行为变异型额颞叶痴呆的影像学研究进展

对额颞叶变性中的行为变异型额颞叶痴呆影像学研究作一简述。     

MAPT基因突变所致额颞叶痴呆家系临床及影像学特征分析

目的报道1例行为变异型额颞叶痴呆(bv-FTD)家系,分析该家系的临床和影像学特征,并行基因诊断。方法对该家系进行调查、详细的病史询问、体格检查,行神经影像学检查(头颅磁共振成像、18F-氟脱氧葡萄糖(FDG)正电子发射断层扫描(PET-CT)和动脉自旋标记核磁灌注成像(ASL-MRI)。对相关致病基因(MAPT、PSEN1、PSEN2、APP)进行直接测序筛查突变。结果先证者基因检测发现MAPT基因P301L位点致病突变。该先证者及家系其他患者均表现为以行为变异型FTD(bvFTD),无帕金森病样表现。结构影像学检查见双侧额颞叶不对称萎缩,功能影像见额颞叶低代谢和低灌注。临床特征和影像学结果支持bv-FTD诊断。家系内患者临床表型高度一致。结论我们报道1例MAPT P301L突变家系,神经影像和基因检测有助于家族史阳性痴呆患者的诊断。     

行为变异型额颞叶痴呆早期主要临床特点及相关影像学特征研究

行为变异型额颞叶痴呆是因额叶和(或)颞叶进行性退变导致的精神行为异常、执行功能障碍等为主要临床特征的痴呆症候群中的一种临床亚型。本文介绍该病的早期主要临床症状与影像学特点的联系,以期提高对该病可能的萎缩模式的认识。     

伴瘙痒症状的Heidenhain变异型克雅氏病3例报告并文献复习

目的分析Heidenhain变异型克雅氏病的临床、实验室、电生理和影像学特点。方法收集3例患者的临床资料、实验室检验结果、电生理和影像学资料。结果 3例患者以视觉快速下降起病,伴难治性瘙痒。PRNP全基因测序一例为E200K点突变,另两例无突变。3例脑脊液14-3-3蛋白阳性,脑电图为广泛慢波背景上后头部三相尖波发放,视觉诱发电位P100未引出,头颅MRI DWI序列上双侧枕叶皮层"缎带征"。PET/CT为从枕叶发展至广泛大脑皮层的葡萄糖低代谢。结论以视觉障碍起病,伴认知功能快速下降、共济失调和锥外体征的老年患者需要与Heidenhain变异型克雅氏病鉴别,建议行头颅MRI和EEG检查。难治性瘙痒更提示克雅氏病的可能。     

~(18)F-FDG PET显像鉴别阿尔茨海默病与额颞叶痴呆临床价值

目的探讨18F-FDG PET显像在阿尔茨海默病与额颞叶痴呆鉴别诊断中的应用价值。方法对临床明确诊断的阿尔茨海默病(20例)和行为异常型额颞叶痴呆(20例)患者的18F-FDG PET显像资料进行回顾,分析两组患者皮质代谢降低脑区间的差异。结果视觉分析显示,两组患者均表现为皮质代谢降低,阿尔茨海默病患者以双侧颞顶叶和后扣带回代谢降低明显,以及部分额叶皮质代谢降低,而基底节和丘脑不受累,18/20患者双侧大脑半球皮质代谢降低范围和程度基本对称;额颞叶痴呆患者额叶和前颞叶皮质代谢均降低,其中11例同时伴部分顶叶皮质和基底节、丘脑等皮质下核团不同程度降低,16/20患者双侧大脑半球代谢降低程度和范围明显不对称,4例以右侧为主、12例以左侧为主。结论由于18F-FDG PET显像所显示的阿尔茨海默病和额颞叶痴呆患者之皮质代谢降低图型不同,故具有较好的鉴别诊断价值。     

