PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (955590)

Clipboard (0)
None

Related Articles

1.  Imaging amyloid deposition in Lewy body diseases 
Neurology  2008;71(12):903-910.
Background:
Extrapyramidal motor symptoms precede dementia in Parkinson disease (PDD) by many years, whereas dementia occurs early in dementia with Lewy bodies (DLB). Despite this clinical distinction, the neuropsychological and neuropathologic features of these conditions overlap. In addition to widespread distribution of Lewy bodies, both diseases have variable burdens of neuritic plaques and neurofibrillary tangles characteristic of Alzheimer disease (AD).
Objectives:
To determine whether amyloid deposition, as assessed by PET imaging with the β-amyloid–binding compound Pittsburgh Compound B (PiB), can distinguish DLB from PDD, and to assess whether regional patterns of amyloid deposition correlate with specific motor or cognitive features.
Methods:
Eight DLB, 7 PDD, 11 Parkinson disease (PD), 15 AD, and 37 normal control (NC) subjects underwent PiB-PET imaging and neuropsychological assessment. Amyloid burden was quantified using the PiB distribution volume ratio.
Results:
Cortical amyloid burden was higher in the DLB group than in the PDD group, comparable to the AD group. Amyloid deposition in the PDD group was low, comparable to the PD and NC groups. Relative to global cortical retention, occipital PiB retention was lower in the AD group than in the other groups. For the DLB, PDD, and PD groups, amyloid deposition in the parietal (lateral and precuneus)/posterior cingulate region was related to visuospatial impairment. Striatal PiB retention in the DLB and PDD groups was associated with less impaired motor function.
Conclusions:
Global cortical amyloid burden is high in dementia with Lewy bodies (DLB) but low in Parkinson disease dementia. These data suggest that β-amyloid may contribute selectively to the cognitive impairment of DLB and may contribute to the timing of dementia relative to the motor signs of parkinsonism.
GLOSSARY
= Automated Anatomic Labeling;
= Alzheimer disease;
= Alzheimer’s Disease Research Center;
= American version of the National Adult Reading Test;
= analysis of covariance;
= Blessed Dementia Scale;
= cerebral amyloid angiopathy;
= Clinical Dementia Rating;
= Clinical Dementia Rating Sum of Boxes;
= dementia with Lewy bodies;
= distribution volume ratio;
= Cued Selective Reminding Test;
= Free Selective Reminding Test;
= Hoehn and Yahr;
= Massachusetts General Hospital;
= Mini-Mental State Examination;
= normal control;
= neurofibrillary tangle;
= Neuropsychiatric Inventory Questionnaire;
= not significant;
= Parkinson disease;
= Parkinson disease dementia;
= Pittsburgh Compound B;
= region of interest;
= Statistical Parametric Mapping;
= UK Parkinson’s Disease Society Brain Bank Research Center;
= United Parkinson’s Disease Rating Scale;
= Wechsler Adult Intelligence Scale–Revised.
doi:10.1212/01.wnl.0000326146.60732.d6
PMCID: PMC2637553  PMID: 18794492
2.  Imaging amyloid deposition in Lewy body diseases 
Neurology  2008;71(12):903-910.
Background
Extrapyramidal motor symptoms precede dementia in Parkinson disease (PDD) by many years, whereas dementia occurs early in dementia with Lewy bodies (DLB). Despite this clinical distinction, the neuropsychological and neuropathologic features of these conditions overlap. In addition to widespread distribution of Lewy bodies, both diseases have variable burdens of neuritic plaques and neurofibrillary tangles characteristic of Alzheimer disease (AD).
Objectives
To determine whether amyloid deposition, as assessed by PET imaging with the β-amyloid–binding compound Pittsburgh Compound B (PiB), can distinguish DLB from PDD, and to assess whether regional patterns of amyloid deposition correlate with specific motor or cognitive features.
Methods
Eight DLB, 7 PDD, 11 Parkinson disease (PD), 15 AD, and 37 normal control (NC) subjects underwent PiB-PET imaging and neuropsychological assessment. Amyloid burden was quantified using the PiB distribution volume ratio.
Results
Cortical amyloid burden was higher in the DLB group than in the PDD group, comparable to the AD group. Amyloid deposition in the PDD group was low, comparable to the PD and NC groups. Relative to global cortical retention, occipital PiB retention was lower in the AD group than in the other groups. For the DLB, PDD, and PD groups, amyloid deposition in the parietal (lateral and precuneus)/posterior cingulate region was related to visuospatial impairment. Striatal PiB retention in the DLB and PDD groups was associated with less impaired motor function.
Conclusions
Global cortical amyloid burden is high in dementia with Lewy bodies (DLB) but low in Parkinson disease dementia. These data suggest that β-amyloid may contribute selectively to the cognitive impairment of DLB and may contribute to the timing of dementia relative to the motor signs of parkinsonism.
doi:10.1212/01.wnl.0000326146.60732.d6
PMCID: PMC2637553  PMID: 18794492
3.  Brain amyloid and cognition in Lewy body diseases 
Background
Many patients with Parkinson disease (PD) develop dementia (PDD), a syndrome that overlaps clinically and pathologically with dementia with Lewy bodies (DLB); PDD and DLB differ chiefly in the relative timing of dementia and parkinsonism. Brain amyloid deposition is an early feature of DLB and may account in part for its early dementia. We sought to confirm this hypothesis and also to determine whether amyloid accumulation contributes to cognitive impairment and dementia in the broad range of parkinsonian diseases.
Methods
29 cognitively normal PD, 14 PD subjects with mild cognitive impairment (PD-MCI), 18 with DLB, 12 with PDD and 85 healthy control subjects (HCS) underwent standardized neurologic and neuropsychological examinations and PiB imaging with PET. Apolipoprotein (APOE) genotypes were obtained in many patients. PiB retention was expressed as the distribution volume ratio using a cerebellar tissue reference.
Results
PiB retention was significantly higher in DLB than in any of the other diagnostic groups. PiB retention did not differ across PDD, PD-MCI, PD, and HCS. Amyloid burden increased with age and with the presence of the APOEε4 allele in all patient groups. Only in the DLB group was amyloid deposition associated with impaired cognition.
Conclusions
DLB subjects have higher amyloid burden than subjects with PDD, PD-MCI, PD or HCS; amyloid deposits are linked to cognitive impairment only in DLB. Early amyloid deposits in DLB relative to PDD may account for their difference in the timing of dementia and parkinsonism.
doi:10.1002/mds.25048
PMCID: PMC3725259  PMID: 22693110
dementia; Lewy; Parkinson; amyloid; PiB
4.  Cognitively unimpaired HIV-positive subjects do not have increased 11C-PiB 
Neurology  2010;75(2):111-115.
Objectives:
Diagnostic challenges exist for differentiating HIV dementia from Alzheimer disease (AD) in older HIV-infected (HIV+) individuals. Similar abnormalities in brain amyloid-β42 (Αβ42) metabolism may be involved in HIV-associated neuropathology and AD. We evaluated the amyloid-binding agent 11C-Pittsburgh compound B (11C-PiB), a biomarker for Αβ42 deposition, in cognitively unimpaired HIV+ (n = 10) participants and matched community controls without dementia (n = 20).
