The differentiation of semantic dementia and frontal lobe dementia (temporal and frontal variants of frontotemporal dementia) from early Alzheimer's disease: A comparative neuropsychological study.

The authors compared age-matched groups of patients with the frontal and temporal lobe variants of frontotemporal dementia (FTD; dementia of frontal type [DFT] and semantic dementia), early Alzheimer's disease (AD), and normal controls (n?=?9 per group) on a comprehensive neuropsychological battery. A distinct profile emerged for each group: Those with AD showed a severe deficit in episodic memory with more subtle, but significant, impairments in semantic memory and visuospatial skills; patients with semantic dementia showed the previously documented picture of isolated, but profound, semantic memory breakdown with anomia and surface dyslexia but were indistinguishable from the AD group on a test of story recall; and the DFT group were the least impaired and showed mild deficits in episodic memory and verbal fluency but normal semantic memory. The frontal and temporal presentations of FTD are clearly separable from each other and from early AD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Heterogeneity of protein profiles of Helicobacter pylori isolated from individual patients

A standardized neuropsychological test battery was administered to 167 patients with different forms of mild-to-moderate dementia: probable Alzheimer dementia (AD: n = 49), multi-infarct dementia (n = 43), idiopathic Parkinson disease with dementia (n = 35), depressive pseudodementia (n = 26), and progressive supranuclear palsy (n = 14). Results obtained were used (a) to analyze the profiles of cognitive impairment shown by the different dementia groups; (b) to assess the incidence of some neuropsychological patterns that we hypothesized to be more characteristic of AD, in the various groups; and hence (c) to evaluate the reliability of these patterns as diagnostic markers of AD. Four of the patterns investigated were derived from a verbal learning task (Rey's Auditory Verbal Learning test): (1) absence of the primacy effect; (2) tendency to produce intrusion errors during free recall of a word list; (3) absolute decay of memory trace; and (4) tendency to produce false alarms during delayed recognition of the same word list. Two additional patterns were derived from visual-spatial tasks (copying drawings and Raven's Coloured Progressive Matrices): (5) occurrence of the closing-in phenomenon in copying drawings; and (6) tendency to choose globalistic or odd responses in Raven's matrices. Though all the six patterns were somewhat useful for identifying AD patients, no pattern met the criteria of being both highly sensitive and highly specific, which should characterize an ideal marker. In fact, intrusions and false alarms were observed in many AD patients, but also in patients affected by other forms of dementia. The absence of the primacy effect, the closing-in phenomenon, and the absolute decay of memory trace were more specific, but could be observed in only one-third of AD patients. We also computed the number of positive patterns shown by each patient and assumed the presence of two or more patterns as a global index suggestive of a dementia of the Alzheimer type. With this cumulative method, a higher level of sensitivity and specificity was achieved in the identification of AD patients.     

Comparative evolution of Alzheimer disease, vascular dementia, and mixed dementia

OBJECTIVE: To compare the evolution of Alzheimer disease (AD), vascular dementia (VaD), and mixed dementia by cognitive domain. SETTING: The University of Western Ontario Dementia Study, which is a registry of cases of dementia seen for secondary and tertiary assessment in a university memory disorders clinica with extensive follow-up data and histopathological confirmation of clinical diagnoses. PATIENTS: One hundred twenty-nine patients with definite or probable AD, 12 patients with definite or probable VaD, and 36 patients with definite or probable mixed dementia. METHODS: Patients were grouped as having an early, moderate, or advanced stage of disease according to the extended scale for dementia (ESD). The ESD was subdivided into cognitive domains, and the domain scores were compared for each stage of disease by diagnostic category with the use of a 2-way analysis of variance with repeated measures. RESULTS: As expected, the scores in all domains decreased significantly with increasing severity. There was a significant difference in the decline in memory among the diagnostic groups (P = .02) that was mostly attributable to the difference between AD and mixed dementia (P = .03), with the difference between AD and VaD only approaching significance (P = .06). There was a similar finding for praxis. The interaction between diagnosis (AD and VaD) and severity was significant only for memory (P = .02), showing a less severe memory deficit at onset but a proportionately more rapid progression in VaD and arithmetic ability (AD and mixed dementia [P = .03]). CONCLUSIONS: Alzheimer disease, VaD, and mixed dementia evolve similarly as assessed using cognitive domains obtained by subdivision of the ESD in a patient population derived from a memory clinic and by analyzing VaD as a single entity. Only memory impairment evolves differently between AD and VaD, with this depending on the severity. Memory is more severely impaired in the early stage of AD; however, with increasing severity of dementia, memory impairment in VaD accelerates and catches up with AD at the level of moderate impairment. The differences between AD and mixed dementia are greater than those between mixed dementia and VaD, suggesting an important role for the ischemic component of mixed dementia. Simple neuropsychological tools (eg, the ESD) may be incapable of distinguishing between AD and VaD, and more focused instruments may be required. Inherent bias in case selection may prevent extrapolation of these results to VaD in general, but the neuropsychological criteria for VaD may need to vary, depending on the severity.     

