额颞叶变性时突触改变:与MAPT单体型和APOE基因型之间的关系

目的采用免疫组织化学技术定量研究额颞叶变性(FTLD)和阿尔茨海默病(AD)病人大脑额叶的突触改变(突出素和SNAP-25)以及其与APOE基因型和MAPT单体型之间的关系。方法采用免疫组织化学方法检测3组(20例FTLD、10例AD和9例年龄匹配的正常人对照)尸解脑组织标本的额叶新皮质中突出素和SNAP-25的表达。结果与对照组和AD病人相比,FTLD病人的突出素表达显著增高,而SNAP-25表达显著降低(P<0.001)。FTLD中突出素上调是疾病特异性改变(P<0.000 1),不受年龄(P=0.787)或者皮质萎缩(P=0.248)影响。SNAP-25下调受多种因素的影响,包括家族史和FTLD的组织学特征、APOE基因型、MAPT单体型和性别。因此,SNAP-25下调在tau蛋白阴性、女性和无家族史的病人更为显著,FTLD病人APOEε4等位基因和MAPT H2单体型的出现显著影响突触蛋白的表达,特别是导致SNAP-25的表达降低。结论本研究提示:FTLD中突触蛋白的表达受多种遗传因素的影响,将来在探讨该疾病神经机制改变的神经病理和生化研究中需将这些因素考虑在内。FTLD中SNAP-25的选择性丢失可...     

不同类型认知障碍患者的尿液AD7c-NTP与头部MRI、MRS的相关性研究

目的研究对不同类型认知障碍患者的尿液AD相关神经丝蛋白(AD7c-NTP)水平与头颅MRI中海马萎缩程度、MRS中N-乙酰天门冬氨酸(NAA)峰值水平的相互关系。方法选取阿尔兹海默病(AD)、血管性痴呆(VD)、轻度认知障碍(MCI)患者各30例,分别设为AD组、VD组、MCI组,另选取同期体检健康者30例作对照组。取所有受检者晨起时尿液,以酶联免疫吸附法测定AD7c-NTP水平,行头颅MRI及MRS检查。对比四组尿液AD7c-NTP水平、海马萎缩MTA评分、NAA峰值水平,分析尿液AD7c-NTP与海马萎缩MTA评分、NAA峰值水平相关性。结果 MCI组尿液AD7c-NTP水平高于对照组,VD组尿液AD7c-NTP水平高于MCI组,AD组尿液AD7c-NTP水平高于Va D组,差异有统计学意义(P0.05);MCI组海马萎缩MTA评分与对照组比较,差异无统计学意义(P0.05),VD组海马萎缩MTA评分高于MCI组,AD组海马萎缩MTA评分高于VD组,差异有统计学意义(P0.05);MCI组NAA峰值水平与对照组比较,差异无统计学意义(P0.05),VD组NAA峰值水平低于MCI组,AD组NAA峰值水平低于VD组,差异有统计学意义(P0.05);尿液AD7c-NTP水平变化与海马萎缩MTA评分呈正相关关系(P0.05);与NAA峰值水平呈负相关关系(P0.05)。结论 AD、Va D、MCI患者尿液AD7c-NTP水平较高,且不同类型认知障碍患者尿液AD7c-NTP、海马萎缩MTA评分、NAA峰值水平存在明显差异,尿液AD7c-NTP水平变化与MRI改变呈正相关性,与MRS改变呈负相关性。     

APOE ε4等位基因与尿AD7c-NTP联合检测在AD早期诊断中的初步研究

目的探讨APOEε4等位基因与尿AD7c-NTP联合检测在阿尔兹海默病(AD)早期诊断预防中的价值。方法根据中国精神障碍分类与诊断标准第三版(CCMD-3)有关精神分裂症及轻度阿尔兹海默病的诊断标准,选取76例临床诊断疑似AD患者(PAD组),另选90例健康者作为对照组。对比两组APOEε4等位基因频率和尿AD7c-NTP含量对AD的诊断价值。结果 (1)APOEε4等位基因表达频率在PAD组显著高于对照组(P≤0.05);(2)尿AD7c-NTP在PAD组中的含量较对照组显著升高(P≤0.01);(3)对APOEε4、AD7c-NTP及二者联合检测进行比较发现,APOEε4对AD诊断的灵敏度、特异度、阳性预测值、阴性预测值、约登指数分别为:44.64%、88.33%、78.13%、63.10%、0.33;尿AD7c-NTP诊断的灵敏度、特异度、阳性预测值、阴性预测值、约登指数分别为:78.57%、83.33%、81.48、80.65%、0.62;APOEε4与AD7c-NTP联合检测的诊断灵敏度、特异度、阳性预测值、阴性预测值、约登指数分别为:91.18%、91.55%、83.78%、95.58%、0.82。结论 APOEε4等位基因与尿AD7c-NTP联合检测是监测及诊断AD早期病变的较好指标,提升二者单独应用时的预测价值,宜作为AD易发人群鉴别和早期诊断的生物标记物。     