Methods:
In this case-control study, all participants had an 11C-PiB scan within 2 years of concomitant CSF studies and neuropsychometric testing. Statistical differences between HIV+ and community controls for demographic and clinical values were assessed by χ2 tests. Participants were further divided into either low (<500 pg/mL) or normal (≥500 pg/mL) CSF Αβ42 groups with Student t tests performed to determine if regional differences in fibrillar amyloid plaque deposition varied with CSF Αβ42.
Results:
Regardless of CSF Αβ42 level, none of the HIV+ participants had fibrillar amyloid plaques as assessed by increased 11C-PiB mean cortical binding potential (MCBP) or binding potential within 4 cortical regions. In contrast, some community controls with low CSF Αβ42 (<500 pg/mL) had high 11C-PiB MCBP with elevated binding potentials (>0.18 arbitrary units) within cortical regions.
Conclusions:
Cognitively unimpaired HIV+ participants, even with low CSF Αβ42 (<500 pg/mL), do not have 11C-PiB parameters suggesting brain fibrillar amyloid deposition. The dissimilarity between unimpaired HIV+ and preclinical AD may reflect differences in Aβ42 production and/or formation of diffuse plaques. Future longitudinal studies of HIV+ participants with low CSF Aβ42 and normal 11C-PiB are required.
GLOSSARY
= amyloid-β42;
= Alzheimer disease;
= antiretroviral therapy;
= Clinical Dementia Rating;
= CNS Highly Activated Retroviral Therapy Effects Research;
= global deficit score;
= HIV-associated neurocognitive disorder;
= lumbar puncture;
= mean cortical binding potential;
= Pittsburgh compound B;
= region of interest;
= Washington University in St. Louis.
doi:10.1212/WNL.0b013e3181e7b66e
PMCID: PMC2905926  PMID: 20534887
5.  In vivo amyloid imaging in autopsy-confirmed Parkinson disease with dementia 
Neurology  2010;74(1):77-84.
Objective:
To investigate the specificity of in vivo amyloid imaging with [11C]–Pittsburgh Compound B (PIB) in Parkinson disease dementia (PDD).
Methods:
We performed detailed neuropathologic examination for 3 individuals with PDD who had PIB PET imaging within 15 months of death.
Results:
We observed elevated cortical uptake of [11C]-PIB on in vivo PET imaging in 2 of the 3 cases. At autopsy, all 3 individuals had abundant cortical Lewy bodies (Braak PD stage 6), and were classified as low-probability Alzheimer disease (AD) based on NIA-Reagan criteria. The 2 PIB-positive individuals had abundant diffuse Aβ plaques but only sparse neuritic plaques and intermediate neurofibrillary tangle pathology. The PIB-negative individual had rare diffuse plaques, no neuritic plaques, and low neurofibrillary tangle burden.
Conclusions:
[11C]–Pittsburgh Compound B (PIB) PET is specific for fibrillar Aβ molecular pathology but not for pathologic diagnosis of comorbid Alzheimer disease in individuals with Parkinson disease dementia. The ability to specifically identify fibrillar Aβ amyloid in the setting of α-synucleinopathy makes [11C]-PIB PET a valuable tool for prospectively evaluating how the presence of Aβ amyloid influences the clinical course of dementia in patients with Lewy body disorders.
GLOSSARY
= Alzheimer disease;
= binding potentials;
= Clinical Dementia Rating;
= dementia of the Alzheimer type;
= dementia with Lewy bodies;
= distribution volume;
= Mental State Examination;
= Neuropsychiatric Inventory Questionnaire;
= Parkinson disease dementia;
= Pittsburgh Compound B;
= Unified Parkinson's Disease Rating Scale.
doi:10.1212/WNL.0b013e3181c7da8e
PMCID: PMC2809026  PMID: 20038776
6.  Multimodality Imaging Characteristics of Dementia with Lewy Bodies 
Neurobiology of Aging  2011;33(9):2091-2105.
Dementia with Lewy bodies (DLB) is the second most common cause of neurodegenerative dementia after Alzheimer's disease (AD). Our objective was to determine whether the 11C–Pittsburgh Compound-B (PiB) retention and regional hypometabolism on PET and regional cortical atrophy on MRI are complementary in characterizing patients with DLB and differentiating them from AD. We studied age, gender and education matched patients with a clinical diagnosis of DLB (n=21), AD (n=21), and cognitively normal subjects (n=42). Hippocampal atrophy, global cortical PiB retention and occipital lobe metabolism in combination distinguished DLB from AD better than any of the measurements alone (area under the receiver operating characteristic=0.98).Five of the DLB and AD patients who underwent autopsy were distinguished through multimodality imaging. These data demonstrate that MRI and PiB PET contribute to characterizing the distinct pathological mechanisms in patients with AD compared to DLB. Occipital and posterior parietotemporal lobe hypometabolism is a distinguishing feature of DLB and this regional hypometabolic pattern is independent of the amyloid pathology.
doi:10.1016/j.neurobiolaging.2011.09.024
PMCID: PMC3288845  PMID: 22018896
Dementia with Lewy bodies; MRI; PET; FDG; PiB; Alzheimer's disease
7.  Early AD pathology in a [C-11]PiB-negative case: a PiB-amyloid imaging, biochemical, and immunohistochemical study 
Acta Neuropathologica  2012;123(3):433-447.
Amyloid-β (Aβ) deposits are detectable in the brain in vivo using positron emission tomography (PET) and [C-11]-labeled Pittsburgh Compound B ([C-11]PiB); however, the sensitivity of this technique is not well understood. In this study, we examined Aβ pathology in an individual who had clinical diagnoses of probable dementia with Lewy bodies and possible Alzheimer’s disease (AD) but with no detectable [C-11]PiB PET retention ([C-11]PiB(−)) when imaged 17 months prior to death. Brain samples were processed in parallel with region-matched samples from an individual with a clinical diagnosis of probable AD and a positive [C-11]PiB PET scan ([C-11]PiB(+)) when imaged 10 months prior to death. In the [C-11]PiB(−) case, Aβ plaques were sparse, occupying less than 2% cortical area, and were weakly labeled with 6-CN-PiB, a highly fluorescent derivative of PiB. In contrast, Aβ plaques occupied up to 12% cortical area in the [C-11]PiB(+) case, and were intensely labeled with 6-CN-PIB. The [C-11]PiB(−) case had low levels of [H-3]PiB binding (<100 pmol/g) and Aβ1–42 (<500 pmol/g) concentration except in the frontal cortex where Aβ1–42 values (788 pmol/g) approached cortical values in the [C-11]PiB(+) case (800–1,700 pmol/g). In several cortical regions of the [C-11]PiB(−) case, Aβ1–40 levels were within the range of cortical Aβ1–40 values in the [C-11]PiB(+) case. Antemortem [C-11]PiB DVR values correlated well with region-matched postmortem measures of Aβ1–42 and Aβ1–40 in the [C-11]PiB(+), and with Aβ1–42 only in the [C-11]PiB(−) case. The low ratios of [H-3]PiB binding levels to Aβ concentrations and 6-CN-PiB to Aβ plaque loads in the [C-11]PiB(−) case indicate that Aβ pathology in the brain may be associated with low or undetectable levels of [C-11]PiB retention. Studies in greater numbers of [C-11]PiB PET autopsy cases are needed to define the Aβ concentration and [H-3]PiB binding levels required to produce a positive [C-11]PiB PET signal.
doi:10.1007/s00401-012-0943-2
PMCID: PMC3383058  PMID: 22271153
Alzheimer’s disease; Brain amyloidosis; Pittsburgh Compound B; Plaques; Imaging
8.  PIB Imaging Predicts Progression from Cognitively Normal to Symptomatic Alzheimer’s Disease 
Archives of neurology  2009;66(12):1469-1475.