A within-modality test of semantic knowledge: The Size/Weight Attribute Test.

Individuals with semantic dementia (SD; n=12) or Alzheimer's disease (AD; n=20) and healthy volunteers (n=40) were tested on tasks probing attribute rather than associative knowledge of animals and objects in the visual and verbal domains. The tasks were within modality, in that they probed knowledge in a single presentation modality (pictures or written words) and did not require cross-modal matching. Participants were required to make the same simple judgment about triads of animal stimuli ("Which is the largest and smallest?") and object stimuli ("Which is the heaviest and lightest?"). Control participants scored at ceiling on this simple task. Overall, the SD patients were significantly more impaired on this task than were the AD patients, who in turn were significantly more impaired than the controls. There was a strong trend for SD but not AD patients to show worse performance with verbal than visual material. However, no significant effects of category were found in either patient group. The Size/Weight Attribute Test has the potential to assess modality-specific deficits of semantic knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Are explicit memory disorders of progressive supranuclear palsy related to damage to striatofrontal circuits? Comparison with Alzheimer's, Parkinson's, and Huntington's diseases

To test the hypothesis that memory disorders of subcortico-frontal dementia result mainly from inefficiency of retrieval processes of stored information, we compared verbal learning in 15 patients with progressive supranuclear palsy, prototypical of "subcortical dementia," in free (California Verbal Learning Test) and controlled (Grober and Buschke's Test) encoding situations, with that of 19 controls, matched for age and level of education. The progressive supranuclear palsy patients showed memory deficits characterized by impaired immediate memory span, disturbed learning and consistency of recall, and abnormal number of false alarms at recognition, which were dramatically alleviated by controlled encoding associated with cued recall, using the same semantic cues. This memory profile was markedly different from that of patients with senile dementia of the Alzheimer type (n = 15), characterized by more rapid forgetting and less improvement in the controlled situation. Instead, it was similar to the memory pattern of patients with Parkinson's (n = 15) and Huntington's (n = 15) diseases. These results show a similar profile of memory disturbance in disorders involving damage to the striatofrontal system and suggest that the cortical and hippocampal lesions of PSP patients are insufficiently severe to interfere with the specific memory profile characteristic of the disease.     

Semantic memory in Alzheimer's disease: Representativeness, ontologic category, and material.

Alzheimer's disease (AD) patients with semantic memory difficulty and AD patients with relatively preserved semantic memory named pictures and judged the category membership of words and pictures of natural kinds and manufactured artifacts that varied in their representativeness. Only semantically impaired patients were insensitive to representativeness in their category judgments. AD subgroup judgments did not differ for natural kinds compared to manufactured artifacts nor for words compared to pictures. AD subgroup differences could not be explained by dementia severity, memory, reading, and visuoperception. The similarity process for relating coordinate members of a taxonomic category contributes to the normal appreciation of word and picture meaning, and this process is compromised in AD patients with semantic difficulty. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intact text-specific implicit memory in patients with Alzheimer's disease.

