Diagnosis Of Vascular Dementia Research Articles

Mirror writing in elderly patients with Alzheimer disease and vascular dementia

Background The results showed that mirror writing (MW) was correlated with the development of written language, so that MW examination may be one of methods to examine the intelligence of elderly people. Objective To study the MW in elderly patients with Alzheimer disease (AD) and vascular dementia (VaD) and take appropriate scale for their evaluation. Design Taking the written portion of the Chinese Aphasia Examination Scale (1994) for assessment. Setting Department of Neurology, Neuropsychological Laboratory, Beijing Hospital. Participants From March 1998 to January 2001, 33 patients with AD, 30 patients with VaD admitted into Department of Neurology, Beijing Hospital was enrolled into study. Criteria according to the Diagnostic and Statistical Manual of Mental Disorder, 4 th edition (DSM-IV), published by the American Psychiatric Association was used to diagnose AD, while criteria according to the National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l' Enseignement en Neurosciences (NINDS-AIREN) and Alzheimer Disease Diagnostic and Treatment Center (ADDCT) were used for diagnosis of VaD. AD group contained 19 males and 14 females aged 60–83 years. Twenty-eight males and 2 females, aged 60–87 years made up the VaD group. The 63 healthy elderly subjects matched on age and education as controls were enrolled into study. The matched controls were categorized AD control ( n =33) and VaD control ( n =30). All patients and controls were understanding and agree with all items of assessment. Methods MW examination, Mini Mental State Examination (MMSE), Hachinski Ischemic Scale, the Global Deterioration Scale (GDS) were examined in all subjects. ▪ Use the written potion of the Chinese Aphasia examination Scale (1994), patient using MW for 91%–100% of dictation had complete MW, those using MW for 51%–90% of dictation had severe MW, those using MW for 11%–50% had moderate MW, those using MW for 1%–10% had mild MW. ▪ According to the MMSE, the patients were considered to have dementia if they were illiterate and had an MMSE score = 17 score or educated time = 6 years and MMSE = 20 score or educated time > 6 years and MMSE = 24 score. ▪ Using the Hachinski Ischemic Scale to differentiate the AD and VaD, it included 6 items and total 9 scores. > 7 score was VaD, < 4 score was AD and 4-7 score was blended dementia. ▪ Using the GDS to assess cognitive function: Standard criteria were divided in 7 degrees: 1 degree: no impairment of cognition and 7 degree: very severe impairment of cognition. Main outcome measures The data of MW examination, evaluation of MMSE, Hachinski Ischemic Scale and the GDS of all assessed subjects. Results All 63 cases of AD and VaD and 63 healthy controls were entered for analysis. ▪ Results of MW examination: A total of 17 patients with AD were characterized as using MW, 3 with moderate MW and 14 patients with mild MW. In the corresponding control group, only 2 subjects were characterized as being mild MW. The VaD group has 23 patients with MW, 2 with moderate and 21 patients with mild MW. ▪ MMSE score: MMSE score of AD group was much lower than that of individuals in control group [(20.15±3.40), (29.73±0.40) score, P < 0.01], MMSE score of VaD group was much lower than that of individuals in control group [(19.33±2.75), (29.12±0.63) score, P < 0.01]. ▪ Hachinski Ischemic Scale and GDS score: Rating according to the Hachinski Ischemic Scale was higher in VaD patients compared to AD patients [(9.61±1.69), (1.09±0.60) score, P < 0.01]. The GDS score did not significantly differ between the AD group and the VaD group. Conclusion ▪ MW examination could be used as an indicator of intelligence in healthy elderly people and also could be used as one of methods to assess the intelligence in AD and VaD patients. ▪ Grade of severity of MW may indirectly reflect the degree of dementia.

