Vascular Cognitive Impairment through the Looking Glass of Transcranial Magnetic Stimulation

In the last years, there has been a significant growth in the literature exploiting transcranial magnetic stimulation (TMS) with the aim at gaining further insights into the electrophysiological and neurochemical basis underlying vascular cognitive impairment (VCI). Overall, TMS points at enhanced brain cortical excitability and synaptic plasticity in VCI, especially in patients with overt dementia, and neurophysiological changes seem to correlate with disease process and progress. These findings have been interpreted as part of a glutamate-mediated compensatory effect in response to vascular lesions. Although a single TMS parameter owns low specificity, a panel of measures can support the VCI diagnosis, predict progression, and possibly identify early markers of "brain at risk" for future dementia, thus making VCI a potentially preventable cause of both vascular and degenerative dementia in late life. Moreover, TMS can be also exploited to select and evaluate the responders to specific drugs, as well as to become an innovative rehabilitative tool in the attempt to restore impaired neural plasticity. The present review provides a perspective of the different TMS techniques by further understanding the cortical electrophysiology and the role of distinctive neurotransmission pathways and networks involved in the pathogenesis and pathophysiology of VCI and its subtypes.

Impact of Hypertension on Cognitive Function: A Scientific Statement From the American Heart Association

BACKGROUND

Age-related dementia, most commonly caused by Alzheimer disease or cerebrovascular factors (vascular dementia), is a major public health threat. Chronic arterial hypertension is a well-established risk factor for both types of dementia, but the link between hypertension and its treatment and cognition remains poorly understood. In this scientific statement, a multidisciplinary team of experts examines the impact of hypertension on cognition to assess the state of the knowledge, to identify gaps, and to provide future directions.

METHODS

Authors with relevant expertise were selected to contribute to this statement in accordance with the American Heart Association conflict-of-interest management policy. Panel members were assigned topics relevant to their areas of expertise, reviewed the literature, and summarized the available data.

RESULTS

Hypertension disrupts the structure and function of cerebral blood vessels, leads to ischemic damage of white matter regions critical for cognitive function, and may promote Alzheimer pathology. There is strong evidence of a deleterious influence of midlife hypertension on late-life cognitive function, but the cognitive impact of late-life hypertension is less clear. Observational studies demonstrated a cumulative effect of hypertension on cerebrovascular damage, but evidence from clinical trials that antihypertensive treatment improves cognition is not conclusive.

CONCLUSIONS

After carefully reviewing the literature, the group concluded that there were insufficient data to make evidence-based recommendations. However, judicious treatment of hypertension, taking into account goals of care and individual characteristics (eg, age and comorbidities), seems justified to safeguard vascular health and, as a consequence, brain health.

A randomised controlled trial of calcium channel blockade (CCB) with Amlodipine For the treatment oF subcortical ischaEmic vasCular demenTia (AFFECT): study protocol

BACKGROUND

Vascular dementia is the second most common cause of dementia affecting over seven million people worldwide, yet there are no licensed treatments. There is an urgent need for a clinical trial in this patient group. Subcortical ischaemic vascular dementia is the most common variant of vascular dementia. This randomised trial will investigate whether use of calcium channel blockade with amlodipine, a commonly used agent, can provide the first evidence-based pharmacological treatment for subcortical ischaemic vascular dementia.

METHODS/DESIGN

This is a randomised controlled trial of calcium channel blockade with Amlodipine For the treatment oF subcortical ischaEmic vasCular demenTia (AFFECT) to test the hypothesis that treatment with amlodipine can improve outcomes for these patients in a phase IIb, multi-centre, double-blind, placebo-controlled randomised trial. The primary outcome is the change from baseline to 12 months in the Vascular Dementia Assessment Scale cognitive subscale (VADAS-cog). Secondary outcomes include cognitive function, executive function, clinical global impression of change, change in blood pressure, quantitative evaluation of lesion accrual based on magnetic resonance imaging (MRI), health-related quality of life, activities of daily living, non-cognitive dementia symptoms, care-giver burden and care-giver health-related quality of life, cost-effectiveness and institutionalisation. A total of 588 patients will be randomised in a 1:1 ratio to either amlodipine or placebo, recruited from sites across the UK and enrolled in the trial for 104 weeks.

DISCUSSION

There are no treatments licensed for vascular dementia. The most common subtype is subcortical ischaemic vascular dementia (SIVD). This study is designed to investigate whether amlodipine can produce benefits compared to placebo in established SIVD. It is estimated that the numbers of people with VaD and SIVD will increase globally in the future and the results of this study should inform important treatment decisions.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN31208535 . Registered on 7 March 2014.

New approaches to understanding dementia

Improving understanding of brain disorders is likely to be one of the core aims of physiological research in the 21st century. This article, the second in a four-part series, looks at the main types of dementia and explores emerging theories about how the condition develops. These theories are improving our understanding of the neurodegeneration that characterises the most common forms of dementia, and will help improve care for those living with dementia.

Gradual Carotid Artery Stenosis in Mice Closely Replicates Hypoperfusive Vascular Dementia in Humans

BACKGROUND

Existing rodent models of vascular cognitive impairment (VCI) show abrupt changes in cerebral blood flow (CBF) and do not reliably replicate the clinical pathogenesis of VCI. We therefore aimed to develop a mouse model of VCI where CBF is gradually reduced, followed by subsequent progressive motor and cognitive impairment, after surgical intervention.

METHODS AND RESULTS

Adult C57BL/6J male mice were subjected to gradual common carotid artery stenosis (GCAS) surgery by using an ameroid constrictor vessel-constricting device with an inner diameter of 0.75 mm. The common carotid arteries narrowed gradually after gradual constriction of ameroid constrictors over 28 days after GCAS, with subsequent 79.3% area stenosis as a result of smooth muscle cell proliferation and macrophage infiltration in the tunica intima. The 28-day survival rate was 91%. Arterial spin labeling demonstrated gradual and continuous reduction of cortical and subcortical CBF (ratio to the preoperative value) to 54.6% and 51.5%, respectively, over 28 days. However, magnetic resonance angiography showed increment of collateral flow signals in the leptomeningeal artery. Rarefaction and proliferation of astrocytes and microglia, with loss of oligodendrocytes, were found in the white matter at 32 days. Hippocampal neuronal loss was observed in only 25% of GCAS mice, consistent with lack of abnormalities in the Morris water maze test. The rotarod test showed motor impairment, and the Y-maze test showed working memory deficits.

CONCLUSIONS

The GCAS model successfully generated gradual and continuous CBF reduction over 28 days, with replication of key histological, radiological, and behavioral features associated with cerebral hypoperfusion leading to VCI.

Trajectory of Mobility Decline by Type of Dementia

Cognitive and physical aspects of functionality are closely related. However, whether physical decline differs by dementia type and progression rate is debatable. To address these issues, we conducted a longitudinal study of 766 older adults whose physical performance and cognitive status were assessed annually with standard assessment tools [eg, Physical Performance Test, Clinical Dementia Rate (CDR)] for 8 years. Compared with participants who remained cognitively normal, those progressing to later-stage dementia (CDR=1) declined in their mobility by a factor of 2.82 (P<0.001), followed by those who maintained a later-stage diagnosis (slope=-1.84, P<0.001), those progressing from early-stage to later-stage (CDR=0.5 to CDR=1) dementia (slope=-1.20, P<0.001), and those who progressed to early-stage dementia (slope=-0.39, P=0.038) suggesting a steeper physical decline with dementia progression, particularly in those with the fastest disease progression. Although all types of dementia experienced mobility decline, those progressing to non-Alzheimer disease (AD) dementias, especially vascular dementia declined faster than those who remained normal (slope=-2.70, P<0.001) or progressed to AD (slope=-2.18, P<0.001). These associations were better captured by the gait/balance component of physical functionality. Our findings suggest that rapidly progressing dementia patients particularly those with non-AD subtypes should be targeted for interventions to maintain or improve gait/balance and prevent functional decline and disability although AD patients may also benefit.