Alzheimer病和血管性痴呆患者APOE及LRP基因多态性与认知及精神行为症状相关性研究

目的 探讨Alzheimer病(AD)和血管性痴呆(VD)患者APOE及LRP基因多态性与认知及精神行为症状(BPSD)的相关性.方法 收集AD患者79例、VD患者85例和健康对照者(对照组)156名,采用简易精神状态检查量表(MMSE)评定认知功能;采用简明精神病量表和汉密尔顿抑郁(HAMD)、焦虑量表(HAMA)评定BPSD.采用PCR-RFLP进行APOEε、LRP基因分型.结果 (1)AD组(17.7％)及VD组(20.5％)APOEε4等位基因频率均高于对照组(5.7％,均P＜0.01).(2)AD组和VD组APOEε4携带者MMSE得分均低于同组APOEε4非携带者[AD组(13.84±2.32)分vs.(14.78±2.54)分,P＜0.01;VD组(15.53±1.87)分vs.(18.45±2.23)分,P＜0.01].(3)AD组患者APOEe4携带者BPSD比例明显高于APOEε4非携带者(55.56％ vs.52.83％,P=0.039).结论 APOEε4可能是AD、VD患者认知障碍的共同危险因素.APOEε4可能是AD的BPSD危险因素.     

额颞叶退行性变的研究进展与FTDC诊断标准介绍

额颞叶退行性变(frontotemporal lobe degeneration,FTLD)是一组以行为和人格改变、失语为特征性表现的疾病,包括3种临床综合征:行为变异额颞叶型痴呆(behavioral variant frontotemporal dementia,bvFTD)即狭义的额颞叶痴呆或额颞叶痴呆额叶型、语义性痴呆(semantic dementia,SD)和进行性非流利性失语(progressive non-fluent aphasia,PNFA).根据美国的流行病学调查和病理学分类,FTLD是仅次于阿尔茨海默病(Alzheimer's disease,AD)引起年轻发病的痴呆类型[1,2].FTD在病理改变和临床表现上都具有多样性,同时,FTD还可合并运动神经元病(MND)或帕金森综合征,使其临床诊断十分困难.     

尿AD7c-NTP水平与载脂蛋白E ε4等位基因联合检测对轻度认知功能障碍的诊断价值

目的探讨尿AD7c-NTP水平与载脂蛋白Eε4等位基因(ApoEε4)联合检测在轻度认知功能障碍(MCI)的诊断价值。方法检测54例MCI患者(MCI组)及60例健康者(正常对照组)的尿AD7c-NTP水平和ApoEε4表达。结果 MCI组尿AD7c-NTP水平及阳性率显著高于正常对照组(均P0.01)。MCI组ApoEε4阳性率显著高于对照组(P0.05)。联合检测的灵敏度、特异度、阳性预测值、阴性预测值及约登指数均高于尿AD7c-NTP检测和ApoEε4检测。结论尿AD7c-NTP水平与ApoEε4联合检测是鉴别及诊断MCI早期病变的较好指标,提升二者单独应用时的预测价值。     

家族性额颞叶痴呆家系的一家系

目的额颞叶痴呆(FTD)是一种异质性很强的神经系统变性疾病。本文报道1个已有5代患病FTD家系,并分析先证者及目前仍存活3例患者的临床和头颅结构磁共振(MRI)表现。方法收集FTD家系1个,对其先证者及目前仍存活3例患者进行病史询问、体格检查、神经心理评估、结构MRI检查。结果该家系5代成员每代均有发病,目前共有26例患者,其中男性11例、女性15例,现存活男性患者1例,女性患者3例。患者发病年龄50～65岁,平均年龄(58.11±3.90)岁,病程1～8年,平均(4.86±2.01)年。多以精神行为异常为首发症状,疾病初期伴或不伴记忆力减退,随病程延长,行为异常、记忆力减退进行性加重。神经心理量表检测示简易精神状态评估量表(MMSE)16～28分、蒙特利尔认知评估量表(MoCA)11～25分,画钟试验1～3分,神经精神量表(NPI)11～17分,额叶行为评定量表(FBI)10～33分。先证者及其他3例患者头颅MRI出现(由基本正常到中度额颞叶皮质萎缩的),不同程度双侧基本对称或不对称的额颞叶为主的脑萎缩。结论家族性FTD为早发性痴呆,以精神行为异常为临床最常见表现,头颅MRI出现双侧基本对称或不对称的额颞叶为主的脑萎缩有助于FTD的早期诊断。     

