Clinical determinants of dementia related to stroke

Untreated type 2 diabetes and its complications are associated with subcortical infarctions

OBJECTIVE

To investigate the association of type 2 diabetes with subcortical infarctions.

RESEARCH DESIGN AND METHODS

We investigated this association in subjects with type 2 diabetes (case subjects; n = 93) and without type 2 diabetes (control subjects; n = 186), matched by age, sex, and years of education. Participants were a subset of the Mayo Clinic Study of Aging (median age 79 years) who had undergone magnetic resonance imaging.

RESULTS

The frequency of subcortical infarctions was 39% in case subjects and 29% in control subjects (odds ratio 1.59 [95% CI 0.91-2.75]). The association was stronger in case subjects without treatment (2.60 [1.11-6.08]) and in case subjects with diabetes-related complications (1.96 [1.02-3.74]) compared with control subjects.

CONCLUSIONS

These findings suggest that untreated type 2 diabetes and type 2 diabetes with complications are associated with subcortical infarctions.

A voxel-based morphometric analysis of cerebral gray matter in subcortical ischemic vascular dementia patients and normal aged controls

BACKGROUND AND PURPOSE

The present study was designed to detect the abnormalities of the cerebral grey-matter density in subcortical ischemic vascular dementia patients by FSL-VBM method to promote the early diagnosis of it.

METHODS

Nine subcortical ischemic vascular dementia patients and nine age-matched normal controls underwent MRI brain structure scanning that was performed on a SIEMENS AVANTO 1.5 Tesla scanner and standard T1-weighted high-resolution anatomic scans of MPRAGE sequence were obtained. The 3-demensional MPRAGE images were processed with FSL-VBM package and the cerebral gray matter density was compared between the subcortical ischemic vascular dementia patients and normal controls.

RESULTS

Compared with the normal control group, the cerebral gray matter density of subcortical ischemic vascular dementia patients was found significantly decreasing, including brain regions of thalamus, parietal lobe, frontal lobe and temporal lobe (P<0.05).

CONCLUSIONS

The cerebral gray matter density alterations have closed correlation with cognitive dysfunction in subcortical ischemic vascular dementia patient and can be detected by MRI. MRI has some potential value in the diagnosis of them.

Poststroke aphasia recovery assessed with functional magnetic resonance imaging and a picture identification task

Stroke patients often display deficits in language function, such as correctly naming objects. Our aim was to evaluate the reliability and the patterns of poststroke language recovery using a picture identification task during functional magnetic resonance imaging (fMRI) at 4 T. Four healthy subjects and 4 subjects with left middle cerebral artery stroke with chronic (>1 year) aphasia were enrolled in the study. In each subject, 10 fMRI scans were performed over a 10-week period using a picture-identification task. The active condition involved presenting subject with a panel of 4 figures (eg, drawings of 4 animals) every 6 seconds and asking the subject to indicate which figure matched the written name in the center. The control condition was a same/different judgment task with pairs of geometric figures (squares, octagons, or combination) presented every 6 seconds. Thirty-second active/control blocks were repeated 5 times each, and responses were recorded. The stoke subjects and controls had similar demographic characteristics, including age (46 vs 53 years), personal handedness (Edinburg Handedness Inventory, 89 vs 95), familial handedness (93 vs 95), and years of education (14.3 vs 14.8). For the active condition, the controls performed better than the stroke subjects (97.7% vs 89.1%; P < .001); the 2 groups performed similarly for the control condition (99.5% vs 98.8%; P = .23). On fMRI, the controls exhibited bilateral, L > R positive blood oxygenation level-dependent (BOLD) activations in frontal and temporal language areas and symmetric retrosplenial and posterior cingulate areas and symmetric negative BOLD activations in bilateral frontotemporal language networks. In contrast, the stroke subjects exhibited positive BOLD activations predominantly in peristroke areas and negative BOLD activations in the unaffected (right) hemisphere. Both groups displayed high activation reliability (as measured by the intraclass correlation coefficient [ICC]) in the left frontal and temporal language areas, although in the stroke subjects the ICC in the frontal regions was spread over a much larger peristroke area. This study documents the utility of the picture-identification task for poststroke language recovery evaluation. Our data suggest that adult stroke patients use functional peristroke areas to perform language functions.

The Levels of Inflammatory Markers in the Treatment of Stroke study (LIMITS): inflammatory biomarkers as risk predictors after lacunar stroke

BACKGROUND

Inflammation is increasingly recognised as playing a central role in atherosclerosis, and peripheral blood markers of inflammation have been associated with incident and recurrent cardiac events. The relationship of these potentially modifiable risk markers to prognosis after ischaemic stroke is less clear. The Levels of Inflammatory Markers in the Treatment of Stroke (LIMITS) study will address hypotheses related to the role of inflammatory markers in secondary stroke prevention in an efficient manner using the well-established framework of the Secondary Prevention of Small Subcortical Strokes (SPS3) trial (NCT00059306).

METHODS

SPS3 is an ongoing Phase III multicentre secondary prevention trial focused on preventing recurrent stroke in patients with small vessel ischaemic stroke, or lacunes. In SPS3, patients are assigned in a factorial design to aspirin vs. aspirin plus clopidogrel, and to usual vs. aggressive blood pressure targets. The purpose of LIMITS is to determine whether serum levels of inflammatory markers - including high-sensitivity C-reactive protein, serum amyloid A, CD40 ligand, and monocyte chemoattractant protein-1 - predict recurrent stroke and other vascular events among lacunar stroke patients. The project will also determine whether these markers predict which people will respond best to dual antiplatelet therapy with clopidogrel and aspirin, as well the relationship to cognitive function.

ANALYSIS

plan Multivariable Cox proportional hazard regression modeling will be used to estimate hazard ratios for the effect of marker levels on risk of recurrent stroke and other outcomes after adjusting for additional potential risk factors, including age, gender, ethnicity, treatment arm, and traditional stroke risk factors. Interactions between marker levels and treatment assignment for both arms of the SPS3 study will be assessed. Observations will be censored at the time of last follow-up visit.

CONCLUSIONS

LIMITS represents an efficient approach to the identification of novel inflammatory biomarkers for use in risk prediction and treatment selection in patients with small vessel disease.

Clinicoradiological features of recurrent ischemic stroke: healthcare for poststroke patients

OBJECTIVE

Little is known about recurrent risk profile of brain infarct (BI) in Japan. The study aimed to clarify clinicoradiological features of recurrent BI patients.