Objective
To determine whether preclinical Alzheimer’s disease (AD), as detected by the amyloid imaging agent Pittsburgh Compound B (PIB) in cognitively normal older adults, is associated with risk of symptomatic AD.
Design
A longitudinal cohort study of cognitively normal older adults assessed with positron emission tomography (PET) to determine the mean cortical binding potential for PIB and followed with annual clinical and cognitive assessments for progression to very mild dementia of the Alzheimer type (DAT).
Setting
Alzheimer’s Disease Research Center
Participants
One hundred and fifty-nine participants with mean age of 71.5 y in a longitudinal study of memory and aging had a PET PIB scan when cognitively normal with Clinical Dementia Rating (CDR) of 0.
Outcome Measure
Progression from CDR 0 status to CDR 0.5 (very mild dementia).
Results
Twenty-three participants progressed to CDR 0.5 at follow-up assessment (range: 1–5 assessments after PET PIB). Of these, 9 also were diagnosed with DAT. Higher MCBP values for PIB (hazard ratio 4.85, 95% CI, 1.22–19.01, p = .02) and age (hazard ratio 1.14, 95% CI 1.02–1.28, p = .03) predicted progression to CDR 0.5 DAT. The CDR 0.5 DAT group showed decline in three cognitive domains (episodic memory, semantic memory, and visuospatial performance) and had volume loss in the parahippocampal gyrus (includes entorhinal cortex) compared with individuals who remained CDR 0.
Conclusions
Preclinical AD, as detected by PET PIB, is not benign as it is associated with progression to symptomatic AD.
doi:10.1001/archneurol.2009.269
PMCID: PMC2798814  PMID: 20008650
9.  Alzheimer disease identification using amyloid imaging and reserve variables 
Neurology  2010;75(1):42-48.
Objective:
Several factors may influence the relationship between Alzheimer disease (AD) lesions and the expression of dementia, including those related to brain and cognitive reserve. Other factors may confound the association between AD pathology and dementia. We tested whether factors thought to influence the association of AD pathology and dementia help to accurately identify dementia of the Alzheimer type (DAT) when considered together with amyloid imaging.
Methods:
Participants with normal cognition (n = 180) and with DAT (n = 25), aged 50 years or older, took part in clinical, neurologic, and psychometric assessments. PET with the Pittsburgh compound B (PiB) tracer was used to measure brain amyloid, yielding a mean cortical binding potential (MCBP) reflecting PiB uptake. Logistic regression was used to generate receiver operating characteristic curves, and the areas under those curves (AUC), to compare the predictive accuracy of using MCBP alone vs MCBP together with other variables selected using a stepwise selection procedure to identify participants with DAT vs normal cognition.
Results:
The AUC resulting from MCBP alone was 0.84 (95% confidence interval [CI] = 0.73–0.94; cross-validated AUC = 0.80, 95% CI = 0.68–0.92). The AUC for the predictive equation generated by a stepwise model including education, normalized whole brain volume, physical health rating, gender, and use of medications that may interfere with cognition was 0.94 (95% CI = 0.90–0.98; cross-validated AUC = 0.91, 95% CI = 0.85–0.96), an improvement (p = 0.025) over that yielded using MCBP alone.
Conclusion:
Results suggest that factors reported to influence associations between AD pathology and dementia can improve the predictive accuracy of amyloid imaging for the identification of symptomatic AD.
GLOSSARY
β = amyloid-β;
= Alzheimer disease;
= area under receiver operating characteristic curve;
= binding potential;
= Clinical Dementia Rating;
= confidence interval;
= dementia of the Alzheimer type;
= distribution volume;
= mean cortical binding potential;
= normalized whole brain volume;
= odds ratio;
= Pittsburgh compound B;
= receiver operating characteristic curve;
= region of interest.
doi:10.1212/WNL.0b013e3181e620f4
PMCID: PMC2906402  PMID: 20603484
10.  Magnetic resonance spectroscopy, β-amyloid load, and cognition in a population-based sample of cognitively normal older adults 
Neurology  2011;77(10):951-958.
Objective:
To determine the relationship between proton magnetic resonance spectroscopy (1H MRS) metabolites and β-amyloid (Aβ) load and the effects of Aβ load on the association between 1H MRS metabolites and cognitive function in cognitively normal older adults.
Methods:
We studied 311 cognitively normal older adults who participated in the population-based Mayo Clinic Study of Aging from January 2009 through September 2010. Participants underwent 11C-Pittsburgh compound B (PiB) PET, 1H MRS from the posterior cingulate gyri, and neuropsychometric testing to assess memory, attention/executive, language, and visual-spatial domain functions within 6 months. Partial Spearman rank order correlations were adjusted for age, sex, and education.
Results:
Higher PiB retention was associated with abnormal elevations in myoinositol (mI)/creatine (Cr) (partial rs = 0.17; p = 0.003) and choline (Cho)/Cr (partial rs = 0.13; p = 0.022) ratios. Higher Cho/Cr was associated with worse performance on Auditory Verbal Learning Test Delayed Recall (partial rs = −0.12; p = 0.04), Trail Making Test Part B (partial rs = 0.12; p = 0.04), Wechsler Adult Intelligence Scale–Revised (WAIS-R) Digit Symbol (partial rs = −0.18; p < 0.01), and WAIS-R Block Design (partial rs = −0.12; p = 0.03). Associations between 1H MRS metabolites and cognitive function were not different among participants with high vs low PiB retention.
Conclusion:
In cognitively normal older adults, the 1H MRS metabolite ratios mI/Cr and Cho/Cr are associated with the preclinical pathologic processes in the Alzheimer disease cascade. Higher Cho/Cr is associated with worse performance on domain-specific cognitive tests independent of Aβ load, suggesting that Cho/Cr elevation may also be dependent on other preclinical dementia pathologies characterized by Cho/Cr elevation such as Lewy body or ischemic vascular disease in addition to Aβ load. Neurology® 2011;77:951–958
doi:10.1212/WNL.0b013e31822dc7e1
PMCID: PMC3171960  PMID: 21865577
11.  Resting bold fMRI differentiates dementia with Lewy bodies vs Alzheimer disease 
Neurology  2011;76(21):1797-1803.
Objective:
Clinicopathologic phenotypes of dementia with Lewy bodies (DLB) and Alzheimer disease (AD) often overlap, making discrimination difficult. We performed resting state blood oxygen level–dependent (BOLD) functional connectivity MRI (fcMRI) to determine whether there were differences between AD and DLB.
Methods:
Participants (n = 88) enrolled in a longitudinal study of memory and aging underwent 3-T fcMRI. Clinical diagnoses of probable DLB (n = 15) were made according to published criteria. Cognitively normal control participants (n = 38) were selected for the absence of cerebral amyloid burden as imaged with Pittsburgh compound B (PiB). Probable AD cases (n = 35) met published criteria and had appreciable amyloid deposits with PiB imaging. Functional images were collected using a gradient spin-echo sequence sensitive to BOLD contrast (T2* weighting). Correlation maps selected a seed region in the combined bilateral precuneus.
