clinical neuro-imaging features]

To analyze the status of risk factors for post-stroke vascular dementia, 128 patients with post-stroke dementia, aged from 50-79 years, have been studied. A control group included 125 patients, aged 50-79 years, with moderate cognitive impairment after stroke. A coronary heart disease was a significant risk factor for the patients aged from 50-59; coronary heart disease, diabetes mellitus, overweight and hyperlipidemia were significant risk factors for the aged 60-69, diabetes mellitus, overweight and hyperlipidemia were significant risk factors for the aged 70-79. The stroke-related factors were cerebral infarction in left hemisphere, frontal and temporo-occipital infarction, thalamic, basal ganglion; cerebral white-matter lesions. The mathematical model of post-stroke dementia prediction was created for patients with post-stroke moderate cognitive impairment.

[Diagnosis and choice of therapy of arterial hypertension]

The clinical concept of evolvement, chronisation and development of hypertensive disease is expounded in the light of recent basic research with reference to the influence of hypotensive (symptomatic) and pathogenetic (basal) therapy on its clinical features. The main stages of pathogenesis, risk of complications, and concomitant diseases are discussed. Analysis of main physiological mechanisms underlying regulation of hemodynamics is presented at different steps of formation of the cardiovascular system and angiogenesis from fetal life to the outset of involutional processes. Effect of environmental factors on these processes and compensatory reactions are considered. Algorithm of differential diagnosis of arterial hypertension and hypertensive disease is proposed along with the approaches to the choice of adequate therapeutic modalities, their role in the treatment and prevention of complications. A review of distribution of hypertensive disease and cardiovascular disorders in developed countries is focused on the elucidation of their causes and prophylactic measures.

[Vascular cognitive impairment]

Vascular cognitive impairment is more prevalent than vascular dementia, but at present this condition is not recognized adequately. Vascular cognitive impairment does not manifest itself as dementia after stroke, but as gradually commencing cognitive impairment with or without a gait disorder. The clinical picture is caused by white matter damage and multiple lacunar strokes, sometimes called 'silent' strokes. Patients with vascular cognitive impairment have an increased risk of cardiovascular events, falling, and further cognitive decline, eventually evolving into dementia. It is important to recognize these patients and to provide advice and appliances and equipment, treat cardiovascular risk factors and prevent the complications of falling.

[Risk factors and prediction of poststroke dementia]

To study the status of risk factors for poststroke dementia, 128 patients, aged 50-79 years, with poststroke dementia have been examined. A control group included 125 patients with moderate cognitive impairment after stroke. Coronary heart disease was a significant factor at the age from 50 to 59; coronary heart disease, diabetes mellitus, overweight and hyperlipidemia were significant risk factors at the age from 60 to 69 and diabetes mellitus, overweight and hyperlipidemia were significant risk factors at the age from 70 to 79. The neuroimaging study revealed that the development of dementia in patients with moderate cognitive impairment was related to the localization of focal poststroke changes in the left hemisphere, frontal and temporal-occipital areas, frontal white matter, thalamus, basal ganglia as well as to the prevalence and severity of subcortical leukoareosis in the frontal areas, basal ganglia and thalamus. An individual prediction model for poststroke dementia in patients with moderate cognitive impairment has been worked out.

Arterioles in cerebral amyloid angiopathy and vascular dementia

BACKGROUND

Small cerebrovascular lesions are one of the most important factors in cerebral amyloid angiopathy (CAA) and vascular dementia (VaD). We analyzed the difference of arteriolar pathology between CAA patients (CAAs) and vascular dementia patients without CAA (VaDs).

METHODS

Ten deceased CAAs and twelve deceased VaDs were available for this study. Five deceased patients without known cerebrovascular diseases served as controls. These patients were all autopsy cases. All transversely cut arterioles in the gray matter and white matter with an external diameter equal to or larger than 30 microm and with a maximum of 300 microm were examined. The internal and external diameters of arterioles were measured.

