Accuracy of the clinical diagnosis of vascular dementia: a prospective clinical and post-mortem neuropathological study

Predictive role of atrial fibrillation in cognitive decline: a systematic review and meta-analysis of 2.8 million individuals

Aims

To systematic review and meta-analyse the association and mechanistic links between atrial fibrillation (AF) and cognitive impairment.

Methods and results

PubMed, EMBASE, and Cochrane Library were searched up to 27 March 2021 and yielded 4534 citations. After exclusions, 61 were analysed; 15 and 6 studies reported on the association of AF and cognitive impairment in the general population and post-stroke cohorts, respectively. Thirty-six studies reported on the neuro-pathological changes in patients with AF; of those, 13 reported on silent cerebral infarction (SCI) and 11 reported on cerebral microbleeds (CMB). Atrial fibrillation was associated with 39% increased risk of cognitive impairment in the general population [n = 15: 2 822 974 patients; hazard ratio = 1.39; 95% confidence interval (CI) 1.25–1.53, I² = 90.3%; follow-up 3.8–25 years]. In the post-stroke cohort, AF was associated with a 2.70-fold increased risk of cognitive impairment [adjusted odds ratio (OR) 2.70; 95% CI 1.66–3.74, I² = 0.0%; follow-up 0.25–3.78 years]. Atrial fibrillation was associated with cerebral small vessel disease, such as white matter hyperintensities and CMB (n = 8: 3698 patients; OR = 1.38; 95% CI 1.11–1.73, I² = 0.0%), SCI (n = 13: 6188 patients; OR = 2.11; 95% CI 1.58–2.64, I² = 0%), and decreased cerebral perfusion and cerebral volume even in the absence of clinical stroke.

Conclusion

Atrial fibrillation is associated with increased risk of cognitive impairment. The association with cerebral small vessel disease and cerebral atrophy secondary to cardioembolism and cerebral hypoperfusion may suggest a plausible link in the absence of clinical stroke. PROSPERO CRD42018109185.

Dementia in the Forensic Setting: Diagnoses Obtained Using a Condensed Protocol at the Office of Chief Medical Examiner, New York City

Individuals with dementia may come to forensic autopsy, partly because of non-natural deaths (e.g. fall-related), and/or concerns of abuse/neglect. At the New York City Office of Chief Medical Examiner (NYC OCME), brains from such cases are submitted for neurodegenerative disease (ND) work-up. Seventy-eight sequential cases were evaluated using a recently published condensed protocol for the NIA-AA guidelines for the neuropathologic assessment of Alzheimer disease (AD), a cost-cutting innovation in diagnostic neuropathology. ND was identified in 74 (94.9%) brains; the most common were AD (n = 41 [52.5%]), primary age-related tauopathy (n = 26 [33.3%]), and Lewy body disease ([LBD], n = 25 [32.1%]). Others included age-related tau astrogliopathy, hippocampal sclerosis of aging, progressive supranuclear palsy, multiple system atrophy, amyotrophic lateral sclerosis, argyrophilic grain disease, and Creutzfeldt-Jakob disease. 26.8% of AD cases involved a non-natural, dementia-related death, versus 40.0% for LBD. Finally, 70 (89.7%) cases had chronic cerebrovascular disease, 53 (67.9%) being moderate-to-severe. We present a diverse distribution of NDs notable for a high rate of diagnoses associated with falls (e.g. LBD), a potential difference from the hospital neuropathology experience. We also report a high burden of cerebrovascular disease in demented individuals seen at the NYC OCME. Finally, we demonstrate that the aforementioned condensed protocol is applicable for a variety of ND diagnoses.

Alzheimer's Disease Neuropathological Comorbidities are Common in the Younger-Old

BACKGROUND

Clinicopathological studies have demonstrated that Alzheimer's disease dementia (ADD) is often accompanied by clinically undetectable comorbid neurodegenerative and cerebrovascular disease that alter the rate of cognitive decline. Aside from causing increased variability in clinical response, it is possible that the major ADD comorbidities may not respond to ADD-specific molecular therapeutics.

OBJECTIVE

As most reports have focused on comorbidity in the oldest-old, its extent in younger age groups that are more likely to be involved in clinical trials is largely unknown; our objective is to provide this information.

METHODS

We conducted a survey of neuropathological comorbidities in sporadic ADD using data from the US National Alzheimer's Coordinating Center. Subject data was restricted to those with dementia and meeting National Institute on Aging-Alzheimer's Association intermediate or high AD Neuropathological Change levels, excluding those with known autosomal dominant AD-related mutations.

RESULTS

Highly prevalent ADD comorbidities are not restricted to the oldest-old but are common even in early-onset ADD. The percentage of cases with ADD as the sole major neuropathological diagnosis is highest in the under-60 group, where "pure" ADD cases are still in the minority at 44%. After this AD as a sole major pathology in ADD declines to roughly 20%in the 70s and beyond. Lewy body disease is the most common comorbidity at younger ages but actually is less common at later ages, while for most others, their prevalence increases with age.

CONCLUSION

Alzheimer's disease neuropathological comorbidities are highly prevalent even in the younger-old.

Amyloid PET in Dementia Syndromes: A Chinese Multicenter Study

Cerebral β-amyloid deposits and regional glucose metabolism assessed by PET are used to distinguish between Alzheimer disease (AD) and other dementia syndromes. In the present multicenter study, we estimated the prevalence of β-amyloid deposits on PET imaging in a wide variety of dementia syndromes and mild cognitive impairment (MCI) within a memory clinic population. Methods: Of the 1,193 consecutive patients with cognitive impairment (CI) who received 1 ¹¹C-PIB PET or ¹⁸F-AV45 PET or both ¹¹C-PIB PET and ¹⁸F-AV45 PET, 960 were diagnosed with AD, 36 with frontotemporal dementia (FTD), 5 with dementia with Lewy bodies, 144 with MCI, 29 with vascular dementia, 4 with corticobasal syndrome, and 15 with unclassifiable dementia. Baseline clinical diagnoses were independently established without access to PET imaging results. Apolipoprotein E (ApoE) genotype analysis was performed on CI patients and 231 sex- and age-matched controls. Results: Of the 1,193 CI patients, 860 (72.1%) were amyloid-positive. The prevalence of amyloid positivity in AD and MCI patients was 86.8% (833/960) and 9.7% (14/144), respectively. In FTD patients, the prevalence of β-amyloid deposits was 5.6% (2/36). In the 4 corticobasal syndrome patients, 2 were amyloid-positive. Three of the 5 patients with dementia with Lewy bodies showed amyloid positivity, as did 6 of the 29 vascular dementia (20.7%) patients. The ApoEε4 allele frequency was significantly increased in amyloid-positive CI patients (30.5%) as compared with other amyloid-negative CI patients (14%) or controls (7.3%). Conclusion: Amyloid imaging may potentially be the most helpful parameter for differential diagnosis in dementia, particularly to distinguish between AD and FTD. Amyloid PET can be used in conjunction with the ApoEε4 allele genetic risk test for amyloid deposits.

Diagnostic Value of Cerebrospinal Fluid Neurofilament Light Protein in Neurology: A Systematic Review and Meta-analysis

IMPORTANCE

Neurofilament light protein (NfL) is elevated in cerebrospinal fluid (CSF) of a number of neurological conditions compared with healthy controls (HC) and is a candidate biomarker for neuroaxonal damage. The influence of age and sex is largely unknown, and levels across neurological disorders have not been compared systematically to date.

