Vascular dementia: a contemporary review of epidemiology, diagnosis, prevention, and treatment

Positive Results from the Fecal Immunochemical Test Can Be Related to Dementia: A Nationwide Population-Based Study in South Korea

BACKGROUND

The fecal immunochemical test (FIT) is widely used in screening for colorectal cancer (CRC), but FIT results can be positive for diseases other than CRC.

OBJECTIVE

We investigated the association between positive results of FIT and the incidence of dementia using a nationwide database.

METHODS

FIT-positive participants were collected from a database provided by the Korean National Health Insurance Service.

RESULTS

The incidence of all kinds of dementia was higher in FIT-positive than FIT-negative subjects (p < 0.0001). FIT-positive participants had a higher risk of Alzheimer's disease (AD) (p < 0.0001) and vascular dementia (p = 0.0002), compared to participants with FIT negativity. The risk of all kinds of dementia or AD in FIT-positive participants was higher in younger (age < 65 years) than older participants (p < 0.0001 for all kinds of dementia; p = 0.0002 for AD).

CONCLUSION

FIT positivity was correlated with an increased risk of dementia, especially in participants under 65 years of age. The study suggests that clinicians can consider dementia when FIT-positive participants fail to show any malignancies.

Prediction of clinical diagnosis of Alzheimer's disease, vascular, mixed, and all-cause dementia by a polygenic risk score and APOE status in a community-based cohort prospectively followed over 17 years

The strongest genetic risk factor for Alzheimer's disease (AD) is the ε4 allele of Apolipoprotein E (APOE) and recent genome-wide association meta-analyses have confirmed additional associated genetic loci with smaller effects. The aim of this study was to investigate the ability of an AD polygenic risk score (PRS) and APOE status to predict clinical diagnosis of AD, vascular (VD), mixed (MD), and all-cause dementia in a community-based cohort prospectively followed over 17 years and secondarily across age, sex, and education strata. A PRS encompassing genetic variants reaching genome-wide significant associations to AD (excluding APOE) from the most recent genome-wide association meta-analysis data was calculated and APOE status was determined in 5203 participants. During follow-up, 103, 111, 58, and 359 participants were diagnosed with AD, VD, MD, and all-cause dementia, respectively. Prediction ability of AD, VD, MD, and all-cause dementia by the PRS and APOE was assessed by multiple logistic regression and receiver operating characteristic curve analyses. The PRS per standard deviation increase in score and APOE4 positivity (≥1 ε4 allele) were significantly associated with greater odds of AD (OR, 95% CI: PRS: 1.70, 1.45-1.99; APOE4: 3.34, 2.24-4.99) and AD prediction accuracy was significantly improved when adding the PRS to a base model of age, sex, and education (ASE) (c-statistics: ASE, 0.772; ASE + PRS, 0.810). The PRS enriched the ability of APOE to discern AD with stronger associations than to VD, MD, or all-cause dementia in a prospective community-based cohort.

Activation of EphA4 induced by EphrinA1 exacerbates disruption of the blood-brain barrier following cerebral ischemia-reperfusion via the Rho/ROCK signaling pathway

Vascular dementia (VD) is a syndrome characterized by progressive cognitive decline. According to previous studies, stroke is considered to be a risk factor for VD. The disruption of the blood-brain barrier (BBB) is pivotal to the pathology of stroke, as it contributes to post-stroke inflammation and edema. It has been reported that the Eph/Ephrin signaling pathway serves an important role in central nervous system injury. However, the role of EphrinA1/EphA4 signaling in BBB damage following ischemic stroke has not yet been reported. Oxygen-glucose deprivation/reperfusion was performed to detect changes in EphrinA1 and EphA4 expression in human brain microvascular endothelial cells (HBMECs). Male mice were randomly divided into four groups [Sham, ischemia-reperfusion (I/R), I/R+EphrinA1 and I/R+EphA4] to observe the role of EphrinA1 and EphA4 under I/R conditions in vivo. The results of the present study revealed that the expression of EphrinA1 and EphA4 was significantly increased following I/R in vitro and in vivo. The administration of soluble ligand EphrinA1 enhanced CD68⁺ cell accumulation, brain edema and dysfunction of the BBB, with lower expression levels of zonula occludens-1 (ZO-1) and Claudin-5. In addition, EphrinA1-treated mice had a higher level of caspase-3 and a lower level of phosphorylated-protein kinase B. However, the effects of EphrinA1 were abolished by EphA4-Fc, an inhibitor of EphA4. These results suggested that EphrinA1 exerted its effects on I/R injury via the activated EphA4 receptor. In addition, EphrinA1 decreased ZO-1 and Claudin-5 expression through the Rho/Rho associated kinase (ROCK) signaling pathway, which was attenuated by the pharmacological inhibition of Rho (C3 transferase) or ROCK (Y-27632). In conclusion, the present study provides evidence that the activation of EphA4 induced by EphrinA1 contributes to BBB damage following ischemic stroke through the Rho/ROCK signaling pathway, which highlights a potential therapeutic strategy for ischemic stroke and may help the development of preventative interventions for VD.

Prediabetes is associated with lower brain gray matter volume in the general population. The Study of Health in Pomerania (SHIP)

BACKGROUND AND AIMS

We investigated the associations of fasting (FG) and 2-h postload (2HG) plasma glucose from oral glucose tolerance test (OGTT) with gray (GMV) and white (WMV) matter volume.

METHODS AND RESULTS

We analyzed data from 1330 subjects without known diabetes mellitus, aged 21 to 81, from the second cohort (SHIP-Trend-0) of the population-based Study of Health in Pomerania (SHIP). Following the OGTT, individuals were classified in five groups (according to the American Diabetes Association criteria): normal glucose tolerance (NGT), isolated impaired fasting glucose (i-IFG), isolated impaired glucose tolerance (i-IGT), combined IFG and IGT (IFG + IGT) and unknown type 2 diabetes mellitus (UDM). GMV and WMV were determined by magnetic resonance imaging. FG, 2HG and OGTT groups were associated with GMV and WMV by linear regression models adjusted for confounders. FG and 2HG were inversely associated with GMV. The adjusted mean GMV, when compared with the NGT group (584 ml [95% CI: 581 to 587]), was significantly lower in the groups i-IFG (578 ml [95% CI: 573 to 582]; p = 0.035) and UDM (562 ml [95% CI: 551 to 573]; p < 0.001), but not different in the i-IGT (586 ml [95% CI: 576 to 596]; p = 0.688) and IFG + IGT (579 ml [95% CI: 571 to 586]; p = 0.209) groups. There were no associations of FG, 2HG and OGTT parameters with WMV.

CONCLUSION

Our findings suggest that elevated FG levels, even within the prediabetic range, might already have some harmful effects on GMV.

