Abnormal EEG slow activity in left temporal areas in senile dementia of the Alzheimer type

Resting 32-channel topographical measures of EEG slow activity were compared in 12 elderly controls and 12 patients with senile dementia of the Alzheimer type. The patients had higher amplitude delta and theta than controls, especially in the left temporal regions. This greater amount of low frequency EEG activity in the left temporal area is consistent with recent EEG, neuropsychological assessment, and positron emission tomography findings in SDAT patients. Five patients with mild-to-moderate dementia (as determined by the Folstein Mini-Mental State scale) primarily exhibited focal, abnormal slow activity in the left temporal regions. Seven patients with severe dementia exhibited increased slow activity across the head, which was still most abnormal in the left temporal regions.     

A visual recognition memory test for the assessment of cognitive function in aging and dementia

Young, non-demented elderly, and elderly demented subjects were administered a computerized visual recognition memory task. In the task, subjects were instructed to point out the new object from a group of objects whose number was progressively incremented. The test was subject-paced and made use of face-valid stimulus materials; it is closely comparable to tests developed for memory assessment in non-human primates that are sensitive to the effects of hippocampal ablation. The present task was found to elicit significant differences in performance between young and non-demented aged subjects, between the non-demented and demented elderly, and between demented subjects in the early and more advanced stages of senile dementia of the Alzheimer type (SDAT). In a discriminant analysis, the visual recognition memory test scores correctly classified 72.6% of the aged subjects and early SDAT patients. No significant difference in task performance was found between SDAT patients and demented patients with a significant cerebrovascular etiological component. Thus, although the task does not appear to be suitable for diagnostic purposes it would be useful for the assessment of treatment effects upon age-related cognitive dysfunction.     

Temporal memory and content memory for actions: adult age differences in acquisition and retention

Young adult and elderly adult subjects were tested under incidental memory conditions for recognition memory of content and temporal memory for the order of a series of actions performed in the laboratory. The tests were conducted both shortly after completion of the series and 24 hours later, with different sets of actions tested on each occasion. Recognition memory of content showed no forgetting for the young subjects, but significant forgetting for the elderly subjects. Memory for temporal information was substantially greater for the young subjects than for the elderly subjects. Both age groups showed substantial forgetting of temporal information over the 24-hour retention interval.     

非痴呆老年人认知功能的差异性:从成功老化到轻度认知损伤

目的：对非痴呆的自诉记忆力减退的老年人,就其总体认知水平而言可能存在相对同源的不同亚型进行初步探讨。方法：对34例调查者进行临床记忆量表等17种神经心理测验,将结果进行Q型聚类分析。结果：15例调查者被诊断为轻度认知损伤,占44％;聚类分析产生6类新样本。结论：在正常老化与早期阿尔茨海默病这一过渡期内,老年人的认知状态是不均质的,其中既有成功老化,也有一般老化,尤其是还存在着具有痴呆发病危险性的认知损伤。     

Anterior brain dysfunctioning as a risk factor in alcoholic behaviors

This study assessed the relationship between neuropsychological and electrophysiological functioning and four alcohol-related measures: the Michigan Alcoholism Screening Test (MAST), the age at which the first drink was taken, frequency of drinking to “get high”, and frequency of drinking to “get drunk”. Ninety-one young adult men with no history of alcohol dependence were recruited. Subjects completed a variety of alcohol-related scales and a battery of neuropsychological tests. Resting EEG activity was also recorded. Stepwise regression analysis found that neuropsychological tests commonly regarded as measuring frontal and/or temporal neocortex functioning predicted the age at which subjects took their first drink and their scores on the MAST. Tests of frontal functioning, along with tests of memory, also predicted the frequency with which subjects reported drinking to “get drunk”. Tests of memory also predicted the frequency at which subjects drank to “get high”. On two of the alcohol measures, including age at which the first drink was taken and frequency of drinking to “get high”, left-frontal slow alpha EEG activity was a significant predictor. These results suggest that markers of anterior brain functioning/dysfunctioning are associated with self-reports of alcohol-related behaviors, and that disturbances in the integrity of the anterior neocortex may be a risk factor in the development of alcohol-related behaviors.     