OBJECTIVES

To assess the associations of age, sex, and diagnosis with NfL in CSF (cNfL) and to evaluate its potential in discriminating clinically similar conditions.

DATA SOURCES

PubMed was searched for studies published between January 1, 2006, and January 1, 2016, reporting cNfL levels (using the search terms neurofilament light and cerebrospinal fluid) in neurological or psychiatric conditions and/or in HC.

STUDY SELECTION

Studies reporting NfL levels measured in lumbar CSF using a commercially available immunoassay, as well as age and sex.

DATA EXTRACTION AND SYNTHESIS

Individual-level data were requested from study authors. Generalized linear mixed-effects models were used to estimate the fixed effects of age, sex, and diagnosis on log-transformed NfL levels, with cohort of origin modeled as a random intercept.

MAIN OUTCOME AND MEASURE

The cNfL levels adjusted for age and sex across diagnoses.

RESULTS

Data were collected for 10 059 individuals (mean [SD] age, 59.7 [18.8] years; 54.1% female). Thirty-five diagnoses were identified, including inflammatory diseases of the central nervous system (n = 2795), dementias and predementia stages (n = 4284), parkinsonian disorders (n = 984), and HC (n = 1332). The cNfL was elevated compared with HC in a majority of neurological conditions studied. Highest levels were observed in cognitively impaired HIV-positive individuals (iHIV), amyotrophic lateral sclerosis, frontotemporal dementia (FTD), and Huntington disease. In 33.3% of diagnoses, including HC, multiple sclerosis, Alzheimer disease (AD), and Parkinson disease (PD), cNfL was higher in men than women. The cNfL increased with age in HC and a majority of neurological conditions, although the association was strongest in HC. The cNfL overlapped in most clinically similar diagnoses except for FTD and iHIV, which segregated from other dementias, and PD, which segregated from atypical parkinsonian syndromes.

CONCLUSIONS AND RELEVANCE

These data support the use of cNfL as a biomarker of neuroaxonal damage and indicate that age-specific and sex-specific (and in some cases disease-specific) reference values may be needed. The cNfL has potential to assist the differentiation of FTD from AD and PD from atypical parkinsonian syndromes.

Association between white matter lesions and the cerebral glucose metabolism in patients with cognitive impairment

AIM

White matter lesions (WMLs), detected as hyperintensities on T2-weighted MRI, represent small vessel disease in the brain and are considered a potential risk factor for memory and cognitive impairment. It has not been sufficiently evident that cognitive impairment in patients with Alzheimer's disease is caused by WMLs as well as β-amyloid (Aβ) pathology. The aim of this study was to evaluate relationship between WMLs and cerebral glucose metabolism in patients with cognitive impairment after adjustment of cerebral Aβ burden.

MATERIALS AND METHODS

Eighty-three subjects with cognitive performance ranging from normal to dementia, who underwent brain MRI and ¹⁸F-florbetaben positron emission tomography (PET) and ¹⁸F-fluorodeoxyglucose PET, were included in this cross-sectional study. The Fazekas scale was used to quantify WMLs on brain T2-weighted MRI. The cerebral Aβ burden and cerebral glucose metabolism were quantitatively estimated using volume-of-interest analysis. Differences in the regional cerebral glucose metabolism were evaluated between low-WML (Fazekas scale<2) and high-WML (Fazekas scale≥2) groups. Multiple linear regression analysis adjusted for age, sex and cerebral Aβ burden was performed to evaluate the relationship between the Fazekas scale score and cerebral glucose metabolism.

RESULTS

The regional cerebral glucose metabolism for the bilateral frontal, temporal, and parietal cortices, and limbic lobes in the high-WML group were significantly lower than those in the low-WML group. There were significant negative correlations between the Fazekas scale score and regional cerebral glucose metabolism in the bilateral frontal, bilateral temporal and left parietal cortices, and bilateral limbic lobes. Multiple linear regression analysis revealed that the Fazekas scale score was an independent determinant of the glucose metabolism in the bilateral frontal and temporal cortices and limbic lobes.

CONCLUSIONS

WMLs are associated with decreased cerebral glucose metabolism. Our findings suggest that small vessel disease, as well as Aβ pathology, may contribute to cognitive impairment in patients with Alzheimer's disease.

Capillary cerebral amyloid angiopathy in Alzheimer's disease: association with allocortical/hippocampal microinfarcts and cognitive decline

Cerebral amyloid angiopathy (CAA) is caused by the deposition of the amyloid β-protein (Aβ) in the wall of cerebral and leptomeningeal blood vessels and is related to Alzheimer's disease (AD). Capillary Aβ deposition is observed in a subset of CAA cases and represents a distinct type of CAA named capillary CAA or CAA type 1. This type of CAA is strongly associated with the presence of the apolipoprotein E ε4 allele. CAA type 1-associated AD cases often exhibit a more severe Aβ plaque pathology but less widespread neurofibrillary tangle (NFT) pathology. The objective of this study was to analyze whether capillary CAA and its effects on cerebral blood flow have an impact on dementia. To address this objective, we performed neuropathological evaluation of 284 autopsy cases of demented and non-demented individuals. We assessed the presence of CAA and its subtypes as well as for that of hemorrhages and infarcts. Capillary CAA and CAA severity were associated with allocortical microinfarcts, comprising the CA1 region of the hippocampus. Allocortical microinfarcts, capillary CAA and CAA severity were, thereby, associated with cognitive decline. In conclusion, allocortical microinfarcts, CAA severity, and the capillary type of CAA were associated with one another and with the development of cognitive decline. Thus, AD cases with CAA type 1 (capillary CAA) appear to develop dementia symptoms not only due to AD-related Aβ plaque and NFT pathology but also due to hippocampal microinfarcts that are associated with CAA type 1 and CAA severity, and that damage a brain region important for memory function.

Focal Solute Trapping and Global Glymphatic Pathway Impairment in a Murine Model of Multiple Microinfarcts

Microinfarcts occur commonly in the aging brain as a consequence of diffuse embolic events and are associated with the development of vascular dementia and Alzheimer's disease. However, the manner in which disperse microscopic lesions reduce global cognitive function and increase the risk for Alzheimer's disease is unclear. The glymphatic system, which is a brain-wide perivascular network that supports the recirculation of CSF through the brain parenchyma, facilitates the clearance of interstitial solutes including amyloid β and tau. We investigated whether glymphatic pathway function is impaired in a murine model of multiple microinfarcts induced by intraarterial injection of cholesterol crystals. The analysis showed that multiple microinfarcts markedly impaired global influx of CSF along the glymphatic pathway. Although suppression of global glymphatic function was transient, resolving within 2 weeks of injury, CSF tracers also accumulated within tissue associated with microinfarcts. The effect of diffuse microinfarcts on global glymphatic pathway function was exacerbated in the mice aged 12 months compared with the 2- to 3-month-old mice. These findings indicate that glymphatic function is focally disrupted around microinfarcts and that the aging brain is more vulnerable to this disruption than the young brain. These observations suggest that microlesions may trap proteins and other interstitial solutes within the brain parenchyma, increasing the risk of amyloid plaque formation.SIGNIFICANCE STATEMENT Microinfarcts, small (<1 mm) ischemic lesions, are strongly associated with age-related dementia. However, how these microscopic lesions affect global cognitive function and predispose to Alzheimer's disease is unclear. The glymphatic system is a brain-wide network of channels surrounding brain blood vessels that allows CSF to exchange with interstitial fluid, clearing away cellular wastes such as amyloid β. We observed that, in mice, microinfarcts impaired global glymphatic function and solutes from the CSF became trapped in tissue associated with microinfarcts. These data suggest that small, disperse ischemic lesions can impair glymphatic function across the brain and trapping of solutes in these lesions may promote protein aggregation and neuroinflammation and eventually lead to neurodegeneration, especially in the aging brain.