Population Base Rates and Disease Course of Common Psychiatric and Neurodegenerative Disorders

Knowledge of population base rates of neurological and psychiatric disorders is fundamental for diagnostic decision making. Consideration of relevant probabilistic information can improve diagnostic efficiency and accuracy. However, such data continue to be misused or underutilized, which can lead to misdiagnoses and negative patient outcomes. The aim of the current review is to create an easily accessible and comprehensive reference of existing age of onset as well as prevalence and incidence data for common neurodegenerative and psychiatric disorders in adults. Relevant epidemiological data were compiled from well-respected and frequently-cited textbooks and scholarly studies. Reviews were collected from PubMed, and publicly-available sources were gathered from Google Scholar. Results are organized and presented in several tables and a figure, which can be used as a diagnostic guide for students and clinicians across healthcare disciplines.

Effects of Physical Activity and Ginkgo Biloba on Cognitive Function and Oxidative Stress Modulation in Ischemic Rats

Either exercise or Ginkgo biloba is reported to improve cognitive functioning. The aim of this study is to compare the protective effects of forced exercise and Ginkgo biloba on oxidative stress as well as memory impairments induced by transient cerebral ischemia. Adult male Wistar rats were treated with treadmill running or Ginkgo biloba extract for 2 weeks before cerebral ischemia. Memory was assessed using a Morris water maze (MWM) task. At the end of the behavioral testing, oxidative stress biomarkers were evaluated in the hippocampus tissue. As expected, the cerebral ischemia induced memory impairment in the MWM task, and oxidative stress in the hippocampus. These effects were significantly prevented by treadmill running. Indeed, it ameliorated oxidative stress and memory deficits induced by ischemia. In contrast, Ginkgo biloba was not as effective as exercise in preventing ischemia-induced memory impairments. The results confirmed the neuroprotective effects of treadmill running on hippocampus-dependent memory.

Characteristics of MR infarcts associated with dementia and cognitive function in the elderly

BACKGROUND

Little information exists on the simultaneous effects of magnetic resonance (MR) infarct characteristics, that may increase the likelihood of dementia or lower cognitive function in community populations.

METHODS

Participants were 580 community-dwelling individuals from the Chicago Health and Aging Project (CHAP) who underwent detailed clinical evaluation and MR imaging. The association of MR infarct characteristics (region, number, side, and size) with dementia, global cognition and cognition in five separate cognitive domains was examined using logistic and linear regression analyses controlling for age, sex, race, education and time elapsed between clinical evaluation and MRI.

RESULTS

A total of 156 persons had MR infarcts: 108 with 1 infarct and 48 with multiple. Poorer cognitive function and, in particular, slower perceptual speed, were associated with infarcts characterized as cortical, multiple, bilateral or large (all p < 0.05). Multiple infarcts in multiple regions were associated with poor performance in all cognitive domains except visuospatial ability (p < 0.05). Race did not modify any of these associations.

CONCLUSIONS

In this community sample, cortical and multiple infarcts in multiple regions were associated with dementia; cortical, multiple, large and bilateral infarcts were associated with lower cognition, particularly lower memory function and perceptual speed. These effects were not modified by race.

Management of mixed dementia

Alzheimer's disease (AD) and vascular dementia (VaD) are the most common causes of dementia in the elderly. Although AD can be diagnosed with a considerable degree of accuracy, the distinction between isolated AD, VaD and mixed dementia (MD) [when both pathologies coexist in the same patient] remains a controversial issue and one of the most difficult diagnostic challenges. MD represents a very common pathology, especially in the elderly, as reported in neuropathological studies. Accurate diagnosis of MD is of crucial significance for epidemiological purposes and for preventive and therapeutic strategies. Until recently, pharmacological studies have generally focused on pure disease, either AD or VaD, and have provided few data on the best therapeutic approach to MD. There is only one original randomized clinical trial on (acetyl)cholinesterase inhibitor therapy (GAL-INT-6, galantamine) for MD; the other studies are post hoc analyses of AD trial subgroups (AD2000, donepezil) or of VaD trial subgroups (VantagE, rivastigmine). Cholinesterase inhibitors have reproducible beneficial effects on cognitive and functional outcomes in patients with MD. These benefits are of a similar magnitude to those previously reported for the treatment of AD. It is likely that the beneficial effects of memantine (an NMDA receptor antagonist) in AD may also apply to MD, but randomized controlled trials are still lacking. Treatment of cardiovascular risk factors, especially hypertension, may protect brain function and should be included in prevention strategies for MD.

Early onset dementia: clinical and social aspects

BACKGROUND

Increasing efforts are being devoted to the study of early onset dementia (EOD), namely dementia in persons under the age of 65. Until recently, it was assumed that dementia occurs primarily among people aged 65 and over. However, since the number of persons with EOD is increasing, its importance as a clinical and social problem is rising accordingly. The aim of the present paper is to summarize research in this area.

METHODS

We reviewed the research published to date on EOD, and divided the current body of knowledge into several main sections.

RESULTS

The first section focuses on clinical aspects and summarizes findings regarding prevalence, causes, symptoms, diagnosis, and management of persons with EOD. The second section focuses on social aspects related to the cost of care for young people with the disease, the challenges faced by individuals and caregivers, and the services available for this population. Finally, conclusions and future directions are suggested.

CONCLUSIONS

Research on EOD is still in its early stages. There is an urgent need to expand research that will lead to more effective diagnosis and management of EOD as well as to the allocation of funds and the development of appropriate services suitable for the unique needs of young people with dementia.

Serum lipids are related to Alzheimer's pathology in nursing home residents

BACKGROUND

Studies of associations between serum lipids and Alzheimer's disease (AD) or other dementias in the elderly show conflicting results, perhaps due to misclassification of the various dementias.

METHODS

For 358 nursing home residents, serum lipids were studied at admission and diagnoses established at autopsy. We used defined neuropathological criteria to distinguish the presence of AD and to avoid errors of clinical dementia assessment.

RESULTS

Residents with any AD pathology, as compared to those without AD pathology, had higher mean serum total cholesterol (TC; 200.4 vs. 185.9 mg/dl; p = 0.02) and higher mean low-density lipoprotein cholesterol (LDL; 124.5 vs. 111.5 mg/dl; p = 0.03). Further, mean TC, LDL and high-density lipoprotein cholesterol levels all increased progressively with increasing pathological certainty of AD (p for trend = 0.001, 0.02 and 0.02).

CONCLUSIONS

TC and LDL were significantly related to pathologically defined AD. If serum lipids have a role in the pathogenesis of AD, interventions may modify the course of disease.

Acupuncture for vascular dementia

BACKGROUND

Dementia is a widespread condition characterized by acquired global impairment of intellect, memory and personality, but with no impairment of consciousness. There is no definitive medical or surgical treatment for vascular dementia. Acupuncture is an ancient Chinese method which has been used for both the prevention and treatment of diseases for over three thousand years. Preliminary searches revealed more than 105 studies of acupuncture for treating vascular dementia. Benefit was reported in up to 70-91% of the treatment group. Body acupuncture and electroacupuncture were the most commonly used techniques. A comparison of electroacupuncture and acupuncture therapy alone suggested that the former was more effective in promoting the recovery of cognitive function.

OBJECTIVES

The objective is to assess the efficacy and possible adverse effects of acupuncture therapy for treating vascular dementia.