[Compensate restructuring of high cortical regulation of movement in aging at chronic cerebral ischemia]

Dynamic praxis was tested in three groups: two groups of old responders with cognitive impairment of varying severity and one group of old responders sick of vascular dementia. These groups were compared. Methodological basis this research is Luriya's theory of system dynamic localization psychic functions. We found changes of dynamic praxis in aging. Motor acts some slow in Old responders with mild cognitive impairment. They compensate this deficit through laud speech, increase of latent period before motor act. Responders with cognitive impairment have motor perseverations, movement slowdown, which were more often at vascular dementia. They could not compensate motor deficits in fully. But same of them can compensate motor deficit after prompting or hit.

Vascular cognitive impairment: Modeling a critical neurologic disease in vitro and in vivo

BACKGROUND

Vascular contributions to cognitive impairment and dementia (VCID) is a complex form of dementia, combining aspects of vascular disease and other forms of dementia, such as Alzheimer's disease. VCID encompasses a wide spectrum of cerebrovascular-driven cognitive impairment, from mild cognitive impairment to fully developed dementia. This disease state is further complicated by metabolic disorders, such as type 2 diabetes and hypertension, and lifestyle factors, like obesity and high fat diets.

SCOPE OF REVIEW

This manuscript is meant to both define VCID and review the in vitro and in vivo models of the disease state. This includes in vitro models of the neurovascular unit, models of chronic cerebral hypoperfusion, animals with NOTCH3 mutations as a model of small vessel disease, large animals with cerebral amyloid angiopathy (CAA), and animal models of mixed dementia.

MAJOR CONCLUSIONS

Synthetic microvessels are a promising technique to study the neurovascular unit and canines, despite the cost, are an excellent model to study CAA. While there are several good models of individual aspects of VCID, the heterogeneity of the disease states prevents them from being a model of all aspects of the disease. Therefore, VCID needs to be further defined into disease states that exist within this umbrella term. This includes specific guidelines for stroke counts and stroke locations and further categorization of overlapping cerebrovascular and AD pathologies that contribute to dementia. This will allow for better models and a more thorough understanding of how vascular disease contributes to dementia.

GENERAL SIGNIFICANCE

VCID is the second most common form of dementia and is expected to increase in coming years. The heterogeneity of VCID makes it difficult to study, but without better definitions and models, VCID presents a major public health problem for our aging population. This article is part of a Special Issue entitled: Vascular Contributions to Cognitive Impairment and Dementia, edited by M. Paul Murphy, Roderick A. Corriveau and Donna M. Wilcock.

Gastrodin improves cognitive dysfunction and decreases oxidative stress in vascular dementia rats induced by chronic ischemia

OBJECTIVE

To study the potential protective effects of gastrodin on reducing tissue oxidative stress and attenuating cognitive deficits in vascular dementia induced by cerebral chronic hyperfusion. To explore the detailed molecular mechanisms.

METHODS

6 to 8 week old male Wistar rats were adopted as experimental animals. Animals were divided into the following groups: Group 1 (sham group with no occlusion), Group 2 (control group with 2VO procedure), Group 3 (sham group with gastrodin administration), Group 4 (2VO group with gastrodin administration). Morris water maze (MWM) test was adopted to test the learning and memory function of rats within different groups. MDA, glutathione peroxidase and total thiol assessment was done to reflect the oxidative stress in the brain tissue. Cell counting kit-8 (CCK8) and flow cytometry (FCM) were performed to examine the cell viability and apoptosis rate of SH-SY5Y cells induced by hydrogen peroxide and rescued by gastrodin treatments. Reactive oxygen species (ROS) generation was determined by the 2', 7'-dichlorofluorescein diacetate (DCFH-DA) assay. qPCR and Western blot (WB) were adopted to detect the molecular mechanisms related to the anti-apoptosis and ROS scavenging effects of gastrodin.

RESULTS

Our results indicated an obvious protective effect of gastrodin on vascular dementia induced brain ischemia. Administration of gastrodin could improve the impaired learning and memory function induced by 2VO procedure in rats. The levels of MDA were partially decreased by the administration of gastrodin. The levels of glutathione peroxidase and total thiol were partially restored by the administration of gastrodin. Cell viability was improved by gastrodin in a dose-dependent pattern on SH-SY5Y cells induced by hydrogen peroxide (P < 0.05). Cell apoptosis rate was reduced by gastrodin in a dose-dependent pattern on SH-SY5Y cells induced by hydrogen peroxide (P < 0.05). Gastrodin could scavenge ROS generation induced by pre-treatment of hydrogen peroxide. Both qPCR and WB results showed significant enhancements on the expression levels of NFE2L2, ADH7, GPX2 and GPX3 (P < 0.05).

CONCLUSION

Gastrodin administration is protective on the learning and memory functions that might be affected by vascular dementia induced oxidative stress due to brain ischemia. On the molecular level, NFE2L2, ADH7, GPX2 and GPX3 were up regulated by gastrodin.

Repetitive transcranial magnetic stimulation enhances spatial learning and synaptic plasticity via the VEGF and BDNF-NMDAR pathways in a rat model of vascular dementia

This study aimed to evaluate the effects of repetitive transcranial magnetic stimulation (rTMS) on learning and memory in a rat model of vascular dementia (VaD) and to analyze the associated mechanisms. Bilateral carotid artery occlusion (2-VO) was used to establish a rat model of VaD. High-frequency (5Hz) rTMS was performed on rats for four weeks. Spatial learning and memory abilities were evaluated using the Morris water maze (MWM), and synaptic plasticity in the hippocampus was assessed via long-term potentiation (LTP). Hippocampal expression of vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor (BDNF) and three subunits of the N-methyl-D-aspartic acid receptor (NMDAR), NR1, NR2A and NR2B, was analyzed by Western blotting. Compared with the VaD group, escape latency was decreased (P<0.05) and the time spent in the target quadrant and the percentage of swimming distance within that quadrant were increased (P<0.05) in the rTMS group. LTP at hippocampal CA3-CA1 synapses was enhanced by rTMS (P<0.05). VEGF expression was up-regulated following 2-VO and was further increased by rTMS (P<0.05). BDNF, NR1 and NR2B expression was decreased in the VaD group and increased by rTMS (P<0.05). There were no significant differences in NR2A expression among the three groups. These results suggest that rTMS improved learning and memory in the VaD model rats via the up-regulation of VEGF, BDNF and NMDARs. In addition, NR2B may be more important than NR2A for LTP induction in the hippocampus during rTMS treatment of VaD.

Cerebral small vessel disease and Alzheimer's disease

Cerebral small vessel disease (CSVD) is a group of pathological processes with multifarious etiology and pathogenesis that are involved into the small arteries, arterioles, venules, and capillaries of the brain. CSVD mainly contains lacunar infarct or lacunar stroke, leukoaraiosis, Binswanger's disease, and cerebral microbleeds. CSVD is an important cerebral microvascular pathogenesis as it is the cause of 20% of strokes worldwide and the most common cause of cognitive impairment and dementia, including vascular dementia and Alzheimer's disease (AD). It has been well identified that CSVD contributes to the occurrence of AD. It seems that the treatment and prevention for cerebrovascular diseases with statins have such a role in the same function for AD. So far, there is no strong evidence-based medicine to support the idea, although increasing basic studies supported the fact that the treatment and prevention for cerebrovascular diseases will benefit AD. Furthermore, there is still lack of evidence in clinical application involved in specific drugs to benefit both AD and CSVD.