Update on Vascular Dementia

Vascular dementia (VaD) is a major contributor to the dementia syndrome and is described as having problems with reasoning, planning, judgment, and memory caused by impaired blood flow to the brain and damage to the blood vessels resulting from events such as stroke. There are a variety of etiologies that contribute to the development of vascular cognitive impairment and VaD, and these are often associated with other dementia-related pathologies such as Alzheimer disease. The diagnosis of VaD is difficult due to the number and types of lesions and their locations in the brain. Factors that increase the risk of vascular diseases such as stroke, high blood pressure, high cholesterol, and smoking also raise the risk of VaD. Therefore, controlling these risk factors can help lower the chances of developing VaD. This update describes the subtypes of VaD, with details of their complex presentation, associated pathological lesions, and issues with diagnosis, prevention, and treatment.

Neuropathological diagnosis of vascular cognitive impairment and vascular dementia with implications for Alzheimer's disease

Vascular dementia (VaD) is recognised as a neurocognitive disorder, which is explained by numerous vascular causes in the general absence of other pathologies. The heterogeneity of cerebrovascular disease makes it challenging to elucidate the neuropathological substrates and mechanisms of VaD as well as vascular cognitive impairment (VCI). Consensus and accurate diagnosis of VaD relies on wide-ranging clinical, neuropsychometric and neuroimaging measures with subsequent pathological confirmation. Pathological diagnosis of suspected clinical VaD requires adequate postmortem brain sampling and rigorous assessment methods to identify important substrates. Factors that define the subtypes of VaD include the nature and extent of vascular pathologies, degree of involvement of extra and intracranial vessels and the anatomical location of tissue changes. Atherosclerotic and cardioembolic diseases appear the most common substrates of vascular brain injury or infarction. Small vessel disease characterised by arteriolosclerosis and lacunar infarcts also causes cortical and subcortical microinfarcts, which appear to be the most robust substrates of cognitive impairment. Diffuse WM changes with loss of myelin and axonal abnormalities are common to almost all subtypes of VaD. Medial temporal lobe and hippocampal atrophy accompanied by variable hippocampal sclerosis are also features of VaD as they are of Alzheimer’s disease. Recent observations suggest that there is a vascular basis for neuronal atrophy in both the temporal and frontal lobes in VaD that is entirely independent of any Alzheimer pathology. Further knowledge on specific neuronal and dendro-synaptic changes in key regions resulting in executive dysfunction and other cognitive deficits, which define VCI and VaD, needs to be gathered. Hereditary arteriopathies such as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy or CADASIL have provided insights into the mechanisms of dementia associated with cerebral small vessel disease. Greater understanding of the neurochemical and molecular investigations is needed to better define microvascular disease and vascular substrates of dementia. The investigation of relevant animal models would be valuable in exploring the pathogenesis as well as prevention of the vascular causes of cognitive impairment.

[The modern approaches to the prognostication of rehabilitation of the patients after stroke on an individual basis: a review of the literature and the results of original investigations]

This article was designed to analyze the results of the investigations with the purpose of elucidation of the prognostic factors relevant to the rehabilitation of the patients who survived after stroke. Special attention is given to the role of demographic (age and sex) factors and the data of the clinical, neurological, psychological, cognitive, and instrumental examination of the patients. The results of the original studies based on the treatment of 203 stroke patients are discussed in the context of modern concepts of the significance of the factors contributing to the recovery of the patients in the course of the post-stroke rehabilitation. The prognostic value of the selected factors, such as leukoareosis (for the patients presenting with hemorrhagic stroke), has been demonstrated for the first time. The new data on the duration of the rehabilitation period are presented with reference to its dependence on the type of stroke and localization of the lesions. Specifically, it is estimated to be 2 years for the patients who suffered from ischemic stroke in the brain stem, 31 months for those with ischemic stroke of the hemispherical localization, and 38 months for the patients presenting with hemorrhagic stroke (hemispherical hematoma). In addition, the data on the magnitude of the post-ischemic atrophic changes of prognostic values are presented.

Stalled cerebral capillary blood flow in mouse models of essential thrombocythemia and polycythemia vera revealed by in vivo two-photon imaging

BACKGROUND

Essential thrombocythemia (ET) and polycythemia vera (PV) are myeloproliferative neoplasms (MPNs) that share the JAK2(V617F) mutation in hematopoietic stem cells, leading to excessive production of predominantly platelets in ET, and predominantly red blood cells (RBCs) in PV. The major cause of morbidity and mortality in PV and ET is thrombosis, including cerebrovascular occlusive disease.

OBJECTIVES

To identify the effect of excessive blood cells on cerebral microcirculation in ET and PV.

METHODS

We used two-photon excited fluorescence microscopy to examine cerebral blood flow in transgenic mouse models that mimic MPNs.

RESULTS AND CONCLUSIONS

We found that flow was 'stalled' in an elevated fraction of brain capillaries in ET (18%), PV (27%), mixed MPN (14%) and secondary (non-MPN) erythrocytosis (27%) mice, as compared with controls (3%). The fraction of capillaries with stalled flow increased when the hematocrit value exceeded 55% in PV mice, and the majority of stalled vessels contained only stationary RBCs. In contrast, the majority of stalls in ET mice were caused by platelet aggregates. Stalls had a median persistence time of 0.5 and 1 h in ET and PV mice, respectively. Our findings shed new light on potential mechanisms of neurological problems in patients with MPNs.

The appropriate use of neuroimaging in the diagnostic work-up of dementia: an evidence-based analysis

BACKGROUND

Diagnosis of dementia is challenging and requires both ruling out potentially treatable underlying causes and ruling in a diagnosis of dementia subtype to manage patients and suitably plan for the future.

OBJECTIVES

This analysis sought to determine the appropriate use of neuroimaging during the diagnostic work-up of dementia, including indications for neuroimaging and comparative accuracy of alternative technologies.

DATA SOURCES

A literature search was performed using Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid Embase, the Wiley Cochrane Library, and the Centre for Reviews and Dissemination database, for studies published between 2000 and 2013.

REVIEW METHODS

Data on diagnostic accuracy and impact on clinical decision making were abstracted from included studies. Quality of evidence was assessed using GRADE.

RESULTS

The search yielded 5,374 citations and 15 studies were included. Approximately 10% of dementia cases are potentially treatable, though less than 1% reverse partially or fully. Neither prediction rules nor clinical indications reliably select the subset of patients who will likely benefit from neuroimaging. Clinical utility is highest in ambiguous cases or where dementia may be mixed, and lowest for clinically diagnosed Alzheimer disease or clinically excluded vascular dementia. There is a lack of evidence that MRI is superior to CT in detecting a vascular component to dementia. Accuracy of structural imaging is moderate to high for discriminating different types of dementia.

LIMITATIONS

There was significant heterogeneity in estimates of diagnostic accuracy, which often prohibited a statistical summary of findings. The quality of data reported by studies prohibited calculation of likelihood ratios in the present analysis. No studies from primary care were found; thus, generalizability beyond tertiary care settings may be limited.