Results:
Participants with DLB had a functional connectivity pattern for the precuneus seed region that was distinct from AD; both the DLB and AD groups had functional connectivity patterns that differed from the cognitively normal group. In the DLB group, we found increased connectivity between the precuneus and regions in the dorsal attention network and the putamen. In contrast, we found decreased connectivity between the precuneus and other task-negative default regions and visual cortices. There was also a reversal of connectivity in the right hippocampus.
Conclusions:
Changes in functional connectivity in DLB indicate patterns of activation that are distinct from those seen in AD and may improve discrimination of DLB from AD and cognitively normal individuals. Since patterns of connectivity differ between AD and DLB groups, measurements of BOLD functional connectivity can shed further light on neuroanatomic connections that distinguish DLB from AD.
doi:10.1212/WNL.0b013e31821ccc83
PMCID: PMC3100121  PMID: 21525427
12.  Epidemiological Pathology of Dementia: Attributable-Risks at Death in the Medical Research Council Cognitive Function and Ageing Study 
PLoS Medicine  2009;6(11):e1000180.
Researchers from the Medical Research Council Cognitive Function and Ageing Neuropathology Study carry out an analysis of brain pathologies contributing to dementia, within a cohort of elderly individuals in the UK who agreed to brain donation.
Background
Dementia drug development aims to modulate pathological processes that cause clinical syndromes. Population data (epidemiological neuropathology) will help to model and predict the potential impact of such therapies on dementia burden in older people. Presently this can only be explored through post mortem findings. We report the attributable risks (ARs) for dementia at death for common age-related degenerative and vascular pathologies, and other factors, in the MRC Cognitive Function and Ageing Study (MRC CFAS).
Methods and Findings
A multicentre, prospective, longitudinal study of older people in the UK was linked to a brain donation programme. Neuropathology of 456 consecutive brain donations assessed degenerative and vascular pathologies. Logistic regression modelling, with bootstrapping and sensitivity analyses, was used to estimate AR at death for dementia for specific pathologies and other factors. The main contributors to AR at death for dementia in MRC CFAS were age (18%), small brain (12%), neocortical neuritic plaques (8%) and neurofibrillary tangles (11%), small vessel disease (12%), multiple vascular pathologies (9%), and hippocampal atrophy (10%). Other significant factors include cerebral amyloid angiopathy (7%) and Lewy bodies (3%).
Conclusions
Such AR estimates cannot be derived from the living population; rather they estimate the relative contribution of specific pathologies to dementia at death. We found that multiple pathologies determine the overall burden of dementia. The impact of therapy targeted to a specific pathology may be profound when the dementia is relatively “pure,” but may be less impressive for the majority with mixed disease, and in terms of the population. These data justify a range of strategies, and combination therapies, to combat the degenerative and vascular determinants of cognitive decline and dementia.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Losing one's belongings and forgetting people's names is often a normal part of aging. But increasing forgetfulness can also be a sign of dementia, a group of symptoms caused by several disorders that affect the structure of the brain. The commonest form of dementia is Alzheimer disease. In this, protein clumps called plaques and neurofibrillary tangles form in the brain and cause its degeneration. Vascular dementia, in which problems with blood circulation deprive parts of the brain of oxygen, is also common. People with dementia have problems with two or more “cognitive” functions—thinking, language, memory, understanding, and judgment. As the disease progresses, they gradually lose their ability to deal with normal daily activities until they need total care, their personality often changes, and they may become agitated or aggressive. Dementia is rare before the age of 65 years but about a quarter of people over 85 years old have dementia. Because more people live to a ripe old age these days, the number of people with dementia is increasing. According to the latest estimates, about 35 million people now have dementia and by 2050, 115 million may have the disorder.
Why Was This Study Done?
There is no cure for dementia but many drugs designed to modulate specific abnormal (pathological) changes in the brain that can cause the symptoms of dementia are being developed. To assess the likely impact of these potentially expensive new therapies, experts need to know what proportion of dementia is associated with each type of brain pathology. Although some brain changes can be detected in living brains with techniques such as computed tomography brain scans, most brain changes can only be studied in brains taken from people after death (post mortem brains). In this study, which is part of the UK Medical Research Council Cognitive Function and Ageing Study (MRC CFAS), the researchers look for associations between dementia in elderly people and pathological changes in their post mortem brains and estimate the attributable-risk (AR) for dementia at death associated with specific pathological features in the brain. That is, they estimate the proportion of dementia directly attributable to each type of pathology.
What Did the Researchers Do and Find?
Nearly 20 years ago, the MRC CFAS interviewed more than 18,000 people aged 65 years or older recruited at six sites in England and Wales to determine their cognitive function and their ability to deal with daily activities. 20% of the participants, which included people with and without cognitive impairment, were then assessed in more detail and invited to donate their brains for post mortem examination. As of 2004, 456 individuals had donated their brains. The dementia status of these donors was established using data from their assessment interviews and death certificates, and from interviews with relatives and carers, and their brains were carefully examined for abnormal changes. The researchers then used statistical methods to estimate the AR for dementia at death associated with various abnormal brain changes. The main contributors to AR for dementia at death included age (18% of dementia at death was attributable to this factor), plaques (8%), and neurofibrillary tangles (11%) in a brain region called the neocortex, small blood vessel disease (12%), and multiple abnormal changes in blood vessels (9%).
What Do These Findings Mean?
These findings suggest that multiple abnormal brain changes determine the overall burden of dementia. Importantly, they also suggest that dementia is often associated with mixed pathological changes—many people with dementia had brain changes consistent with both Alzheimer disease and vascular dementia. Because people with dementia live for variable lengths of time during which the abnormal changes in their brain are likely to alter, it may be difficult to extrapolate these findings to living populations of elderly people. Furthermore, only a small percentage of the MRC CFAS participants have donated their brains so the findings of this study may not apply to the general population. Nevertheless, these findings suggest that the new therapies currently under development may do little to reduce the overall burden of dementia because most people's dementia involves multiple pathologies. Consequently, it may be necessary to develop a range of strategies and combination therapies to deal with the ongoing dementia epidemic.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000180.
The US National Institute on Aging provides information for patients and carers about forgetfulness and about Alzheimer disease (in English and Spanish)
The US National Institute of Neurological Disorders and Stroke provides information about dementia (in English and Spanish)
The UK National Health Service Choices Web site also provides detailed information for patients and their carers about dementia and about Alzheimer disease
MedlinePlus provides links to additional resources about dementia and Alzheimer disease (in English and Spanish)
More information about the UK Medical Research Council Cognitive Function and Ageing Study (MRC CFAS) is available
doi:10.1371/journal.pmed.1000180
PMCID: PMC2765638  PMID: 19901977
13.  Antemortem amyloid imaging and β-amyloid pathology in a case with dementia with Lewy Bodies 
Neurobiology of Aging  2010;33(5):878-885.