SEARCH STRATEGY

The trials were identified from a search of the Cochrane Dementia and Cognitive Improvement group's Specialized Register on 2 February 2007 which contains records from all major health care databases and many ongoing trials databases. In addition the Allied and Complementary Medicine Database was searched and the web was searched using the search engine Copernic.

SELECTION CRITERIA

Randomized controlled trials testing acupuncture therapy in the treatment of vascular dementia were included regardless of language and publication types. The intervention and control group had to receive identical treatment apart from the acupuncture intervention. In view of possible confounding, studies in which acupuncture was combined with other treatments were subjected to subgroup analyses.

DATA COLLECTION AND ANALYSIS

Titles and abstracts identified from the searches were checked by two reviewers. If it was clear that the study did not refer to a randomized controlled trial in vascular dementia, it was excluded. If it was not clear from the abstract and title, then the full text of study was obtained for an independent assessment by two reviewers. The outcomes measured in clinical trials of dementia and cognitive impairment often arise from ordinal rating scales. Summary statistics were required for each rating scale at each assessment time for each treatment group in each trial for change from baseline.

MAIN RESULTS

In the absence of any suitable randomised placebo-controlled trials in this area, we were unable to perform a meta-analysis.

AUTHORS' CONCLUSIONS

The effectiveness of acupuncture for vascular dementia is uncertain. More evidence is required to show that vascular dementia can be treated effectively by acupuncture. There are no RCTs and high quality trials are few. Randomised double-blind placebo controlled trials are urgently needed.

A pilot study evaluating the efficacy and safety of rivastigmine in patients with mixed dementia

BACKGROUND AND OBJECTIVE

The two most common causes of dementia in the elderly are Alzheimer's disease (AD) and vascular dementia (VaD), which can coexist as mixed dementia. The object of this study was to assess the efficacy and safety of rivastigmine in patients with mixed dementia (AD with VaD).

STUDY DESIGN

This 26-week open-label pilot study was conducted at 19 centres in the US. To reduce bias, the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog) raters were blinded to all efficacy measures and to patient dosage information. Patients were treated with rivastigmine and titrated to their highest tolerated dose, up to 12 mg/day (6 mg twice daily). The primary efficacy measure was cognitive function assessed by the ADAS-Cog subscale (without the concentration/distractibility item, to be consistent with cognitive outcome measures used in previous rivastigmine trials).

RESULTS

Forty-seven percent of patients treated with rivastigmine 6-12 mg/day demonstrated improvement on the ADAS-Cog at 26 weeks, with >25% of patients having a clinically significant improvement of > or =4 points. Treatment with rivastigmine (6-12 mg/day) was well tolerated by the majority of patients. The most common adverse effects occurring in >10% of patients were nausea, vomiting, dizziness and diarrhoea.

CONCLUSION

This pilot study suggests that rivastigmine treatment may have beneficial effects in the treatment of patients with mixed dementia.

Neuroradiological findings in vascular dementia

INTRODUCTION

There are multiple diagnostic criteria for vascular dementia (VaD) that may define different populations. Utilizing the criteria of the National Institute of Neurological Disorders and Stroke and Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN) has provided improved consistency in the diagnosis of VaD. The criteria include a table listing brain imaging lesions associated with VaD.

METHODS

The different neuroradiological aspects of the criteria are reviewed based on the imaging data from an ongoing large-scale clinical trial testing a new treatment for VaD. The NINDS-AIREN criteria were applied by a centralized imaging rater to determine eligibility for enrollment in 1,202 patients using brain CT or MRI.

RESULTS

Based on the above data set, the neuroradiological features that are associated with VaD and that can result from cerebral small-vessel disease with extensive leukoencephalopathy or lacunae (basal ganglia or frontal white matter), or may be the consequence of single strategically located infarcts or multiple infarcts in large-vessel territories, are illustrated. These features may also be the consequence of global cerebral hypoperfusion, intracerebral hemorrhage, or other mechanisms such as genetically determined arteriopathies.

CONCLUSION

Neuroimaging confirmation of cerebrovascular disease in VaD provides information about the topography and severity of vascular lesions. Neuroimaging may also assist with the differential diagnosis of dementia associated with normal pressure hydrocephalus, chronic subdural hematoma, arteriovenous malformation or tumoral diseases.

Differential verbal fluency deficits in the preclinical stages of Alzheimer's disease and vascular dementia

We examined patterns of early and late word generation in category and letter fluency among persons in the preclinical stages of Alzheimer's disease (AD) and vascular dementia (VaD). The sample consisted of 20 preclinical VaD persons, 66 preclinical AD persons, and 267 control persons, sampled from the community. Persons in the preclinical phase of AD and VaD were similarly impaired in letter fluency, although the preclinical VaD group outperformed their AD counterparts in category fluency. This pattern of results is consistent with the notion that category fluency is relatively more dependent on the medial-temporal lobe, whereas letter fluency relies more on frontal regions. The patterns of fluency impairment in preclinical AD and VaD generalized across early and late word retrieval.

Vascular cognitive impairment

Vascular cognitive impairment encompasses a spectrum of clinically defined syndromes ranging from vascular cognitive impairment-no dementia, to vascular dementia. The underlying cerebrovascular pathology includes both overt infarction as well as rarefaction of gray and white matter. Alzheimer's pathology may coexist with vascular pathology. Diagnosis rests on identifying acquired cognitive impairment in the setting of documented cerebrovascular disease, based on clinical presentation and neuroimaging; MRI is more sensitive than CT. The course can be stepwise or gradually progressive. The clinical picture is typically dominated by deficits in executive function rather than the short-term memory deficit typical of Alzheimer's disease. No specific therapies exist, but treatment with anticholinesterase agents and N-methyl-d-aspartate antagonists may result in clinical improvement. Prevention remains paramount, with early recognition of populations at risk and early and aggressive management of risk factors, including hypertension, dyslipidemia, diabetes, and tobacco use as well as antithrombotic therapy, in appropriate populations.

Longitudinal volumetric MRI change and rate of cognitive decline

OBJECTIVE

To examine how baseline and change of volumetric MRI relate to cognitive decline in older individuals.

BACKGROUND

Memory is associated with hippocampal integrity, whereas executive function has been linked to impaired frontal lobe function. Previous studies have shown that hippocampal and cortical atrophy are more strongly related to cognition than are measures of subcortical cerebrovascular disease (CVD). The authors hypothesized that memory (MEM) decline would be related to change in hippocampal volume (HC), whereas decline in executive function (EXEC) would be related to change of cortical gray matter volume (CGM) and measures of subcortical CVD.

METHODS

Subjects from a multicenter study (n = 103) included cognitively normal, mildly impaired, and demented cases with and without subcortical lacunes. All had longitudinal cognitive evaluation (mean = 4.8 years) and two or more MRI scans at least one year apart (mean = 3.4 years). MRI measures included HC, CGM, total lacune volume (LAC), and white matter hyperintensity volume (WMH). Random effects modeling of longitudinal data assessed effects of MRI baseline and MRI change on baseline and change of psychometrically matched measures of MEM and EXEC.