Short-term evolution as a marker of vascular dementia versus Alzheimer's disease

The diagnosis of vascular dementia (VaD) remains a controversial issue in many aspects and concepts. These nosologic problems are caused both by the methods, insufficient to ascertain the diagnosis, as well as by the weak consistency of the clinical concept of VaD itself. One of the most intriguing issues on VaD, and in particular on post-stroke dementia (PSD), is related to the time of development of cognitive decline. In clinical practice, the 3-month time threshold is usually chosen to enable resolution of a possible acute post-stroke delirium, and to obtain a more reliable cognitive assessment with a complete regression of acute neuropsychological stroke-related deficits. Another relevant issue is the possibility to predict which patient will develop PSD. In this regard, recent data indicate an overlap between Alzheimer's disease (AD) and PSD, which seems to share risk factors and neuropathology. In most population samples these two disorders appear together, and the consensus is growing that a degenerative component has a more important role in determining PSD onset shortly after stroke than previously recognized. Therefore, anamnestic data have a fundamental role in this prognostic approach.

Apolipoprotein E Genotypes in Hospitalized Elderly Patients with Vascular Dementia

Background: Polymorphism in the apolipoprotein E (APOE) gene is the major genetic risk factor associated with late-onset Alzheimer’s Disease (AD). However, it is still unclear if a relationship exists between the APOE Ε4 allele and vascular dementia (VaD) in elderly subjects. Objectives: To evaluate the prevalence of APOE alleles in elderly patients with VaD compared to AD patients and to control subjects with no cognitive impairment (NoCI). Patients and Methods: We evaluated 396 consecutive patients aged ≧65 years with definite or suspected cognitive impairment with a clinical (Mini-Mental State Examination, Clinical Dementia Rating, Geriatric Depression Scale), functional (Activities of Daily Living, Instrumental Activities of Daily Living), comorbidity (Cumulative Illness Rating Scale) and instrumental (CT scan, NMR) assessment. Diagnosis of dementia was made according to NINCDS-ADRDA and NINDS-AIREN Work Group and the DSM-IV. APOE genotypes were analyzed by a recently described method resulting in positive/negative chain reaction products for each APOE genotype. Statistical analysis was carried out using the Pearson χ², the Kruskal-Wallis test and the ANOVA post hoc comparisons. Results: A total of 287 elderly patients (males = 138, females = 149, mean age = 77.8 ± 6.9 years, range = 65–98) with diagnoses of VaD (n = 97), AD (n = 82) or NoCI (n = 108) were included in the study. A significantly higher APOE Ε4 allele frequency was observed in AD patients compared to VaD and/or NoCI subjects, while no differences were found between VaD patients and subjects with NoCI (AD = 24.3%, VaD = 10.3, NoCI = 8.7, p < 0.05). Furthermore, a significantly lower APOE Ε3 allele frequency was observed in AD patients compared to VaD and/or NoCI subjects but not between VaD and NoCI patients (AD = 71.3%, VaD = 80.9, NoCI = 83.4, p < 0.05). No significant differences were observed in the APOE Ε2 allele (VaD = 8.8%, AD = 4.4, NoCI = 7.9, p = n.s.) among the 3 groups. Conclusions: In this population, the frequency of the APOE Ε4 allele is lower in VaD than in AD.

General Characteristics of Treatable, Reversible, and Untreatable Dementias

The modification of cognitive function with age has been the focus of numerous studies. Most of the research has suggested that these changes, at least in the majority of individuals, occur only at a very advanced stage; however, those conditions that are treatable and potentially reversible are acute in onset and often associated with acute confusional states. Therefore, physicians should be aware of the possibility of reversible causes of cognitive change in their elderly patients, including certain medications responsible for memory loss and other organ system diseases. In addition, the authors stress that not all memory loss in geriatric patients is due to Alzheimer's disease and that when history and physical examination provide evidence of hypertension and magnetic resonance imaging provides evidence of leukoaraiosis, a diagnosis of vascular dementia should be considered.