The association between antemortem [11C]-Pittsburgh Compound B (PiB) retention and β-amyloid (Aβ) load, Lewy body (LB) and neurofibrillary tangle (NFT) densities were investigated in a pathologically confirmed case of dementia with LB (DLB). 76-year-old man presenting with a clinical diagnosis of DLB had undergone PiB–positron emission tomography (PET), 18F FDG-PET and MRI 18 months before death. The pathologic diagnosis was DLB neocortical-type with low-likelihood of Alzheimer's disease by NIA-Reagan criteria. Sections from regions of interest (ROI) on post-mortem examination were studied. A significant correlation was found between cortical Aβ density and PiB retention in the 17 corresponding ROIs (r=0.899; p<0.0001). Bielschowsky silver stain revealed mostly sparse neocortical neuritic plaques; whereas diffuse plaques were frequent. There was no correlation between LB density and PiB retention (r=0.13; p=0.66); nor between NFT density and PiB retention (r=−0.36; p=0.17). The ROI-based analysis of imaging and histopathological data confirms that PiB uptake on PET is a specific marker for Aβ density, but cannot differentiate neuritic from diffuse amyloid plaques in this case with DLB.
doi:10.1016/j.neurobiolaging.2010.08.007
PMCID: PMC3026854  PMID: 20961664
Dementia with Lewy bodies; amyloid imaging; PET; pathology; amyloid
14.  HIV Associated Neurocognitive Disorder (HAND) is Not Associated with Increased Fibrillar Amyloid Deposits Using 11C-PiB in Middle-Aged HIV+ Participants 
Archives of neurology  2012;69(1):72-77.
Objectives
Diagnostic challenges exist for differentiating HIV associated neurocognitive disorders (HAND) from symptomatic Alzheimer’s disease (AD) in HIV+ participants. Both disorders have cerebral amyloid containing plaques associated with abnormalities in amyloid beta protein 1–42 (Aβ42) metabolism. We evaluated if the amyloid-binding agent 11C-Pittsburgh compound B (11C-PiB) could discriminate AD from HAND in middle-aged HIV+ participants.
Design
11C-PiB scanning, clinical assessment, and cerebrospinal fluid (CSF) analysis were performed. χ2 and t-tests assessed differences in clinical and demographic variables between HIV+ participants and community-living individuals followed by Alzheimer Disease Research Center (ADRC). An analysis of variance (ANOVA) assessed for regional differences in Aβ42 using 11C-PiB.
Setting
ADRC and HIV clinic
Participants
16 HIV+ participants (11 cognitively normal, 5 with HAND) and 19 ADRC participants (8 cognitively normal, 11 with symptomatic AD).
Main Outcome Measure(s)
Mean and regional 11C-PiB binding potentials
Results
Symptomatic AD were older (p < 0.001), had lower CSF Aβ42 (p < 0.001), and had higher CSF tau levels (p < 0.001) than other groups. Regardless of degree of impairment, HIV+ participants did not have increased 11C-PiB. Mean and regional binding potentials were elevated for symptomatic AD participants (p <0.0001).
Conclusions
Middle-aged HIV+ participants, even with HAND, do not exhibit increased 11C-PiB while symptomatic AD individuals have increased fibrillar Aβ42 deposition in cortical and subcortical regions. Observed dissimilarities between HAND and AD may reflect differences in Aβ42 metabolism. 11C-PiB may provide a diagnostic biomarker for distinguishing symptomatic AD from HAND in middle-aged HIV+ participants. Future cross sectional and longitudinal studies are required to assess utility of 11C-PiB in older HAND individuals.
doi:10.1001/archneurol.2011.761
PMCID: PMC3536500  PMID: 22232345
HIV; Pittsburgh compound B (PIB); amyloid; HIV associated neurocognitive disorders; Alzheimer’s disease
15.  Mild cognitive impairment associated with limbic and neocortical lewy body disease: a clinicopathological study 
Brain  2009;133(2):540-556.
There are little data on the relationship between Lewy body disease and mild cognitive impairment syndromes. The Mayo Clinic aging and dementia databases in Rochester, Minnesota, and Jacksonville, Florida were queried for cases who were diagnosed with mild cognitive impairment between 1 January 1996 and 30 April 2008, were prospectively followed and were subsequently found to have autopsy-proven Lewy body disease. The presence of rapid eye movement sleep behaviour disorder was specifically assessed. Mild cognitive impairment subtypes were determined by clinical impression and neuropsychological profiles, based on prospective operational criteria. The diagnosis of clinically probable dementia with Lewy bodies was based on the 2005 McKeith criteria. Hippocampal volumes, rate of hippocampal atrophy, and proton magnetic resonance spectroscopy were assessed on available magnetic resonance imaging and spectroscopy scans. Eight subjects were identified; six were male. Seven developed dementia with Lewy bodies prior to death; one died characterized as mild cognitive impairment. The number of cases and median age of onset (range) for specific features were: seven with rapid eye movement sleep behaviour disorder—60 years (27–91 years), eight with cognitive symptoms—69 years (62–89 years), eight with mild cognitive impairment—70.5 years (66–91 years), eight with parkinsonism symptoms—71 years (66–92 years), six with visual hallucinations—72 years (64–90 years), seven with dementia—75 years (67–92 years), six with fluctuations in cognition and/or arousal—76 years (68–92 years) and eight dead—76 years (71–94 years). Rapid eye movement sleep behaviour disorder preceded cognitive symptom onset in six cases by a median of 10 years (2–47 years) and mild cognitive impairment diagnosis by a median of 12 years (3–48 years). The mild cognitive impairment subtypes represented include: two with single domain non-amnestic mild cognitive impairment, three with multi-domain non-amnestic mild cognitive impairment, and three with multi-domain amnestic mild cognitive impairment. The cognitive domains most frequently affected were attention and executive functioning, and visuospatial functioning. Hippocampal volumes and the rate of hippocampal atrophy were, on average, within the normal range in the three cases who underwent magnetic resonance imaging, and the choline/creatine ratio was elevated in the two cases who underwent proton magnetic resonance spectroscopy when they were diagnosed as mild cognitive impairment. On autopsy, six had neocortical-predominant Lewy body disease and two had limbic-predominant Lewy body disease; only one had coexisting high-likelihood Alzheimer's disease. These findings indicate that among Lewy body disease cases that pass through a mild cognitive impairment stage, any cognitive pattern or mild cognitive subtype is possible, with the attention/executive and visuospatial domains most frequently impaired. Hippocampal volume and proton magnetic resonance spectroscopy data were consistent with recent data in dementia with Lewy bodies. All cases with rapid eye movement sleep behaviour disorder and mild cognitive impairment were eventually shown to have autopsy-proven Lewy body disease, indicating that rapid eye movement sleep behaviour disorder plus mild cognitive impairment probably reflects brainstem and cerebral Lewy body disease.
doi:10.1093/brain/awp280
PMCID: PMC2822633  PMID: 19889717
mild cognitive impairment; dementia; dementia with Lewy bodies; Lewy body disease; neuropathology
16.  Performance on the dementia rating scale in Parkinson's disease with dementia and dementia with Lewy bodies: comparison with progressive supranuclear palsy and Alzheimer's disease 
Background: The relation between dementia with Lewy bodies (DLB) and Parkinson's disease with dementia (PDD) is unknown.
Objectives: To compare the cognitive profiles of patients with DLB and PDD, and compare those with the performance of patients with a subcortical dementia (progressive supranuclear palsy) and a cortical dementia (Alzheimer's disease).
Design: Survey of cognitive features.
Setting: General community in Rogaland county, Norway, and a university dementia and movement disorder research centre in the USA.
Patients: 60 patients with DLB, 35 with PDD, 49 with progressive supranuclear palsy, and 29 with Alzheimer's disease, diagnosed by either standardised clinical procedures and criteria (all PDD and Alzheimer cases and 76% of cases of progressive supranuclear palsy), or necropsy (all DLB cases and 24% of cases of progressive supranuclear palsy). Level of dementia severity was matched using the total score on the dementia rating scale adjusted for age and education.