Hyperfamiliarity in Dementia and Mild Cognitive Impairment

INTRODUCTION

Hyperfamiliarity, a phenomenon in which feelings of familiarity are evoked by novel stimuli, is well described in epilepsy and the lesioned brain. Abnormality of familiarity in Alzheimer's disease (AD) and mild cognitive impairment (MCI) have also been described in the literature, but more from a neuropsychological approach perspective. Currently, there is a lack of study on the real-life experience of familiarity abnormality in dementia and MCI. Our aim was to compare the occurrence of hyperfamiliarity among dementia and MCI.

MATERIALS AND METHODS

We recruited 73 participants, 29 with AD, 10 with vascular dementia, 7 with MCI and 27 healthy controls, and administered a questionnaire to assess hyperfamiliarity frequency.

RESULTS

Hyperfamiliarity was observed in real-life in cognitive impairment, but was unrelated to its severity or underlying aetiology.

CONCLUSION

This study highlights the similar rate of occurrence of hyperfamiliarity in the daily life of individuals with cognitive impairment. Future research should examine neuropsychological correlations and mechanisms that contribute to such observations.

Interaction between hypertension and cerebral hypoperfusion in the development of cognitive dysfunction and white matter pathology in rats

Hypertension is the most significant modifiable risk factor for vascular cognitive impairment. However, influence of hypertension on the development of ischemic white matter injury and cognitive dysfunction is not fully understood. We compared cognitive functions and neuropathological outcomes of chronic cerebral hypoperfusion induced by bilateral common carotid artery occlusion (BCCAO) between normotensive rats (NRs) and spontaneously hypertensive rats (SHRs). SHRs developed earlier and more severe deficits in spatial memory performance than NRs following BCCAO. Although no significant changes in the gross structure of myelinated white matter or oligodendrocyte number were noted, BCCAO resulted in subtle myelin degeneration and paranodal structural alterations at the nodes of Ranvier, regardless of hypertension. Disruption of the blood-brain barrier (BBB) was predominantly observed in the white matter of SHRs following BCCAO, implying a role of hypertension in BBB dysfunction in chronic cerebral hypoperfusion. In chronic cerebral ischemia, long-standing hypertension may aggravate impairment of BBB integrity, and the leaky BBB may in turn exacerbate dysfunction in the white matter leading to worsening of spatial cognitive performance.

Gait and apathy as relevant symptoms of subcortical vascular dementia

BACKGROUND

Subcortical vascular dementia relates to small-vessel disease and hypoperfusion, resulting in focal and diffuse ischemic white matter lesions. The main target of the disease are the frontal subcortical neural networks. There is no clinical standard definition of the pathology, on the contrary, everyday clinical practice suggests dominant behavioral alterations and dysexecutive syndrome.

METHODS

The aim of this study was to investigate gait disorders, behavioral alteration, and drug intake of a subcortical population with dementia (n = 1155). A complete neuropsychological examination was conducted at baseline and every 6 months, and the results were compared.

RESULTS

Our data suggest that there is a significant increment in apathy levels and a dramatic decrease in gait and equilibrium control in the patients examined during follow-up.

CONCLUSION

Subcortical vascular dementia may be associated with gait and balance alteration and apathy per se; we suggest to implement clinical data with these major aspects.

Puerarin attenuates cognitive dysfunction and oxidative stress in vascular dementia rats induced by chronic ischemia

OBJECTIVE

To explored the effects of puerarin on cognitive deficits and tissue oxidative stress and the underlying mechanisms.

METHODS

6 to 8 week old male Wistar rats were adopted as experimental animals. Morris water maze (MWM) test was adopted to test the learning and memory function of rats. MDA, glutathione peroxidase and total thiol assessment was done to reflect the oxidative stress in the brain tissue. Cell Counting Kit-8 (CCK8) and flow cytometry (FCM) were performed to examine the cell viability and apoptosis rate. Reactive oxygen species (ROS) generation was determined by the 2', 7'-dichlorofluorescein diacetate (DCFH-DA) assay. qPCR and Western blot (WB) were adopted to test the molecular function mechanisms of puerarin.

RESULTS

Our results indicated a protective effect of puerarin on vascular dementia. Administration of puerarin could improve the impaired learning and memory function. The levels of MDA were partially decreased by puerarin. The levels of glutathione peroxidase and total thiol were partially restored. Cell viability was improved in a dose-dependent pattern (P<0.05). Cell apoptosis rate was reduced in a dose-dependent pattern (P<0.05). Puerarin could scavenge ROS generation induced by pre-treatment of hydrogen peroxide. The results showed up-regulated levels of Nrf2, FoxO1, FoxO3 and FoxO4 (P<0.05).

CONCLUSION

Puerarin is protective on the vascular dementia by reducing oxidative stress and improving learning and memory functions. On the molecular level, Nrf2, FoxO1, FoxO3 and FoxO4 were up regulated by puerarin.

Trajectories of cognitive decline in different types of dementia

BACKGROUND

To investigate trajectories of cognitive decline in patients with different types of dementia compared to controls in a longitudinal study.

METHOD

In 199 patients with Alzheimer's disease (AD), 10 with vascular dementia (VaD), 26 with dementia with Lewy bodies (DLB), 20 with behavioural variant frontotemporal dementia (bvFTD), 15 with language variant frontotemporal dementia (lvFTD) and 112 controls we assessed five cognitive domains: memory, language, attention, executive and visuospatial functioning, and global cognition (Mini-Mental State Examination, MMSE). All subjects had at least two neuropsychological assessments (median 2, range 2-7). Neuropsychological data were standardized into z scores using baseline performance of controls as reference. Linear mixed models (LMMs) were used to estimate baseline cognitive functioning and cognitive decline over time for each group, adjusted for age, gender and education.

RESULTS

At baseline, patients with dementia performed worse than controls in all cognitive domains (p < 0.05) except visuospatial functioning, which was only impaired in patients with AD and DLB (p < 0.001). During follow-up, patients with AD declined in all cognitive domains (p < 0.001). DLB showed decline in every cognitive domain except language and global cognition. bvFTD showed rapid decline in memory, language, attention and executive functioning (all p < 0.01) whereas visuospatial functioning remained fairly stable. lvFTD declined mostly in attention and executive functioning (p < 0.01). VaD showed decline in attention and executive functioning.

CONCLUSIONS

We show cognitive trajectories of different types of dementia. These estimations of natural disease course have important value for the design of clinical trials as neuropsychological measures are increasingly being used as outcome measures.

[Effects of scalp-acupuncture on astrocyte apoptosis in hippocampal CA 1 region in rats with vascular dementia]

OBJECTIVE

To observe the effect of scalp-acupuncture intervention on the expression of Bcl-2 of astrocytes in the hippocampus in vascular dementia (VD) rats, so as to reveal its underlying mechanism in improving VD.

METHODS

A total of 40 male SD rats were randomly divided into normal control, sham-operation, VD model, and scalp-acupuncture groups (n=10 in each group). The VD model was established by using modified Pulsinelli 4-vessel-occlusion method. Scalp-acupuncture was applied to bilateral "Daozang Shangjiao" and bilateral "Jiyi", and "Siwei" acupoints according to FANG's scalp-acupuncture therapy for 30 min, once daily for 10 days. The rat's learning-memory ability was detected by Morris water maze tests, and the expression of apoptosis related proteins Bcl-2 of astrocytes in the hippocampus was detected by immunofluorescence double labeling technique and Western blot, respectively.