Logopenic型进行性失语五例的临床、神经心理学及影像特征分析

目的研究Logopenic型进行性失语(LPA)的临床表现、神经心理学和影像特点。方法对5例患者进行病史、临床查体、神经心理学、语言评估和血液、脑脊液检查,以及头颅磁共振(MRI)、氟18-氟脱氧葡萄糖(FDG)、PET/CT或SPECT,碳11-匹兹堡复合物B(PIB)PET/CT检查。结果 5例LPA患者为自发语言和命名过程中单个词语的取词困难,语言复述和复杂长句理解障碍,伴语音错语和记忆力减退。头颅MRI示左侧颞顶叶明显萎缩。FDG-PET显示左侧额、颞、顶和枕叶葡萄糖代谢减低。2例患者显示皮质淀粉样蛋白沉积。结论取词困难是LPA语言损害的核心特点,详细的包含语言测评的神经心理学检查和头颅影像学有利于LPA诊断。     

眶额区病变及脑脊膜膨出表现为颞叶内侧发作一例

眶额区位于双侧额叶下方前颅凹中,与边缘系统及额颞叶有广泛的双相联系,发作时的症状缺乏特异性,为发作活动扩布的结果.根据临床症状可以分为额叶型、颞叶型及额颞叶型.眶额区起源的癫痫少见.本文报道一例颞叶型眶额区癫痫,以期为该类疾病的临床诊治提供一定参考.     

额颞叶变性的临床及生物学标记物特点

目的探讨额颞叶变性(FTLD)患者的临床、影像以及生物学标记物的特点。方法回顾性分析入组的43例FTLD患者的临床资料,包括一般资料、临床特点、行为-认知量表评分[如蒙特利尔认知评估量表(MoCA)、简易精神状态检查量表(MMSE)、日常活动能力量表(ADL)、额叶行为量表(FBI)、神经精神量表(NPI)和汉密尔顿抑郁量表(HAMD)评分]、头MRI、血APOEε4、尿液Alzheimer相关神经丝蛋白(AD7c-NTP)以及FDG-PET检查结果。结果 FTLD患者早期主要表现为执行功能障碍、行为去抑制;头颅MRI检查结果表现为单/双侧对称(或)不对称性额颞叶萎缩,可伴或不伴海马萎缩;FDG-PET检查结果显示大脑半球前部对称/不对称性葡萄糖低代谢改变;FTLD患者APOEε4等位基因的表达频率为15.12%,尿液AD7c-NTP平均值(3.23±1.78)ng/mL,高于正常值范围(0~1.5ng/mL);P300波的潜伏期不同程度延长,波幅均降低。结论FTLD患者早期临床表现以行为、执行功能障碍多见,也可出现记忆障碍。行为-认知量表和FDG-PET检查可能有助于FTLD诊断。FTLD患者P300波的潜伏期和波幅也可出现变化,可能有助于发现患者记忆、推理功能障碍。FTLD患者也可以出现APOEε4等位基因表达以及尿AD7c-NTP表达的变化。     

阿尔茨海默病~(18)F-FDG PET显像诊断的研究

目的 探讨阿尔茨海默病（AD）脑葡萄糖代谢及其18F-脱氧葡萄糖正电子发射计算机断层扫描（18F-FDG PET）显像的影像学特征和PET诊断标准。方法 静脉注射18F-FDG后行脑断层显像,检查13例 AD、13例非AD痴呆及13例正常人。获得纹状体、丘脑、黑质、顶叶、颞叶、额叶、枕叶、海马单位面积放射性计数与小脑计数的比值（Rcl/cb）,进行半定量分析,并与MR进行对照。结果AD患者PET异常率为100％,MR异常者占10/13。PET显像特征:①对称性双侧颞顶叶及海马伴额叶或枕叶代谢减低占9例（9/13）;②双侧颞叶对称性代谢减低伴海马或额叶代谢下降占3例（3/13）;③双顶叶对称性代谢降低1例（1/13）。12例（12/13）非AD痴呆表现为不对称、多发性代谢降低,降低区位于黑质、纹状体、丘脑及脑皮质区,MR异常率为11/13。结论 在除外脑内结构特异性损害基础上,PET发现对称性双颞顶叶、海马或颞叶、顶叶,伴或不伴枕叶、额叶代谢下降,可诊断AD。PET对AD早期诊断及鉴别诊断具有临床意义。     