Main outcome measures: Dementia rating scale subscores corrected for age.
Results: No significant differences between the dementia rating scale subscores in the PDD and DLB groups were found in the severely demented patients; in patients with mild to moderate dementia the conceptualisation subscore was higher in PDD than in DLB (p = 0.03). Compared with Alzheimer's disease, PDD and DLB had higher memory subscores (p < 0.001) but lower initiation and perseveration (p = 0.008 and p=0.021) and construction subscores (p = 0.009 and p = 0.001). DLB patients had a lower conceptualisation subscore (p = 0.004). Compared with progressive supranuclear palsy, PDD and DLB patients had lower memory subscores (p < 0.001).
Conclusions: The cognitive profiles of patients with DLB and PDD were similar, but they differed from those of patients with Alzheimer's disease and progressive supranuclear palsy. The cognitive pattern in DLB and PDD probably reflects the superimposition of subcortical deficits upon deficits typically associated with Alzheimer's disease.
doi:10.1136/jnnp.74.9.1215
PMCID: PMC1738667  PMID: 12933921
17.  PET imaging of amyloid with Florbetapir F 18 and PET imaging of dopamine degeneration with 18F-AV-133 (florbenazine) in patients with Alzheimer’s disease and Lewy body disorders 
BMC Neurology  2014;14:79.
Background
Biomarkers based on the underlying pathology of Alzheimer’s disease (AD) and Dementia with Lewy Bodies (DLB) have the potential to improve diagnosis and understanding of the substrate for cognitive impairment in these disorders. The objective of this study was to compare the patterns of amyloid and dopamine PET imaging in patients with AD, DLB and Parkinson’s disease (PD) using the amyloid imaging agent florbetapir F 18 and 18F-AV-133 (florbenazine), a marker for vesicular monamine type 2 transporters (VMAT2).
Methods
Patients with DLB and AD, Parkinson’s disease (PD) and healthy controls (HC) were recruited for this study. On separate days, subjects received intravenous injections of florbetapir, and florbenazine. Amyloid burden and VMAT2 density were assessed quantitatively and by binary clinical interpretation. Imaging results for both tracers were compared across the four individual diagnostic groups and for combined groups based on underlying pathology (AD/DLB vs. PD/HC for amyloid burden and PD/DLB vs. AD/HC for VMAT binding) and correlated with measures of cognition and parkinsonism.
Results
11 DLB, 10 AD, 5 PD, and 5 controls participated in the study. Amyloid binding was significantly higher in the combined AD/DLB patient group (n = 21) compared to the PD/HC groups (n = 10, mean SUVr: 1.42 vs. 1.07; p = 0.0006). VMAT2 density was significantly lower in the PD/DLB group (n = 16) compared to the AD/ HC group (n = 15; 1.83 vs. 2.97; p < 0.0001). Within the DLB group, there was a significant correlation between cognitive performance and striatal florbenazine binding (r = 0.73; p = 0.011).
Conclusions
The results of this study show significant differences in both florbetapir and florbenazine imaging that are consistent with expected pathology. In addition, VMAT density correlated significantly with cognitive impairment in DLB patients (ClinicalTrials.gov identifier: NCT00857506, registered March 5, 2009).
doi:10.1186/1471-2377-14-79
PMCID: PMC4027995  PMID: 24716655
PET imaging; Alzheimer’s disease; Parkinson’s disease; Biomarkers
18.  The Aging Brain and Cognition 
JAMA neurology  2013;70(4):488-495.
Importance
β-Amyloid (Aβ) deposition and vascular brain injury (VBI) frequently co-occur and are both associated with cognitive decline in aging. Determining whether a direct relationship exists between them has been challenging. We sought to understand VBI’s influence on cognition and clinical impairment, separate from and in conjunction with pathologic changes associated with Alzheimer disease (AD).
Objective
To examine the relationship between neuroimaging measures of VBI and brain Aβ deposition and their associations with cognition.
Design and Setting
A cross-sectional study in a community- and clinic-based sample recruited for elevated vascular disease risk factors.
Participants
Clinically normal (mean age, 77.1 years [N=30]), cognitively impaired (mean age, 78.0 years [N=24]), and mildly demented (mean age, 79.8 years [N=7]) participants.
Interventions
Magnetic resonance imaging, Aβ (Pitts-burgh Compound B–positron emission tomographic [PiB-PET]) imaging, and cognitive testing.
Main Outcome Measures
Magnetic resonance images were rated for the presence and location of infarct (34 infarct-positive participants, 27 infarct-negative participants) and were used to quantify white matter lesion volume. The PiB-PET uptake ratios were used to create a PiB index by averaging uptake across regions vulnerable to early Aβ deposition; PiB positivity (29 PiB-positive participants, 32 PiB-negative participants) was determined from a data-derived threshold. Standardized composite cognitive measures included executive function and verbal and nonverbal memory.
Results
Vascular brain injury and Aβ were independent in both cognitively normal and impaired participants. Infarction, particularly in cortical and subcortical gray matter, was associated with lower cognitive performance in all domains (P<.05 for all comparisons). Pittsburgh Compound B positivity was neither a significant predictor of cognition nor interacted with VBI.
Conclusions and Relevance
In this elderly sample with normal cognition to mild dementia, enriched for vascular disease, VBI was more influential than Aβ in contemporaneous cognitive function and remained predictive after including the possible influence of Aβ. There was no evidence that VBI increases the likelihood of Aβ deposition. This finding highlights the importance of VBI in mild cognitive impairment and suggests that the impact of cerebrovascular disease should be considered with respect to defining the etiology of mild cognitive impairment.
doi:10.1001/2013.jamaneurol.405
PMCID: PMC3771392  PMID: 23400560
19.  REM sleep behavior disorder preceding other aspects of synucleinopathies by up to half a century(e–Pub ahead of print)(CME) 
Neurology  2010;75(6):494-499.
Background:
Idiopathic REM sleep behavior disorder (RBD) may be the initial manifestation of synucleinopathies (Parkinson disease [PD], multiple system atrophy [MSA], or dementia with Lewy bodies [DLB]).
Methods:
We used the Mayo medical records linkage system to identify cases presenting from 2002 to 2006 meeting the criteria of idiopathic RBD at onset, plus at least 15 years between RBD and development of other neurodegenerative symptoms. All patients underwent evaluations by specialists in sleep medicine to confirm RBD, and behavioral neurology or movement disorders to confirm the subsequent neurodegenerative syndrome.
Results:
Clinical criteria were met by 27 patients who experienced isolated RBD for at least 15 years before evolving into PD, PD dementia (PDD), DLB, or MSA. The interval between RBD and subsequent neurologic syndrome ranged up to 50 years, with the median interval 25 years. At initial presentation, primary motor symptoms occurred in 13 patients: 9 with PD, 3 with PD and mild cognitive impairment (MCI), and 1 with PDD. Primary cognitive symptoms occurred in 13 patients: 10 with probable DLB and 3 with MCI. One patient presented with primary autonomic symptoms, diagnosed as MSA. At most recent follow-up, 63% of patients progressed to develop dementia (PDD or DLB). Concomitant autonomic dysfunction was confirmed in 74% of all patients.