绵阳市中老年人群尿液阿尔茨海默病相关神经丝蛋白水平及相关因素

目的 探讨绵阳市中老年人群尿液阿尔茨海默病相关神经丝蛋白（AD7c-NTP）水平及与常见代谢性指标的相关性。方法 于2017年3月-2020年3月,选取在四川省科学城医院与绵阳市第三人民医院健康体检中心体检的1 150名中老年人为研究对象,采用酶联免疫吸附法检测其尿液AD7c-NTP水平,采用常规方法检测血液生化指标。根据尿液AD7c-NTP水平是否≤1.5 ng/mL将研究对象分为正常组（n=956）和升高组（n=194）,收集两组一般人口学资料和血液生化指标数据。结果 中老年人群的尿液AD7c-NTP水平为0.60(0.30～1.20) ng/mL,女性尿液AD7c-NTP水平高于男性[1.04(0.40～1.30)ng/mL vs. 0.84(0.30～1.00) ng/mL,Z=4.202,P＜0.01],正常组尿液AD7c-NTP水平低于升高组[0.50(0.30～0.90) ng/mL vs. 2.10(1.70～2.10) ng/mL,Z=22.035,P＜0.01]。单因素比较结果显示,正常组与升高组的年龄（Z=6.545）、空腹血糖（Z=3.506）、血尿酸（Z=2....     

额叶变异型阿尔茨海默病的临床和影像学特征一例

目的额叶变异型阿尔茨海默病(AD)是一种以精神行为等症状为主要表型的少见特殊类型AD,本文报道1例额叶变异型AD的临床特点、影像学特征,以增加临床医生对该病的认识。方法报道1例额叶变异型AD患者的临床资料,分析其临床表现、辅助检查及影像学资料。结果本例患者以妄想和行为异常等为主要和最早临床表现,发病2年后才出现记忆力减退、言语表达困难、计算不能等症状,头颅MRI提示双侧额颞叶萎缩,以左侧为著。头颅SPECT显示:双侧额叶、颞叶和顶叶葡萄糖摄取普遍减低。PIB-PET(淀粉样蛋白PET):大脑皮质PIB显著滞留,考虑为PIB阳性显像。结论额叶变异型AD与行为变异型额颞叶痴呆临床表现类似,淀粉样蛋白PET检查可有效区分两者。     

额颞痴呆

额颞痴呆(FTD)为一组临床综合征,1987年Gustafson首先提出这一概念,包括:Pick病、额颞叶变性(FTLD)、进行性失语(progressiveaphasia)、语义性痴呆(semanticdementia)。FTD早期有各种行为异常,易被误诊为Alzheimer病(AD)或精神分裂症、双相情感障碍等。FTD可合并运动神经元病(M     

TDP-43 in Alzheimer’s disease is not associated with clinical FTLD or Parkinsonism

Widespread deposition of TAR DNA-binding protein of 43 kDa (TDP-43), a major protein inclusion commonly found in frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS) can also be seen in a subset of cases with Alzheimer’s disease (AD). Some of these AD cases have TDP-43 immunoreactivity in basal ganglia (BG) and substantia nigra (SN), regions that when affected can be associated with parkinsonian signs or symptoms, or even features suggestive of frontotemporal dementia. Here, we examined the presence of clinical features of FTLD, parkinsonian signs and symptoms, and BG atrophy on MRI, in 51 pathologically confirmed AD cases (Braak neurofibrillary tangle stage IV–VI) with widespread TDP-43 deposition, with and without BG and SN involvement. All 51 cases had presented with progressive cognitive impairment with prominent memory deficits. None of the patients demonstrated early behavioral disinhibition, apathy, loss of empathy, stereotyped behavior, hyperorality, and/or executive deficits. Furthermore, TDP-43 deposition in BG or SN had no significant association with tremor (p = 0.80), rigidity (p = 0.19), bradykinesia (p = 0.19), and gait/postural instability (p = 0.39). Volumes of the BG structures were not associated with TDP-43 deposition in the BG. The present study demonstrates that TDP-43 deposition in pathologically confirmed AD cases is not associated with a clinical manifestation suggestive of FTLD, or parkinsonian features.     