RESULTS

The external diameter of gray matter arterioles in the CAAs was significantly greater than in controls. In gray matter arterioles, the diameter of the lumen in VaDs was markedly smaller than in the CAAs, whereas there was no significant difference between CAAs and controls. CAAs and VaDs may cause remarkable thickening of the arteriolar walls in either white matter or gray matter. The sclerotic index of arterioles in VaDs was significantly greater than in CAAs and controls.

CONCLUSIONS

Stenosis of arterioles occurred in both CAA and VaD, but the tendency was greater in VaD. Arterioles of CAA were also expanded in gray matter, which may be related to lobar hemorrhage. The loss and/or degeneration of vascular smooth muscle cells was predominant in CAA, while the over-proliferation of vascular smooth muscle cells was greater in VaD.

White matter diffusion is higher in Binswanger disease than in idiopathic normal pressure hydrocephalus

OBJECTIVES

To explore diagnostic differences in periventricular white matter (PWM) and deep white matter (DWM) diffusion patterns in patients diagnosed with Binswanger disease (BD) and in patients diagnosed with probable idiopathic normal pressure hydrocephalus (INPH) using diffusion-weighted imaging (DWI).

MATERIALS AND METHODS

Apparent diffusion coefficient (ADC) values were calculated in the PWM and DWM in patients with INPH (n = 14) and BD (n = 9) and in controls (n = 10) using an spin echo echo planar imaging single-shot diffusion sequence and region of interest (ROI) analysis.

RESULTS

Patients with BD had higher ADC values than patients with INPH in the PWM and DWM in the frontal and occipital regions (P < 0.05) and higher values than controls in the frontal PWM and DWM (P < 0.01). After shunt surgery, ADC values were reduced in the frontal PWM in patients with INPH (P < 0.05).

CONCLUSIONS

Increased diffusion in the PWM and DWM in patients with BD may reflect irreversible breakdown of axonal integrity caused by the subcortical ischaemic vascular disease. By contrast, the normal white matter diffusion in patients with INPH indicates structurally intact axons, compatible with the reversibility of this disorder. DWI may be an important non-invasive diagnostic tool for differentiating between INPH and BD and identifying shunt responders and reversible brain damage in patients with INPH. However, the overlap between patients with INPH and BD in this study restricts the predictive value of the method.

A multicenter, open-label, 24-week follow-up study for efficacy on cognitive function of donepezil in Binswanger-type subcortical vascular dementia

OBJECTIVES

To evaluate the efficacy and tolerability of donepezil in patients with Binswanger type subcortical vascular dementia.

METHODS

Patients (n = 34, mean age = 71.8 + 7.12) with Binswanger type subcortical vascular dementia from 8 multicenter, according to clinical and neuroradiological working criteria, were selected to receive donepezil 5 mg/day (n = 2) or donepezil 10 mg/day (n = 32, after 5 mg/day) for 24 weeks. Our primary endpoints were change from baseline to weeks 12 and 24 in the Seoul Neuropsychological Screening Battery-Dementia version (SNSB-D) and the Korean version of neuropsychiatric inventory (K-NPI).

RESULTS

A total of 24 patients received donepezil completed the study (mean age = 72.0 + 7.5 K-Mini-Mental State Examination [MMSE] = 21.0 + 5.1). After 12 weeks and 24 weeks, patients showed improvements in cognitive function on the SNSB-D compared baseline of 16.29 points at 12 weeks (P < .05) and 12.44 points at 24 weeks (P < .05). Significant improvements were shown in only memory domain, immediate verbal recall and delayed recall tests. Subgroup with better cognitive function (SNSB-D > 100) were more effective in frontal and memory domains than the other subgroup (SNSB-D < 100). Withdrawal rates due to adverse events were very low (4.16%).

CONCLUSIONS

Donepezil-treated patients with Binswanger type subcortical vascular dementia demonstrated significant improvement in cognition compared with baseline, and donepezil was well tolerated.