The ability of patients with Alzheimer's disease (AD) to acquire and retain text-specific knowledge was investigated in a rereading study. Ten AD patients (aged 59–84 yrs) and 10 normal control Ss read 2 passages 3 times, each as quickly as possible, and answered recognition memory questions after the 3rd reading of each passage. The AD patients had poor explicit memory as evidenced by impaired recognition memory for the passages. In contrast, normal decreases in the times required for successive readings of each passage for AD patients indicated intact implicit memory for the passages. The absence of facilitation across passages indicated that the rereading effect was text specific, suggesting that AD patients may retain the ability to form certain kinds of implicit new associations. Alternative accounts of the mechanism underlying text-specific priming, and of the nature of intact and impaired implicit memory in AD, are considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive estimation impairment in Alzheimer disease and mild cognitive impairment.

Intact executive functioning is believed to be required for performance on tasks requiring cognitive estimations. This study used a revised version of a cognitive estimations test (CET) to investigate whether patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) were impaired on the CET compared with normal elderly controls (NECs). Neuropsychological tests were administered to determine the relationship between CET performance and other cognitive domains. AD patients displayed impaired CET performance when compared with NECs but MCI patients did not. Negative correlations between tests of working memory (WM) and semantic memory and the CET were found in NECs and AD patients, indicating that these cognitive domains were important for CET performance. Regression analysis suggests that AD patients were unable to maintain semantic information in WM to perform the task. The authors conclude that AD patients display deficits in working memory, semantic memory, and executive function, which are required for adequate CET performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cloning, functional expression and tissue distribution of rabbit alpha 1d-adrenoceptor

We attempt to determine the utility of CERAD in detecting early Alzheimer's disease (AD). CERAD battery was administered to a group of 14 control subjects, 12 patients with possible dementia prodromes and to patients with Alzheimer's disease stratified according to severity (16 mild, 8 moderate). Other measures as some subtest of the Wechsler memory scale and the Rey Complex Figure Test were also applied. Delayed recall as well as logical memory of Wechsler memory scale were found to be the best discriminators for detecting very mild cases of AD (Prodromes) (p < 0.05). None of the memory test proved of value in staging the disorder. Visuospatial functions are better determinants of the progression of the illness. Fluency also distinguish between control subjects and very mild cases. These findings suggest that delayed recall memory and probably executive function are the most useful and sensitive indicators of Alzheimer's disease.     

Risk factors for clinically diagnosed Alzheimer's disease: a case-control study of a Greek population

Many efforts have been made to trace the causes of Alzheimer's disease (AD). There are, however, many points of controversy among reports from the same country as well as among reports from different countries. The current study is a case-control study to determine the risk factors in the development of AD in Greece. Sixty-five patients with AD and 69 age-matched controls were examined. All patients with AD fulfilled the DSM-IV criteria for AD and NINCDS-ADRDA criteria for probable AD. Demographic characteristics such as gender, current marital status, who he/she is living with, education, main place of residence in childhood, adulthood, and late life, occupational hazards, patient's medical history (history of diabetes mellitus and hypertension), life habits like alcohol consumption and smoking, and a history of head trauma, heart attack, stroke, parkinsonism, or depression were collected from the subject or from an informant. A family history of selected diseases (hypertension, diabetes mellitus, dementia, Parkinson's disease, Down's syndrome, stroke) was also elicited. Ages of father and mother at birth were also recorded. Chi-square test, Kruskal-Wallis analysis of variance, cluster analysis, and logistic regression analysis were used for statistical analysis. The results (chi-square test) showed a statistically significant difference between patients with dementia of the Alzheimer type and controls as far as marital status (p = .04), the subject's history of major depressive episode (p = .02), and family history of dementia (p = .002) were concerned. Logistic regression analysis results produced a complex model of family aggregation of dementia, with patients with a history of depression and family history of dementia having an up to seven times higher risk of developing AD. These findings, especially a family history of dementia, are consistent with most of the literature.     

Anomia as a marker of distinct semantic memory impairments in Alzheimer's disease and semantic dementia.