Visual assessment of atrophy on magnetic resonance imaging in the diagnosis of pathologically confirmed young-onset dementias

OBJECTIVES: To investigate the diagnostic accuracy of visual inspection of magnetic resonance imaging (MRI) in a range of pathologically confirmed diseases causing young-onset dementia and to assess the sensitivity and specificity of atrophy patterns for Alzheimer disease (AD) and frontotemporal lobar degeneration (FTLD). DESIGN: Sixty-two patients with pathologically confirmed diseases that may present as young-onset dementia were selected from a biopsy and postmortem series. The first diagnostic T1-weighted volumetric MRI was obtained for each patient, together with images from 22 healthy control subjects. All MRIs were assessed for regional atrophy independently by 3 neuroradiologists, blinded to all clinical details except age. Observers were also asked to use their clinical judgment to form a diagnosis. RESULTS: Eighty-seven percent of dementia cases were distinguished from controls after visual inspection of MRI, and a correct pathologically confirmed diagnosis was given in 58% of cases. Hippocampal atrophy was noted in 92% of AD cases but was commonly seen in other dementias and controls. A bilateral symmetrical pattern of hippocampal atrophy discriminated AD from FTLD with 47% specificity, while posterior greater than anterior gradient of atrophy was 92% specific for AD. Atrophy of the anterior, inferior, and lateral temporal lobes was suggestive of FTLD pathology (> or =90% sensitivity), while anterior greater than posterior gradient of atrophy and hemispheric asymmetry of atrophy were each at least 85% specific for FTLD. CONCLUSION: Despite variation and overlap of atrophy patterns, visual inspection of regional atrophy on MRI may aid in discriminating AD and FTLD.     

Odour identification in frontotemporal lobar degeneration

Abstract Little information is available concerning olfactory processing in frontotemporal lobar degeneration (FTLD). We undertook a case-control study of olfactory processing in three male patients fulfilling clinical criteria for FTLD. Odour identification (semantic analysis) and odour discrimination (perceptual analysis) were investigated using tests adapted from the University of Pennsylvania Smell Identification Test. General neuropsychometry and structural volumetric brain magnetic resonance imaging (MRI) were also performed. The three patients with FTLD exhibited a disorder of olfactory processing with the characteristics of a predominantly semantic (odour identification) deficit. This olfactory deficit was more prominent in patients with greater involvement of the temporal lobes on MRI. Central deficits of odour identification may be more common in FTLD than previously recognised, and these deficits may assist in clinical characterisation.     

Quantifying change in individual subjects affected by frontotemporal lobar degeneration using automated longitudinal MRI volumetry

A novel method of automated MRI volumetry was used to study regional atrophy and disease progression in repeated MRI measurements of patients with frontotemporal lobar degeneration (FTLD). Fifty-nine structural MRI data sets of 17 clinically diagnosed FTLD patients were acquired over up to 30 months in intervals of 6 months and compared with data of 30 age-matched healthy controls. Patients were further subgrouped into behavioral variant FTLD (bvFTLD), progressive nonfluent aphasia (PNFA), and semantic dementia (SemD). Gray matter (GM) volumes of frontal lobes (FL) and temporal lobes (TL) were determined by voxel-based volumetry based on SPM5 algorithms and a probabilistic brain atlas. MRI volumetry revealed frontal and temporal GM atrophy across FTLD patients, with further progression over time. Significant side asymmetry of TL volumes was found in SemD. The ratio of TL to FL volumes was significantly reduced in SemD and increased in bvFTLD. Using this ratio, 6/7 SemD patients and 5/6 bvFTLD patients could be correctly differentiated. TL/FL ratios in bvFTLD and SemD further diverged significantly over a time span of only 6 months. Rates of temporal GM loss per 6 months were 3-4% in SemD, and 2.5% for frontal GM loss in bvFTLD, and thereby clearly exceeded published cerebral volume loss in healthy elderly subjects. The study presents a fully automated, observer-independent volumetric assessment of regional atrophy which allows differentiation of FTLD subgroups. Its sensitivity for atrophy progression--even in such short intervals like 6 months--might benefit future clinical trials as treatment outcome measure.     