METHODS

374 consecutive BI patients (231 men and 143 women) were admitted to our department between 2007 and 2008. Recurrent BI was defined as a prior history of BI. Cardiovascular disease (CVD) risk profile, stroke mechanism subtypes and Bamford subtypes were compared between the first BI and the recurrent BI group. CVD risk factors, stroke subtypes of the first BI and preventative medication were analyzed in recurrent BI patients.

RESULTS

Recurrent BI existed in 72 patients (40 men and 32 women). Age of the recurrent BI group was significantly older than the first BI group (P < 0.01). In comparison to the first BI group, the recurrent BI group had a high frequency of hypertension (P < 0.01) and CVD comorbidity (P < 0.05). Recurrent rates were increased significantly in cardioembolic patients as compared to the first BI patients (P < 0.05). Bamford BI subtypes did not differ between both groups. Mean recurrent interval (SD) was 3.1 (2.3) years. Approximately half the patients experienced recurrent BI less than 2 years after the first BI. Antiplatelet agents were used in 33 patients and warfarin was used in 12 patients as preventative medication. The remaining 27 patients had no prevention therapy by self-cessation. Nine warfarin users were controlled poorly. There were no significant correlations between the first and recurrent Bamford subtypes in recurrent BI patients.

CONCLUSIONS

The present study indicated that the recurrent frequency of BI was 19.3%. Causative profile of recurrent BI suggested elderly age (≥65 years), hypertension, prior history of CVD, cardioembolism, 2 years poststroke, insufficient treatment of warfarin and self-cessation of preventative medication. Thus, physicians should pay more attention to these aspects for prophylaxis of recurrent BI in poststroke patients.

Lacune-associated cerebral hypoperfusion correlates with cognitive testing

The hypothesis was tested among 83 patients with multiple lacunar infarctions that cerebral hypoperfusion will correlate with cognitive impairments. Patients were subdivided according to Cognitive Capacity Screening Examination (CCSE) scores into a cognitively impaired group (Group D, n = 40; mean age, 68.2 years) with CCSE scores between 6 and 25 (mean, 19.9) and a cognitively intact group (Group I, n = 43; mean age, 66.0) with normal scores (mean, 29.4). Gray and white matter tissue densities were measured by plain computed tomography (CT), and their compartmental perfusions were estimated during stable xenon inhalation. Eighty infarcts in basal ganglia and white matter were detected in Group D and 62 in Group I. Cognitive impairments correlated with (a) multiplicity and bilaterality of lacunes; (b) hypertension, diabetes mellitus, and multiplicity of risk factors for stroke; (c) hypoperfusion of white and gray matter, but particularly of frontal white matter; (d) leuko-araiosis; (e) aging; and (f) lower education. The conclusion was that hypertension and diabetes mellitus are potent risk factors for cerebral small vessel disease or arteriolosclerosis ultimately resulting in lacunar infarcts, leuko-araiosis, white matter hypoperfusion, and impaired cognitive test performance.

Insulin resistance, diabetes and cognitive function: consequences for preventative strategies

Cognitive decline and dementia both place a heavy burden on patients and their relatives, and any means of preventing such age-related changes are worthy of consideration. Those who have the metabolic syndrome with or without diabetes suffer more often from dysexecutive problems and slower psychomotor speed than do other patients. In epidemiological studies, diabetes has appeared to be a risk factor for all types of dementia, including vascular dementia, although the role of the metabolic syndrome in the risk of Alzheimer's disease is still a matter of debate. The possible mechanisms of cognitive alterations are multiple, and may differ according to age group and duration of diabetes or the metabolic syndrome. Drug interventional trials addressing the prevention of cognitive decline through action on the metabolic syndrome are disappointing-albeit scarce at this time. Lifestyle interventions in middle-aged or younger-elderly subjects should also be implemented in the general population.

Outcomes after stroke: risk of recurrent ischemic stroke and other events

Stroke is a common and debilitating disease, and much is known about the incidence and risk factors for first stroke. Much less is known, however, about outcomes after stroke. The epidemiology of outcomes after stroke has been relatively less studied for several reasons, including the traditional study of populations in which rates of cardiac disease are higher than those of stroke, the heterogeneity of stroke, and the absence until recently of effective therapies. The importance of recurrent stroke, cardiac events, dementia, depression, and other vascular and nonvascular events will increase as the population ages and as more patients survive a first stroke. This article discusses the relative importance of recurrent stroke and other events after initial ischemic stroke or transient ischemic attack, and proven and potential risk factors for recurrent stroke. Based on growing evidence regarding the high rates of cardiovascular events after stroke, and the efficacy of statin therapy in reducing the risk of stroke as well as cardiac disease, it may be time to consider expanding the "coronary risk equivalent" category to include patients with stroke. Patients who have had a stroke are likely at high enough risk for subsequent events to warrant the same aggressive treatment, including statins and antihypertensive drugs, as would be given to patients with other forms of cardiovascular disease. Future clinical trials will better define the optimal management of patients after stroke.

Diastolic blood pressure cut-off predicts major cerebrovascular events after minor ischaemic stroke: a post-hoc modelling study

Only few follow-up studies have studied in detail the role of most important risk factors, but no reports were found on critical values (cut-offs) for such factors in prospectively predicting cerebrovascular events (CVE) in patients with minor ischaemic stroke (MIS). Estimates of predictive importance of such cut-offs may better inform and contribute to optimize treatment. This was a post-hoc modelling study with unique data from Bulgaria on 54 consecutive patients with MIS, aged ł 40, followed for 12 months for nonfatal or fatal CV events. A set of routine clinical demographic and known risk factors (SBP, DBP, HDL cholesterol, etc.) were explored using univariate statistics and multivariate regression models to identify the most important independent predictors of secondary CVE. An artificial neural network (ANN) model, irrespective of usual statistical constraints, also confirmed the specific role and importance of identified predictors. A receiver operating characteristics (ROC) curve and stratified survival analyses were used to define the best cut-off of most important predictors and validate the final model. During follow-up period of 11.1±2.4 months, 8 secondary CV events (14.8%) were observed only in males with MIS at the 5.8±2.7 months mark. No difference in age of patients with CV event (61.1±12.6 years) vs. those without (62.1±9.6 years) was found (p>0.05). The one-year risk for CVE was.15% (95%CI 7.1, 27.7%). The two most important risk factors in patients with versus without CV events were acute MIS onset (62.5 vs. 13.0%) and mean DBP at day 30 post-MIS (101.3±9.9 vs. 92.3±10.8 mmHg), with a relative importance by ANN of 20.92 versus 15.9 points, respectively. At multivariate logistic analysis only MIS onset and DBP were independently associated with the risk for secondary CVE (79.6% model accuracy, p model=0.0015). An increase of DBP with 1 mmHg was associated with 8% higher risk of CVE [adjusted OR=1.08 (95%Cl 1.004, 1.158)]. With this method, a novel cut-off predictive DBP value of 95 mmHg (ROCAUC=0.79, 95%Cl 0.60, 0.99, p=0.009) for CV events in patients with MIS has been found. In conclusions the new DBP cut-off (sensitivity >87%, specificity >69%) clearly discriminated between absence and presence of secondary CVE as also confirmed by stratified survival analysis (7 vs. 1 events, plog-rank =0.0103). This cut-off may be applied to better precisely evaluate and define, as earlier as possible, MIS patients at increased risk of secondary CV events.