CONCLUSIONS

A diagnosis of reversible dementia is rare. Imaging has the most clinical utility in cases where there is potentially mixed dementia or ambiguity as to the type of dementia despite prolonged follow-up (e.g., 2 years or more). Both CT and MRI are useful for detecting a vascular component of dementia.

Cognitive deficits and delayed neuronal loss in a mouse model of multiple microinfarcts

Microinfarcts are a common clinical feature of the aging brain, particularly in patients with cognitive decline or vascular or Alzheimer's dementia. However, the natural history of these lesions remains largely unexplored. Here we describe a mouse (C57BL/6J) model of multiple diffuse microinfarcts induced by unilateral internal carotid artery injection of cholesterol crystals (40-70 μm). Microinfarcts were spread throughout the deep cortex, subcortical tissue, and hippocampus and were comprised of a core positive for CD68 (a marker for reactive microglia and macrophages), surrounded by large regions of glial fibrillary acidic protein-positive reactive astrogliosis. Widespread reactive gliosis, including mislocalization of the astrocytic water channel aquaporin 4 persisted long after injury, recovering only after 1 month after stroke. Within the cortex, neuronal cell death progressed gradually over the first month, from ∼35% at 3 d to 60% at 28 d after stroke. Delayed demyelination was also observed in lesions, beginning 28 d after stroke. These findings demonstrate that microinfarct development follows a distinct course compared to larger regional infarcts such as those induced by middle cerebral artery occlusion. The long-lasting gliosis, delayed neuronal loss, and demyelination suggest that the therapeutic window for microinfarcts may be much wider (perhaps days to weeks) than for larger strokes.

Is MRI better than CT for detecting a vascular component to dementia? A systematic review and meta-analysis

BACKGROUND

Identification of causes of dementia soon after symptom onset is important, because appropriate treatment of some causes of dementia can slow or halt its progression or enable symptomatic treatment where appropriate. The accuracy of MRI and CT, and whether MRI is superior to CT, in detecting a vascular component to dementia in autopsy confirmed and clinical cohorts of patients with VaD, combined AD and VaD ("mixed dementia"), and AD remain unclear. We conducted a systematic review and meta-analysis to investigate this question.

METHODS

We searched eight databases and screened reference lists to identify studies addressing the review question. We assessed study quality using QUADAS. We estimated summary diagnostic accuracy according to imaging finding, and ratios of diagnostic odds ratios (RDORs) for MRI versus CT and high versus low risk of bias.

RESULTS

We included 7 autopsy and 31 non-autopsy studies. There was little evidence that selective patient enrolment and risk of incorporation bias impacted on diagnostic accuracy (p = 0.12 to 0.95). The most widely reported imaging finding was white matter hyperintensities. For CT (11 studies) summary sensitivity and specificity were 71% (95% CI 53%-85%) and 55% (44%-66%). Corresponding figures for MRI (6 studies) were 95% (87%-98%) and 26% (12%-50%). General infarcts was the most specific imaging finding on MRI (96%; 95% CI 94%-97%) and CT (96%; 93%-98%). However, sensitivity was low for both MRI (53%; 36%-70%) and CT (52%; 22% to 80%). No imaging finding had consistently high sensitivity. Based on non-autopsy studies, MRI was more accurate than CT for six of seven imaging findings, but confidence intervals were wide.

CONCLUSION

There is insufficient evidence to suggest that MRI is superior to CT with respect to identifying cerebrovascular changes in autopsy-confirmed and clinical cohorts of VaD, AD, and 'mixed dementia'.

Cerebral microinfarcts: a systematic review of neuropathological studies

Vascular cognitive impairment is an umbrella term for cognitive dysfunction associated with and presumed to be caused by vascular brain damage. Autopsy studies have identified microinfarcts as an important neuropathological correlate of vascular cognitive impairment that escapes detection by conventional magnetic resonance imaging (MRI). As a frame of reference for future high-resolution MRI studies, we systematically reviewed the literature on neuropathological studies on cerebral microinfarcts in the context of vascular disease, vascular risk factors, cognitive decline and dementia. We identified 32 original patient studies involving 10,515 people. The overall picture is that microinfarcts are common, particularly in patients with vascular dementia (weighted average 62%), Alzheimer's disease (43%), and demented patients with both Alzheimer-type and cerebrovascular pathology (33%) compared with nondemented older individuals (24%). In many patients, multiple microinfarcts were detected. Microinfarcts are described as minute foci with neuronal loss, gliosis, pallor, or more cystic lesions. They are found in all brain regions, possibly more so in the cerebral cortex, particularly in watershed areas. Reported sizes vary from 50 μm to a few mm, which is within the detection limit of current high-resolution MRI. Detection of these lesions in vivo would have a high potential for future pathophysiological studies in vascular cognitive impairment.

Vascular dementia: Diagnostic criteria and supplementary exams. Recommendations of the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology. Part I

Vascular dementia (VaD) is the most prevalent form of secondary dementia and the second most common of all dementias. The present paper aims to define guidelines on the basic principles for treating patients with suspected VaD (and vascular cognitive impairment - no dementia) using an evidence-based, systematized approach. The knowledge used to define these guidelines was retrieved from searches of several databases (Medline, Scielo, Lilacs) containing scientific articles, systematic reviews, meta-analyses, largely published within the last 15 years or earlier when pertinent. Information retrieved and selected for relevance was used to analyze diagnostic criteria and to propose a diagnostic system encompassing diagnostic criteria, anamnesis, as well as supplementary and clinical exams (neuroimaging and laboratory). Wherever possible, instruments were selected that had versions previously adapted and validated for use in Brazil that take into account both schooling and age. This task led to proposed protocols for supplementary exams based on degree of priority, for application in clinical practice and research settings.

Psychotic symptoms in a population-based sample of 85-year-old individuals with dementia

Psychotic symptoms are common in elderly persons with dementia. These symptoms affect a person's ability to function in daily life and put strain on the caregiver. Most studies focus on psychotic symptoms in clinical samples with Alzheimer disease (AD). Thus, their prevalence and relation with dementia subtype and severity in very old populations is unclear. We assessed a representative sample of 85-year-old individuals living in Gothenburg, Sweden (n = 494) using neuropsychiatric examinations, key informant interviews, and medical record reviews; 147 had dementia. Dementia and its severity were diagnosed in accordance with Diagnostic and Statistical Manual of Mental Disorders (Third Edition, Revision [DSM-III-R]) criteria. Alzheimer disease according to the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) criteria was diagnosed in 64 persons and vascular dementia (VaD) according to Erkinjuntti criteria was observed in 69. Fourteen had dementia due to other causes. Psychotic symptoms were classified according to DSM-III-R. The prevalence of psychotic symptoms in this very old population was 36% among AD cases compared to 54% in VaD cases (P = .04). Proportions with psychotic symptoms increased with increasing dementia severity in individuals with AD. No such association could be shown in those with VaD. This finding of a high proportion of psychotic symptoms also in individuals with mild severity of VaD should alert health professionals to evaluate dementia in very old patients who present with hallucinations or delusions.

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.

Prevalence and cognitive impact of cerebrovascular findings in Alzheimer's disease: a retrospective, naturalistic study

AIMS

Cerebrovascular disease (CVD) is a major risk factor for cognitive decline associated with progression to Alzheimer's disease (AD) and dementia. The objective of this study was to retrospectively assess the prevalence of CVD and its cognitive impact in patients with AD in everyday clinical practice.