RESULTS

Morris water maze tests showed that the average escape latency of place navigation test and the duration of the first platform-site crossover (space probing test) were significantly increased in the model group compared with the normal control group (P<0.01), and the number of platform-site crossovers in 2 min was markedly decreased in the model group (P<0.01). The increased average escape latency and the increased duration of first platform-site crossover were markedly shortened in the scalp-acupuncture group in comparison with the model group (P<0.01), and the number of the platform crossovers in 2 min was significantly increased in the scalp-acupuncture group (P<0.01). The expression of Bcl-2 protein and the number of GFAP/Bcl-2-labeled cells of hippocampal CA 1 region in the model group were remarkably decreased compared with the normal control group (P<0.01). After scalp-acupuncture intervention, the decreased Bcl-2 protein expression level and the number of double-labeled GFAP/Bcl-2 cells were significantly up-regulated in the scalp-acupuncture group compared with the model group (P<0.01). No significant differences were found between the normal control and sham-operation groups in the escape latency, duration of the first platform-site crossover, number of platform crossovers in 2 min, number of GFAP/Bcl-2 double labeled cells and the expression level of hippocampal Bcl-2 protein (P>0.05).

CONCLUSION

Scalp-acupuncture can effectively regulate the expression of apoptosis related proteins Bcl-2 of astrocytes in the CA 1 region of hippocampus in rats with VD, which may contribute to its effect in the improvement of VD.

Abnormal intrinsic brain activity patterns in patients with subcortical ischemic vascular dementia

Objectives

To investigate the amplitude of low-frequency fluctuations (ALFF) alteration of whole brain in patients with subcortical ischemic vascular dementia (SIVD).

Materials and Methods

Thirty patients with SIVD and 35 control subjects were included in this study. All of them underwent structural MRI and rs-fMRI scan. The structural data were processed using the voxel-based morphometry 8 toolbox (VBM8). The rs-fMRI data were processed using Statistical Parametric Mapping (SPM8) and Data Processing Assistant for Resting-State fMRI (DPARSF) software. Within-group analysis was performed with a one-sample Student's t-test to identify brain regions with ALFF value larger than the mean. Intergroup analysis was performed with a two-sample Student's t-test to identify ALFF differences of whole brain between SIVD and control subjects. Partial correlations between ALFF values and Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) scores were analyzed in the SIVD group across the parameters of age, gender, years of education, and GM volume.

Results

Within-group analysis showed that the bilateral anterior cingulate cortex (ACC), posterior cingulate cortex, medial prefrontal cortex (MPFC), inferior parietal lobe (IPL), occipital lobe, and adjacent precuneus had significantly higher standardized ALFF values than the global mean ALFF value in both groups. Compared to the controls, patients with SIVD presented lower ALFF values in the bilateral precuneus and higher ALFF values in the bilateral ACC, left insula and hippocampus. Including GM volume as an extra covariate, the ALFF inter-group difference exhibited highly similar spatial patterns to those without GM volume correcting. Close negative correlations were found between the ALFF values of left insula and the MoCA and MMSE scores of SIVD patients.

Conclusion

SIVD is associated with a unique spontaneous aberrant activity of rs-fMRI signals, and measurement of ALFF in the precuneus, ACC, insula, and hippocampus may aid in the detection of SIVD.

[P300 potential parameters at the stages of formation of the subcortical vascular dementia in elderly]

Auditory P300 latency and amplitude values were assessed in 11 elderly persons without cognitive impairments (WCI), mean age--(70.73 +/- 4.24) years, 20 patients with subcortical vascular mild cognitive impairment (SCMCI), mean age--(75.35 +/- 5.48) years and 20 patients with subcortical vascular dementia (SCVaD), mean age (75.80 +/- 6.51) years. Obtained data suggest that P300 latency value increase at the stages of the SCVaD progression. Mean values of P300 latency were (341.09 +/- 107.70) ms in WCI group, (655.70 +/- 87.08) ms in SCMCI patients, (732.45 +/- 74.64) ms in SCVaD patients. There were significant differences between the groups. This parameter allows differentiating patients with SCMCI from elderly persons WCI, and patients with SCVaD from SCMCI. Increasing P300 latency has sufficient relationship to severity and specificity of cognitive deficit of SCVaD stages development reflecting progressive deterioration of attention, working memory, kinetic and regulator praxis.

The pathobiology of vascular dementia

Vascular cognitive impairment defines alterations in cognition, ranging from subtle deficits to full-blown dementia, attributable to cerebrovascular causes. Often coexisting with Alzheimer's disease, mixed vascular and neurodegenerative dementia has emerged as the leading cause of age-related cognitive impairment. Central to the disease mechanism is the crucial role that cerebral blood vessels play in brain health, not only for the delivery of oxygen and nutrients, but also for the trophic signaling that inextricably links the well-being of neurons and glia to that of cerebrovascular cells. This review will examine how vascular damage disrupts these vital homeostatic interactions, focusing on the hemispheric white matter, a region at heightened risk for vascular damage, and on the interplay between vascular factors and Alzheimer's disease. Finally, preventative and therapeutic prospects will be examined, highlighting the importance of midlife vascular risk factor control in the prevention of late-life dementia.

Effects of acupuncture on Chinese medicine syndromes of vascular dementia

OBJECTIVE

To study the effects of acupuncture on Chinese medicine syndromes of vascular dementia (VaD).

METHODS

Sixty-three VaD patients were divided into three groups. Those willing to be randomized were randomly assigned to receive either acupuncture (random acupuncture group, 24 cases) or rehabilitation training (guided rehabilitation group, 24 cases) for 6 weeks. Those unwilling to be randomized also received acupuncture for 6 weeks (non-random acupuncture group, 19 cases). Patient syndromes and their severity were evaluated before treatment (baseline), at the end of treatment, and at 4-week follow-up after the completion of treatment using a CM scoring system (scale of differentiation of syndromes of vascular dementia, SDSVD). The SDSVD scores of the random and non-random acupuncture groups, and of all patients who received acupuncture (combined acupuncture group, 43 cases), were compared with those in the guided rehabilitation group.

RESULTS

In the random, non-random, and combined acupuncture groups, SDSVD scores were significantly reduced at the end of treatment and at follow-up than at baseline. In the guided rehabilitation group, SDSVD scores were similar to baseline scores at the end of treatment and at follow-up. However, there were no significant differences in SDSVD scores among the three groups or between the combined acupuncture group and the guided rehabilitation group at any time points. In the non-random and combined acupuncture groups, SDSVD scores were significantly reduced at the end of treatment than at baseline in patients with hyperactivity of Liver (Gan)-yang or phlegm obstruction of the orifices.

CONCLUSIONS

Acupuncture reduced the severity of VaD. The improvement was the greatest in patients undergoing their treatment of choice. Treatments in this study were more effective for excess syndromes, such as Liver-yang hyperactivity or phlegm obstruction of the orifices than deficiency syndromes, such as Kidney (Shen)-essence deficiency.