Pattern of vascular dementia in India: study of clinical features, imaging, and vascular mechanisms from a hospital dementia registry

Vascular dementia (VaD) is heterogeneous in its clinical, imaging, and etiological characteristics. Although VaD is common in India, its pattern is not completely known. In a hospital-based cohort, we aimed to characterize VaD by its subtypes and study patterns of risk factors and clinical, and neuropsychological profiles. Vascular mechanisms, known to have racial and genetic variations were identified. NINDS-AIREN criteria were used to diagnose VaD. Patients were subtyped into subcortical, cortical, cortical-subcortical, and strategic infarct dementia. Vascular mechanisms were detected by vascular imaging, cardiac evaluation, and laboratory tests. In the 42 consecutive patients with VaD, subcortical dementia was the most common type (52.4%), followed by cortical-subcortical (26.2%), strategic infarcts in (14.3%), and cortical dementia (7.1%). Stroke (81%), hypertension (71.4%), and diabetes (35.7%) were important risk factors. Small artery disease was the underlying vascular mechanism in 42.9%; intracranial large artery disease, in 16.7%; extracranial disease, in 2.3%; cardioembolism, in 2.3%; multiple mechanisms, in 19%; and unknown, in 16.7%. Subtypes were similar in risk factor profile and neuropsychological features but differed in clinical characteristics and vascular mechanisms. Gait disorder (59.1% vs. 0%) and urinary symptoms (77.3% vs. 16.7%) were more common in subcortical dementia than in strategic infarct dementia (P < .05). Small artery disease was most common in subcortical dementia (72.7%). Intracranial large artery disease was associated with all subtypes. The pattern of VaD demonstrated in our study is a reflection of mechanisms of cerebrovascular disease in India. Outcome depends on underlying mechanisms and thus is likely to differ from that in other ethnic populations.

Cognitive function in chronic kidney disease

Chronic kidney disease (CKD) is a growing public health problem. The incidence of kidney failure is rising in all age groups but particularly in older adults. Individuals in all stages of CKD are at higher risk for development of cognitive impairment and this may be a major determinant in their quality of life. Furthermore, cognitive impairment is associated with an increased risk of death in dialysis patients. Cerebrovascular disease is a strong risk factor for development of cognitive impairment and vascular disease is a more likely cause of cognitive impairment than Alzheimer's disease in patients with CKD. Both traditional and nontraditional vascular risk factors are more common in CKD and dialysis patients may also be at risk for cognitive impairment via nonvascular risk factors and the hemodialysis procedure itself. Unfortunately, because risk factors for cognitive impairment in CKD have not been thoroughly ascertained, evaluation of potential treatments has been limited. Given the high prevalence of cognitive impairment in all stages of CKD, additional studies are needed to evaluate potential risk factors and treatments in this vulnerable population.

Construct Validity of the Wisconsin Card Sorting Test-64 in Patients with Stroke

This study examined the factor structure and contrasted-group validity of the Wisconsin Card Sorting Test-64 (WCST-64) in a stroke sample (n = 112). Confirmatory factor analyses were used to compare five different models suggested by prior factor analyses. The results indicated that the WCST-64 was best represented by a three-dimensional model comprising response inflexibility (factor 1), ineffective hypothesis-testing strategy (factor 2), and set maintenance (factor 3). A significant overall multivariate effect for group (F = 2.87, df = 18,495.46, p <.001) was found in a multivariate analysis of covariance with WCST scores as dependent variables and four different groups (three stroke subgroups with different levels of cognitive function and a normal control group) as independent variable, after controlling for gender. The results of discriminant analysis supported the use of the WCST-64 in stroke patients with cognitive impairment.

Hypertension, cognitive decline, and dementia: an epidemiological perspective

Hypertension is a known risk factor for stroke, and thus for vascular dementia. However, recent large observational studies have suggested that high blood pressure may also play a role in Alzheimer's disease. The mechanisms linking hypertension to Alzheimer's disease remain to be elucidated, but white matter lesions seen on cerebral magnetic resonance imaging appear to be a good marker of this association. It is not yet clearly established whether lowering blood pressure reduces the risk of white matter lesions and dementia, so large trials dealing with this question are eagerly awaited. These future trials could confirm the hope that, by lowering blood pressure, we may have a preventive treatment for dementia. This issue is of major importance, as the number of cases of dementia is expected to rise sharply in the near future.

Polymorphisms and vascular cognitive impairment after ischemic stroke

Environmental and genetic factors may both affect the risk of vascular cognitive impairment developing after a stroke. To identify factors affecting this risk, the cognitive status of 121 patients was examined 3 months after an ischemic stroke. In all patients and in 270 control subjects, 7 polymorphisms reported to affect risk of vascular ischemic disease were genotyped. In 51 patients (42.1%), vascular cognitive impairment resulted, defined by a Mini-Mental State Examination score of less than 24. These patients were older and more likely to be women. Alleles of none of the polymorphisms differed between patients with or without vascular cognitive impairment, except for glutamate-cysteine ligase modifier (GCLM) (odds ratio = 2.8, P = .006). When all stroke patients were considered, the GCLM genotype did not affect Mini-Mental State Examination scores. Testing the GCLM genotype in an independent group of stroke patients may determine whether this association with vascular cognitive impairment is genuine.

Early epileptic seizures after stroke are associated with increased risk of new-onset dementia

BACKGROUND

Subclinical vascular or degenerative lesions occur in the brain before the clinical expression of dementia. Those lesions in a brain that just experienced a stroke may have lower thresholds for early epileptic seizures. Therefore, epileptic seizures may be a marker of subclinical brain lesions, which may lead to dementia.