Characteristics of instrumental activities of daily living and everyday memory in elderly women--method for assessment of abilities in early dementia

AIM: To demonstrate the characteristics of the Instrumental Activities of Daily Living (IADL), assessed by the Assessment of Motor and Process Skills (AMPS), and everyday memory functions (memory necessary function for daily life) assessed by the Rivermead Behavioral Memory Test (RBMT) in elderly people with dementia. To compare the ability and the function between them and community-dwelling normal subjects. METHODS: We divided the RBMT result into three categories: prospective memory, retrospective memory, and prospective memory+retrospective memory. The study was performed in102 women (68-92 years old) with dementia who lived in a healthcare facility or three group homes (n=52) and cognitively normal subjects who lived in their own homes (n=50). RESULTS: There were no associations between AMPS motor and prospective memory, retrospective memory, and prospective memory+retrospective memory in both groups. There were associations between the AMPS process and retrospective memory in both groups, but no associations between the AMPS process and prospective memory in either groups and a scatter chart revealed some subjects with a prospective memory deficit even though they had a normal IADL performance ability level. From those results, we found that IADL performance ability and everyday memory were not simultaneously damaged. CONCLUSION: When assessing elderly people, it is necessary to assess both IADL performance and everyday memory, including prospective memory. According to these methods, mild cognitive impairment may be screened more accurately.     

Remember NIBS? tACS improves memory performance in elders with subjective memory complaints

Subjective memory complaints (SMC), the main cognitive component of which is event memory, is a predictor of Alzheimer’s disease in elderly people. The purpose of this trial was to investigate the effect of transcranial alternating current stimulation (tACS) with theta frequency (6 Hz) on the medial prefrontal cortex (mPFC) in the improvement of episodic memory in individuals with SMC in a double blind, randomized, and sham-controlled parallel study. Sixteen participants with SMC received either active or sham theta tACS on the mPFC. EEG was recorded, and Rey Auditory Verbal Learning Test (RAVLT) was administered. tACS resulted in a significant improvement in episodic memory performance as measured by RAVLT. EEG data revealed a decrease in theta power; decrease in theta, alpha, and gamma current source density (CSD) in the postcentral, insula, and cingulate gyrus; and decrease in theta and gamma phase synchronization as a result of active tACS, compared to the sham group. Moreover, a significant correlation between delayed recall score of RAVLT and CSD in left inferior gyrus in theta frequency band was observed. The results of the current study showed that theta tACS of the mPFC can improve event memory in individuals with SMC through modulating the activity in the frontal and temporal regions in the brain and thus can be considered a potential therapeutic intervention for this population.

     

Electroencephalography, visual evoked potentials, and cerebral CAT-scan as diagnostic tools in senile dementia of Alzheimer type

The usefulness of a cerebral computed tomogram (CAT-scan), an electro-encephalogram (EEG), and flash visual evoked responses (FVER) as diagnostic tools in dementia was studied in 36 mentally impaired and 32 unimpaired persons aged 75 yr and above, who were recruited from a random sample of elderly people living at home. The clinical diagnosis of dementia was made after a full psychogeriatric assessment supplemented by a follow-up 18 mo later. When the measures of cortical atrophy from a cerebral CAT-scan, the presence/absence of diffuse slow activity on a standard EEG, and FVER P200 and FVER P100 latencies were introduced in a logistic regression model, the clinical diagnoses being the dependent variable, an effective prediction of senile dementia of Alzheimer type (SDAT) was obtained (sensitivity 93%, specificity 86%, misclassification rate 12%). We conclude that the use of FVER, an EEG, and a cerebral CAT-scan may facilitate the diagnosis of senile dementia of Alzheimer type.     