The current situation on vascular cognitive impairment after ischemic stroke in Changsha

The objectives of the study were to explore the prevalence and effects of vascular cognitive impairment (VCI) among ischemic stroke patients and to provide a basis for prevention and treatment strategies. A stratified cluster random sampling method was performed, and 689 ischemic stroke patients (over 40 years of age) were enrolled. All of the patients had received a neuropsychological assessment battery to assess cognitive function and self-designed questionnaires to collect relevant information. According to the cognitive status, the patients were divided into two groups, a case group and a control group. The caregivers of the patients were given a questionnaire concerning the awareness of and attitudes toward VCI. In this study, we determined that the prevalence of VCI was 41.8%. Aging, paraventricular white matter lesion (WML), macroangiopathy, high levels of alcohol, a lack of hobbies, and excessive sleep were risk factors for vascular cognitive impairment no dementia (VCIND). A high level of education, manual-work, low level of alcohol use, regular health checks, a vegetable-based diet, and more fruit and milk were protective factors for VCIND. Living alone, hyperlipidemia, transient ischemic attack, a family history of stroke, and brain atrophy were risk factors of vascular dementia (VD). A high educational level, a vegetable-based diet, and tea were protective factors for VD. The general public awareness of VCI was found to be insufficient, and there was a prejudice toward and lack of funding for the care of VCI patients. The prevalence of VCI is high in ischemic stroke patients, and there are different impact factors at different stages. Despite the high prevalence of VCI, the general public awareness is limited. Appropriate prevention measures should be developed to reduce the prevalence of VCI.

Hypertension and vascular dementia in the elderly: the potential role of anti-hypertensive agents

BACKGROUND

Vascular dementia (VaD) - a severe form of vascular cognitive impairment - and cognitive decline are associated with hypertension and therefore it seems logical to consider that reducing BP with anti-hypertensive therapy may protect against the development/onset of cognitive function impairment or dementia.

SCOPE

This narrative, non-systematic review discusses the available evidence on the potential correlation between the use of anti-hypertensive agents and the risk of VaD and cognitive decline.

METHODS

MEDLINE was searched for inclusion of relevant studies. No limitations in time were considered.

RESULTS

A consensus on the potential effects of anti-hypertensive treatment in the reduction of VaD and associated cognitive decline has not been reached. A protective effect of anti-hypertensive agents has been observed in a number of studies although it is still unclear whether different classes of anti-hypertensive agents have a different effect on the development of VaD.

CONCLUSIONS

The protective effect of anti-hypertensive agents appears to depend on the specific drug used - positive effects have been observed with calcium channel blockers (CCBs), such as lercanidipine and nitrendipine, the combination perindopril-indapamide and telmisartan.

Cluster-based statistics for brain connectivity in correlation with behavioral measures

Graph theoretical approaches have successfully revealed abnormality in brain connectivity, in particular, for contrasting patients from healthy controls. Besides the group comparison analysis, a correlational study is also challenging. In studies with patients, for example, finding brain connections that indeed deepen specific symptoms is interesting. The correlational study is also beneficial since it does not require controls, which are often difficult to find, especially for old-age patients with cognitive impairment where controls could also have cognitive deficits due to normal ageing. However, one of the major difficulties in such correlational studies is too conservative multiple comparison correction. In this paper, we propose a novel method for identifying brain connections that are correlated with a specific cognitive behavior by employing cluster-based statistics, which is less conservative than other methods, such as Bonferroni correction, false discovery rate procedure, and extreme statistics. Our method is based on the insight that multiple brain connections, rather than a single connection, are responsible for abnormal behaviors. Given brain connectivity data, we first compute a partial correlation coefficient between every edge and the behavioral measure. Then we group together neighboring connections with strong correlation into clusters and calculate their maximum sizes. This procedure is repeated for randomly permuted assignments of behavioral measures. Significance levels of the identified sub-networks are estimated from the null distribution of the cluster sizes. This method is independent of network construction methods: either structural or functional network can be used in association with any behavioral measures. We further demonstrated the efficacy of our method using patients with subcortical vascular cognitive impairment. We identified sub-networks that are correlated with the disease severity by exploiting diffusion tensor imaging techniques. The identified sub-networks were consistent with the previous clinical findings having valid significance level, while other methods did not assert any significant findings.

[Effects of acupuncture of "Zhongchong" (PC 9) and "Yongquan" (KI 1) on P300 of event-related potentials in rats with vascular dementia]

OBJECTIVE

To observe the effect of electroacupuncture (EA) stimulation of "Zhongchong" (PC 9) and "Yongquan" (KI 1) on P 300 of event-related potentials (ERPs) in rats with vascular dementia.

METHODS

A total of 48 Wistar rats were randomly divided into sham group (n = 12), model group (n = 12), EA group (n = 12) and medication group (n = 12). Vascular dementia model was established by occlusion of the bilateral vertebral arteries and cervical arteries. EA (1-2 mA, 2 Hz/20 Hz) was applied to bilateral "Zhongchong" (PC 9) and "Yongquan" (KI 1) for 15 min, once daily for 28 days. Rats of the medication group were treated by intragastric perfusion of Nimodipine (12 mg/kg), twice daily for 28 days. The rats' learning-memory ability was detected by step-down passive and active avoidance tests, and P 300 of ERPs detected by Neuroscan Nuamps system.

RESULTS

Compared with the sham group, the reaction time and error times of learning performance and error times of memory performance as well as P 300 latency in the model group were significantly increased (P < 0.01), and the latency of memory performance and the amplitude of P 300 were markedly decreased in the model group (P < 0.01). While in comparison with the model group, the reaction time and error times of learning performance, and the error times of memory performance as well as P300 latencies were obviously decreased in both EA and medication groups (P < 0.01), and the latencies of memory performance and P300 amplitudes were evidently increased in the EA and medication groups (P < 0.01). No significant differences were found between the EA and medication groups in these 6 indexes (P > 0.05).

CONCLUSION

EA of PC 9 and KI 1 can significantly improve the ability of learning and memory and the latency and amplitude of P 300 in rats with vascular dementia.

Transcranial and extracranial ultrasound assessment of cerebral hemodynamics in vascular and Alzheimer's dementia

BACKGROUND

Increasing life expectancy of the population leads to a higher incidence of dementia. Exact differentiation between the most common types, vascular dementia (VD) and Alzheimer's dementia (AD), is crucial to the development and application of new treatment strategies. Both conditions are thought to differ greatly by their extent of microvascular affection. Transcranial and extracranial ultrasound permits analysis of cerebral hemodynamics and should help to differentiate between VD and AD. We compare multimodal ultrasound data between VD, AD and controls, and give an overview of the literature on this topic.

METHODS

Twenty VD and 20 AD patients were studied and compared with 12 age-matched controls. Transcranial color-coded ultrasound was performed to assess blood flow velocity (V(mean)) and pulsatility indices (PI) of the middle cerebral artery (MCA). Extracranial duplex and Doppler ultrasound techniques were used to assess the blood volume flow (BVF) in the anterior circulation (both internal carotid arteries [ICA]) and posterior circulation (both vertebral arteries [VA]), the global cerebral blood flow (CBF = BVF(ICA) + BVF(VA)), the global cerebral circulation time (CCT = time delay of echo-contrast bolus arrival between ICA and internal jugular vein) and global cerebral blood volume (CBV = CCT x CBF).

RESULTS

MCA V(mean) in VD (36 +/- 8 cm/s) and AD (43 +/- 13 cm/s) were significantly lower than in controls (59 +/- 13 cm/s) but did not differ significantly between VD and AD groups. PI (1.1 +/- 0.2; 1 +/- 0.2; 0.9 +/- 0.2) only differed significantly between VD group and controls. CBF and CCT in VD (570 +/- 61 ml/min; 8.8 +/- 2.6 s) and AD (578 +/- 77 ml/min; 8.2 +/- 1.4 s) were similar but differed significantly from controls (733 +/- 54 ml/min; 6.4 +/- 0.8 s). BVF in the anterior and posterior circulation of VD group (412 +/- 62 and 158 +/- 38 ml/min) and AD group (428 +/- 62 and 150 +/- 41 ml/min) were significantly lower than in controls (537 +/- 48 and 199 +/- 26 ml/min) but did not differ significantly between the patient groups.