Conclusions:
These cases illustrate that the α-synuclein pathogenic process may start decades before the first symptoms of PD, DLB, or MSA. A long-duration preclinical phase has important implications for epidemiologic studies and future interventions designed to slow or halt the neurodegenerative process.
GLOSSARY
= dementia with Lewy bodies;
= mild cognitive impairment;
= multiple system atrophy;
= Parkinson disease;
= PD with associated mild cognitive impairment;
= Parkinson disease dementia;
= polysomnogram;
= REM sleep behavior disorder.
doi:10.1212/WNL.0b013e3181ec7fac
PMCID: PMC2918473  PMID: 20668263
20.  Dementia with Lewy bodies and Alzheimer disease 
Neurology  2010;74(22):1814-1821.
Objective:
To identify the patterns of diffusivity changes in patients with dementia with Lewy bodies (DLB) and Alzheimer disease (AD) and to determine whether diffusion tensor MRI (DTI) is complementary to structural MRI in depicting the tissue abnormalities characteristic of DLB and AD.
Methods:
We studied clinically diagnosed age-, gender-, and education-matched subjects with DLB (n = 30), subjects with AD (n = 30), and cognitively normal (CN) subjects (n = 60) in a case-control study. DTI was performed at 3T with a fluid-attenuated inversion recovery–based DTI sequence that enabled cortical diffusion measurements. Mean diffusivity (MD) and gray matter (GM) density were measured from segmented cortical regions. Tract-based diffusivity was measured using color-coded fractional anisotropy (FA) maps.
Results:
Patients with DLB were characterized by elevated MD in the amygdala and decreased FA in the inferior longitudinal fasciculus (ILF). ILF diffusivity was associated with the presence of visual hallucinations (p = 0.007), and amygdala diffusivity was associated with Unified Parkinson's Disease Rating Scale (r = 0.50; p = 0.005) in DLB. In contrast, patients with AD were characterized by elevated MD in the medial temporal, temporal, and parietal lobe association cortices and decreased FA in the fornix, cingulum, and ILF. Amygdala diffusivity was complementary to GM density in discriminating DLB from CN; hippocampal and parahippocampal diffusivity was complementary to GM density in discriminating AD from CN.
Conclusion:
Increased amygdalar diffusivity in the absence of tissue loss in dementia with Lewy bodies (DLB) may be related to microvacuolation, a common pathology associated with Lewy body disease in the amygdala. Diffusivity measurements were complementary to structural MRI, demonstrating that measures of diffusivity on diffusion tensor MRI are valuable tools for characterizing the tissue abnormalities characteristic of Alzheimer disease and DLB.
GLOSSARY
= Alzheimer disease;
= cognitively normal;
= dementia with Lewy bodies;
= diffusion tensor MRI;
= fractional anisotropy;
= false discovery rate;
= fluid-attenuated inversion recovery;
= gray matter;
= inferior longitudinal fasciculus;
= Lewy body;
= mean diffusivity;
= REM sleep behavior disorder;
= region of interest;
= superior longitudinal fasciculus;
= echo time;
= inversion time;
= repetition time;
= Unified Parkinson's Disease Rating Scale;
= white matter.
doi:10.1212/WNL.0b013e3181e0f7cf
PMCID: PMC2882217  PMID: 20513818
21.  Relative preservation of MMSE scores in autopsy-proven dementia with Lewy bodies 
Neurology  2009;73(14):1127-1133.
Background:
Recent studies raised questions about the severity of cognitive impairment associated with dementia with Lewy bodies (DLB). However, there have been few analyses of large, multicenter data registries for clinical–pathologic correlation.
Methods:
We evaluated data from the National Alzheimer's Coordinating Center registry (n = 5,813 cases meeting initial inclusion criteria) and the University of Kentucky Alzheimer's Disease Center autopsy series (n = 527) to compare quantitatively the severity of cognitive impairment associated with DLB pathology vs Alzheimer disease (AD) and AD+DLB pathologies.
Results:
Mini-Mental State Examination (MMSE) scores showed that persons with pure DLB had cognitive impairment of relatively moderate severity (final MMSE score 15.6 ± 8.7) compared to patients with pure AD and AD+DLB (final MMSE score 10.7 ± 8.6 and 10.6 ± 8.6). Persons with pure DLB pathology from both data sets had more years of formal education and were more likely to be male. Differences in final MMSE scores were significant (p < 0.01) between pure DLB and both AD+DLB and pure AD even after correction for education level, gender, and MMSE–death interval. Even in cases with extensive neocortical LBs, the degree of cognitive impairment was most strongly related to the amount of concomitant AD-type neurofibrillary pathology.
Conclusions:
Dementia with Lewy bodies can constitute a debilitating disease with associated psychiatric, motoric, and autonomic dysfunction. However, neocortical Lewy bodies are not a substrate for severe global cognitive impairment as assessed by the Mini-Mental State Examination. Instead, neocortical Lewy bodies appear to constitute or reflect an additive disease process, requiring Alzheimer disease or other concomitant brain diseases to induce severe global cognitive deterioration.
GLOSSARY
= Alzheimer disease;
= AD Center;
= Consortium to Establish a Registry for Alzheimer's Disease;
= dementia with Lewy bodies;
= Lewy bodies;
= Mini-Mental State Examination;
= National Alzheimer's Coordinating Center;
= neurofibrillary;
= National Institute of Aging-Reagan Institute;
= University of Kentucky Alzheimer's Disease Center.
doi:10.1212/WNL.0b013e3181bacf9e
PMCID: PMC2764396  PMID: 19805729
22.  Relation of neuropathology with cognitive decline among older persons without dementia 
Objective: Although it is now widely accepted that dementia has a long preclinical phase during which neuropathology accumulates and cognition declines, little is known about the relation of neuropathology with the longitudinal rate of change in cognition among older persons without dementia. We quantified the burden of the neuropathologies of the three most common causes of dementia [i.e., Alzheimer’s disease (AD), cerebrovascular disease (CVD), and Lewy body disease (LBD)] and examined their relation with cognitive decline in a large cohort of persons without dementia proximate to death.
Methods: A total of 467 deceased participants without dementia from two longitudinal clinical-pathologic studies, Rush Memory and Aging Project and Religious Orders Study, completed a mean of 7 annual evaluations including 17 cognitive tests. Neuropathologic examinations provided quantitative measures of AD (i.e., amyloid load, tangle density), CVD (i.e., macroscopic infarcts, microinfarcts), and neocortical Lewy bodies. Random coefficient models were used to examine the relation of the neuropathologies with rates of global cognitive decline as well as decline in four specific cognitive systems.
Results: At autopsy, 82% of persons without dementia had amyloid, 100% had tangles, 29% had macroscopic infarcts, 25% had microinfarcts, and 6% had neocortical Lewy bodies. Global cognition declined a mean of 0.034 unit per year (SE = 0.003, p < 0.001). In separate analyses, amyloid, tangles (p-values <0.001) and neocortical Lewy bodies (p = 0.015) were associated with an increased rate of global cognitive decline; macroscopic infarcts and microinfarcts were not. Further, when analyzed simultaneously, amyloid, tangles, and neocortical Lewy bodies remained associated with global cognitive decline (p-values <0.024). Finally, measures of AD were associated with decline in three of four systems, including episodic memory (i.e., tangles), semantic memory (i.e., amyloid and tangles), and working memory (i.e., amyloid). Lewy bodies also were associated with decline in three of four systems (i.e., semantic memory, working memory, and perceptual speed).