Neuropsychological abnormalities in cirrhosis include learning impairment

BACKGROUND/AIMS: Minimal hepatic encephalopathy is a neurocognitive disorder secondary to liver failure that is characterized by a pattern of subcortical impairment. The most conspicuous neuropsychological abnormalities are on attention and psychomotor tests; memory has been inconsistently implicated. We designed a study to assess the presence of memory abnormalities in cirrhotic patients and the effects of liver transplantation. METHODS: Ninety-seven cirrhotics without overt hepatic encephalopathy underwent neuropsychological assessment, including the Auditory Verbal Learning Memory Test. The results were compared to those of healthy controls (n=75) and the assessment was repeated at one year of follow-up (n=33) or after liver transplantation (n=23). RESULTS: Cirrhotic patients exhibited multiple neuropsychological abnormalities, including several disturbances of the Auditory Verbal Learning memory test: learning, long-term memory and recognition. Abnormalities of long-term memory and recognition were corrected after adjusting for learning impairment. Memory abnormalities correlated to attention impairment and to parameters of liver function. Neuropsychological indexes following liver transplantation did not differ from controls. Repeated testing did not have a major effect on neuropsychological tests in healthy subjects and in non-transplanted cirrhotics. CONCLUSIONS: Learning impairment is present in cirrhotic patients with neuropsychological abnormalities. This abnormality is consistent with attention deficit secondary to minimal hepatic encephalopathy.     

Depression as prognostic factor: 6 months follow-up in a geriatric institution

Depression in the elderly and especially in the demented elderly is common, but it is unclear to what extent depression affects the prognosis of dementia. We performed a 6 months follow-up on the elderly to evaluate the effect of depression on the prognosis of dementia. Among the residents in a Korean geriatric institution, a total of 141 elderly residents were included in this study. Those residents who had geriatric depression scale (GDS) scores over 20 were considered as having depression. The subjects were assessed at baseline and at 6 months later with the Korean Mini-Mental State Examination (K-MMSE), Clinical Dementia Rating (CDR) and Barthel index (BI). For all the 141 subjects, the changes of the K-MMSE, CDR and BI scores were first compared between the depressed and non-depressed groups. Then, for the 58 depressed subjects subdivided into three groups (36 subjects in the non-demented group, 14 subjects in the Alzheimer disease (AD) group and 8 subjects in the vascular dementia (VaD) group), the changes of the scores among the three groups were compared. For all subjects, the changes of the K-MMSE and CDR scores were more severe in the depressed group than in the non-depressed group. For the 58 depressed subjects, the changes were significantly different among the three groups (p=0.02 for the K-MMSE, p<0.001 for the CDR), and the changes were the most severe in the VaD group. For the elderly, depression has a significant influence on the cognitive deterioration. Moreover, the effect of depression on the cognitive dysfunction and on the prognosis of dementia is more severe in the demented elderly, and especially for the VaD patients.     

遗忘型轻度认知障碍和轻度阿尔茨海默病的认知损害特征研究

目的明确遗忘型轻度认知障碍（amnesia-mild cognitive impairment,a-MCI）患者和轻度阿尔茨海默病（alzheimer＇s disease,AD）患者的认知损害特征。方法对13例a-MCI患者、22例轻度AD患者和37例正常对照进行全面的认知测查,除简易精神状态检查（mini-mental state examination,MMSE）外,测验可覆盖4个认知域：记忆力、信息处理速度、执行功能、视空间结构能力,进行组间比较。结果 3组患者在年龄、受教育程度及性别组成上匹配。轻度AD组的所有认知测验成绩都差于正常对照组,而且多数测验较a-MCI组也有减退。a-MCI组的MMSE、记忆相关测验以及多个执行功能相关测验结果都差于正常对照组,信息处理速度和视空间结构能力相关测验与对照组间无统计学差异。结论轻度AD患者表现为全面的认知功能减退。a-MCI患者除存在显著的记忆障碍外,还存在执行功能的异常,信息处理速度和视空间结构能力尚正常。     