METHODS

Medical notes were retrospectively reviewed for all individuals who presented at East Sussex Memory Clinic (2004-2008) for investigation of cognitive impairment and had brain magnetic resonance imaging (MRI) as part of their clinical work-up. Global cognitive status was assessed with Mini-Mental State Examination (MMSE) and Cambridge Cognitive Examination. The extent of cerebrovascular abnormalities was qualitatively evaluated with MRI.

RESULTS

Notes were reviewed for 232 patients (109 males, 123 females), mean age 76 years (range 62-93), who underwent MRI. Of these, 167 (72%) patients were diagnosed with AD. CVD was present in 89% of AD patients and 47% of patients had moderate to severe cerebrovascular abnormalities. The majority of patients (57%) had MMSE scores in the 21-26 range, indicative of mild AD. There was a trend towards worse cognitive status in patients with more severe CVD, which did not reach significance. Hachinski Ischaemic score indicated these patients did not have vascular dementia (VaD) (mean +/- standard deviation 1.1 +/- 1.3).

CONCLUSION

These findings, based on qualitative MRI, indicate that cerebrovascular pathology is a very common associated feature in patients with mild to moderate AD, without VaD. Although the study suggests that CVD does not contribute to cognitive decline, and is not associated with the development of VaD, a non-significant trend was observed towards worsening cognitive status with increasing severity of CVD. The finding of this trend suggests a need for additional research, especially a prospective quantitative method of assessing CVD, to improve our understanding of how CVD contributes to cognitive impairment in AD.

Validation of clinical criteria for possible vascular dementia in the oldest-old

Although vascular dementia (VaD) is a main pathology in nonagenarians and centenarians, the validity of clinical criteria for this diagnosis is unknown. We analyzed 110 autopsy cases and reported sensitivities and specificities of the State of California Alzheimer's Disease Diagnostic and Treatment Centers (ADDTC) and National Institute for Neurological Disorders and Stroke (NINDS-AIREN) criteria for possible VaD as well as Hachinski ischemic score (HIS). Among them, there were 36 neuropathologically confirmed VaD cases. All criteria displayed comparable sensitivities (0.56-0.58). Specificities values were 0.74, 0.73 and 0.66, respectively. There was an age-related decrease on ADDTC criteria sensitivity due to the fact that 42% of pure VaD cases did not present with stroke. Thirty percent of mixed dementia (MD) cases were diagnosed as VaD by both NINDS-AIREN and ADDTC criteria. This proportion reached 45.9% for the HIS. These data demonstrate that the new diagnostic criteria for possible VaD do not provide a substantial gain of sensitivity compared to the HIS. Although their specificity was significantly lower in this age group compared to younger cohorts, all of them successfully exclude AD cases.

The enigma of vascular cognitive disorder and vascular dementia

The prevalence, morphology and pathogenesis of vascular dementia (VaD), recently termed vascular cognitive impairment, are a matter of discussion, and currently used clinical diagnostic criteria show moderate sensitivity (average 50%) and variable specificity (range 64-98%). In Western clinic-based series, VaD is suggested in 8-10% of cognitively impaired aged subjects. Its prevalence in autopsy series varies from 0.03 to 58%, with reasonable values of 8-15%, while in Japan it is seen in 22-35%. Neuropathologic changes associated with cognitive impairment include multifocal and/or diffuse disease and focal lesions: multi-infarct encephalopathy, white matter lesions or arteriosclerotic subcortical (leuko)encephalopathy, multilacunar state, mixed cortico-subcortical type, borderline/watershed lesions, rare granular cortical atrophy, post-ischemic encephalopathy and hippocampal sclerosis. They result from systemic, cardiac and local large or small vessel disease. Recent data indicate that cognitive decline is commonly associated with widespread small ischemic/vascular lesions (microinfarcts, lacunes) throughout the brain with predominant involvement of subcortical and functionally important brain areas. Their pathogenesis is multifactorial, and their pathophysiology affects neuronal networks involved in cognition, memory, behavior and executive functioning. Vascular lesions often coexist with Alzheimer disease (AD) and other pathologies. Minor cerebrovascular lesions, except for severe amyloid angiopathy, appear not essential for cognitive decline in full-blown AD, while both mild Alzheimer pathology and small vessel disease may interact synergistically. The lesion pattern of "pure" VaD, related to arteriosclerosis and microangiopathies, differs from that in mixed-type dementia (AD with vascular encephalopathy), more often showing large infarcts, which suggests different pathogenesis of both types of lesions. Due to the high variability of cerebrovascular pathology and its causative factors, no validated neuropathologic criteria for VaD are available, and a large variability across laboratories still exists in the procedures for morphologic examination and histology techniques.

Dementing Diseases Among Elderly Persons Who Suffered Fatal Accidents

The demographics and forensic autopsy findings of 125 elderly persons were analyzed to identify the risk factors of fatal accidents among elderly and to develop preventive measures to minimize such events. Cliniconeuropathologic dementing diseases were diagnosed in 13 of the 69 accidental death but only 1 of the 56 nonaccidental death cases, indicating that dementing diseases are associated with accidental deaths of elderly in forensic autopsy populations and suggesting that interventions for preventing fatal accidents should focus on elderly persons with dementia. Blood alcohol was only detected in persons without dementia, indicating that dementing diseases and drunkenness are not coexisting factors for fatal accidents among elderly. Living alone might increase the risk of mortalities associated with accidental injuries because of the absence of a caregiver at the scene and delayed medical help. The majority of fatal accidents occurred outdoors, emphasizing the need for interventions to reduce environmental hazards such as those related to traffic, open water, and cold weather. Increased public awareness of accident risks and preventive interventions will reduce accidental deaths among community-dwelling elderly people.

Assessing the cognitive impact of Alzheimer disease pathology and vascular burden in the aging brain: the Geneva experience

The progressive development of Alzheimer disease (AD)-related lesions, such as neurofibrillary tangles (NFT), amyloid deposits and synaptic loss, and the occurrence of microvascular and small macrovascular pathology within the cerebral cortex are conspicuous neuropathologic features of brain aging. Recent neuropathologic studies strongly suggested that the clinical diagnosis of dementia depends more on the severity and topography of pathological changes than on the presence of a qualitative marker. However, several methodological problems, such as selection biases, case-control design, density-based measures and masking effects, of concomitant pathologies persisted. In recent years, we performed several clinicopathologic studies using stereological counting of AD lesions. In order to define the cognitive impact of lacunes and microvascular lesions, we also analyzed pure vascular cases without substantial AD pathology. Our data revealed that total NFT numbers in the CA1 field, cortical microinfarcts and subcortical gray matter lacunes were the stronger determinants of dementia. In contrast, the contribution of periventricular and subcortical white matter demyelinations had a modest cognitive effect even in rare cases with isolated microvascular pathology. Importantly, in cases with pure AD pathology, more than 50% of Clinical Dementia Rating scale variability was not explained by NFT, amyloid deposits and neuronal loss in the hippocampal formation. In cases with microvascular pathology or lacunes, this percentage was even lower. The present review summarizes our data in this field and discusses their relevance within the theoretical framework of the functional neuropathology of brain aging and with particular reference to the current efforts to develop standardized neuropathological criteria for mixed dementia.