Neuropathological evaluation of mixed dementia

Mixed dementia (MD) refers to a combination of definite Alzheimer disease (AD) and vascular encephalopathy, but the distinction between both disorders is controversial. For the diagnosis of MD the clinical/neuroimaging criteria of possible AD plus cerebrovascular disease (CVD) as separate entities are used, but causal relations between vascular brain lesions and dementia are unclear. We proposed the combination of autopsy-proven AD with multiple vascular or ischemic lesions with about 30–50 ml of infarcted/damaged brain tissue. The population-based prevalence of MD is unknown. In retrospective and prospective autopsy studies, it ranges from 2 to 58% with reasonable means of 6–12%. In a consecutive autopsy series of 1500 demented elderly subjects, 830 of which with clinically probable AD, in Vienna, Austria, 41.5 to 52.0% showed “pure” AD, 7% atypical AD, 16–20% AD plus cerebrovascular lesions, and 9% AD plus Lewy body pathology; MD was diagnosed in 4.6 and 2.4%, and “pure” vascular dementia (VaD) in 11 and 2.0%, respectively, while 16.3/6.1% were other dementing disorders, and 1% showed no specific pathology. Like the MRC-CFAS and other studies, this indicates frequent coexistence of AD with multiple cerebrovascular lesions in cognitively impaired patients. In both AD and VaD, vascular lesions frequently involved subcortical regions (basal ganglia, thalamus, hippocampus, and white matter) or were multiple microinfarcts, whereas in MD, large/hemispheral infarcts and multiple microinfarcts were more frequent, suggesting different pathogenic mechanisms. In early/mild AD, critically located small vascular lesions may induce/promote cognitive decline, but in full-blown AD they appear of minor importance. Discussion of the major pathogenic factors inducing AD, VaD and MD suggests synergistic relations between these disorders. However, currently available morphological criteria for AD and VaD are of limited value for the diagnosis of MD and generally accepted and validated histopathological criteria for the diagnosis of VaD and MD are currently not available. Therefore, more distinct and critically evaluated clinico-pathological criteria are warranted.

Neuroradiological findings in vascular dementia

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. 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. 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. 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.

Circle of Willis atherosclerosis: association with Alzheimer’s disease, neuritic plaques and neurofibrillary tangles

The role of intracranial atherosclerosis in Alzheimer's disease (AD) has been a subject of debate since the first decade of the last century. The initial "vascular hypothesis" of AD was rejected after a series of mid-twentieth century gross anatomical postmortem studies that showed an inconstant relationship between intracranial atherosclerosis and senile dementia. These early studies did not utilize statistical methods, however, and the investigators did not appear to consider the possibility that intracranial atherosclerosis might have a probabilistic, rather than an absolute, effect on AD risk. Recent studies by three independent groups have found a significant statistical association between postmortem measures of circle of Willis atherosclerosis and AD. The present study was undertaken to further address the validity of this association in a large autopsy series, including cases diagnosed neuropathologically with vascular dementia (VaD) and non-AD dementias. Postmortem gross anatomical grading of circle of Willis atherosclerosis was performed in 397 subjects classified by neuropathological diagnosis, including 92 non-demented elderly controls, 215 with AD, 30 with VaD and 60 with non-AD dementias. Circle of Willis atherosclerosis was more severe in subjects with AD and VaD than in control subjects, while it was equivalent between control subjects and subjects with non-AD dementias. Increasing atherosclerotic grade increased the odds ratios (OR) for the diagnoses of both AD and VaD and also increased the ORs for both increased neuritic plaque density and higher Braak neurofibrillary tangle stage. The significance of these associations was retained after consideration of the effects of age, gender and the apolipoprotein E-epsilon4 allele. The results suggest that the statistical association between intracranial atherosclerosis and AD is not an artifact of diagnostic misclassification or of unequal distribution of the apolipoprotein E-epsilon4 allele.

Anterior-medial thalamic lesions in dementia: frequent, and volume dependently associated with sudden cognitive decline

Background: The anterior-medial thalamus (AMT), which is associated with memory processing, is severely affected by Alzheimer’s disease pathology and, when damaged, can be the sole cause of dementia. Objective: To...