阻塞性睡眠呼吸暂停综合征事件相关电位和记忆功能的相关性

目的 探讨阻塞性睡眠呼吸暂停综合征(OSAS)患者的P300指标变异情况和记忆功能状况的关系.方法 对浙江大学医学院附属第一医院2008年7月至2009年12月睡眠呼吸障碍专科门诊就诊的患者,进行夜间至少7h多导睡眠监测,共纳入OSAS患者30例,其中男22例,女8例,平均年龄(42±6)岁;对照组为健康志愿者20名,其中男15名,女5名,平均年龄(40±6)岁,分别进行韦氏记忆量表评定和事件相关电位P300检查.采用t检验、卡方检验和Pearson等级相关法对各组数据进行检验及比较.结果 OSAS组的记忆商评分为(86±13)分,与对照组比较有显著降低(P＜0.01);OSAS组的P300检查显示Cz、Pz点的潜伏期分别为(410±80) ms和(409±80) ms,较对照组明显延长(P＜0.01);Cz、Pz点的潜伏期与记忆商评分呈显著负相关(r=-0.581,-0.583,均P＜0.01),与睡眠呼吸紊乱指数呈正相关,差异有统计学意义(r=0.653,0.64,均P＜0.01);与平均血氧及最低SaO2呈负相关,差异有统计学意义(r=-0.755,-0.745,均P＜0.01;r=-0.67,-0.656,均P＜0.01).结论 OSAS患者存在明显的记忆功能障碍,P300潜伏期的延长可作为评估OSAS记忆功能障碍的电生理学指标之一;慢性间歇低氧可能导致与记忆相关的脑功能区域发生损伤性变化.     

Classifying late-onset dementia with MRI: Is arteriosclerotic brain degeneration the most common cause of Alzheimer’s syndrome?

Our aim was to use early magnetic resonance imaging (MRI) to investigate the causes of cognitive decline in elderly people with mild cognitive impairment (MCI). Baseline structural and flow quantification MR sequences, and clinical and neuropsychological follow-up for at least two years, were performed on 62 elderly subjects with MCI. Of these subjects, 17 progressed to dementia, and 15 of these progressed to dementia of the Alzheimer type (DAT). Conversion to clinically diagnosed DAT was related to six distinct MR profiles, including one profile suggesting severe AD (20% of these converters) and five profiles suggesting severe cerebrovascular dysfunction. Two profiles suggested arteriosclerotic brain degeneration, one profile suggested severe venous windkessel dysfunction, and two suggested marked cerebral hypoperfusion associated with very low craniospinal compliance or marked brain atrophy. As compared with vascular MR type converters, AD MR type converters showed high executive and mobility predementia performances. Severe whole anteromesial temporal atrophy and predominantly left brain atrophy on visual MR analysis was only observed in AD MR type converters. In conclusion, these observations enhance the pathogenic complexity of the Alzheimer syndrome, and suggest that the role of arteriosclerotic brain degeneration in late life dementia is underestimated.     

Memory training and drug therapy act differently on memory and metamemory functioning: evidence from a pilot study

The aim of this study was to assess the influence of drug therapy (DT) with pramiracetam and memory training (MT), each alone, and in combination (DTMT), on both the objective memory and metamemory performance. Thirty-five non-depressed, non-demented healthy elderly (mean age: 64.8 years) with objective (story recall) and/or subjective (cognitive difficulties scale) memory loss were randomly included in four open-label conditions: an MT condition (n = 10), a DT condition (n = 8), a DTMT condition (n = 10), and a control (CTR) condition (n = 7). MT and DTMT subjects participated in 12 real-life tutor-guided MT sessions, once weekly, each lasting 1.5 hrs. The subjects were tested for objective (Randt memory test) and subjective (Sehulster metamemory scale; memory functioning questionnaire) memory proficiency prior to (t(0)) and shortly after treatment (t(1)). Results showed that objective memory gains of the two groups receiving pramiracetam were significantly larger than that of the MT and CTR groups. The ranking order in terms of decreasing score improvements was DTMT - DT - MT - CTR. Metamemory, on the other hand, displayed only a trend to between-group differences with opposite patterns for the DT and DTMT groups. In the DT group, the level of depression, negatively interfered with metamemory but not with actual memory performance. The present findings stress, once again, the complex relationships between memory, metamemory and affective status, which may be differently modified by DT and MT.     