阿尔茨海默病18F-FDG PET显像诊断的研究☆

目的探讨阿尔茨海默病(AD)脑葡萄糖代谢及其18F-脱氧葡萄糖正电子发射计算机断层扫描(18F-FDGPET)显像的影像学特征和PET诊断标准.方法静脉注射18F-FDG后行脑断层显像,检查13例AD、13例非AD痴呆及13例正常人.获得纹状体、丘脑、黑质、顶叶、颞叶、额叶、枕叶、海马单位面积放射性计数与小脑计数的比值(Rcl/cb),进行半定量分析,并与MR进行对照.结果AD患者PET异常率为100%,MR异常者占10/13.PET显像特征①对称性双侧颞顶叶及海马伴额叶或枕叶代谢减低占9例(9/13);②双侧颞叶对称性代谢减低伴海马或额叶代谢下降占3例(3/13);③双顶叶对称性代谢降低1例(1/13).12例(12/13)非AD痴呆表现为不对称、多发性代谢降低,降低区位于黑质、纹状体、丘脑及脑皮质区,MR异常率为11/13.结论在除外脑内结构特异性损害基础上,PET发现对称性双颞顶叶、海马或颞叶、顶叶,伴或不伴枕叶、额叶代谢下降,可诊断AD.PET对AD早期诊断及鉴别诊断具有临床意义.     

Surface dyslexia in chinese

abstract

We report a diagnostically challenging case of a 64-year-old man with a history of remote head trauma who developed mild behavioral changes and dyscalculia. He was diagnosed with clinical Alzheimer’s disease (AD), with additional features consistent with behavioral variant frontotemporal dementia. Structural magnetic resonance imaging revealed atrophy in bilateral frontal and parietal cortices and hippocampi on visual inspection and left frontal pole and bilateral anterior temporal encephalomalacia, suspected to be due to head trauma. Consistent with the diagnosis of Alzheimer’s pathology, positron emission tomography (PET) with Pittsburgh compound B suggested the presence of beta-amyloid. Fluorodeoxyglucose PET demonstrated hypometabolism in bilateral frontal and temporoparietal cortices. Voxel-based morphometry showed atrophy predominant in ventral frontal regions (bilateral orbitofrontal cortex, pregenual anterior cingulate/medial superior frontal gyrus), bilateral mid cingulate, bilateral lateral temporal cortex, and posterior insula. Bilateral caudate, thalamus, hippocampi, and cerebellum were prominently atrophied. Unexpectedly, a pathologic hexanucleotide repeat expansion in C9ORF72 was identified in this patient. This report underscores the clinical variability in C9ORF72 expansion carriers and the need to consider mixed pathologies, particularly when imaging studies are inconsistent with a single syndrome or pathology.     

Functional ability in executive variant Alzheimer's disease and typical Alzheimer's disease

A frontal, or executive, variant of Alzheimer's disease (EAD) has been described in the literature in which frontal dysfunction accompanies temporal and parietal changes in the early stages of the illness. However, no study has empirically investigated associated aspects, such as neuropsychiatric symptoms, instrumental activities of daily living, or caregiver burden in this EAD subgroup. We compared the performance of two subgroups of mild Alzheimer's disease patients (e.g., EAD and typical Alzheimer's disease; TAD) on neuropsychological and associated measures. Results revealed that the EAD group, selected based on poor executive scores, did not significantly differ from the TAD group on nonexecutive neuropsychological tests of intelligence, language, verbal and nonverbal memory, or visual-spatial abilities. However, the EAD group evidenced more severe neuropsychiatric symptoms, impaired activities of daily living, and greater caregiver distress than the TAD group. Thus, the EAD subgroup is characterized by executive dysfunction, neuropsychiatric symptoms, and functional disability in excess of that seen in TAD. Whether our EAD subgroup represents an actual frontal variant of Alzheimer's disease awaits replication in a larger sample including neuroimaging and pathological confirmation, as well as longitudinal assessment of cognition and neuropsychiatric symptoms.     