RESULTS

Change in MEM was related to HC baseline and HC change. Change in EXEC was related to baseline CGM and to change in CGM, HC, and LAC. Results were unchanged when demented cases were excluded. WMH was not associated with change in MEM or EXEC independent of HC, CGM, and LAC.

CONCLUSION

Hippocampal volume was the primary determinant of memory decline, whereas executive function (EXEC) decline was related to multiple brain components. Results support a hypothesis that MEM decline is strongly influenced by Alzheimer disease (AD), whereas EXEC decline may be complexly determined by cerebrovascular disease and AD.

Dementia with cerebrovascular disease: the benefits of early treatment

Patients with vascular dementia (VaD) and Alzheimer's disease with cerebrovascular disease (AD + CVD) have dementia associated with underlying CVD. Although diagnosis of VaD is challenging, VaD is typically characterized by a stepwise progression of dementia that is closely associated with stroke and focal neurological findings, and a symptom profile that often includes executive dysfunction leading to decreased ability to perform instrumental activities of daily living (IADL). In contrast, AD + CVD patients typically present with progressive deterioration of cognition/memory that may also be influenced by concurrent cerebrovascular events. Early diagnosis and intervention are desirable to prevent further decline due to subsequent vascular events. Management of CVD can limit deterioration of cognitive symptoms in VaD patients, and treatment benefits with cholinesterase inhibitors may be realized as improvement above baseline levels in dementia symptoms. Results from a combined analysis of two 24-week, placebo-controlled clinical trials show that donepezil-treated VaD patients improve in cognition, global function, and performance of IADL. In contrast, AD + CVD patients may continue to decline despite management of CVD, and treatment benefits should be recognized as initial improvements followed by stabilization or slowed decline of dementia symptoms over time. In post-marketing studies, donepezil-treated AD and AD + CVD patients show similar benefits in cognition, global function, and quality of life. The results of these studies support the use of donepezil in treatment of patients with VaD or AD + CVD.

1H MRS in stroke patients with and without cognitive impairment

The pathophysiological basis of cognitive impairment in patients with cerebrovascular disease (CVD) is not well understood, particularly in relation to the role of non-infarction ischemic change and associated Alzheimer-type pathology. We used single voxel 1H MRS to determine the differences in brain neurometabolites in non-infarcted frontal white matter and occipito-parietal gray matter of 48 stroke patients with or without cognitive impairment and 60 elderly controls. The results showed that there were no significant neurometabolite differences between the stroke cohort and healthy elderly controls, but there was a difference in NAA/H2O between the stroke patients that had cognitive impairment (vascular dementia (VaD) and vascular cognitive impairment (VCI)) compared with those patients with no impairment. This was significant in the occipito-parietal gray matter, but not in the frontal white matter, although the results were in the same direction for the latter. This suggests that cognitive impairment in stroke patients may be related to cortical neuronal dysfunction rather than purely subcortical change. Moreover, cortical regions not obviously infarcted may have dysfunctional neurons, the pathophysiological basis for which needs further study.

Left ventricular mass indexed to height and prevalent MRI cerebrovascular disease in an African American cohort: the Atherosclerotic Risk in Communities study

BACKGROUND AND PURPOSE

Previous studies have demonstrated that echocardiographic left ventricular mass (LVM) is an independent risk factor for stroke in whites. Despite the greater burden of stroke, the echocardiographic predictors of stroke in African Americans remain poorly understood.

METHODS

This investigation is a retrospective analysis of prospectively collected data from the Jackson, Miss (all African American), cohort of the Atherosclerotic Risk in the Communities study. Between 1993 and 1995, 2445 participants received an echocardiogram, and a random subset (n=778) received cerebral MRI evaluating presence of infarcts or white matter disease (WMD; >3 on a scale of 0 to 9). Compared with the entire Jackson cohort, the random subset was older, had a lower body mass index (BMI), and a higher systolic blood pressure (SBP). Logistic regression models examined the relations of LVM indexed by height (LVM/height) to MRI findings adjusted for age, gender, BMI, SBP, hypertensive medications, diabetes, total/high-density lipoprotein cholesterol, smoking status, and history of myocardial infarction.

RESULTS

The 667 participants (63% women; 62+/-4 years of age) had a high prevalence of hypertension (68%), obesity (46%), echocardiographic left ventricular hypertrophy (49%), MRI stroke (n=133), and WMD (n=92). Adjusted LVM/height was significantly associated with prevalent MRI stroke (odds ratio [OR], 1.3; 95% CI, 1.1 to 1.7; P=0.02) and WMD (OR, 1.5; 95% CI, 1.1 to 1.9; P=0.006; OR expressed per 1 SD LVM/height, 45 g/m).

CONCLUSIONS

In this randomized subset of a population-based cohort of African American adults, LVM/height was related to MRI evidence of prevalent cerebrovascular disease. The current study supports the hypothesis that LVM/height is an important risk factor for stroke in multiple ethnicities.

Dementia and serious coexisting medical conditions: a double whammy

Research-based information about the prevalence of other serious medical conditions in people with dementia has become available only recently, and the true prevalence is not known, primarily because many people with dementia do not have a diagnosis. The existing information is sufficient, however, to show that these other conditions are common in people with dementia. It is also clear that coexisting medical conditions increase the use and cost of health care services for people with dementia, and conversely, dementia increases the use and cost of health care services for people with other serious medical conditions. Nurses and other healthcare professionals should expect to see these relationships in their elderly patients. They should know how to recognize possible dementia and assess, or obtain an assessment of, the patient's cognitive status. They should expect the worsening of cognitive and related symptoms in acutely ill people with dementia and try to eliminate factors that cause this worsening, to the extent possible, while assuring the family that the symptoms are likely to improve once the acute phase of illness or treatment is over. Families, nurses, and other health care professionals are challenged by the complex issues involved in caring for a person with both dementia and other serious medical conditions. Greater attention to these issues by informed and thoughtful clinicians will improve outcomes for the people and their family and professional caregivers.

Similar patterns of cognitive deficits in the preclinical phases of vascular dementia and Alzheimer's disease

We investigated whether (1) cognitive deficits are present among persons who will be diagnosed with vascular dementia (VaD) 3 years later, and (2) the pattern of such deficits is similar to that observed in preclinical Alzheimer's disease (AD). The VaD diagnosis was a diagnosis of post-stroke dementia. Population-based samples of 15 incident VaD cases, 43 incident AD cases, and 149 normal controls were compared on tests of episodic and short-term memory, verbal fluency, and visuospatial skill. Both dementia groups showed preclinical impairment relative controls on tasks assessing episodic memory 3 years before diagnosis, and there were no differences between these groups on any cognitive measure. The existence of a preclinical phase in the present VaD cases suggests that circulatory disturbance may affect cognitive performance before the occurrence of stroke that leads to clinical VaD. These results extend previous findings of similar patterns of cognitive deficits in the early clinical phases of AD and VaD to the preclinical phases of these diseases.