DISCUSSION

Transcranial and extracranial ultrasound does not help to distinguish between VD and AD. However, our results add insight into the pathophysiology of dementia, arguing in favor of a common 'vascular' pathway in both conditions.

Changes over time in memory, processing speed and clock drawing tests help to discriminate between vascular cognitive impairment, mild cognitive impairment and Alzheimer's disease

Measures of cognitive change over time may help to better discriminate between mild cognitive impairment, Alzheimer's disease and vascular cognitive impairment than single assessments. Our hypothesis was that performance in processing speed and executive function would decline with mild cognitive impairment and Alzheimer's disease. Subjects included 36 controls, 18 cases with mild cognitive impairment, eight with vascular cognitive impairment and 24 with Alzheimer's disease who were tested on a cognitive battery at two episodes with a 12-month interval. Changes in performance were determined for each group with paired means tests. Controls improved in pattern comparison speed and the CLOX, a clock-drawing task to detect dysexecutive function. Those with vascular cognitive impairment declined in letter comparison speed, but improved in paragraph recall. Alzheimer's disease patients declined in CLOX and the Hopkins Verbal Learning Test. The mild cognitive impairment group showed no significant changes. Alzheimer's disease patients on treatment declined in Hopkins Verbal Learning Test, while those without treatment declined in The Placing Test and CLOX. Processing speed decline may be a marker of cerebrovascular disease, while decline in memory and executive function was more evident with Alzheimer's disease.

Phenotypic profiles and functional genomics in Alzheimer's disease and in dementia with a vascular component

Alzheimer's disease (AD) and dementia with vascular component (DVC) are the most prevalent forms of dementia. Both clinical entities share many similarities, but they differ in major phenotypic and genotypic profiles as revealed by structural and functional genomics studies. Comparative phenotypic studies have identified significant differences in 25% of more than 100 parametric variables, including anthropometry, cardiovascular function, aortic atherosclerosis, brain atrophy, blood pressure, blood biochemistry, hematology, thyroid function, folate and vitamin B12 levels, brain hemodynamics and lymphocyte markers. The phenotypic profile of patients with DVC differs from that of AD patients in the following: anthropometric values (weight, height); cardiovascular function (ECG, heart rate); blood pressure; lipid metabolism (HDL-CHO, TGs); uric acid metabolism; peripheral calcium homeostasis; liver function (GOT, GPT, GGT); alkaline phosphatase; lactate dehydrogenase; red and white blood cells; regional brain atrophy (left temporal region, inter-hippocampal distance); and left anterior blood flow velocity. Functional genomics studies incorporating APOE-related changes in biological markers extended the difference between AD and DVC up to 57%. Brain perfusion studies show a severe brain hypoperfusion in dementia associated with enlarged age-dependent arterial perfusion times. Structural genomics studies with AD-related genes, including APP, MAPT, APOE, PS1, PS2, A2M, ACE, AGT, cFOS and PRNP genes, demonstrate different genetic profiles in AD and DVC, with an absolute genetic variation rate ranging from 30% to 80%, depending upon genes and genetic clusters. Single gene analysis identifies relative genetic variations ranging from 0% to 5%. The relative polymorphic variation in genetic clusters integrated by two, three or four genes associated with AD ranges from 1% to 3%. The main phenotypic differences between AD and DVC are genotype-dependent, especially in AD, probably indicating that different genomic factors are determinant for the expression of dementia symptoms which might be accelerated or induced by environmental and/or cerebrovascular factors.

Determination of vascular dementia brain in distinct frequency bands with whole brain functional connectivity patterns

Recent studies have shown that multivariate pattern analysis (MVPA) can be useful for distinguishing brain disorders into categories. Such analyses can substantially enrich and facilitate clinical diagnoses. Using MPVA methods, whole brain functional networks, especially those derived using different frequency windows, can be applied to detect brain states. We constructed whole brain functional networks for groups of vascular dementia (VaD) patients and controls using resting state BOLD-fMRI (rsfMRI) data from three frequency bands - slow-5 (0.01 ≈ 0.027 Hz), slow-4 (0.027∼0.073 Hz), and whole-band (0.01 ≈ 0.073 Hz). Then we used the support vector machine (SVM), a type of MVPA classifier, to determine the patterns of functional connectivity. Our results showed that the brain functional networks derived from rsfMRI data (19 VaD patients and 20 controls) in these three frequency bands appear to reflect neurobiological changes in VaD patients. Such differences could be used to differentiate the brain states of VaD patients from those of healthy individuals. We also found that the functional connectivity patterns of the human brain in the three frequency bands differed, as did their ability to differentiate brain states. Specifically, the ability of the functional connectivity pattern to differentiate VaD brains from healthy ones was more efficient in the slow-5 (0.01 ≈ 0.027 Hz) band than in the other two frequency bands. Our findings suggest that the MVPA approach could be used to detect abnormalities in the functional connectivity of VaD patients in distinct frequency bands. Identifying such abnormalities may contribute to our understanding of the pathogenesis of VaD.

An fMRI study of prefrontal cortical function in subcortical ischemic vascular cognitive impairment

Functional magnetic resonance imaging (fMRI) technology has not been used to investigate the frontal lobe function of subcortical ischemic vascular cognitive impairment (SIVCI). In this study 11 healthy elderly controls, 12 patients with subcortical ischemic vascular cognitive impairment no dementia (SIVCIND), and 12 patients with subcortical ischemic vascular dementia (SIVD) underwent fMRI examination on a SIEMENS Trio 3.0 Tesla scanner during Stroop task performance. Compared to the controls, participants with SIVCIND showed markedly increased activation in prefrontal cortex. By contrast, participants with SIVD exhibited decreased fMRI responses in the regions described above. A close correlation was found between the cognitive score in Montreal Cognitive Assessment test and the activation area of frontal and parietal lobule of patients with SIVD. Our results suggest that the alterations of cortical activation in SIVCI were bidirectional. There is a prefrontal dysfunction in SIVD and a compensation in SIVCIND. These findings might help guide a clinical differentiation among normal controls, SIVCIND, and SIVD.

Behavioral neurology in language and aphasia: from basic studies to clinical applications

With increasing aging population, cognitive deteriorations due to neuro- degenerative diseases or stroke are so commonly observed that it is thought to be inevitable with aging. For dementia and stroke, a communication disorder due to language deterioration is one of the main problems. Behavioral neurology aims to clarify the relationship between brain function and behavior; language deterioration is one of the main targets, and its clinical applications are really useful for making better understanding of patients. Language is sequences of sound or characters that carry meanings for communication. From the evolutionary perspective, "language" can be thought about by considering birds and dogs: the basal ganglia and anterior cingulate, and the thalamus and cerebral cortex are thought to provide the neurobiological background, respectively. Humans can use language. The language area is a newly developed brain area in evolution and is mainly localized in the left cerebral hemisphere. Semantic memory has also developed in humans. There are two routes, the superficial and deep routes, with the latter associated with meaning, and three brain areas are involved: the peri-Sylvian area, per-peri-Sylvian area, and right hemisphere. Using these principles, language symptoms of dementia with progressive non-fluent aphasia (PA), semantic dementia (SD), Alzheimer's disease (AD), and vascular dementia (VaD) can be understood. Namely, the symptoms of PA is understood by the dysfunction of peri-Sylvian language area, those of SD and AD by that of peri-peri-Sylvian language area, and those of some VaD cases and AD cases by that of right hemisphere.

[Effect of three-line puncture on the Governor Vessel and Bladder Meridian on head on cognitive function of vascular dementia patients]

OBJECTIVE

To verify the therapeutic effect of vascular dementia treated with three-line puncture on the Governor Vessel and Bladder Meridian on head.