OBJECTIVE

To test the hypothesis that patients with stroke who have epileptic seizures without dementia have an increased risk of new-onset dementia.

METHODS

169 consecutive patients with stroke without pre-existing dementia recruited in the Lille Stroke/Dementia Study were investigated (90 men; 150 ischaemic strokes; median age 73 years). Pre-stroke cognitive functions were evaluated with the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE), with a cut-off of 104 for the diagnosis of dementia. The patients were followed up over a 3-year period. Dementia was diagnosed with International Classification of Diseases, 10th revision criteria in survivors who underwent neurological visits, and with the IQCODE score in those who could not. The relationship between epileptic seizures and new-onset dementia was studied within 3 years, using life-table methods.

RESULTS

9 patients (5.3%; 95% CI 2.9 to 8.7%) had early seizures. Epileptic seizures were independent predictors of new-onset dementia within 3 years after stroke (HR 3.81; 95% CI 1.13 to 12.82), with increasing age (HR 1.04; 95% CI 1.01 to 1.08), IQCODE scores at admission (HR 1.08; 95% CI 1.02 to 1.13) and diabetes mellitus (HR 3.52; 95% CI 1.46 to 8.47).

CONCLUSION

Patients with stroke who have epileptic seizures may be at increased risk of dementia. Whether cognitive follow-up should be systematically performed in those patients remains to be validated.

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.

Diabetes mellitus and dementia

Alzheimer's disease (AD) and diabetes mellitus (DM) are two of the most common and devastating health problems in the elderly. They share a number of common features amongst which high prevalence after 65 years, important impact of patient's quality of life, substantial health care costs. Reviews on the epidemiological studies on cognitive impairment in patients with DM found evidence of cross-sectional and prospective associations between type 2 DM and moderate cognitive impairment, on memory and executive functions. There is also evidence for an elevated risk of both vascular dementia and AD in patients with type 2 DM, albeit with strong interaction of other factors such as hypertension, dyslipidaemia and ApoE genotype. DM is an independent predictor of post-stroke dementia. DM being an atherogenic risk factor, it may increase the risk of dementia through associations with stroke, causing vascular dementia. In addition, vascular reactivity may be adversely affected by advanced glycosylation end products resulting in more subtle perfusion abnormalities. Cerebrovascular disease may exacerbate AD through direct interactions between the two pathological processes or through cognitive impairment secondary to cerebrovascular disease "unmasking" AD at an earlier stage than it would otherwise become apparent. The increased risk of AD may also be mediated by the exacerbation of B-amyloid neurotoxicity by advanced glycosylation end products identified in the matrix of neurofibrillary tangles and amyloid plaques in AD brains, or associations with insulin functions. Decreased cholinergic transport across the blood-brain barrier observed in diabetic animals may exacerbate cognitive impairment in AD. Many interventions could reduce the cognitive decline associated with DM, yet not enough are taken into account so far.

Post-stroke dementia and depression: frontosubcortical dysfunction as missing link?

OBJECTIVE

Testing the hypothesis that depressive symptoms in dementia reflect dysfunction in fronto-subcortical pathways.

BACKGROUND

Both depression and dementia can be the result of vascular damage of the brain. The nature of the depressive symptomatology seems to be related to concommittant cognitive disturbances in that subjects show more so-called motivational symptoms of depression. These symptoms can be the result of frontal-subcortical dysfunction. It could be very helpful for clinical practice if these subjects could be identified by simple diagnostic procedures.

METHODS

Associations were computed between measures of depressive symptoms and a set of neuropsychological tests in a sample of 54 subjects with a post-stroke dementia.

RESULTS

Although we used an extensive set of neuropsychological tests, most subjects were able to participate only in a small part of them, because of disease severity. Our hypothesis was supported by a negative correlation between scores on the verbal semantic fluency task and the total numbers of motivational depressive symptoms. None of the neuropsychological tests was significantly related to the number of mood symptoms neither did they correlate with the total number of depressive symptoms.

CONCLUSION

This study gives further evidence for the assumption that motivational-based depressive symptoms partially originate from fronto-subcortical dysfunction.

Predictors of poststroke dementia: results of a hospital-based study in poland

Dementia affects up to 30% of stroke survivors 3 months after stroke. The goal of this study was to determine the risk factors of poststroke dementia (PSD) in a cohort of consecutive stroke patients in Poland. A standard stroke evaluation was conducted on admission in 220 consecutive patients with ischemic/hemorrhagic stroke after excluding 30 (12%) patients with prestroke dementia. After 3 months, the survivors completed a comprehensive neuropsychological examination. The DSM-IV definition was used for diagnosis of dementia. Dementia was diagnosed in 44 (22.6%) patients 3 months after stroke. In logistic regression analysis, age (OR 1.08, 95% CI 1.04-1.14, p < 0.001), diabetes mellitus (OR 2.67, 95% CI 1.06-6.57, p = 0.03) and neurological deficit on admission (OR 0.92, 95% CI 0.89-0.96, p < 0.001) were independently associated with PSD in the Polish hospital-based population.

Clinical determinants of dementia and mild cognitive impairment following ischaemic stroke: the Sydney Stroke Study

BACKGROUND

Dementia following stroke is common but its determinants are still incompletely understood.

METHODS

In the Sydney Stroke Study, we performed detailed neuropsychological and medical-psychiatric assessments on 169 patients aged 50-85 years, 3-6 months after a stroke, and 103 controls with a majority of both groups undergoing MRI brain scans. Stroke subjects were diagnosed as having vascular mild cognitive impairment (VaMCI) or vascular dementia (VaD) or no cognitive impairment by consensus. Demographic, functional, cerebrovascular risk factors and neuroimaging parameters were examined as determinants of dementia using planned logistic regression.

RESULTS

21.3% of subjects were diagnosed with VaD, with one case in those aged 50-59 years, 24% in those aged 60-69 years and 23% in those 70-79 years. There was no difference by sex. The prevalence of VaMCI was 36.7%. VaD subjects had lower premorbid intellectual functioning and had 0.9 years less education than controls. The VaD and VaMCI groups did not differ from the no cognitive impairment group on any specific cerebrovascular risk factor, however overall those with impairment had a greater number of risk factors. They did not differ consistently on depression severity, homocysteine levels and neuroimaging parameters (atrophy, infarct volume and number of infarcts) except for an excess of white matter lesions on MRI and greater number of infarcts in the VaD and VaMCI groups. On a series of logistic regression analyses, stroke volume and premorbid function were significant determinants of cognitive impairment in stroke patients.