Cognitive impairment

As populations continue to age, the prevalence of dementia is expected to increase. AD is by far the most common cause of dementia. The clinical course of dementia represents the challenges that this disease presents. There are no truly effective therapies for treating dementia, and the cost effectiveness of ChEIs has been challenged; however, there has been an explosion of information about AD. Evidence-based practice parameters for diagnosis and management of dementia have been developed. There has been an increased interest in the possible prodromal states of dementia, such as MCI. The concept of MCI has risen in prominence in recent years; it is speculated that initiation of therapies early in the course of disease may be needed for them to be effective. Considering the enormous burdens that AD places on individuals and society, disease-modifying treatments for AD are needed desperately. There are promising avenues for the development of potentially disease-modifying therapies for this devastating disease.

A vascular risk factor index in relation to mortality and incident dementia

To develop a method for quantifying risks of death and dementia in relation to vascular risk factors the Gothenburg H-70 1901-02 birth cohort was studied (n=380, was followed over 20 years, with 103 incident dementia cases). Separate vascular risk factor indices were calculated using 23 vascular risk factors to predict: (i) dementia-free-survival, and (ii) incident dementia derived from post hoc optimal separation of affected and unaffected cases. Classification of adverse outcomes (dementia/non-dementia; alive/dead) was assessed using receiver-operator characteristic (ROC) curves, and the area under the curve (AUC). Each index showed high separation between affected and unaffected cases. For dementia/non-dementia, the AUC was 0.74+/-0.02 for 10 year and 0.67+/-0.02 for 20 year; for death/survival, the AUC was 0.75+/-0.02 for 10 years and 0.79+/-0.03 for 20 years. Of note, few items were important in both indexes, and most showed reciprocal effects (e.g. decreased the risk of death but increased the risk of dementia). Our results suggest that vascular risk factor indexes can give robust estimates of dementia and life span prognoses in elderly people, but death and dementia have different risk profiles. This may be because of death being a competing risk for incident late-onset dementia.

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.

Small vessel disease and subcortical vascular dementia

Atherothromboembolism and intracranial small vessel disease are considered to be the main causes of cerebrovascular injury, which may lead to cognitive impairment and vascular dementia (VaD). VaD appears to be the second most common type of dementia with prevalence estimates of 10-15%. Cortical or multi-infarct dementia and subcortical vascular dementia (SVD) are suggested to be the two main forms of VaD. The main clinical features of SVD comprise decreased motor performance, early impairment of attention and executive function with slowing of information processing. SVD results from lacunar infarcts or multiple microinfarcts in the basal ganglia, thalamus, brainstem and white matter and are associated with more than 50% of the VaD cases. White matter changes including regions of incomplete infarction are usually widespread in VaD but their contribution to impairment of subcortical regions is unclear. While most of VaD occurs sporadically only a small proportion of cases bear clear familial traits. CADASIL is likely the most common form of hereditary VaD, which arises from subcortical arteriopathy. SVD needs unambiguous definition to impact on preventative and treatment strategies, and critical for selective recruitment to clinical trials.

Cognitive Consequences of Thalamic, Basal Ganglia, and Deep White Matter Lacunes in Brain Aging and Dementia

Background and Purpose— Most previous studies addressed the cognitive impact of lacunar infarcts using radiologic correlations that are known to correlate poorly with neuropathological data. Moreover, absence of systematic bilateral assessment of vascular lesions and masking effects of Alzheimer disease pathology and macrovascular lesions may explain discrepancies among previous reports. To define the relative contribution of silent lacunes to cognitive decline, we performed a detailed analysis of lacunar and microvascular pathology in both cortical and subcortical areas of 72 elderly individuals without significant neurofibrillary tangle pathology or macrovascular lesions.

Methods— Cognitive status was assessed prospectively using the Clinical Dementia Rating (CDR) scale; neuropathological evaluation included Aβ-protein deposition staging and bilateral assessment of microvascular ischemic pathology and lacunes; statistical analysis included multivariate models controlling for age, amyloid deposits, and microvascular pathology.

Results— Thalamic and basal ganglia lacunes were negatively associated with CDR scores; cortical microinfarcts, periventricular and diffuse white matter demyelination also significantly affected cognition. In a multivariate model, cortical microinfarcts and thalamic and basal ganglia lacunes explained 22% of CDR variability; amyloid deposits and microvascular pathology explained 12%, and the assessment of thalamic and basal ganglia lacunes added an extra 17%. Deep white matter lacunes were not related to cognitive status in univariate and multivariate models.

Conclusions— In agreement with the recently proposed concept of subcortical ischemic vascular dementia, our autopsy series provides important evidence that gray matter lacunes are independent predictors of cognitive decline in elderly individuals without concomitant dementing processes such as Alzheimer disease.

NINDS AIREN neuroimaging criteria do not distinguish stroke patients with and without dementia

OBJECTIVE

To determine the utility of the neuroimaging component within the National Institute of Neurological Disorders and Stroke (NINDS) Association Internationale pour la Recherche et l'Enseignement en Neurosciences (AIREN) criteria for vascular dementia for distinguishing between patients with and without dementia in the context of cerebrovascular disease.

METHOD

One hundred twenty-five poststroke patients age > or =75 (27 with and 98 without poststroke dementia) from representative hospital-based stroke registers in the North East of England were evaluated using a 1.5 T MR scanner. The proportion of patients with and without poststroke dementia meeting the imaging component of the NINDS AIREN criteria was determined, and hippocampal atrophy (measured using the Schelten scale) was compared between the two groups.

RESULTS

There were no significant differences between the patients with and without poststroke dementia on any criteria of the imaging parameters within the NINDS AIREN criteria. In addition, there were no significant differences in the number or size of cortical or subcortical infarcts between the two groups, with 13 patients without dementia having cortical infarcts >50 mm. Patients with dementia had greater hippocampal atrophy (right: Mann-Whitney U test, Z = 2.5, p = 0.01; left: Mann-Whitney U test, Z = 2.5, p = 0.01).

CONCLUSION

The neuroimaging component of the NINDS AIREN criteria does not distinguish between older patients with and without poststroke dementia.

The influence of dementia on the prevalence of urinary and faecal incontinence in 85-year-old men and women

The influence of dementia on the prevalence of urinary and faecal incontinence was investigated in a random sample (n = 485) of the total population of 85-year-olds from the city of Gothenburg, Sweden. The subjects were assessed by a psychiatric interview, physical examinations, computed tomography of the head and analysis of cerebrospinal fluid. Urinary and faecal incontinence were assessed by a urotherapist. Dementia, urinary and faecal incontinence were defined according to strict, internationally accepted criteria. The prevalences of urinary and faecal incontinence, and dementia were 38%, 17% and 29% respectively. Demented men (50%) and women (60%) were more often urinary incontinent than non-demented men (18%) and women (36%). Faecal incontinence was more prevalent in demented (34.8%) than non-demented subjects (6.7%). Both urinary and faecal incontinence were more prevalent in women (43% and 20% respectively) than men (27% and 11%, respectively). The prevalences of urinary and faecal incontinence, and dementia were higher in residents of a nursing home or hospital (74%, 51% and 92%, respectively) than in subjects living at home (32%, 9% and 18%, respectively). Of the demented subjects resident in an institution, 78% were incontinent compared with 37% living at home. Incontinence aids were used by 18% of the men and 33% of the women, and their use increased with increasing severity of dementia. Dementia influenced the prevalence of urinary incontinence, and both conditions independently of each other strongly influenced the need for institutional care.