METHODS

Sixty cases were randomly divided into a head-line puncture group and a routine acupuncture group, 30 cases in each group. In head-line puncture group, line puncture was applied on three lines of the Governor Vessel and Bladder Meridian from anterior hairline to occipital tuberosity. In routine acupuncture group, Yintang (GV 29), Fengchi (GB 20), Sishencong (EX-HN 1) penetrating to Baihui (GV 20) and Shenting (GV 24) penetrating to Shangxing (GV 23) were selected. Once a day, 5 times in a week and 8 weeks totally. Score was evaluated with Mini-Mental State Examination scale (MMSE) before and after treatment, and the therapeutic effects in both groups were compared.

RESULTS

The total effective rate of cognitive function was 76. 7% (23/30) in head-line puncture group, superior to that of 43.3% (13/30, P < 0.05) in routine acupuncture group. The MMSE scores in both groups were improved after treatment (both P < 0.01), and it in head-line puncture group was superior to that in routine acupuncture group (P < 0.01).

CONCLUSION

Three-line acupuncture on the Governor Vessel and Bladder Meridian on head can remarkably improve the cognitive function of vascular dementia, and the therapeutic effect is superior to that of routine acupuncture.

[Serum level of S100B as a marker of progression of vascular mild cognitive impairment into subcortical vascular dementia and therapy effectiveness]

We evaluated serum level of S100B in 11 patients with subcortical vascular dementia (SVD) and 19 patients with subcortical vascular mild cognitive impairment (SVMCI). Comparable groups were age-matched (79.18 +/- 7.76 in SVD group, 77.84 +/- 3.83 in SVMCI; P = 0.53). 22 patients were assessed after 1 month therapy. It was shown that the serum S100B level significantly increased--(0.065 +/- 0.020) micro/l (P = 0.0005) in SVD patients comparing to SVMCI ones - (0.043 +/- 0.010) microg/l. S100B level was significantly correlated with the clinical parameters: MMSE performance (r(s) = -0.61), CDR (r(s) = 0.58), attention task (r(s) = -0.46), pseudobulbar syndrome severity (r(s) = 0.37) and walking alteration (r(s)= 0.37). In patients with reduction of S100B level due to therapy (positive dynamics, n = 12) we registered significant improvement of some clinical parameters: MMSE, attention level, walking. In patients with increasing of S100B level (negative dynamics, n = 10) we didn't registered improvement of any clinical parameters. We made the conclusion that the serum level of S100B could be used as marker of progression SVMCI into SVD and therapy effectiveness.

[Effect of ferulic acid on learning and memory impairments of vascular dementia rats and its mechanism of action]

This study is to investigate the effect of ferulic acid on learning and memory impairments of vascular dementia (VD) rats and its mechanism of action. VD rats model was replicated by permanent bilateral common carotid artery occlusion (2VO). The learning and memory capability of VD rats was evaluated by Morris water maze. The activity of acetylcholinesterase (AChE) and superoxide dismutase (SOD) and the content of glutamic acid (Glu) and malondialdehyde (MDA) in hippocampus of VD rats' brain were determined, separately. The results showed that ferulic acid could alleviate learning and memory deficits of VD rats significantly. Ferulic acid was found to inhibit the activity of AChE and increased the activity of SOD in rat hippocampus. In addition, ferulic acid could also decrease the content of Glu and MDA in rat hippocampus. These results suggested that ferulic acid could alleviate VD rats' learning and memory deficits, which might be due to antioxidation, the improvement of cholinergic system in brain, or the inhibitory of nerve injury by excitatory amino acids.

Cardiorespiratory fitness as a predictor of dementia mortality in men and women

There is evidence that physical activity may reduce the risk of developing Alzheimer disease and dementia. However, few reports have examined the physical activity-dementia association with objective measures of physical activity. Cardiorespiratory fitness (hereafter called fitness) is an objective reproducible measure of recent physical activity habits.

PURPOSE

We sought to determine whether fitness is associated with lower risk for dementia mortality in women and men.

METHODS

We followed 14,811 women and 45,078 men, age 20-88 yr at baseline, for an average of 17 yr. All participants completed a preventive health examination at the Cooper Clinic in Dallas, TX, during 1970-2001. Fitness was measured with a maximal treadmill exercise test, with results expressed in maximal METs. The National Death Index identified deaths through 2003. Cox proportional hazards models were used to examine the association between baseline fitness and dementia mortality, adjusting for age, sex, examination year, body mass index, smoking, alcohol use, abnormal ECGs, and health status.

RESULTS

There were 164 deaths with dementia listed as the cause during 1,012,125 person-years of exposure. Each 1-MET increase in fitness was associated with a 14% lower adjusted risk of dementia mortality (95% confidence interval (CI) = 6%-22%). With fitness expressed in tertiles, adjusted hazard ratios (HRs) for those in the middle- and high-fitness groups suggest their risk of dementia mortality was less than half that of those in the lowest fitness group (HR = 0.44, CI = 0.26-0.74 and HR = 0.49, CI = 0.26-0.90, respectively).

CONCLUSIONS

Greater fitness was associated with lower risk of mortality from dementia in a large cohort of men and women.

The central histamine level in rat model of vascular dementia

The histaminergic system plays an important role in memory and learning. Deficient histaminergic transmission in the human brain in vascular dementia (VD) has been suggested. To get a better insight into the problem, a rat model of VD based on permanent bilateral occlusion of the common carotid arteries (BCCAO) leading to chronic cerebral hypoperfusion was used. Prior to the BCCAO, male Wistar rats underwent 7 days training and only those animals that positively passed the holeboard memory test were chosen for the study. The rats which were operated on were injected i.p. daily for 6 days with either a monoamine oxidase B inhibitor - PF9601N (40 mg/kg), an acetycholinesterase inhibitor - tacrine (3 mg/kg), a histamine H(3) receptor blocker - DL76 (6 mg/kg) or saline. The first retest (R1) was performed one week after the surgery while each subsequent test was 5-7 days apart. The rats were euthanized 2 or 4 weeks following the operation. The concentration of brain histamine (HA) and the activity of histamine metabolising enzymes were measured using current procedures. The BCCAO drastically increased latency and run time (p<0.001) 54 ± 30 vs. 3.4 ± 1.2 and 268 ± 18 vs. 74 ± 9, respectively, and affected working memory rather than reference memory as measured by the 1(st) retest (R1). Treatment with either PF9601N or tacrine seems to exert a positive effect on working memory. This tendency disappeared after the drug treatment stopped. Latency and run time, although they improved in R2-R4, never attained the preoperative values. The brain tissues from rats treated with PF9601N showed only 15% and 50% of untreated rat MAO B and MAO A activity, respectively, despite the drug administration having been discontinued for 3 weeks. Other drugs examined did not influence MAO enzymes. Neither did histamine N-methyltransferase activity show changes related to BCCAO nor to the treatments. The hypothalamic HA concentration was significantly reduced after BCCAO: 1.13 ± 0.1 vs. 1.91 ± 0.16. Noteworthy, the rats treated with PF9601N or DL76 had brain HA levels not significantly different from their intact counterparts. The rat vascular dementia model supports deficiency in histaminergic system in VD.

[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.

Baseline and longitudinal increases in diastolic blood pressure are associated with greater white matter hyperintensity volume: the northern Manhattan study

BACKGROUND AND PURPOSE

Elevated blood pressure (BP) is a risk factor for stroke and dementia, but the effect of BP, and change in BP over time, on white matter hyperintensity volume (WMHV) is not fully understood. Few studies have included Hispanics, who are at greater risk of stroke and dementia than non-Hispanic whites. We examined BP in relation to WMHV in a stroke-free cohort.