CONCLUSION

Post-stroke dementia and MCI are common, especially in older individuals. Cerebrovascular risk factors are not independent risk factors for VaD, but stroke volume is a significant determinant of dementia. Premorbid functioning is a determinant of post- stroke impairment.

Small vessel strokes

Small vessel disease is a common cause of cerebrovascular disease. It is responsible for ischemic and hemorrhagic strokes, cognitive decline, and asymptomatic disease. Millions of Americans are affected by silent strokes and white matter abnormalities. Lacunar stroke is the most common manifestation. Despite its importance, small vessel strokes remain understudied. There is a need for research focused on this prevalent stroke subtype to define optimal interventions to prevent stroke recurrence and cognitive impairment.

Changes in Mini Mental State Examination score after stroke: lacunar infarction predicts cognitive decline

Stroke and cognitive impairment are inter-related. The purpose of this study was to show the natural evolution of cognitive performance during the first year after a stroke, and to show which factors that predict cognitive decline. Subjects were patients with a first-ever stroke who were treated in a stroke unit. A total of 160 patients were included. At baseline patients were evaluated with regard to stroke type, stroke severity, pre-stroke dementia and other risk factors. Mini Mental State Examinations (MMSE) were performed after 1 week and after 1 year. Patients had a median increase of 1 point (range -8 to +9) on the MMSE. Thirty-two pre cent of the patients deteriorated, 13% were unchanged, and 55% improved. Lacunar infarction (LI) and left-sided stroke were associated with a failure to exhibit improvement. Patients with LI had an average decline of 1.7 points, whilst patients with other stroke types had an average increase of 1.8 points. Most stroke survivors improve cognitively during the first year after the event. The outcome for LI patients is worse, which suggests that LI may serve as a marker for concomitant processes that cause cognitive decline.

Poststroke Dementia

The association between stroke and dementia is frequent. The prevalence of poststroke dementia (PSD) ranges from 6 to 32%, depending on the population studied, the criteria used for the diagnosis of dementia, and the time interval between the stroke and the neuropsychological assessment. The risk of PSD is high immediately after stroke and remains higher than in controls in stroke patients nondemented 3 months after stroke. Not all cases of PSD are vascular in origin, with about one third of demented patients diagnosed as having Alzheimer's disease plus stroke. The pathophysiology of PSD is probably multifactorial, with an influence of vascular lesions, associated Alzheimer's lesions and white matter changes. The risk of dementia is higher in older patients and in patients with preexisting cognitive decline - no dementia, severe stroke, a history of stroke, white matter changes and cerebral atrophy. The influence of stroke location, vascular risk factors and silent infarcts remains to be determined. PSD adversely influences the outcome in stroke patients.

Poststroke dementia

Dementia is one of the major causes of dependency after stroke. The prevalence of poststroke dementia (PSD)-defined as any dementia occurring after stroke-is likely to increase in the future. In community-based studies, the prevalence of PSD in stroke survivors is about 30% and the incidence of new onset dementia after stroke increases from 7% after 1 year 48% after 25 years. Having a stroke doubles the risk of dementia. Patient-related variables associated with an increased risk of PSD are increasing age, low education level, dependency before stroke, prestroke cognitive decline without dementia, diabetes mellitus, atrial fibrillation, myocardial infarction, epileptic seizures, sepsis, cardiac arrhythmias, congestive heart failure, silent cerebral infarcts, global and medial-temporal-lobe atrophy, and white-matter changes. Stroke-related variables associated with an increased risk of PSD are stroke severity, cause, location, and recurrence. PSD might be the result of vascular lesions, Alzheimer pathology, white-matter changes, or combinations of these. The cause of PSD differs among studies in relation to the mean age of patients, ethnicity, criteria used, and time after stroke. In developed countries, the proportion of patients with presumed Alzheimer's disease among those with PSD is between 19% and 61%. Patients with PSD have high mortality rates and are likely to be functionally impaired. These patients should be treated according to the current guidelines for stroke prevention.

Pre-existing hypertension and the impact of stroke on cognitive function

Hypertension has been associated with subclinical injury in the brain and may therefore increase the impact of an incident stroke on cognitive function. The Study of Osteoporotic Fractures (SOF) is a prospective, observational study of 9,704 women aged 65 years and older recruited from four U.S. metropolitan areas. Blood pressure was measured at study entry, and cognitive decline was defined by the change from prestroke to poststroke cognitive testing. During an average follow-up of 6.8 years, incident stroke occurred in 260 participants (3.1%) who had previously completed baseline cognitive testing. Among participants with stroke, 119 completed follow-up cognitive testing a median of 1.9 years after the stroke, 80 died before the next study visit, and 61 did not complete further cognitive testing. After adjustment for demographic factors and other confounders, pre-existing hypertension was a strong predictor of cognitive decline when a stroke occurred (odds ratio [OR], 4.07; 95% confidence interval [CI], 1.37-12.1). In contrast, hypertension was only weakly associated with cognitive decline in the absence of stroke (OR, 1.13; 95% CI, 1.04-1.22) (p for interaction = 0.032). Pre-existing hypertension in women is associated with a greater impact of stroke on cognitive function, possibly by influencing the ability to tolerate or recover from brain injury.

Poststroke Dementia in the Elderly

Risk of dementia increases after stroke, and poststroke dementia (PSD) is an important cause of disability in the elderly. The prevalence rates of PSD vary from 12.2% to 31.8% within 3 months to 1 year after stroke, depending on patient populations and the diagnostic criteria used in the numerous studies. Incidence rates of PSD increase with time after the stroke. Although vascular lesions and white matter changes can explain the cognitive disorders seen in stroke patients, an underlying neurodegenerative disorder may contribute to the development of PSD. Cognitive decline may pre-date the stroke and follow a progressive course after the stroke. The vascular and degenerative processes involved share common environmental and genetic risk factors. This review explains the mechanisms of dementia in stroke patients and identifies predictive factors for PSD. The following points are successively considered: (i) demographic characteristics of the patients, including age and level of education; (ii) prestroke cognitive decline; (iii) vascular risk factors, including diabetes mellitus and prior strokes; (iv) stroke characteristics, including severity and location of the vascular lesion; (v) co-morbid disorders; and (vi) abnormalities on brain imaging, including location, size and number of vascular lesions, white matter changes and cerebral atrophy. Older age, prestroke cognitive decline, stroke recurrence, hypoxic-ischaemic disorders, left-side infarcts, strategic infarcts and white matter lesions appear to be the main predictive factors of PSD. Prevention of stroke should reduce the morbidity and mortality associated with PSD. In addition, management of PSD with secondary prevention treatments could reduce occurrence of further strokes. Cholinesterase inhibitors may be beneficial not only in Alzheimer's disease associated with cerebrovascular lesions, but also for the treatment of cholinergic dysfunction arising from pure vascular dementia. Better knowledge of the risk factors for PSD, including environmental and genetic factors, should increase the effectiveness of preventive strategies in patients with this condition.