Alzheimer's disease with and without cerebral infarcts

OBJECTIVE

To compare the clinical and pathological features of Alzheimer's disease (AD) patients with and without associated cerebral infarcts (CI).

METHODS

The consecutive records of 57 prospectively studied demented patients fulfilling the CERAD criteria for the pathological diagnosis of AD were reviewed. Cases with cortical Lewy bodies were excluded. CI were found in 22 cases (39%) (AD+CI group): large infarcts (5), lacunes (13) and/or hippocampal sclerosis (4), and were absent in 35 cases (AD group). Microscopic infarcts, cribiform change, amyloid angiopathy, and white matter rarefaction were not considered in this classification, but were quantified. Cortical atrophy, neurofibrillary tangle and senile plaque (diffuse and neuritic) load were also measured. Pathological evaluation was independent of clinical information. Clinical and pathological data were compared between both groups.

RESULTS

AD+CI cases were significantly older, more commonly female, less educated, and more often had blue collar occupations, sleep disturbances, frontal release signs, and EEG spikes than AD cases. Other differences found (acute/subacute onset, behavioral disturbances, and leukoaraiosis on CT scan) disappeared after controlling for age. The frequency of known vascular risk factors and focal motor and sensory signs did not differ between the groups, which showed remarkable clinical similarity overall. The only significant differences on pathological exam were hippocampal microinfarcts and white matter lesions, although there was a trend for lower neurodegenerative lesion load in the AD+CI group. The ischemic lesions were located in temporal lobe in 50% of AD+CI patients; these cases had a significantly lower neocortical neurodegenerative lesion load than those with CI in other sites.

CONCLUSIONS

The presence of CI in AD increases significantly with age, but has scarce influence on the clinical features, and cannot be predicted from common vascular risk factors. In spite of a trend, there are no major differences in neurodegenerative lesion load between AD and AD+CI groups, except when CI are located in the temporal lobe (including hippocampus), suggesting that this location may be important in the physiopathology of mixed vascular and AD dementia.

Towards defining the neuropathological substrates of vascular dementia

Cerebrovascular disease is highly heterogeneous but can culminate in vascular cognitive impairment or vascular dementia (VaD). As much as the clinical diagnosis warrants scrutiny, the neuropathological substrates of VaD also need to be better defined. Atherosclerosis and small vessel disease are the main causes of brain infarction. Lacunar infarcts or multiple microinfarcts in the basal ganglia, thalamus, brainstem and white matter are associated with more than half of VaD cases consistent with subcortical ischaemic VaD. White matter changes including regions of incomplete infarction are usually widespread in VaD, but their contribution to impairment is not explicit. Other pathologies including hippocampal injury and Alzheimer type of lesions may also modify the course of dementia. Similar to other common dementias consensus criteria for VaD need unambiguous definition to impact on preventative and treatment strategies and are critical for selective recruitment to clinical trials.

Effect of vascular lesions on cognition in Alzheimer's disease: a community-based study

OBJECTIVES

To investigate whether clinical and neuropathological differences exist between Alzheimer's disease (AD) cases with and without vascular lesions neuropathologically diagnosed using Consortium to Establish a Registry for Alzheimer's Disease (CERAD) criteria.

DESIGN

Descriptive observational study.

SETTING

A community-based registry that identified incident dementia cases.

PARTICIPANTS

Of the 124 subjects with available clinical and neuropathological assessments, 30 had AD lesions alone, and 18 had AD with vascular lesions. Patients with other neuropathological findings were excluded.

MEASUREMENTS

Dependent measures included demographic, clinical, and neuropathological characteristics. Neuropathological diagnoses were made using the CERAD criteria and Braak and Braak staging.

RESULTS

Of the 124 autopsied cases, 85 cases were diagnosed with neuropathological AD. Of these, 30 had pathology consistent with "pure" AD, whereas 18 had AD pathology with significant vascular lesions (AD/V). There were no differences in age, sex, or education between groups. AD/V cases had higher baseline and final Mini-Mental State Examination (MMSE) scores than pure AD cases, but after adjusting for education, differences in MMSE scores were not statistically significant. The AD/V group had significantly lower Braak staging than the pure AD group, after adjusting for education and final MMSE scores.

CONCLUSION

In this comparison study of AD cases with and without vascular lesions, AD/V cases had less severe AD pathology than those with AD alone, indicating that cerebrovascular disease likely contributes to the severity of cognitive impairment in those with AD. Controlling for vascular risk factors in patients with AD may have a significant effect on severity of dementia.

Cortical Microinfarcts and Demyelination Significantly Affect Cognition in Brain Aging

Background and Purpose— Microvascular lesions are common in brain aging, but their clinical impact is debated. Methodological problems such as the masking effect of concomitant pathologies may explain discrepancies among previous studies. To evaluate the cognitive consequences of such lesions, we prospectively investigated elderly individuals with various degrees of cognitive impairment but without significant neurofibrillary tangle pathology or macrovascular lesions.

Methods— This was a clinicopathological study of 45 elderly individuals. Cognitive status was assessed prospectively with the Clinical Dementia Rating (CDR) scale; neuropathological evaluation included Aβ-protein deposition staging and bilateral semiquantitative assessment of cortical microinfarcts, focal cortical and white matter glioses, and diffuse white matter and periventricular demyelination.

Results— In a univariate logistic regression model, cortical microinfarcts explained 36.1% of the variability in CDR; periventricular demyelination, 10.6%; and diffuse white matter demyelination, 4.6%. After controlling for age and Aβ-protein deposition, cortical microinfarcts were the best predictor of cognitive status (19.9% of CDR variability), whereas periventricular and diffuse white matter demyelination accounted for 9.7% and 5.4% of CDR variability, respectively. Altogether, these 3 types of microvascular lesions explained 27.9% of the clinical variability. Focal cortical and white matter glioses were not related to clinical outcome.

Conclusions— Our data imply that cortical microinfarcts and both periventricular and deep white matter demyelination contribute significantly to the progression of cognitive deficits in brain aging. In contrast, the neuropathological evaluation of focal cortical and white matter gliosis has no clinical validity.

Psychiatric epidemiology of old age: the H70 study--the NAPE lecture 2003

OBJECTIVE

To describe methodological issues and possibilities in the epidemiology of old age psychiatry using data from the H70 study in Göteborg, Sweden.

METHOD

A representative sample born during 1901-02 was examined at 70, 75, 79, 81, 83, 85, 87, 90, 92, 95, 97, 99 and 100 years of age, another during 1906-07 was examined at 70 and 79 years of age, and samples born between 1922 and 1930 were examined at 70 years of age. The study includes psychiatric examinations and key informant interviews performed by psychiatrists, physical examinations performed by geriatricians, psychometric testings, blood sampling, computerized tomographies of the brain, cerebrospinal fluid analyses, anthropometric measurements, and psychosocial background factors.

RESULTS

Mental disorders are found in approximately 30% of the elderly, but is seldom detected or properly treated. Incidence of depression and dementia increases with age. The relationship between blood pressure and Alzheimer's disease is an example of how cross-sectional and longitudinal studies yield completely different results. Brain imaging is an important tool in epidemiologic studies of the elderly to detect silent cerebrovascular disease and other structural brain changes. The high prevalence of psychotic symptoms is an example of the importance to use several sources of information to detect these symptoms. Dementia should be diagnosed in all types of studies in the elderly, as it influences several outcomes such as mortality, blood pressure, and rates of depression. Suicidal feelings are rare in the elderly and are strongly related to mental disorders.