Interpretation: The neuropathologies of the common causes of dementia, particularly AD and neocortical LBD, are associated with decline in multiple cognitive abilities among older persons without dementia.
doi:10.3389/fnagi.2013.00050
PMCID: PMC3766823  PMID: 24058343
cognitive aging; Alzheimer’s disease; neuropathology; vascular disease; Lewy bodies
23.  Dementia with Lewy Bodies versus Alzheimer's Disease and Parkinson's Disease Dementia: A Comparison of Cognitive Profiles 
Background and Purpose
It is particularly difficult to differentiate dementia with Lewy bodies (DLB) from the related dementias of Alzheimer's disease (AD) and Parkinson's disease dementia (PDD). Few studies have been designed to comparatively analyze detailed neuropsychological assessments of DLB patients and patients with AD and PDD.
Methods
Three groups of patients participated in this study: 10 with DLB, 76 with AD, and 17 with PDD, who had been diagnosed as probable DLB, AD, and PDD, respectively, according to the clinical criteria of the consortium on DLB, National Institute of Neurological and Communicative Diseases and Stroke/Alzheimer's Disease and Related Disorder Association, and the clinical diagnostic criteria for PDD. All patients were evaluated by careful neurological examination with detailed neuropsychological testing.
Results
Significant differences among the three groups were found for attention, memory, and executive function, which included tasks of backward digit span, three-word recall, verbal delayed recall, and the Stroop test. Post hoc analysis revealed that the deficiencies of attention on the digit span task were greater in the DLB group than in the AD and PDD groups. The scores for episodic verbal memory tasks were significantly lower in the DLB and AD groups than in the PDD group. The performance in frontal executive function, as indicated by the Stroop test, was significantly worse in the DLB and PDD groups than in the AD group.
Conclusions
The results of the present study show that the pattern of cognitive dysfunction, in terms of attention, episodic memory, and executive functions, differ between patients with DLB and patients with AD and PDD.
doi:10.3988/jcn.2011.7.1.19
PMCID: PMC3079155  PMID: 21519522
dementia with lewy bodies; Alzheimer's disease; Parkinson's disease dementia; cognition; neuropsychology
24.  Comparison of cognitive decline between dementia with Lewy bodies and Alzheimer's disease: a cohort study 
BMJ Open  2012;2(1):e000380.
Objectives
Dementia with Lewy bodies (DLB) accounts for 10%–15% of dementia cases at autopsy and has distinct clinical features associated with earlier institutionalisation and a higher level of carer distress than are seen in Alzheimer's disease (AD). At present, there is on-going debate as to whether DLB is associated with a more rapid cognitive decline than AD. An understanding of the rate of decline of cognitive and non-cognitive symptoms in DLB may help patients and carers to plan for the future.
Design
In this cohort study, the authors compared 100 AD and 58 DLB subjects at baseline and at 12-month follow-up on cognitive and neuropsychiatric measures.
Setting
Patients were recruited from 40 European centres.
Participants
Subjects with mild–moderate dementia. Diagnosis of DLB or AD required agreement between consensus panel clinical diagnosis and visual rating of 123I-FP-CIT (dopamine transporter) single photon emission computed tomography neuroimaging.
Outcome measures
The Cambridge Cognitive Examination including Mini-Mental State Examination and Neuropsychiatric Inventory (NPI).
Results
The AD and DLB groups did not differ at baseline in terms of age, gender, Clinical Dementia Rating score and use of cholinesterase inhibitors or memantine. NPI and NPI carer distress scores were statistically significantly higher for DLB subjects at baseline and at follow-up, and there were no differences between AD and DLB in cognitive scores at baseline or at follow-up. There was no significant difference in rate of progression of any of the variables analysed.
Conclusions
DLB subjects had more neuropsychiatric features at baseline and at follow-up than AD, but the authors did not find any statistically significant difference in rate of progression between the mild–moderate AD and DLB groups on cognitive or neuropsychiatric measures over a 12-month follow-up period.
Article summary
Article focus
Dementia with Lewy bodies (DLB) has distinct neuropsychiatric features.
At present, we do not know whether the poorer prognosis of DLB is due to a more rapid cognitive decline compared with Alzheimer's disease (AD).
Key messages
In this fairly large cohort of patients with DLB and AD, while there was no difference in level of cognitive impairment (Cambridge Cognitive Examination (CAMCOG) score) at baseline and at 12-month follow-up, DLB patients had significantly higher Neuropsychiatric Inventory (NPI) and NPI carer distress scores both at baseline and at 12-month follow-up.
Therefore, the worse prognosis of DLB is likely to be mediated by neuropsychiatric or other symptoms and not only by cognitive decline.
Strengths and limitations of this study
Inclusion of high number of subjects from 40 European clinical centres.
Well-characterised cases with both consensus panel clinical diagnosis (three clinical experts) and dopaminergic transporter single photon emission computed tomography imaging.
No autopsy data were available and therefore it is possible that more rapid cognitive decline may be present in pure DLB.
Only 1 year of follow-up.
There was higher attrition rate (no-follow-up assessment) in the DLB group, and DLB patients that did not return for follow-up were more impaired than AD patients.
doi:10.1136/bmjopen-2011-000380
PMCID: PMC3330257  PMID: 22318660
25.  Abnormal daytime sleepiness in dementia with Lewy bodies compared to Alzheimer’s disease using the Multiple Sleep Latency Test 
Introduction
Excessive daytime sleepiness is a commonly reported problem in dementia with Lewy bodies (DLB). We examined the relationship between nighttime sleep continuity and the propensity to fall asleep during the day in clinically probable DLB compared to Alzheimer’s disease (AD) dementia.
Methods
A full-night polysomnography was carried out in 61 participants with DLB and 26 with AD dementia. Among this group, 32 participants with DLB and 18 with AD dementia underwent a daytime Multiple Sleep Latency Test (MSLT). Neuropathologic examinations of 20 participants with DLB were carried out.
Results
Although nighttime sleep efficiency did not differentiate diagnostic groups, the mean MSLT initial sleep latency was significantly shorter in participants with DLB than in those with AD dementia (mean 6.4 ± 5 minutes vs 11 ± 5 minutes, P <0.01). In the DLB group, 81% fell asleep within 10 minutes compared to 39% of the AD dementia group (P <0.01), and 56% in the DLB group fell asleep within 5 minutes compared to 17% in the AD dementia group (P <0.01). Daytime sleepiness in AD dementia was associated with greater dementia severity, but mean MSLT latency in DLB was not related to dementia severity, sleep efficiency the night before, or to visual hallucinations, fluctuations, parkinsonism or rapid eye movement sleep behavior disorder. These data suggest that abnormal daytime sleepiness is a unique feature of DLB that does not depend on nighttime sleep fragmentation or the presence of the four cardinal DLB features. Of the 20 DLB participants who underwent autopsy, those with transitional Lewy body disease (brainstem and limbic) did not differ from those with added cortical pathology (diffuse Lewy body disease) in dementia severity, DLB core features or sleep variables.
Conclusions
Daytime sleepiness is more likely to occur in persons with DLB than in those with AD dementia. Daytime sleepiness in DLB may be attributed to disrupted brainstem and limbic sleep–wake physiology, and further work is needed to better understand the underlying mechanisms.
doi:10.1186/s13195-014-0076-z
PMCID: PMC4266572  PMID: 25512763

Results 1-25 (955590)