A volumetric magnetic resonance imaging study of the amygdala in frontotemporal lobar degeneration and Alzheimer's disease

The amygdala is severely atrophied at post-mortem in frontotemporal lobar degeneration (FTLD), and may contribute to the prominent behavioural changes that are early features of FTLD. The aim of this study was to assess amygdala atrophy using MRI in the main syndromic variants of FTLD and Alzheimer's disease (AD). Brain and amygdala volumes, adjusted for intracranial volume, were measured on 46 clinically diagnosed FTLD patients [22 frontal variant FTD (FTD), 14 semantic dementia (SD), 10 progressive non-fluent aphasia (PNFA)], 20 AD patients, and 17 controls. While severe amygdala atrophy was present in both FTLD (41% smaller than controls on the left; 33% on the right) and in AD (22% on the left; 19% on the right), the FTLD group had significantly greater amygdala atrophy (z = 3.21, p = 0.001 left, z = 2.50, p = 0.01 right) and left/right asymmetry (z = 2.03, p = 0.04) than AD. Amygdala atrophy was greater in SD than FTD, PNFA and AD (p < 0.02 for all). Highly asymmetrical atrophy was present in SD, greater on the left (z = 3.23, p = 0.001), and to a lesser extent in PNFA. Despite an overlap between clinical and radiological features of FTLD and AD, marked amygdala atrophy points towards a diagnosis of FTLD, with left greater than right atrophy suggestive of one of the language variants.     

The contribution of TMS to frontotemporal dementia variants

Objective – Frontotemporal lobar degeneration (FTLD) includes different heterogeneous conditions mainly characterized by personality changes and cognitive deficits in language and executive functions; movement disorders have also been associated with FTLD. The present study aimed to measure the primary motor cortex (M1) inhibitory and facilitatory functions in patients affected by FTLD. Materials and methods – The study included 17 FTLD patients, 8 age‐matched healthy controls and 8 Alzheimer’s disease (AD) patients. Transcranial magnetic stimulation (TMS) was used to study intracortical inhibition (ICI) and facilitation (ICF) by using a double‐pulse paradigm. Results – FTLD patients were comparable with controls and AD patients for ICI and ICF. Corticobasal degeneration (CBD) patients presented significant reduced inhibition at ISI3; moreover two out of seven CBD patients had only ipsilateral responses. Discussion – The present study reveals a selective impairment of M1 ICI inhibitory response in CBD, which may help in distinguishing among the FTLD clinical spectrum.     

Hippocampal atrophy on MRI in frontotemporal lobar degeneration and Alzheimer's disease

BACKGROUND: Hippocampal atrophy on magnetic resonance imaging (MRI) is an early characteristic of Alzheimer's disease. However, hippocampal atrophy may also occur in other dementias, such as frontotemporal lobar degeneration (FTLD). OBJECTIVE: To investigate hippocampal atrophy on MRI in FTLD and its three clinical subtypes, in comparison with Alzheimer's disease, using volumetry and a visual rating scale. METHODS: 42 patients with FTLD (17 frontotemporal dementia, 13 semantic dementia, and 12 progressive non-fluent aphasia), 103 patients with Alzheimer's disease, and 73 controls were included. Hippocampal volumetry and the easily applicable medial temporal lobe atrophy (MTA) rating scale were applied to assess hippocampal atrophy. RESULTS: Multivariate analysis of variance for repeated measures showed an effect of diagnostic group on hippocampal volume. There was a significant diagnosis by side (left v right) interaction. Both FTLD and Alzheimer's disease showed hippocampal atrophy compared with controls. Results of the visual MTA rating scale confirmed these findings. Within the FTLD subtypes there were marked differences in hippocampal atrophy. Frontotemporal dementia and semantic dementia showed bilateral hippocampal atrophy, and in semantic dementia the left hippocampus was smaller than in Alzheimer's disease. No significant hippocampal atrophy was detected in non-fluent progressive aphasia. CONCLUSIONS: Hippocampal atrophy is not only a characteristic of Alzheimer's disease but also occurs in FTLD. The three clinical subtypes of FTLD show different patterns of hippocampal atrophy.     