DIFFERENTIAL PERFORMANCE OF ALZHEIMER'S AND VASCULAR DEMENTIA PATIENTS ON A BRIEF BATTERY OF NEUROPSYCHOLOGICAL TESTS

The purpose of this article was to examine the differences in neuropsychological test performance between groups with Alzheimer's and vascular dementia. Patients included in this study were those diagnosed with Alzheimer's Disease (AD) or Vascular Dementia (VAD) through a series of neuroradiological tests that included at a minimum a CT or MRI scan and a SPECT scan. Of the 113 AD patients, the average age was 80.08 (SD = 5.91) years and average education was 12.85 (SD = 2.88). Of the 109 VAD patients, average age was 78.67 (SD = 5.35) and average education was 13.10 (SD = 2.65). Tests included selected subtests of the WAIS-R, Word Fluency, Rey Figure, Boston Naming Test, Math, Reading, and subtests from the WMS-R. Five tests showed significant differences in favor of the VAD group: Information, Similarities, Picture Completion, WRAT Mathematics, and the Boston Naming Test. Both groups did well on Reading, while both did poorly on the Rey and Word Fluency. Although both groups did poorly on memory measures, the VAD patients showed better performance. Overall, the two groups did not differ significantly on the more complex tests, but did differ on more basic tests and all the memory tests. This pattern of similar score on complex tests and different scores on basic tests demonstrates the theory that both types of dementia affected higher, more complex skills. Differences between the groups were only apparent when basic skills were compared and were not reflected in more complex and neuropsychologically "sensitive" tests.

Microvasculature changes and cerebral amyloid angiopathy in Alzheimer's disease and their potential impact on therapy

The introduction of immunotherapy and its ultimate success will require re-evaluation of the pathogenesis of Alzheimer's disease particularly with regard to the role of the ageing microvasculature and the effects of APOE genotype. Arteries in the brain have two major functions (a) delivery of blood and (b) elimination of interstitial fluid and solutes, including amyloid-beta (Abeta), along perivascular pathways (lymphatic drainage). Both these functions fail with age and particularly severely in Alzheimer's disease and vascular dementia. Accumulation of Abeta as plaques in brain parenchyma and artery walls as cerebral amyloid angiopathy (CAA) is associated with failure of perivascular elimination of Abeta from the brain in the elderly and in Alzheimer's disease. High levels of soluble Abeta in the brain correlate with cognitive decline in Alzheimer's disease and reflect the failure of perivascular drainage of solutes from the brain and loss of homeostasis of the neuronal environment. Clinically and pathologically, there is a spectrum of disease related to functional failure of the ageing microvasculature with "pure" Alzheimer's disease at one end of the spectrum and vascular dementia at the other end. Changes in the cerebral microvasculature with age have a potential impact on therapy with cholinesterase inhibitors and especially on immunotherapy that removes Abeta from plaques in the brain, but results in an increase in severity of CAA and no clear improvement in cognition. Drainage of Abeta along perivascular pathways in ageing artery walls may need to be improved to maximise the potential for improvement of cognitive function with immunotherapy.

[Effect of geniposide on vascular dementia in rats]

OBJECTIVE

To investigate the effect of geniposide on vascular dementia (VaD) in rats.

METHODS

VaD rat model was established by permanent ligation of bilateral common carotid arteries. Morris water maze performance was assessed after 4 weeks of treatment with geniposide, followed by pathological examinations of hippocampus and cerebral cortex.

RESULTS

The VaD rats had significantly longer escape latency and lower percentage of activities in platform quadrant than the rats in the sham surgery group (P<0.05). The VaD rats treated with geniposide [50 mg/(kg x d), 75 mg/(kg x d)] had significantly shorter escape latency (except the first day of the test) and significantly higher percentage of activities in platform quadrant than the VaD rats without treatment (P<0.05). No significant differences were found between the geniposide treated group and the Donepezil treated group and the sham surgery control group. Geniposide significantly alleviated neurons,apoptosis and necrosis induced by chronic cerebral hypoperfusion of cortex and hippocampus.

CONCLUSION

Chronic cerebral hypoperfusion can induce cognitive impairment. Geniposide can improve cognitive ability of Vascular Dementia in rats. This may represent a potential treatment strategy for vascular dementia.