Quantitative EEG in type 1 diabetic adults with childhood exposure to severe hypoglycaemia: a 16 year follow-up study

Aims/hypothesis  

In diabetic children and adolescents, a history of severe hypoglycaemia (SH) has been associated with increased slow EEG activity and reduced cognition, possibly due to harmful effects of SH on the developing brain. In a group of type 1 diabetic patients with early exposure to SH, who had EEG abnormalities and reduced cognition in childhood, we have recently demonstrated that the reduced cognition may persist into adulthood. We have now assessed whether the reduced cognition was accompanied by lasting EEG abnormalities.     

老年精神分裂症和Alzheimer病性痴呆患者的认知功能与脑电地形图检查的相关性研究

目的：探讨老年精神分裂症和Alzheimer病性痴呆患者认知功能与脑电地形图检查的相关性.方法：50例老年精神分裂症患者（SS）、50例Alzheimer病性痴呆患者（AD）和52名健康老年人（NC）依次完成脑电地形图检查（BEAM）、简易智力状态检查（MMSE）、威斯康星卡片分类测验（WCST）、临床记忆量表（CMS）、连线测验（TMT-A）、数字符号（DSy）及数字广度（DSp）测验.结果：①SS组认知功能与8个脑区的18个BEAM指标显著相关,AD组与6个部位（前额部、前中后颞区、中央及顶部）的9个BEAM指标显著相关,NC组则与8个脑区的31个BEAM指标显著相关.②SS组及NC组均有8个BEAM变量进入以MMSE为因变量的回归方程,SS组的决定系数明显大于NC组（R2=0.637,R2=0.363）,AD组仅有2个变量进入以MMSE为因变量的回归方程,且决定系数最低（R2=0.222）.③右侧额部（F4）β波功率、左中央部（C3）δ波功率、左中颞部（T3）β波功率分别对SS患者、AD患者及正常老人MMSE的回归贡献最大,且有统计学意义（P〈0.01）.结论：SS的认知功能与BEAM检查的相关范围介于NC与AD之间,其相关强度大于NC及AD;BEAM-EEG结合NPT检查对于SS和AD有重要的鉴别诊断价值.     

Instructional variation and adult age differences in activity memory

Recall of a series of 12 activities was compared for young and elderly subjects performing under four instructional conditions: incidental memory, standard intentional memory, intentional-emphasis, and interpolated recall (intermediate recall tests after every three activities had been performed). Relative to the incidental memory condition, superior recall was found for subjects in the intentional-emphasis and intentional-interpolated recall conditions. An age-related deficit in recall was found, but the Age X Instructional Condition interaction was not significant. Instructional variation was also found to affect temporal memory scores for the order in which the activities has been performed. An age-related deficit in temporal memory proficiency was found for all conditions except that of interpolated recall. On the other hand, instructional variation had a negligible effect on performance scores for the 12 specific activities.     

Topographic brain mapping of EEG after acute application of ergotalkaloids in the elderly

In a double-blind, placebo-controlled, crossover study the encephalotropic and nootropic effects of single doses of two ergotalkaloids (30 and 60 mg nicergoline and 5 mg co-dergocrine mesylate (CDM)) were investigated in 12 elderly subjects (mean age 67 years), utilizing topographic brain mapping of the EEG. Evaluation of EEG, memory, pulse and blood pressure were carried out at 0, 2, 4, 6 and 8 h. Topographic brain maps demonstrated an augmentation of total power, an acceleration of the centroid of the total activity, a decrease of delta/theta and an increase of beta activity (mostly in the alpha-adjacent frequency bands), as well as an acceleration of the centroid of the delta/theta and a slowing of the beta centroid. These changes are indicative of improvement in vigilance of elderly subjects after ergotalkaloids, which was also reflected in the significant improvement of memory after nicergoline. Topographically, the main effect was found over the frontal, central and temporal regions. Timewise, the pharmacodynamic peak fell into the 4th h, although with 60 mg significant encephalotropic effects could be observed in the 2nd and in the 6th h. The drugs were well tolerated.