Clinical and psychometric distinction of frontotemporal and Alzheimer dementias

BACKGROUND: A proportion of patients who meet the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Associations criteria for Alzheimer disease (AD) have frontotemporal lobar degeneration (FTLD) confirmed at autopsy, with or without concomitant AD. Thus, the clinical phenotypes of the 2 disorders may overlap. OBJECTIVE: To identify clinical and psychometric indicators that distinguish AD from FTLD at initial presentation. DESIGN: Longitudinal study of memory and aging. SETTING: Alzheimer's Disease Research Center, Washington University School of Medicine. PARTICIPANTS: Forty-eight clinically well-characterized cases of autopsy-confirmed FTLD (27 with psychometric testing results) were compared with 27 autopsy-confirmed AD cases. RESULTS: Behavioral abnormalities, particularly impulsivity (P<.001), disinhibition (P<.001), social withdrawal (P = .01), and progressive nonfluent aphasia, distinguished individuals with FTLD from those with AD. The individuals with FTLD performed better than those with AD on a visual test of episodic memory (P = .01), but worse on word fluency (P = .02) (performance correlated with aphasic features). Other cognitive and clinical features, including executive dysfunction and memory impairment, were comparable between the FTLD and AD groups. Concomitant histopathological AD was present in 11 of the 48 individuals with FTLD. CONCLUSIONS: Clinical and cognitive features of FTLD may overlap with AD, although behavioral and language difficulties distinguish those with FTLD. Memory loss in those with FTLD may in part reflect word-finding difficulties stemming from language dysfunction. Compounding the overlap of FTLD and AD clinical phenotypes is the presence of histopathological AD in almost one fourth of individuals with FTLD.     

Different patterns of magnetic resonance imaging atrophy for frontotemporal lobar degeneration syndromes

BACKGROUND: Frontotemporal lobar degeneration (FTLD) is an uncommon degenerative dementia that presents with focal cognitive and behavioral deficits. OBJECTIVE: To determine the correlation of the different presentations of FTLD with structural neuroimaging findings. DESIGN AND PATIENTS: In a blinded study, we retrospectively evaluated the clinical presentations and magnetic resonance imaging (MRI) patterns of atrophy in 59 patients with FTLD and 26 patients with probable Alzheimer disease at a memory disorders clinic. RESULTS: Analysis of variance revealed a significant difference in the patterns of atrophy in the FTLD and Alzheimer disease groups. Patients with FTLD presenting with altered personal conduct had significant bifrontal atrophy, whereas patients presenting with semantic dementia had significant left temporal and bifrontal atrophy compared with other groups. Disinhibited behavior and hyperphagia correlated with right frontal atrophy, and fluent, anomic aphasia correlated with left temporal atrophy. CONCLUSIONS: We found that the type of clinical presentation of FTLD correlates with specific areas of atrophy. Our method of analysis may be useful to elicit further anatomic-behavioral relationships in degenerative brain disorders.     

Clinical Features of Pittsburgh Compound-B-Negative Dementia

Background/Aims: We previously found that some cases of clinically diagnosed Alzheimer's disease (AD) were rated as Pittsburgh compound B (PiB) negative by amyloid imaging (i.e. cases of PiB-negative dementia). The present study was designed to analyze the clinical features of PiB-negative dementia patients in detail. Methods: Of the 64 cases of clinically diagnosed AD, 14 were rated PiB negative. Eleven of these were further analyzed using CSF biomarker levels and findings from MRI, FDG-PET, (123)I-MIBG myocardial scintigraphy and voxel-based morphometry (VBM). Results: When examined by (123)I-MIBG myocardial scintigraphy, the heart/mediastinum ratio was significantly higher in the PiB-negative dementia group than in the dementia with Lewy bodies (DLB) group. Analyses of CSF biomarkers and MRI and FDG-PET findings suggested argyrophilic grain disease (AGD) in 3 cases, frontotemporal lobar degeneration (FTLD) in 3 cases, neurofibrillary tangle-predominant dementia (NFTD) in 1 case, and AD in 2 cases. In the VBM data analysis, the PiB-positive AD group showed significant atrophy of both hippocampi compared with the healthy control group, while the PiB-negative dementia group presented with significant atrophy of the left precuneus. Conclusion: PiB-negative dementia is unlikely to include DLB, while it most likely includes diseases of tauopathy, such as FTLD, AGD and NFTD. A better understanding of PiB-negative dementia is expected to further improve the accuracy of the clinical AD diagnosis.