Common carotid artery intima media thickness and post-stroke cognitive impairment

BACKGROUND AND PURPOSE

Acute stroke and other forms of cerebrovascular disease are well-recognized causes of cognitive impairment. Common carotid artery intima media thickness (CCA-IMT) has been associated with certain forms of cerebrovascular disease, but its association with cognitive impairment of vascular origin has not been elucidated. The purpose of this study was to investigate whether CCA-IMT is associated with cognitive impairment 1 year after an acute ischemic stroke.

METHODS

A total of 171 consecutive patients with the first ever stroke (mean age 66+/-11.5, 41% female) underwent carotid ultrasonography during hospitalization. Demographic data, vascular risk factors and presenting stroke features were also recorded. One year later, patients' cognitive performance and depression were assessed using the Mini-Mental State Examination (MMSE), and the Montgomery Asberg Depression Rating Scale (MADRS).

RESULTS

Cognitive impairment (MMSE score<24) was found in 67 (39%) of the 171 patients. CCA-IMT was significantly associated with cognitive impairment, and this association remained unchanged (OR 1.94; 95% CI 1.19-3.18) after adjustment for demographic data, vascular risk factors, stroke features, other carotid ultrasonography measurements and depression. Older age, low education level, large hemispheric lesions, hyperdense carotid plaques and depression were also independently associated with post-stroke cognitive impairment.

CONCLUSIONS

In this study, CCA-IMT was independently associated with cognitive impairment 1 year after an acute ischemic stroke, and thus, it might help with the screening of stroke patients at risk of cognitive impairment.

Demographic and CT scan features related to cognitive impairment in the first year after stroke

OBJECTIVE

Little is known about the relation between stroke related features and cognitive performance over time when stroke patients with dementia or less severe cognitive disorders are considered separately. We aimed to study the features (computed tomography (CT) scan and demographic) that could be related to vascular cognitive impairment one, six, and 12 months after stroke.

METHODS

A total of 176 patients with a first-ever brain infarct, a Mini Mental State Examination score > or = 15, age older than 40 years, and without pre-stroke dementia and other neurological or psychiatric disorders participated in this study. The following CT scan features were recorded: side of infarct, lacunar or territorial infarct, white matter lesions, silent infarcts, and brain atrophy. The demographic features studied were: age, level of education, and sex. Univariate and multivariate logistic regression analyses were performed to compare the three groups of patients (patients with dementia, patients with vascular cognitive impairment (VCI), and patients with vascular mild cognitive impairment (MCI)) with patients without cognitive disorders.

RESULTS

At one month none of the variables were predictors of dementia; at six months older age (odds ratio (OR) 9.4), low education (OR 14.7), and territorial infarct (OR 10.6) predicted dementia; and at 12 months low education (OR 8.7) and pre-stroke cerebrovascular damage (OR 7.4) predicted dementia. Predictors of VCI were low education (OR 3.4) and territorial infarct (OR 2.4) at one month post stroke; older age (OR 4.3) and low education (OR 4.1) at six months; and older age (OR 3.5) at 12 months. Predictors of vascular MCI were low education (OR 4.96) and territorial infarct (OR 3.58) at one month; and older age and lower education at six months (OR 3.4 and 3.7, respectively) and at 12 months (OR 3.5 and 2.28, respectively).

CONCLUSIONS

Territorial infarct, older age, and low educational level are predictors of cognitive disorders after stroke.

Neuropsychological characteristics of mild vascular cognitive impairment and dementia after stroke

BACKGROUND

Post-stroke cognitive impairment is frequent, with characteristic impairments of attentional and executive performance.

OBJECTIVE

The study aims to determine whether the profile and severity of impairment in vascular Cognitive Impairment No Dementia (vascular CIND) is intermediate between that seen in stroke patients without significant cognitive impairment and patients with post-stroke dementia and thus to establish if the potential value of vascular CIND is a useful concept for predicting further cognitive decline and dementia in stroke patients.

METHODS

Stroke patients (n=381) > 75 were recruited from representative hospital-based stroke registers in Tyneside and Wearside, UK. Sixty six age matched controls were also recruited. A detailed battery of neuropsychological assessments was completed 3 months post stroke.

RESULTS

Deficits of attention (z=5.7; p <0.0001) and executive function (z=5.9; p <0.0001) were seen even in stroke patients without vascular CIND, compared to controls. However, stroke patients with CIND were significantly more impaired again on tests of executive function (z=10.3; p <0.0001) compared to those not meeting CIND criteria; and also had greater impairments of memory (z=10.4; p <0.0001) and language expression (z=10.1; p <0.0001). A similar overall profile of deficits was evident in the CIND and the dementia group, but specific deficits were significantly more pronounced in those with dementia, particularly in orientation (z=7.2; p <0.0001) and memory (z=5.8; p <0.0001).

CONCLUSIONS

The current study indicates that attentional and executive impairments are frequent in stroke patients, but deficits of memory, orientation and language are more indicative of CIND and dementia. Further longitudinal studies are required to clarify the relationship between specific lesions and the progression of specific cognitive deficits in post-stroke patients.

Frequency and risk factors of vascular cognitive impairment three months after ischemic stroke in china: the Chongqing stroke study

BACKGROUND

Frequency of poststroke cognitive impairment is high in western countries, and the risk factors of poststroke cognitive impairment have not been fully understood yet. We sought to examine the frequency and risk factors of cognitive impairment after ischemic stroke in a large stroke cohort of China.

METHODS

A total of 434 consecutive patients with ischemic stroke were enrolled. The cognitive status before and 3 months after stroke was evaluated using the Informant Questionnaire on Cognitive Decline in the Elderly and the Mini-Mental State Examination, respectively. Poststroke cognitive impairment was defined as cognitive impairment with concomitant stroke, stroke-related cognitive impairment was defined as cognitive impairment developing after index stroke, and cognitive impairment after first-ever stroke was defined as cognitive impairment developing after first-ever stroke. Logistic regression analysis was used to find the risk factors of cognitive impairment after stroke.