CONCLUSION

Modern epidemiologic studies in population samples should be longitudinal and include assessments of psychosocial risk factors as well as comprehensive sets of biologic markers, such as brain imaging, neurochemical analyses, and genetic information to maximize the contribution that epidemiology can provide to increase our knowledge about the etiology of mental disorders.

The prevalence of frontal variant frontotemporal dementia and the frontal lobe syndrome in a population based sample of 85 year olds

OBJECTIVES

To investigate the prevalence of the frontal lobe syndrome (FLS) and the frontal variant of frontotemporal dementia (fvFTD) in a population based sample of 85 year olds.

METHODS

A representative sample of 85 year olds (n = 451) in Gothenburg, Sweden was examined with a neuropsychiatric examination and a key informant interview performed by an experienced psychiatrist. A subsample underwent computed tomography (CT) of the head. The Lund-Manchester research criteria were used as a basis for a symptom algorithm to identify individuals with FLS and fvFTD. These were diagnosed blindly to the diagnosis of dementia according to DSM-III-R.

RESULTS

A total of 86 individuals (19%) fulfilled the criteria for FLS, and 14 of them fulfilled criteria for fvFTD. There were no differences between men and women. Among those with FLS, 75 (87%) fulfilled DSM-III-R criteria for other types of dementia, mainly Alzheimer's disease and vascular dementia. Among the 14 fvFTD cases, only five were demented according to DSM-III-R. Moderate to severe frontal atrophy was found in 93% of those with FLS (and in all cases with fvFTD), but also in 49% of those without FLS. FLS was found in 35% of those with moderate to severe frontal atrophy, and in 3% of those without these changes.

CONCLUSIONS

The prevalence of fvFTD was 3% in 85 year olds, which is higher than previously expected in this age group. Only a minority of those with fvFTD were detected by the DSM-III-R criteria for dementia. FLS was even more common, especially in those diagnosed with a dementia disorder.

Diagnosis and management of vascular cognitive impairment and dementia

Vascular dementias (VaDs) are the second most common cause of dementia. Cerebrovascular disease (CVD) and stroke relates to high risk of cognitive impairment, but also relate to Alzheimer's disease (AD): Vascular cognitive impairment (VCI) and dementias extend beyond the traditional multi-infarct dementia. Pathophysiology of VaD incorporates interactions between vascular etiologies (CVD and vascular risk-factors), changes in the brain (infarcts, white matter lesions, atrophy), host factors (age, education) and cognition. Variation in defining the cognitive syndrome, in vascular etiologies, and allowable brain changes in current criteria have resulted in variable estimates of prevalence, of groups of subjects, and of the types and distribution of putative causal brain lesions. Should new criteria be developed? Ideally in constructing new criteria the diagnostic elements should be tested with prospective studies with clinical-pathological correlation: replace dogma with data. Meanwhile focus on more homogenous subtypes of VaD, and on imaging criteria could be a solution. Subcortical ischemic vascular disease and dementia (SIVD) incorporate small vessel disease as the chief vascular etiology, lacunar infarct and ischaemic white matter lesions as primary type of brain lesions, subcortical location as the primary location of lesions, and subcortical syndrome as the primary clinical manifestation. It incorporates two clinical entities "Binswanger's disease" and "the lacunar state". AD with VaD (mixed dementia) has been underestimated as a prevalent cause in the older population. In addition to simple co-existence, VaD and AD have closer interaction: several vascular risk factors and vascular brain changes relate to clinical manifestation of AD, and they share also common pathogenetic mechanisms. Vascular cognitive impairment (VCI) is a category aiming to replace the "Alzhemerized" dementia concept in the setting of CVD, and substitute it with a spectrum that includes subtle cognitive deficits of vascular origin, post-stroke dementia, and the complex group of the vascular dementias. As far there is no standard treatment for VaDs, and still little is known on the primary prevention (brain at risk for CVD) and secondary prevention (CVD brain at risk for VCI/VaD). There is no standard symptomatic treatment for VaD. Recently symptomatic cholinergic treatment has shown promise in AD with VaD, as well as probable VaD. Future focus should be directed to the distinct etiological and pathological factors: the vascular and the AD burden of the brain.

Hypertension and cognitive function: pathophysiologic effects of hypertension on the brain

Accumulating evidence supports a causal role of hypertension for cognitive decline above and beyond its relationship to frank stroke. Hypertension-associated pathologic changes in the brain and its vasculature include vascular remodeling, impaired cerebral autoregulation, cerebral microbleeds, white matter lesions, unrecognized lacunar infarcts, and Alzheimer-like changes such as amyloid angiopathy and cerebral atrophy. White matter lesions and retinal vascular changes, both of which can be imaged noninvasively, may reveal the general condition of the cerebral vasculature or the presence of arteriosclerotic or hypertensive encephalopathy. These noninvasive indicators may also identify a subgroup in whom infarct prevention, particularly via blood pressure reduction, is of paramount importance. Optimal control of blood pressure on a population-wide basis, but particularly in those prone to cognitive loss, is thus a critically important but as yet elusive goal that should be fully exploited for its potential to reduce future cognitive impairment.

The role of neuroimaging in the diagnosis of vascular dementia

Vascular dementia (VaD) and Alzheimer's disease share many pathological and clinical characteristics. Whereas clinical criteria can help differentiate VaD from other types of dementia, neuroimaging is required for confirmation of vascular lesions. Neuroimaging also provides information about location and size of vascular lesions that can lead to a better understanding of symptoms and may help guide therapy.

Differences in the behavioral and psychological symptoms between Alzheimer's disease and vascular dementia: are the different pharmacologic treatment strategies justifiable?

BACKGROUND

This study aimed (1) to compare the behavioral and psychological symptoms of dementia (BPSD) between patients with Alzheimer's disease (AD) and vascular dementia (VaD); (2) to investigate the differences in the correlates of BPSD between them; and (3) to suggest potential different pharmacological strategies in treating BPSD of either etiology.

METHODS

In a study group of 135 patients with dementia (99 AD, 36 VaD), information on age, gender, education, age at onset and duration of dementia was collected. The severity of dementia was measured by the following assessment scales: Korean version of Mini-Mental State Examination (MMSE-K) for cognitive function; Blessed Dementia Scale (BDS) for functional activities of daily living (ADL); Barthel Index (BI) for physical ADL; and Brief Psychiatric Rating Scale (BPRS), Hamilton Depression Scale (HAM-D) and Hamilton Anxiety Scale (HAM-A) for BPSD. The independent variables between the patients with AD and VaD were compared, and then the correlations of BPSD with other variables were estimated.

RESULTS

HAM-D and HAM-A scores were higher in patients with VaD than in those with AD, while other variables demonstrated no statistical differences. BPRS score correlated with scores on MMSE-K, BDS and BI in AD, but only with BDS in VaD. The HAM-D score correlated with scores on BDS and BI in AD, but only with BDS in VaD. The HAM-A score was correlated with score on BDS in AD not in VaD.

CONCLUSIONS

BPSD were more severe in the patients with VaD. However, BPSD correlated more prominently with cognitive or ADL impairments in patients with AD. Different treatment approaches to BPSD may be required according to the clinical differentiation of dementia type.