P2-096: Ischemic lesion determines dementia outcome in Alzheimer’s disease with mixed pathology

Alzheimer's disease (AD) and vascular dementia (VaD) behave differently in neuropsychology and disease progression. However, cerebral ischemic pathology commonly coexists in AD, and studies suggest the cognitive profile in mixed dementia resembles VaD rather than AD. The impact of ischemic lesion on the clinical progression of AD with mixed pathology is unclear. To define the role of ischemic lesion in dementia progression in AD patients with mixed pathology. A retrospective observational study on consecutive AD, mixed dementia and VaD patients seen in a multidisciplinary memory clinic of a tertiary hospital from 1 Jan 1999 to 30 Jun 2004. Mixed dementia and AD patients were reclassified according to the published radiology operational NINDS–AIREN criteria for VaD into AD–N, no ischemic lesion on CT or MRI; AD–I, presence of ischemic lesion but not fulfilled the operational criteria; and AD–V, fulfilled operational criteria. A radiologist blinded to clinical diagnosis reviewed the imaging findings. Patients followed for more than 1 year were included in the study. Need for institution care and loss of self independence as indicated by score 3 in clinical dementia rating (CDR) were used as composite endpoints for poor outcome. One hundred seventy–three patients were included in the study. Their mean age was 76.3, 38.7% was male. The initial MMSE was 15.8±0.4, and the average duration of follow up was 29.7 months. Forty–three patients were diagnosed VaD, 53, 42 and 35 patients had AD–N, AD–I and AD–V respectively. There was no difference in the rate of change in MMSE among 4 groups of patients. Grouping patients with and without operational VaD criteria showed a significant worse performance on outcome endpoint in those with operational VaD criteria (VaD + AD–V), regardless on the clinical diagnosis of AD or VaD (figure 1). Presence of operational VaD criteria remained the only significant independent risk factor in the Cox–regression proportional hazard model after controlling for age, sex and ChEI treatment, the hazard ratio was 1.9 (1.1–3.3). Kaplan–Meier curve after regrouping patients according to the presence of radiological criteria for VaD. Log rank χ2 5.28, df=1, p value– 0.02.

Cerebrospinal Fluid Amyloid ss42/Phosphorylated Tau Ratio Discriminates Between Alzheimer's Disease and Vascular Dementia

The differentiation of Alzheimer's disease (AD) from vascular dementia (VaD) is hampered by clinical diagnostic criteria with disappointing sensitivity and specificity. The objective of this study was to investigate whether cerebrospinal fluid (CSF) levels of total tau protein (t-tau), amyloid beta42 protein (Abeta42), and tau phosphorylated at threonine 181 (p-tau181) are useful biomarkers to distinguish AD patients from VaD patients. We measured CSF levels of p-tau181, Abeta42, and t-tau in 86 patients with a clinical diagnosis of AD or VaD and in 30 control participants. Optimal differentiation between AD and VaD was achieved by using the ratio of the CSF levels of Abeta42 and p-tau181 (Q Abeta42/p-tau) with sensitivity, specificity, positive and negative predictive values all > or = 85%. Our results support further efforts to prospectively validate the use of Q Abeta42/p-tau as a biomarker to discriminate between AD and VaD.

Buspirone for Stereotypic Movements in Elderly With Cognitive Impairment

Buspirone for Stereotypic Movements in Elderly With Cognitive Impairment

Evaluation of total cerebral blood flow volume in cerebral atrophy

The goal of our study is to determine total cerebral blood flow volume (tCBFV) via extracranial Doppler ultrasound and to investigate its value in the differential diagnosis of dementia. Twenty-eight outpatients with cerebral atrophy confirmed by cranial computed tomography were enrolled into the study. Nine patients with Alzheimer's disease (AD) and nine patients with vascular dementia (VaD) based on neuropsychologic test and imaging findings, as well as 10 neurologically normal elderly subjects underwent Doppler sonographic examination of extracranial internal carotid artery (ICA) and vertebral artery (VA). Angle corrected time averaged flow velocity and cross-sectional areas of vessels have been measured. Flow volumes and tCBFV have been calculated. The measures of tCBFV, anterior CBFV (aCBFV), right CBFV (rCBFV) and right ICA flow volume were significantly lower in patients with dementia. The amounts of tCBFV, aCBFV, rCBFV and right ICA flow volume have been found to be low in AD and VaD patients compared with normal elderly group. Of all parameters measured for AD and VaD, no significant difference was found except Mini-Mental State Examination (MMSE) scores. To the best of our knowledge, this is the first reporting the CBF measurements using Doppler ultrasound of extracranial ICA and VA in the differential diagnosis of dementia in cerebral atrophy. The tCBFV, aCBFV, rCBFV and right ICA flow volumes and MMSE scores are significant in the diagnosis of dementia, whereas only MMSE scores are significant in the differential diagnosis of AD and VaD.