METHODS

The Northern Manhattan Study includes 1290 stroke-free participants who had brain MRI. We examined baseline systolic and diastolic (DBP) BP, and changes in BP from baseline to MRI, and WMHV.

RESULTS

There were 1281 participants with brain MRI and 2 BP measurements (mean age, 64 years; SD=8; range, 40 to 94 years). Baseline DBP was associated with greater WMHV (P<0.0001) independent of sociodemographic and vascular risk factors. Each 10 mm Hg above the mean baseline DBP (83±11 mm Hg) was associated with a 1.17% greater WMHV. Over 7 years average follow-up, participants with an increase >5 mm Hg DBP from baseline to MRI had 1.21% greater WMHV relative to those whose BP did not increase (P=0.02). The association between baseline DBP and WMHV was strongest for blacks compared with Hispanics and whites (interaction P=0.04).

CONCLUSIONS

Baseline DBP and longitudinal increases in DBP were independently associated with a greater WMHV, and the association between DBP and WMHV was greatest among blacks.

[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.

Balance control improves following replacement of paroxetine with venlafaxine and levodopa in a case of microvascular dementia

BACKGROUND

Postural instability is a concern in several neurologic conditions and also among the elderly. Dysfunction in serotonergic, noradrenergic, and dopaminergic pathways may be involved in the etiology of postural imbalance.

OBJECTIVE

The objective of this case report was to quantify, using computerized posturography, substitution with venlafaxine, and later levodopa, in a suspected case of postural instability with paroxetine.

CASE SUMMARY

Presented is an 86-year-old woman with frequent falls and a Parkinson-like syndrome of the lower limbs secondary to microvascular dementia. Paroxetine was gradually discontinued and exchanged for venlafaxine, 37.5 mg twice daily. Before and after medication changes, static posturography was performed under eyes open and closed conditions. Following 3 months of venlafaxine, the patient showed significant improvement from baseline, however, venlafaxine was then reduced to 37.5 mg at bedtime. Six months later, levodopa was introduced and further improvement was observed. It is possible that venlafaxine, which maintains a more balanced affinity for serotonin and norepinephrine transporters, may have provided postural benefit. Decreased sedation secondary to venlafaxine reduction may have elicited further improvements in addition to the increased lower limb functionality observed with levodopa.

CONCLUSIONS

For patients on antidepressants, switching medications may be worthwhile in those with balance problems. The prudent addition of medications may also be an option.

Vascular cognitive impairment in small vessel disease: clinical and neuropsychological features of lacunar state and Binswanger's disease

BACKGROUND

ischaemic cerebrovascular small vessel disease (SVD) is a prevalent and under-diagnosed condition that triggers vascular cognitive impairment (VCI).

OBJECTIVE

to describe the neuropsychological and clinical profiles in SVD (Binswanger's disease, BD; lacunar state, LS) from the clinician's perspective at the VCI stage.

METHODS

a total of 1257 patients admitted to a tertiary center with a diagnosis of stroke, neuroradiological vascular disease, cognitive impairment/dementia, during a 13-year period were investigated. We prospectively assessed cognition in a subset of 141 patients with VCI (LS n = 28, BD n = 69, large vessel disease-LVD-n = 44) with MMSE, CAMDEX-H, WAIS-R, EXIT-25 and Trail making test.

RESULTS

executive dysfunction (ECD) (n = 89, 91.7% versus n = 10, 22.7%; P < 0.001) and gait disturbances (n = 74, 76.3% versus n = 15, 34.1%; P < 0.001) characterized SVD. Prior strokes (n = 9, 9.3% versus n = 23, 52.3%; P < 0.001) and embologenous cardiopathy (n = 39, 40.2% versus n = 28, 63.6%; P < 0.04) featured LVD cases. BD was defined by hypertension (n = 52, 75.4% versus n = 30, 44.1%; P < 0.001), ECD (n = 65, 94.2% versus n = 34, 47.2%; P < 0.001) and VCI onset with cognitive impairment but not strokes (n = 44, 63.8% versus n = 34, 50%; P < 0.01).

CONCLUSIONS

ECD and a frontal gait are SVD's clinical landmarks in our sample. LS and BD cases share a similar cognitive profile.

A review of transcranial magnetic stimulation in vascular dementia

Vascular dementia (VaD) is a clinical syndrome that encompasses a wide spectrum of cognitive disorders caused by cerebrovascular disease. The subcortical ischemic form of VaD is clinically homogeneous and a major cause of cognitive impairment in the elderly. Vascular lesions contribute to cognitive decline in neurodegenerative dementias, and VaD and Alzheimer's disease often coexist and share clinical features and multiple neurotransmission involvement. These similarities have led several investigators to use transcranial magnetic stimulation (TMS) to enucleate a neurophysiological profile of VaD. TMS studies have identified a pattern of cortical hyperexcitability probably related to the disruption of the integrity of white matter lesions due to cerebrovascular disease. The present review provides a perspective of these TMS techniques by further understanding the role of different neurotransmission pathways and plastic remodeling of neuronal networks in the pathogenesis of VaD.

[Acetyl-L-carnitine (carnicetine) in the treatment of early stages of Alzheimer's disease and vascular dementia]

Efficacy, safety and tolerability of acetyl-L-carnitine (ALC) were studied during the double-blind placebo-controlled 12-week trial in patients with mild (initial) dementia caused by the Alzheimer's disease (AD) and vascular dementia (VD). ALC was administered in doses from 2250 to 3000 mg per day. Patient's state was assessed with some scales (MMSE, CGI etc) and a battery of neuropsychological tests. The treatment effect of ALC was 2,8 times higher than in placebo-treated patients. The clinical improvement by CGI scores was significantly better in AD patients compared to VD and did not depend on the severity of baseline cognitive deficit. The drug was well-tolerated. Carnicetine can be recommended in the abovementioned doses for treatment of early stages of AD and VD.

Late life depression and late onset depression: are the same clinical and pathopsysiological picture?

Phenomenological differences between older patients with late- and early-onset depression may reflect differences in aetiology and neuropathological processes involved in these two types of depression. Early- onset depression has been mainly correlated to a family history of depression while late-onset depression has been principally correlated to vascular dysfunction. The same cortical and sub-cortical areas are involved in both types of depression. However, lesions in these brain areas and cognitive impairment are most pronounced in late-onset depression. Based on these observations we propose a common neuroanatomical substrate but different pathophysiological processes implicated in these two types of depression.

Kallikrein-related peptidase 6 in Alzheimer's disease and vascular dementia

Human kallikrein-related peptidase 6 (KLK6) is highly expressed in the central nervous system. Although the physiological roles of this serine protease are unknown, in vitro substrates include amyloid precursor protein and components of the extracellular matrix, which are altered in neurological disease, particularly Alzheimer's disease (AD). We have compared KLK6 expression in post-mortem brain tissue in AD, vascular dementia (VaD) and controls. We studied the distribution of KLK6 in the temporal cortex and white matter by immunohistochemistry, and measured KLK6 mRNA and protein levels in the frontal and temporal cortex from 15 AD, 15 VaD and 15 control brains. Immunohistochemistry showed KLK6 to be restricted to endothelial cells. After adjustment for variations in vessel density by measurement of factor VIII-related antigen, we found KLK6 protein and mRNA levels to be significantly decreased in the frontal but not the temporal cortex in AD. In VaD, KLK6 protein level was significantly increased in the frontal cortex. Our findings suggest that an altered KLK6 expression may contribute to vascular abnormalities in AD and VaD.