Drug therapy of neurovascular disease

Recent advances in the prevention and pharmacotherapy of cerebrovascular disease have provided more favorable clinical outcomes. For the treatment of an acute ischemic stroke, the early use of thrombolytic agents can reduce the degree of brain damage while improving functional outcomes. However, trials evaluating various classes of other neuroprotective agents have not shown benefit to date. For the prevention of second stroke, the use of antiplatelet drugs, HMG-CoA reductase inhibitors, and angiotensin-converting enzyme inhibitors with a diuretic have shown benefit in reducing new events. In patients with underlying heart disease or atrial fibrillation, warfarin appears to be the drug of choice in preventing stroke. Early treatment of hemorrhagic stroke with calcium channel blockers can improve the functional outcome. Innovative therapies are now available for the treatment of migraine and vascular dementia. Primary prevention of stroke remains the optimal therapeutic strategy and includes treatment of systemic hypertension and hypercholesterolemia.

The vascular lesions in vascular and mixed dementia: the weight of functional neuroanatomy

Vascular dementia appears rarer than previously thought, but the contribution of vascular lesions to cognitive impairment in Alzheimer's disease (AD) affected patients (mixed dementias) is now recognized as frequent. The role of strategic areas of the brain involved in the cognitive decline induced by vascular lesions and their relative contributions to the severity of the dementing process remain poorly understood. We determined the relationship between the severity of clinical dementia and the volume of different brain areas affected by infarcts in a prospective clinicopathological study in elderly patients. A volumetric study of the functional zones of Mesulam's human brain map affected by vascular lesions was made and correlations between quantified neuropathological data and the severity of dementia were performed in cases with large vascular lesions only, pure AD, and both lesions. The severity of cognitive impairment was significantly correlated with the total volume of infarcts but in a multi-variate model the volume destroyed in the limbic and heteromodal association areas, including the frontal cortex and in the white matter explained 50% of the variability in MMSE and GDS. The total volume of ischemic lesions explained only 0.1-5% of the variability in MMSE and GDS. Age only explained an extra of 0.1-1.6%. This study confirms that infarcts located in strategic areas have a role in the mechanism of cognitive impairment and brings a key for their quantification. It may be useful for developing neuropathological criteria in multi-infarct and mixed dementias.

The efficacy of pentoxifylline in the treatment of vascular dementia: a systematic review

This systematic review seeks to (1) summarize the pharmacologic effects of pentoxifylline on the cerebrovasculature and (2) review critically the studies evaluating pentoxifylline in the treatment of vascular dementia. To retrieve all relevant published and unpublished studies, we performed with no language restrictions computer keyword searches of MEDLINE, EMBASE, and Cochrane Library databases; reviewed bibliographies; and contacted the pharmaceutical manufacturer. We included pertinent articles if they met three quality criteria: randomized, double-blinded, and placebo-controlled study design; objective diagnostic criteria for vascular dementia; and reported original data. The literature search identified a total of 20 articles; however, only four studies met the quality criteria for inclusion in this systematic review. All four studies suggested a trend toward improved cognitive function in patients treated with pentoxifylline. Three of the studies performed a subgroup analysis using a stricter definition for vascular dementia. In these secondary analyses, the studies noted statistically significant differences in cognitive function between placebo and treatment groups. In conclusion, this systematic review suggested a potential therapeutic role for pentoxifylline in vascular dementia. However, few studies met the quality criteria for inclusion in this systematic review, and most of these studies were small and had methodologic limitations.

Patient populations in clinical trials of the efficacy and tolerability of donepezil in patients with vascular dementia

There is increasing evidence to suggest that patients with vascular dementia (VaD) exhibit a cholinergic deficit. These patients may therefore benefit from treatment with cholinesterase (ChE) inhibitors such as donepezil. However, there are difficulties in accurately defining patients with VaD. Clinical trials to assess the efficacy and tolerability of donepezil in patients with VaD have been completed. National Institute of Neurological Disorders and Stroke and the Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN) criteria were used to establish inclusion and exclusion criteria: evidence of dementia (impaired memory and two other cognitive domains), and evidence of cerebrovascular disease (CVD) from neuroimaging and physical examination and a possible or probable relationship between dementia and CVD were required for enrollment. Patients with a diagnosis of Alzheimer's disease (AD) or dementia caused by other conditions not associated with the cardiovascular system (e.g., MS, chronic infections, hypothyroidism) were excluded. These criteria ensured that only patients with probable or possible VaD were enrolled. Enrolled patients had a mean Hachinski score of 9.7, with memory impairment the most prominent feature of their dementia. Sixty percent of patients had a history of at least one stroke and 18% of patients had a history of transient ischemic attack (TIA) pre-dementia. Cortical and subcortical infarcts were among the lesions observed on computer-assisted tomography and magnetic resonance imaging scans with significant white matter lesions also present in some patients. Placebo-treated patients demonstrated stable cognitive and global function over the 24 weeks of the study. These observations suggest that the patients enrolled in these trials have a broad range of CVD, and are different from those enrolled in AD trials.

Donepezil treatment of vascular dementia

Cholinergic deficits are clinicopathological hallmarks of Alzheimer's disease (DAT) and during the past decade have been the sole target for clinically effective treatments. By contrast, vascular dementia subtypes (VaD) are heterogeneous clinical syndromes, and therapeutic approaches have been directed toward control of vascular risk factors. Little attention has been paid to cholinergic deficits as a mechanism contributing to cognitive impairments in VaD as a potential target for treatment. The purpose of the study was to determine whether there are therapeutic benefits from long-term treatment with cholinesterase inhibitors among VaD patients. Ten VaD patients were diagnosed according to DSM-III-R and NINDS-AIREN criteria and classified into subtypes by neuroimaging. All were treated with titrated doses of donepezil for a mean interval of 15 months. At baseline and follow-up clinic visits, patients underwent medical and neurological examinations, as well as neuropsychological testing including Mini-Mental Status Examinations (MMSE) and Cognitive Capacity Screening Examinations (CCSE). Cognitive statuses of 10 treated patients were then compared before and after treatment. Net changes were expressed as annual MMSE score changes (DeltaMMSE/year) and annual CCSE score changes (DeltaCCSE/year). Of the 10 treated VaD patients, cognitive improvements were found when comparisons were made before and after treatment. Ten treated patients also showed greater cognitive improvements, while untreated patients showed continued cognitive decline. This study suggests that cholinergic deficits in VaD are due to neuronal ischemic damage with loss of acetylcholine and that treatment of VaD with cholinesterase inhibitors is a rational therapy.

Mixed dementia: epidemiology, diagnosis, and treatment

Alzheimer's disease (AD) and vascular dementia (VaD) are the most frequent causes of dementia in older people. Although AD can be diagnosed with a considerable degree of accuracy, the distinction between isolated AD, VaD, and mixed dementia (MD), where both pathologies coexist in the same patient, remains a controversial issue and one of the most difficult diagnostic challenges. Although MD represents a very frequent pathology, especially in older people, as reported in neuropathological studies, the respective importance of degenerative and vascular lesions, their interaction in the genesis of dementia, and the mere existence of MD are still debated. Accurate diagnosis of MD is of crucial significance for epidemiological purposes and for preventive and therapeutic strategies. Until recently, pharmacological studies have generally focused on pure disease, AD or VaD, and have provided little information on the best therapeutic approach to MD. This article provides an overview of MD in older people. A retrospective review of the recent literature on prevalence, incidence, course, risk factors, diagnosis, and treatment of MD was performed. The article also emphasizes the need for further studies, including neuropsychological and functional evaluations, and neuroimaging and clinicopathological correlations to develop a better understanding of MD, which appears to be one of the most common forms of dementia.