RESULTS

(1) Frequency of poststroke cognitive impairment was 37.1%, that of stroke-related cognitive impairment was 32.2%, and that of cognitive impairment after first-ever stroke was 29.6%. (2) The patients with cognitive impairment more often had older age, low educational level, atrial fibrillation, prior stroke, everyday drinking, left carotid territory infarction, multiple lesions, embolism, and dysphasia. (3) The factors associated with poststroke cognitive impairment in logistic regression analysis were age (OR 1.215, 95% CI 1.163-1.268), low educational level (OR 2.023, 95% CI 1.171-3.494), prior stroke (OR 5.130, 95% CI 2.875-9.157), everyday drinking (OR 2.013, 95% CI 1.123-3.607), dysphasia (OR 3.994, 95% CI 1.749-9.120), and left carotid territory infarction (OR 2.685, 95% CI 1.595-4.521).

CONCLUSIONS

Cognitive impairment is common 3 months after ischemic stroke in Chinese people. Risk factors for poststroke cognitive impairment include age, low educational level, everyday drinking, prior stroke, dysphasia, and left carotid territory infarction.

Effect of White Matter Changes on Cognitive Impairment in Patients With Lacunar Infarcts

BACKGROUND AND PURPOSE

Cerebral white matter changes (WMC) and lacunar infarct are both believed to be consequence of small vessel disease. Whether the extent of WMC affect the type and degree of cognitive impairment in patients with lacunar infarct is not clear. The study was undertaken to determine if WMC influences cognition in patients with lacunar infarcts.

METHODS

We recruited consecutive patients who were admitted to the acute stroke unit because of acute lacunar infarcts, mainly documented by diffusion-weighted magnetic resonance imaging. WMC were measured qualitatively and quantitatively. Patients were divided into quartiles according to the distribution of the volume of WMC. Cognition was assessed 12 weeks after stroke by psychometric tests (Chinese version of Mini-Mental State Examination [MMSE], Alzheimer's Disease Assessment Scale-cognition [ADAS-cog], Mattis Dementia Rating Scale-Initiation/ Perseveration subscale [MDRS I/P]) and was compared between patients with varying severity of WMC. Multivariate linear regression analysis was performed to find variables that influenced performance in the psychometric tests.

RESULTS

Among the 94 included patients with acute lacunar infarcts, those patients (n=25) within the highest quartile of WMC were older, had more lacunar infarcts, more severe stroke, and lower prestroke cognitive function compared with those with less WMC. In addition, their performances in psychometric tests were significantly more impaired. Multivariate linear regression analysis revealed that WMC significantly influenced performance in MDRS I/P. WMC did not independently influence performance in MMSE and ADAS-cog.

CONCLUSIONS

Extent of WMC appears to be associated with executive dysfunction in stroke patients with lacunar infarcts. Further large prospective studies with extensive scales of executive function testing are required to confirm this issue.

White Matter Hyperintensities Are Associated With Impairment of Memory, Attention, and Global Cognitive Performance in Older Stroke Patients

BACKGROUND

The importance of white matter hyperintensities (WMH) for cognitive performance in older stroke patients is largely unknown. We hypothesized that processing speed and executive dysfunction will be associated with frontal WMH whereas impaired memory will be associated with temporal WMH.

METHODS

Neuropsychological assessments using the Cambridge Cognitive Examination (CAMCOG) and the Cognitive Drug Research (CDR) were completed for 96 stroke survivors aged older than 75 and 23 age-matched controls. Magnetic resonance imaging whole-brain axial FLAIR images were undertaken to visualize WMH and an automated threshold technique was used to determine their volume.

RESULTS

In comparison to controls, the stroke patients had significantly greater volume of WMH in all key areas. Within the stroke group, a consistent pattern of significant association was identified between total and frontal WHM volumes and attention and processing speed tasks (eg, choice reaction time [right: R=0.24 P=0.02; left: R=0.26, P=0.01]), but not with executive function. There were significant associations between memory and temporal WMH volumes (right: R=0.27, P=0.008; left: R=0.20, P=0.047).

CONCLUSIONS

In older stroke patients, cognitive processing speed and performance on measures of attention are significantly associated with WMH volume, particularly in the frontal lobe regions, whereas memory impairment is associated with the volume of temporal lobe WMH.

Frequency and Determinants of Poststroke Dementia in Chinese

BACKGROUND AND PURPOSE

Both dementia and stroke are major health problems in Chinese societies. Stroke is a frequent cause of dementia. Only a few studies have been published on poststroke dementia (PSDE), none of which has investigated a consecutive stroke cohort in Asian patient populations. The objective of this study was to examine the prevalence and clinical correlates of PSDE in Chinese stroke patients in Hong Kong.

METHODS

Two hundred eighty stroke patients consecutively admitted to the medical wards of a university-affiliated regional hospital were interviewed by a psychiatrist 3 months after stroke. The presence of dementia and vascular dementia was diagnosed according to the Diagnostic and Statistical Manual, 4th edition. In addition, a wide range of demographic and clinical variables were examined.

RESULTS

Fifty-five participants (20%) had PSDE. Univariate analysis found that PSDE was associated with age; level of education; prestroke Rankin Scale score; prestroke Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) score; National Institutes of Health Stroke Scale (NIHSS) best language score, dysarthria score, and total score; urinary incontinence; cortical infarct; leukoaraiosis; bilateral lesions; number of lesions; involvement of middle cerebral artery circulation; and cerebral atrophy index. Multivariate logistic regression suggested that prestroke IQCODE score, NIHSS total score, leukoaraiosis, involvement of middle cerebral artery territory, and cerebral atrophy index were independent risk factors of PSDE. After removal of 22 patients with prestroke dementia, which was defined as a prestroke IQCODE score > or =4.0, the frequency of PSDE dropped to 15.5%. Furthermore, involvement of the middle cerebral artery territory and cerebral atrophy index were replaced by level of education and bilateral lesions as independent predictors in the final logistic model.

CONCLUSIONS

PSDE is common among Chinese stroke patients in Hong Kong. Its frequency is comparable to that in white populations. The clinical determinants of PSDE, after the exclusion of patients with prestroke dementia, include premorbid level of cognitive function, severity of stroke, leukoaraiosis, level of education, and bilateral lesions.