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.

Cystatin C as biological marker in mild cognitive impairment predicting for VAD

Nowadays, there are no consistence evidences of the existence of a biological marker for Mild Cognitive Impairment (MCI) able to indicate the course of cognitive deficits. Cystatin C (Cys C) has been already studied as possible biological marker in the cerebrospinal fluid (CSF) in which the protein concentration increases in patients with Vascular Dementia (VAD) when compared to Alzheimer disease subjects (AD) and controls. Nevertheless, this finding was not confirmed at peripheral levels. to investigate the plasma levels of Cys C as putative biological marker for dementias (AD and VAD) and for MCI. Forty-eight patients with MCI (28 of vascular type-vMCI and 20 of amnesic type-aMCI), 26 with VAD, 34 with AD and 24 CTR were included. Cys C concentration {Cys C} in plasma samples was evaluated using ELISA test. compared with CTR, mean {Cys C} was increased in patients with MCI (p<0.05). A cut-off score of 2.3 mg/L separate MCI from CTR with 70% of sensitivity and 68% of specificity. Moreover, {Cys C} in VAD were significantly higher than AD (p<0.0001); a cutoff score of 1.7 mg/L separated VAD from AD with 95% of specificity and 85% of sensitivity. {Cys C} in vMCI is increased as compared to aMCI (p<0.001). A cutoff of 3.1 mg/L separated vMCI from aMCI patients with 70% of specificity and 60% of sensitivity. Cys C could be used as specific marker able to identify cognitive decline, distinguish the cognitive decline between amnesic and vascular type and also make a distinction between VAD and AD diagnosis. Longitudinal studies are now needed to investigate if Cys C could be also a prognostic marker predicting the conversion to VAD.

Can ‘Football-Team Color-Code’ Compensate for Anomia? The case study of FN, a patient with color anomia

A case study is reported on large ischemic infracts involving cortical and subcortical areas of the parietal lobes bilaterally, especially left temporo-parietal and right parietal. On examination, the diagnosis of vascular dementia with color anomia, optic aphasia for colors, was established. The patient (FN) showed great difficulty in understanding a scene as a whole and in describing complex scenes. FN’s oral comprehension skills at word and sentence level were satisfactory and he exhibited communicative effectiveness during conversation. He could read letter by letter, but could not make simple judgments of shapes. FN exhibited a marked inability to name colors presented to him visually and to indicate or point to the color requested from the examiner. The most interesting of all the patient’s characteristics was the strategy – a football-team color-code – he had developed for compensating for his inability to name colors.

Classification of vascular dementia in the Cardiovascular Health Study Cognition Study

To describe the diagnostic classification of subjects with incident vascular dementia (VaD) participating in the Cardiovascular Health Study (CHS) Cognition Study. The CHS classified 480 incident cases between 1994 and 1999 among 3,608 CHS participants who had brain MRI in 1992 through 1994 and in 1997 through 1998. The patients were diagnosed before and after reviewing the brain MRI. The pre-MRI classification showed that 52 participants had VaD and 76 had both Alzheimer disease (AD) and VaD. The post-MRI classification showed that the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) criteria classified 61 subjects as having VaD, the National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN) criteria classified 43 subjects as having probable VaD and 10 as possible VaD, and the State of California Alzheimer's Disease Diagnostic and Treatment Center (ADDTC) criteria classified 117 as having probable VaD and 96 as possible. The combination of the ADDTC and National Institute of Neurological and Communication Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria was used to examine the spectrum of vascular disease in dementia. The dementia was attributable to only vascular factors in 56 cases (probable VaD); VaD coexisted with AD in 61 cases, although the VaD component was the leading cause of dementia (probable VaD with AD); AD was the leading cause of dementia in 61 cases (possible VaD and probable AD); and in 29 cases, it was not clear that either AD or VaD was the primary diagnosis (possible AD and possible VaD). None of the clinical criteria for VaD identified the same group of subjects. The diagnosis of vascular dementia is difficult in epidemiologic studies because poststroke dementia can be due to Alzheimer disease (AD) and evidence of vascular disease can be found in the MRI of dementia cases without clinical strokes. Whether the clinical progression is related to AD pathology or vascular disease is difficult to establish.