Pharmacologic treatments of dementia

The management of dementia patients encompasses pharmacologic, behavioral, and psychosocial intervention strategies. Before pharmacologic intervention is instituted, it is important that sources of excess disability and comorbidity be eliminated or reduced. Identification of comorbid medical and psychiatric conditions, such as depression and delirium, should be identified and appropriately treated. Providing caregivers with education, support, and practical advice is a critical component of the management of the demented patient. The current standard of care for pharmacologic management of the cognitive and functional disabilities of AD consists of the combination of a cholinesterase inhibitor and high-dose vitamin E. This standard is based on the results of large-scale, double-blind, placebo-controlled trials. Cholinesterase inhibitors are the only FDA-approved pharmacologic treatments for AD. Cholinesterase inhibitors have been shown to be effective in the treatment of the cognitive, behavioral, and functional deficits of AD. Large-scale placebo-controlled trials of tacrine, donepezil, rivastigmine, and galantamine have demonstrated moderate benefits in patients with mild to moderate AD. Donepezil, rivastigmine, and galantamine are the first-line choices in the treatment of AD because of their lack of hepatotoxicity, ease of administration, few significant drug-drug interactions, and mild to moderate side effects. There are few contraindications to the use of cholinesterase inhibitors. Known hypersensitivity to a specific drug or its derivatives is the only true contraindication. Cautious administration of cholinesterase inhibitors is advised in patients who have a previous history of allergy or adverse reactions to prior cholinesterase inhibitors, severe liver disease, preexisting bradycardia, peptic ulcer disease, current alcoholism, asthma, or chronic obstructive pulmonary disease. Nausea, vomiting, diarrhea, and anorexia are the most common side effects of cholinesterase inhibitors. These gastrointestinal side effects can be minimized by gradual dose increases, administration with food, adequate hydration, and judicious use of an antiemetic. Vitamin E has been demonstrated to slow the progression of AD in several small and one large placebo-controlled trials. Because of its low cost and safety, it is recommended in addition to a cholinesterase inhibitor for the treatment of AD. There are no FDA-approved treatments for DLB and VaD. One small placebo-controlled trial demonstrated that rivastigmine may be effective in the treatment of DLB. More large-scale placebo-controlled trials are needed to confirm the results of this study. Treatment of VaD focuses on the control, identification, and management of cerebrovascular disease and vascular risk factors. Although there are no peer-reviewed reports on the efficacy of cholinesterase inhibitors for VaD or mixed AD/VaD, early reports suggest that these agents may also be effective for mixed AD/VaD. The indications for the use of cholinesterase inhibitor drugs are eventually likely to broaden to include DLB, mixed AD/VaD, and AD in its more advanced stages.

Dementia epidemiology

Determining the incidence and prevalence of dementia is an inexact science. Dementia is difficult to define and detect in the population. Even with the difficulties of determining prevalence and incidence, it is clear that dementia causes a substantial burden on our society. Problems with diagnostic inaccuracy and insidious disease onset influence our ability to observe risk factor associations; factors related to survival may be mistaken for risk/protective factors. Current studies suggest that factors influencing brain development or cognitive reserve may delay the onset of AD, perhaps through a protective mechanism or a delay in diagnosis caused by improved performance on cognitive tests. The recent identification of genes that cause dementia suggests that these genes or their biochemical pathways may be involved in the pathogenesis of nonfamilial cases. The contribution of genes that cause disease in and of themselves may be smaller than that of genes that act to metabolize or potentiate environmental exposures. The interaction between gene and environment should be increasingly well studied in the future. Epidemiology must take advantage of these molecular advances. The tasks of public health and epidemiology should still involve prevention, the nonrandom occurrence of disease, and its environmental context in addition to heredity. The tools to address these tasks should continue to be refined.

Cytomegalovirus is present in a very high proportion of brains from vascular dementia patients

We previously found that herpes simplex type 1 virus (HSV1), when present in brain of carriers of the apolipoprotein E type 4 allele is a strong risk factor for Alzheimer's disease. To find if HSV1 or certain other herpesviruses are involved in vascular dementia (VaD), we searched post mortem brain specimens from patients suffering from VaD for the presence of HSV1, cytomegalovirus (CMV), and human herpesvirus type 6 DNA, using polymerase chain reaction. We have found that a very high proportion of the VaD patients, 93% (14/15), but not of age-matched normals, 34% (10/29), harbor CMV DNA (P = 0.0002); the proportions of the patients harboring the other viruses in brain do not differ significantly from those of the normals. Further studies are needed to reveal whether or not the association of CMV with VaD is causal.

Understanding and managing behavioural symptoms in Alzheimer's disease and related dementias: focus on rivastigmine

Behavioural and psychological symptoms of dementia (BPSD) are among the most distressing manifestations of dementia and result in considerable social and economic costs. Practical, non-pharmacological approaches such as environmental and behavioural changes may provide some benefit for patients in managing mild BPSD. In addition, various pharmacological approaches to treatment have been employed, such as neuroleptics and atypical antipsychotics, which differ in neurochemical target and clinical effectiveness. Growing evidence suggests that the neurobiological basis of BPSD in Alzheimer's disease (AD) and related dementias is a loss of cholinergic neurones and a resultant decline in acetylcholine (ACh) in brain regions which regulate behavioural and emotional responses, such as the limbic system. This cholinergic deficit can be partly corrected by inhibiting cholinesterase enzymes (ChEs). Studies of ChE inhibitors have shown positive effects to improve or stabilise existing BPSD and delay the emergence of new behavioural symptoms. In placebo-controlled studies, donepezil has reported efficacy in non-institutionalised moderate to moderately severe patients over a period of 24 weeks, but has failed to demonstrate efficacy in mild to moderate AD and in institutionalised patients with severe disease. Galantamine has been shown to delay the onset of BPSD in mild to moderate AD patients in one placebo-controlled study, and improve BPSD in a similar study of patients with cerebrovascular disease or probable vascular dementia. Studies with rivastigmine have shown efficacy in placebo-controlled studies of mild to moderately severe AD and in patients with Lewy body variant AD. Institutionalised patients with severe disease also show symptomatic benefits in BPSD with rivastigmine, resulting in a reduction in concomitant psychoactive medication use. Symptom complexes responding to ChE inhibitors appear to differ - all agents improve apathy, depression and anxiety, while rivastigmine additionally improves hallucinations and delusions, possibility as a result of dual inhibition of acetylcholinesterase and butyrylcholinesterase. The presence of hallucinations has been shown to predict response to rivastigmine. Accumulating data from studies of ChE inhibitors suggest that early intervention and long-term treatment, in addition to providing cognitive benefits, improves BPSD and offers potential to enhance quality of life. Differences seen between the agents in terms of efficacy in BPSD, tolerability and safety profiles may be the result of differences in neuropharmacological profiles.