Increased risk of type 2 diabetes in Alzheimer disease

Alzheimer disease and type 2 diabetes are characterized by increased prevalence with aging, a genetic predisposition, and comparable pathological features in the islet and brain (amyloid derived from amyloid beta protein in the brain in Alzheimer disease and islet amyloid derived from islet amyloid polypeptide in the pancreas in type 2 diabetes). Evidence is growing to link precursors of amyloid deposition in the brain and pancreas with the pathogenesis of Alzheimer disease and type 2 diabetes, respectively. Given these similarities, we questioned whether there may be a common underlying mechanism predisposing to islet and cerebral amyloid. To address this, we first examined the prevalence of type 2 diabetes in a community-based controlled study, the Mayo Clinic Alzheimer Disease Patient Registry (ADPR), which follows patients with Alzheimer disease versus control subjects without Alzheimer disease. In addition to this clinical study, we performed a pathological study of autopsy cases from this same community to determine whether there is an increased prevalence of islet amyloid in patients with Alzheimer disease and increased prevalence of cerebral amyloid in patients with type 2 diabetes. Patients who were enrolled in the ADPR (Alzheimer disease n = 100, non-Alzheimer disease control subjects n = 138) were classified according to fasting glucose concentration (FPG) as nondiabetic (FPG <110 mg/dl), impaired fasting glucose (IFG, FPG 110-125 mg/dl), and type 2 diabetes (FPG >126 mg/dl). The mean slope of FPG over 10 years in each case was also compared between Alzheimer disease and non-Alzheimer disease control subjects. Pancreas and brain were examined from autopsy specimens obtained from 105 humans (first, 28 cases of Alzheimer disease disease vs. 21 non-Alzheimer disease control subjects and, second, 35 subjects with type 2 diabetes vs. 21 non-type 2 diabetes control subjects) for the presence of islet and brain amyloid. Both type 2 diabetes (35% vs. 18%; P < 0.05) and IFG (46% vs. 24%; P < 0.01) were more prevalent in Alzheimer disease versus non-Alzheimer disease control subjects, so 81% of cases of Alzheimer disease had either type 2 diabetes or IFG. The slope of increase of FPG with age over 10 years was also greater in Alzheimer disease than non-Alzheimer disease control subjects (P < 0.01). Islet amyloid was more frequent (P < 0.05) and extensive (P < 0.05) in patients with Alzheimer disease than in non-Alzheimer disease control subjects. However, diffuse and neuritic plaques were not more common in type 2 diabetes than in control subjects. In cases of type 2 diabetes when they were present, the duration of type 2 diabetes correlated with the density of diffuse (P < 0.001) and neuritic plaques (P < 0.01). In this community cohort from southeast Minnesota, type 2 diabetes and IFG are more common in patients with Alzheimer disease than in control subjects, as is the pathological hallmark of type 2 diabetes, islet amyloid. However, there was no increase in brain plaque formation in cases of type 2 diabetes, although when it was present, it correlated in extent with duration of diabetes. These data support the hypothesis that patients with Alzheimer disease are more vulnerable to type 2 diabetes and the possibility of linkage between the processes responsible for loss of brain cells and beta-cells in these diseases.

The role of cardiovascular risk factors in Alzheimer's disease

The distinction between Alzheimer's disease and vascular dementia, the two most common types of dementia, has been undermined by recent advances in epidemiologic, clinical, imaging, and neuropathological studies. Cardiovascular risk factors, traditionally regarded as distinguishing criteria between the two entities, have been shown to be associated with both AD and vascular dementia. In this article, we propose mechanisms of action of cardiovascular risk factors in AD, suggest possible explanations for the overlap with vascular dementia and discuss the implications this might have on future differential diagnosis, research, and treatment strategies.

Prospective follow-up study between 3 and 15 months after stroke: improvements and decline in cognitive function among dementia-free stroke survivors >75 years of age

BACKGROUND AND PURPOSE

Poststroke cognitive impairment is frequent. There are, however, few longitudinal studies examining delayed changes in poststroke cognition.

METHODS

As part of a longitudinal study of incident dementia after stroke, 115 older stroke survivors (>75 years of age) without dementia were evaluated at 3 and 15 months with a detailed neuropsychological evaluation (including memory, attention, executive performance, and language).

RESULTS

we found that 9% of older stroke patients developed incident dementia, with significant deterioration in global cognition, memory, and attention. Only the severity of expressive language performance at 3 months was associated with dementia at follow-up. Conversely, 57 patients (50%) experienced some improvement in global cognition. None of the criteria for early cognitive impairment identified people at increased risk for dementia.

CONCLUSIONS

Delayed dementia is frequent in older stoke patients, but current criteria for early cognitive impairment are not useful as predictors of cognitive deterioration. Improvement in cognition occurred in most patients.

Vascular factors and cognition: toward a prevention of dementia?

High blood pressure is a known risk factor for stroke and dementia. However, very little is known about the prevention of dementia by lowering blood pressure. Perindopril pROtection aGainst REcurrent Stroke Study (PROGRESS) was designed to determine the effects of an angiotensin-converting enzyme (ACE) inhibitor-based blood pressure-lowering regimen on the risk of stroke among individuals with a prior stroke or transient ischaemic attack (TIA). One of the important aims of the study was to test the hypothesis that treatment would reduce the incidence of dementia and cognitive decline. A total of 6105 patients were randomized to active treatment or placebo. Active treatment comprised perindopril for all participants, and indapamide for those with neither a specific indication for, nor a contraindication to, a diuretic. Dementia was diagnosed according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition. Cognitive decline was defined as a drop of 3 points or more on the Mini-Mental State Examination (MMSE) between baseline and final follow-up. During a median follow-up of 3.9 years, dementia was diagnosed in 410 patients and cognitive decline in 610. Active treatment reduced the risk of cognitive decline (risk reduction [RR] 19%; 95% confidence interval [CI], 4-32; P = 0.01] but there was no clear reduction in the risk of dementia (RR, 12%; 95% CI, -8-28; P = 0.2]). The RR for cognitive outcomes preceded by a recurrent stroke was 34% (95% CI, 3-55; P = 0.03) for dementia and 45% (95% CI, 21-61; P = <0.001) for cognitive decline. Among individuals with a history of stroke or TIA, blood pressure-lowering treatment reduced the risk of cognitive decline by about one fifth. Cognitive decline and dementia associated with recurrent stroke during follow-up were each reduced by between one third and one half. These findings provide further support for the recommendation that blood pressure lowering with perindopril and indapamide be considered for all patients with cerebrovascular disease.