The Association between Psychiatric and Cognitive Symptoms after Stroke: A Prospective Study

Background: Stroke patients often have neuropsychiatric symptoms and cognitive deficits. The aim of this study was to investigate whether stroke patients with psychiatric symptoms are at increased risk of developing cognitive deficits. Methods: Cognitive function (assessed with a neuropsychological test battery) and presence of psychiatric symptoms (assessed with the 90-item Symptom Checklist) were evaluated at 1, 6, 12 and 24 months after stroke. Results: At baseline, 156 patients entered the study, 15 had a diagnosis of vascular dementia, 113 one of post-stroke mild cognitive impairment. Patients with psychiatric symptoms were found to be at increased risk of being diagnosed as having vascular dementia at baseline (OR = 6.9, CI = 1.3–36.8) and showed more decline on cognitive function 6 months after stroke. Conclusions: Patients with psychiatric symptoms after stroke are at increased risk of cognitive deficits and decline in cognitive functioning.

Dementia Subtypes in China

Prevalences of Alzheimer disease (AD) and vascular dementia (VaD) in China reportedly differ from those in Western countries. To estimate prevalence of AD and VaD in 4 regions of China. Cross-sectional, population-based prevalence survey with a stratified, multistage cluster sampling design. Rural (n = 99) and urbanized (n = 71) communities of Beijing, Xian, Shanghai, and Chengdu. A sample of 34 807 community residents (94% of those eligible) 55 years or older. Participants were screened with the Chinese Mini-Mental State Examination. Those who screened positive (n = 3950) underwent a standardized diagnostic workup. Screening sensitivity was assessed in a 3.3% random sample (n = 1008 of the 30 857 who passed the screening). Diagnoses of AD and VaD were made according to National Institute of Neurological and Communicative Diseases and Stroke-Alzheimer Disease and Related Disorders Association and National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences criteria, respectively. Final diagnoses were made after a 6-month confirmation interval. We identified 732 AD cases and 295 VaD cases. Prevalence in persons 65 years or older was 3.5% (95% confidence interval, 3.0%-3.9%) for AD and 1.1% (95% confidence interval, 0.9%-1.1%) for VaD. After post hoc correction for negative screening errors, prevalence increased to 4.8% for AD and remained at 1.1% for VaD. Prevalence of dementia subtypes in China is comparable with that in Western countries.

Vascular dementia

PREVIEWThe symptoms of vascular dementia are often distinct from those of Alzheimer's disease. The memory deficits that define Alzheimer's disease are not always observed in the initial stages of vascular dementia, which is usually characterized by greater impairment of executive function. However, increasing evidence supports an involvement of the cholinergic system in vascular dementia similar to that seen in Alzheimer's disease. In this article, Dr Black reviews the pathogenesis and diagnosis of vascular dementia, risk factors for the disease, and current treatment approaches, including possible use of Cholinesterase inhibitors.

VASCULAR DEMENTIA AND ALZHEIMER'S DISEASE: THE UNSOLVED PROBLEM OF CLINICAL AND NEUROPSYCHOLOGICAL DIFFERENTIAL DIAGNOSIS

The definition of clinical criteria for differential diagnosis of Vascular Dementia (VaD) and Alzheimer's disease (AD) remains controversial. A large group of patients selected was affected by chronic cerebrovascular disease classified as VaD or not (VND), according to DSM IV criteria. Neuropsychological performances of VaD patients were compared with a group of patients affected by probable AD, matched for age, education, and severity of disease. The comparison of performances did not reach statistical significance in single neuropsychological tasks. The results suggest that neuropsychological examination might not clearly differentiate between VaD and AD patients; the similar pattern of cognitive impairment is probably indicative of several common pathogenetic mechanisms.