Methodological issues and therapeutic perspectives in vascular dementia: a review

Vascular dementia (VaD) is the most common form of dementia after Alzheimer's disease (AD). However, it is now increasingly recognized that not only is VaD a heterogeneous syndrome but also that VaD and AD are not mutually exclusive. Thus, the currently used criteria may no longer be sufficient for an accurate diagnosis of VaD. In addition, although it is widely assumed that risk factors for vascular disease are also risk factors for VaD, the evidence, in most cases, is circumstantial. For the effective prevention of VaD, therefore, large-scale and long-term clinical trials are required to investigate the validity of these putative risk factors. These trials should also include the VaD subtypes in their outcome measurements and to this end a simplified classification system should be adopted. Additional large-scale trials are required to facilitate the secondary prevention and symptomatic treatment of VaD, in particular to investigate the potential application of several nootropic and neuroprotective drugs. In both cases, these clinical trials should aim to move the field of VaD from opinion-based medicine to evidence-based medicine.

Longitudinal follow-up of depressive symptoms among normal versus cognitively impaired elderly

OBJECTIVES

This prospectively designed longitudinal study assesses prevalence, incidence and prognosis of depressive symptoms among cognitively normal elderly volunteers compared with patients with mild cognitive impairment (MCI), dementia of Alzheimer type (DAT), and vascular dementia (VAD). Possible relationships between depressive symptoms, cognitive performance, disease types, and effects of antidepressant treatment were analyzed.

METHODS

Two hundred and ninety four subjects exhibiting different levels of cognitive performance were admitted to this study. Demographics, cardiovascular and neurodegenerative risk factors, together with measures of neuropsychological test performance, were obtained at sequential visits. Depressive symptoms were selectively treated with antidepressant medications.

RESULTS

One hundred and forty six subjects with normal cognition, 19 subjects with MCI, 42 patients with DAT, and 32 patients with VAD were followed for a mean of 3.5 years. With the passage of time, there were trends showing prevalence of depressive symptoms to decrease among DAT and to increase among VAD patients. VAD patients exhibited the highest incidences of new-onset depressive symptoms, followed in incidence by DAT and MCI groups. Depressive symptoms among VAD and MCI patients were more persistent and refractory to antidepressant medications than for DAT patients. Trends suggested that antidepressant treatment might benefit MCI and VAD subjects more than DAT patients. Motivationally related depressive symptoms accounted for major components of elevated Hamilton depression rating scale scores.

CONCLUSIONS

Depressive symptoms among DAT patients have higher rates of spontaneous resolution, without requiring intensive drug treatment, than among VAD patients in whom depressive symptoms are more persistent and refractory to drug treatment. Early depressive symptoms among subjects with MCI may represent a preclinical sign and should be considered as a risk factor for impending DAT or VAD among the elderly.

Lipoprotein(a) and cognitive performances in an elderly white population: Cross-sectional and follow-up data

BACKGROUND AND PURPOSE

Elevated lipoprotein(a) [Lp(a)] serum levels have been associated with an increased risk of vascular diseases, and preliminary observations suggest that they are a risk factor for vascular dementia. The relationship between Lp(a) levels and cognitive performances in the general population has never been investigated. Our aim was to evaluate the effect of elevated Lp(a) levels on cognitive functions in the elderly.

METHODS

Cognitive performances were assessed by means of the Mini-Mental State Examination (MMSE), the Babcock Short Story, and the Matrix Test in a population sample of 435 white subjects aged 65 to 84 years who were evaluated at baseline and after 3 years. Lp(a) levels were determined by ELISA.

RESULTS

No statistically significant difference was found in neuropsychological test scores between subjects with and without elevated Lp(a) levels, although subjects with elevated Lp(a) levels had slightly better cognitive performances. This difference reached a statistical significance level only in a subscore of the Matrix Test (number of correct responses) when adjusted for age, sex, education, smoking, and history of stroke. At follow-up, no statistically significant difference was found in cognitive performances between subjects with and without elevated Lp(a) serum levels in either univariate or multivariate analyses. Subjects with and without elevated Lp(a) showed a similar decline rate during follow-up.

CONCLUSIONS

In this sample of elderly white subjects, elevated Lp(a) levels were not associated with poorer cognitive performances or with an increased rate of cognitive decline. Elevated Lp(a) levels do not appear to be a major determinant of cognitive impairment in the elderly.

Caracterização clínica da demência vascular: avaliação retrospectiva de uma amostra de pacientes ambulatoriais

OBJETIVO: analisar as características clínicas e as condições mórbidas (CM) associados em uma amostra de pacientes com demência vascular (DV). MÉTODOS: foram estudados retrospectivamente 25 pacientes com diagnóstico de DV, estabelecidos com base critérios do grupo State of California Alzheimer´s Disease Diagnostic and Treatment Centers (ADDTC). Os dados clínicos e de neuroimagem e os exames laboratoriais foram computados para caracterização da amostra. RESULTADOS: a média da faixa etária foi de 68,7 ± 14,6 anos (64,0% homens), com escolaridade média de 5,2 ± 4,4 anos. A instalação súbita do quadro foi observada em 48,0% dos pacientes e a evolução em degraus e o curso flutuante, em 4,0% e 16,0% dos casos, respectivamente. Apresentavam déficit neurológico focal como sintoma inicial 48,0%, sendo constatado déficit ao exame em 80,0%. As principais CM foram: hipertensão arterial sistêmica (92,0%); hipercolesterolemia (64,0%); insuficiência coronariana (40,0%); tabagismo (40,0%); hipertrigliceridemia (36,0%); diabete melito (32,0%); doença de Chagas (8,0%). CONCLUSÕES: observou-se forte correlação entre DV e hipertensão e hipercolesterolemia. A presença de dois pacientes com doença de Chagas sugere que esta doença possa constituir possível fator de risco regional.

Genetic polymorphisms in older subjects with vascular or Alzheimer's dementia

OBJECTIVES

Paraoxonase, angiotensin-converting enzyme (ACE), methylenetetrahydrofolate reductase (MTHFR), and apo E gene polymorphisms were evaluated in older patients with vascular dementia (VD) or late-onset Alzheimer's disease (LOAD).

MATERIAL AND METHODS

Sixty patients with VD, 45 patients with LOAD, and 54 non-demented controls were compared.

RESULTS

No differences in the distribution of paraoxonase, ACE, and MTHFR polymorphisms were found. The overall frequency of apo E epsilon4 allele was "low"; epsilon4 allele was more frequent in LOAD (17.5%) and VD (13.3%) compared with controls (9.2%), but the difference was not statistically significant.

CONCLUSION

Paraoxonase, ACE, and MTHFR polymorphisms were not associated with VD or LOAD; these common polymorphisms might have a marginal role in the pathogenesis of dementia in older subjects. In spite of a "low" frequency of the apo E epsilon4 allele in our sample, the frequency of epsilon4 allele was about double in LOAD compared with controls.