Glucose metabolism in sporadic Creutzfeldt-Jakob disease: a statistical parametric mapping analysis of (18) F-FDG PET

Background and purpose: Reports describing functional neuroimaging techniques, such as positron emission tomography (PET) and single‐photon emission computed tomography (SPECT), in sporadic Creutzfeldt–Jakob disease (sCJD) have consistently suggested that these tools are sensitive for the identification of areas of hypoperfusion or hypometabolism, even in the early stages of sCJD. However, there are few reports on the use of [18F]fluoro‐2‐deoxy‐D‐glucose (FDG) PET in sCJD, and most of them are single case reports. Only two small cohort studies based on visual inspection or a region of interest method have been published to date. Using a statistical parametric mapping (SPM) analysis of ¹⁸F‐FDG PET, we investigated whether there are brain regions preferentially affected in sCJD. Methods: After controlling for age and gender, using SPM 2, we compared the glucose metabolism between (i) 11 patients with sCJD and 35 controls and (ii) the subset of five patients with the Heidenhain variant of sCJD and 35 controls. Results: The patients with sCJD showed decreased glucose metabolism in bilateral parietal, frontal and occipital cortices. The Heidenhain variant of sCJD showed glucose hypometabolism mainly in bilateral occipital areas. Conclusions: Glucose hypometabolism in sCJD was detected in extensive cortical regions; however, it was not found in the basal ganglia or thalamus, which are frequently reported to be affected on diffusion‐weighted images. The medial temporal area, which is possibly resistant to the prion deposits, was also less involved in sCJD.     

Cerebral blood flow and cerebral oxygen metabolism in patients with dementia of frontal lobe type

This study was designed to investigate the differences in cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) between patients with dementia of frontal lobe type and patients with Alzheimer's disease. Positron emission tomography (PET) using 15O steady state inhalation technique was carried out in 5 patients with a clinical diagnosis of dementia of frontal lobe type and 7 patients with a clinical diagnosis of Alzheimer's disease. CBF and CMRO2 were significantly decreased in the frontal cortex except for precentral region in patients with dementia of frontal lobe type in comparison to those values in patients with Alzheimer's disease. However, in patients with dementia of frontal lobe type CBF and CMRO2 in the parietal cortex and the occipital cortex were relatively preserved when compared with patients with Alzheimer's disease. In comparison with values for CBF and CMRO2 in the posterior part of brain [frontal or temporal/(parietal + occipital)/2 ratio], both values in the frontal cortex were markedly decreased in all 5 patients with dementia of frontal lobe type, but there was no marked reduction in the frontal cortex in patients with Alzheimer's disease. In addition, in 2 patients with dementia of frontal lobe type whose duration of the disease was more than 7 years, CBF and CMRO2 in the temporal cortex were markedly reduced in comparison with values in the posterior part of brain. These results suggested that PET findings of marked reduction in CBF and CMRO2 in the frontal cortex are useful to distinguish dementia of frontal lobe type from Alzheimer's disease.     

Familial presenile dementia with bitemporal atrophy

This study describes the clinical, neuropsychological, neuroimaging and genetic characteristics in two generations of a Swedish family affected by presenile dementia. The pedigree includes 5 cases (mother and 4 of 5 children) of progressive dementia with onset between 54 and 62 years. The clinical picture is characterized by insidious onset and progressive decline in episodic memory without spatial impairment or dyspraxia, followed by changes in personality and behaviour, with signs of disinhibition, irritability, impulsivity and loss of social awareness. Three siblings, examined after 10 years of duration, showed moderate language deficits but preserved spatial function and praxis. CT and MRI showed progressive bilateral temporal atrophy and moderate frontal white matter changes. Regional cerebral blood flow measurements showed hypoperfusion in temporal areas bilaterally. Quantitative EEG was normal within 5 years after symptom onset and thereafter showed a moderate increase in relative theta power. Sequencing of the tau gene (chromosome 17) revealed the previously described R406W mutation in exon 13 as a likely cause of the disease. This mutation was identified in all affected cases. The clinical picture of this family shows striking similarities not only to frontotemporal dementia but also to Alzheimer's disease.     

Cerebral glucose metabolism in unilateral entorhinal cortex-lesioned rats: an animal PET study.

To evaluate the effect of entorhinal cortical lesion on cerebral cortical function, we studied cerebral glucose utilization (CMRGlc) using a high resolution PET scanner after quinolinic acid lesion of the unilateral entorhinal cortex in rats. [18F]Fluorodeoxyglucose PET was performed at 4 days and 4 weeks after surgery, and CMRGlc in the bilateral frontal, parietal and temporal regions were analyzed. At 4 days, the entorhinal lesion induced a 12-15% decrease in CMRGlc of frontal, parietal and temporal regions ipsilateral to the lesion. The hypometabolism continued at 4 weeks in the temporal region. These findings suggest that entorhinal lesion induces cerebral cortical hypometabolism, which implies a pathogenetic role of entorhinal area on the cortical hypometabolism in Alzheimer's disease.     

Frontotemporal dementia in Oman: cognitive behavioural profile and neuroimaging characteristics; a prospective hospital-based study

Frontotemporal dementia is increasingly recognised as an important cause of early-onset dementia and is considered to be the second commonest neurodegenerative dementia after Alzheimer's disease. We describe the cognitive, behavioural profile and neuroimaging characteristics of 6 patients with frontal variant of Frontotemporal dementia that were evaluated at the cognitive behavioural clinic at this tertiary referral teaching hospital. All patients underwent clinical, neuropsychological, structural/functional neuroimaging, and laboratory evaluations. The male to female ratio was 1:1; mean age of onset was 54 years, and the mean duration of symptoms were 30 months. The mean scores for Addenbrooke's cognitive examination, Frontal Assessment Battery, and Mini-Mental State Examination were 70.5, 6.33 and 23.6 respectively. The mean VLOM ratio was 2.04. MRI revealed significant asymmetrical regional frontal/temporal atrophy supplemented by the evidence of circumscribed hypoperfusion in SPECT imaging. We conclude that a combination of behavioural and cognitive assessment using short bedside tests, along with structural and functional neuroimaging does facilitate early identification, and increase the diagnostic specificity of Frontotemporal dementia.     

CSF biomarkers in frontotemporal lobar degeneration: relations with clinical characteristics, apolipoprotein E genotype, and neuroimaging

In order to better understand the large variation in cerebrospinal fluid (CSF) tau and amyloid-beta(1-42) (Abeta42) in frontotemporal lobar degeneration (FTLD), relations between these biomarkers and clinical parameters, neuroimaging characteristics, and apolipoprotein E (ApoE) genotype were studied in 31 patients with FTLD, including 16 patients with the frontal variant and 15 with the temporal variant. CSF tau was highest in FTLD with predominant temporal involvement. In the frontal subgroup, CSF tau level was influenced by the number of ApoE epsilon3 alleles. In the temporal subgroup, CSF tau level was dependent on a combination of CSF Abeta42, age, disease duration, and disease severity. No relation with degree of atrophy or asymmetry on neuroimaging could be established. CSF Abeta42 variability remained unexplained. Future research could study the role of ApoE genotype and Abeta42 in FTLD, as well as establish measures for disease intensity.