Dementia in rural primary care practices in Lake County, Oregon

Procedures used in assessing patients with dementia in rural settings are little studied. Among all patients aged 65 years and older in the four primary care practices in Lake County, Oregon, dementia cases were identified from computerized office databases using preselected International Classification of Diseases, Ninth Edition, codes. A semi-structured chart review determined (1) a dementia diagnosis, (2) cognitive and functional domains assessed, and (3) diagnostic studies performed. Of 1540 available records, 30 had dementia. Nineteen of them met National Institute of Neurological and Communicative Diseases and Stroke-Alzheimer's Disease and Related Disorders Association criteria for Alzheimer's disease (AD). Cognitive impairment was documented in 73% of the 51 identified charts and all with AD. Laboratory studies were recorded in 33% overall and in 42% with AD. Neuroimaging was documented in 18% overall and in 16% with AD. The prevalence of documented dementia in these rural practices may be low, possibly because cases of mild dementia may not be labeled as such. Laboratory studies were performed in a minority of cases of dementia.

Protective effect of Oren-gedoku-to (Huang-Lian-Jie-Du-Tang) against impairment of learning and memory induced by transient cerebral ischemia in mice

The protective effect of Oren-gedoku-to (OGT; Huang-Lian-Jie-Du-Tang), a traditional Chinese medicine, against impairment of learning and memory induced by transient cerebral ischemia was investigated in mice. The cerebral ischemia caused a reduction of step-down latency and an increase of step-down errors in the passive avoidance task. Pretreatment with oral administration of OGT (2, 4 or 8 g of herbs per kg) once daily for 5 days prolonged the step-down latency significantly and decreased the step-down errors as compared with those of sham-operated controls. In the Morris water maze test, the cerebral ischemia caused an increase in the latency until finding the platform in the training trial and a decrease in the percentage of swimming in the quadrant of the former platform in the probe trial. Oren-gedoku-to (OGT; 2, 4 and 8 g/kg, p. o.) shortened the latency of escaping markedly onto the platform in the training trial and increased the percentage of crossing the former platform quadrant in the probe trial. A reference drug, tacrine (0.5 and 1.0 mg/kg, p.o.), prevented the reduction of step-down latency in the passive avoidance task and shortened the escape latency in the Morris water maze task. Furthermore, OGT significantly protected against cerebral ischemia-induced reduction in the acetylcholine (ACh) content of the cerebral cortex, hippocampus and striatum. These results indicate that the protective effects of OGT against the impairment of learning and memory induced by transient cerebral ischemia may be associated with preventing the decrease in the ACh content of the mouse brain.

The role of routine laboratory studies and neuroimaging in the diagnosis of dementia: a clinicopathological study

OBJECTIVE

To determine the neuropathological diagnoses of longitudinally followed patients with potentially reversible causes of dementia and to examine the results of the "dementia work-up," especially neuroimaging, by comparison with the pathological diagnosis.

DESIGN

A neuropathologic series of 61 consecutive patients, with review of clinical, laboratory, neuroimaging, and pathological results.

RESULTS

Of the 61 patients, forty-eight (79%) had a clinical diagnosis of probable or possible Alzheimer's disease (AD). Compared with the pathological diagnosis, the sensitivity and specificity of the clinical diagnosis of AD were 96% and 79%, respectively. Of the 61 patients, 9 had abnormal laboratory tests, the correction of which did not improve the subsequent course. These patients were found to have AD8 and frontotemporal dementia on pathology. In two patients, neuroimaging was helpful in the clinical diagnoses of frontotemporal dementia and progressive supranuclear palsy (PSP). Neuroimaging revealed cerebrovascular disease in 18 patients, only two of whom were suspected clinically. Pathology confirmed AD in 17 and PSP in 1 of these patients. Sensitivity and specificity for the clinical diagnosis of cerebrovascular disease in comparison with pathology were 6% and 98%, respectively. With the added information from neuroimaging, that sensitivity increased to 59% and specificity decreased to 81%.

CONCLUSIONS

All cases with abnormal laboratory or neuroimaging results had AD or some other neurodegenerative disease on pathology. The "dementia work-up" did not reveal any reversible causes for dementia in this group of patients. Neuroimaging may have a role, especially in the diagnosis of possible AD with concomitant cerebrovascular disease.

Vascular dementia : incidence and risk factors in the Canadian study of health and aging

BACKGROUND AND PURPOSE

Very few population-based studies have systematically examined incident vascular dementia (VaD). From the Canadian Study of Health and Aging cohort, incidence rates of VaD were determined and risk factors analyzed.

METHODS

This was a cohort incidence study that followed 8623 subjects presumed to be free of dementia over a 5-year period. The risk factors were examined with a nested prospective case-control study. Exposure was determined by means of a risk factor questionnaire administered to the subject or a proxy at the beginning of the study.

RESULTS

On the basis of 38 476 person-years at risk, the annual incidence rate was estimated to be 2.52 per thousand undemented Canadians (95% CI 2. 02 to 3.02). Including an estimation of the probability of VaD among the decedents, this figure rose to 3.79. For the risk factors study, 105 incident cases of VaD according to the NINCDS-AIREN criteria were compared with 802 control subjects. Significant risk factors were: age (OR=1.05), residing in a rural area (2.03), living in an institution (2.33), diabetes (2.15), depression (2.41), apolipoprotein E epsilon4 (2.34), hypertension for women (2.05), heart problems for men (2.52), taking aspirin (2.33), and occupational exposure to pesticides or fertilizers (2.05). Protective factors were eating shellfish (0.46) and regular exercise for women (0.46). There was no relation with sex, education, or alcohol.

CONCLUSIONS

The study confirmed some previously reported risk factors but also suggested new ones. It raised concerns about the prescription of aspirin and perhaps other factors related to rural life.

Stroke in African Americans

There is an excess burden of cerebrovascular disease in African Americans. This article will define possible reasons for excess stroke risk, review racial differences in stroke subtype and stroke prevention programs in the African American Community, and delineate sequelae of stroke. The authors provide insights about stroke prevention in African Americans and highlight challenges to reduce the burden of cerebrovascular disease in this high-risk group.

Subcortical vascular dementia as a specific target for clinical trials

Vascular cognitive impairment is considered the second most common form of mental deterioration in the elderly after degenerative dementias. Therapeutic approaches to vascular dementia mainly rely on the identification and treatment of risk factors. A number of drugs have also been tested with the aim of improving or slowing cognitive decline in patients affected by various forms of cerebrovascular disease. Most of these trials have yielded unsatisfactory results. We hypothesize that some of these failures depend on the inclusion of patients with pathophysiologically heterogeneous types of vascular cognitive decline. In this paper, we review some of the most important trials that tested drugs with a preventive or therapeutic aim in vascular dementia patients. Preliminary results suggest that some beneficial effects can be detected only when the trial population is homogeneous on a clinical and pathogenic basis. In particular, subcortical vascular dementia, a form with a rather univocal clinical, radiological, and pathological picture, seems a particularly apt choice as a target for future clinical studies. At present, only one therapeutic trial is being conducted in patients affected by this specific form of vascular dementia.