Objective: Many neurologically constrained models of semantic memory have been informed by two primary temporal lobe pathologies: Alzheimer's disease (AD) and Semantic Dementia (SD). However, controversy persists regarding the nature of the semantic impairment associated with these patient populations. Some argue that AD presents as a disconnection syndrome in which linguistic impairment reflects difficulties in lexical or perceptual means of semantic access. In contrast, there is a wider consensus that SD reflects loss of core knowledge that underlies word and object meaning. Object naming provides a window into the integrity of semantic knowledge in these two populations. Method: We examined naming accuracy, errors and the correlation of naming ability with neuropsychological measures (semantic ability, executive functioning, and working memory) in a large sample of patients with AD (n = 36) and SD (n = 21). Results: Naming ability and naming errors differed between groups, as did neuropsychological predictors of naming ability. Despite a similar extent of baseline cognitive impairment, SD patients were more anomic than AD patients. Conclusions: These results add to a growing body of literature supporting a dual impairment to semantic content and active semantic processing in AD, and confirm the fundamental deficit in semantic content in SD. We interpret these findings as supporting of a model of semantic memory premised upon dynamic interactivity between the process and content of conceptual knowledge. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Differential effects of aging and Alzheimer's disease on conceptual implicit and explicit memory.

The effects of aging and Alzheimer's disease (AD) on conceptual explicit and implicit memory were examined. Three groups of participants patients with AD; age-matched, older control participants; and younger control participants made deep (semantic) or shallow (nonsemantic) judgments about low-dominant category exemplars. Explicit memory was measured by category cued recall and implicit memory was measured by priming on a category-exemplar generation task. Younger participants had enhanced cued recall and priming following deep, relative to shallow, encoding; this indicated that both memory measures were conceptually driven. Aging reduced explicit, but not implicit, test performance, and it did not reduce conceptually driven processes for either test. In contrast, AD reduced explicit and implicit test performance, and it impaired conceptually driven memory processes for both tests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Executive function deficits in mild Alzheimer's disease.

Twenty mildly impaired patients with Alzheimer's disease (AD; Mini-Mental State Examination; [MMSE]?=?25.1) and 20 controls (MMSE?=?29.4) were administered 7 tests to assess executive function. Tests of memory, naming, and copying were included. The executive function tests were the Self-Ordering Test, Controlled Oral Word Association Test (FAS), Trail Making Test, Hukok Logical Matrices, the Proverb Interpretation Test, the Similarities subtest of the Wechsler Adult Intelligence Scale—Revised, and the Cued Reaction Time Test. AD patients differed significantly from controls on 4 executive function tests (the Self-Ordering, Hukok, Trail Making, and FAS) and on the memory test. The executive function tasks on which the AD patients were impaired in comparison with controls primarily required concurrent manipulation of information. Tests of simple concept formation, cue-directed behavior, attention, naming, or figure copying did not differentiate the groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Disparate letter and semantic category fluency deficits in autopsy-confirmed frontotemporal dementia and Alzheimer's disease.

Patients with autopsy-confirmed frontotemporal dementia (FTD; n = 16) and Alzheimer's disease (AD; n = 32) were compared on first-letter and semantic category fluency tasks. Despite being matched on age, education, and dementia severity, FTD patients performed worse overall and showed similar impairment in letter and semantic category fluency, whereas AD patients showed greater impairment in semantic category than letter fluency. A measure of the disparity between letter and semantic category fluency (the semantic index) was effective in differentiating FTD from AD patients, and this disparity increased with increasing severity of dementia. These unique patterns of letter and semantic category fluency deficits may be indicative of differences in the relative contribution of frontal-lobe-mediated retrieval deficits and temporal-lobe-mediated semantic deficits in FTD and AD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Overdependence on degraded gist memory in Alzheimer's disease.

Alzheimer's disease (AD) reduces associative effects on false recognition in the Deese-Roediger-McDermott task, either due to impaired memory for gist or impaired use of gist in memory decisions. Gist processes were manipulated by blocking or mixing studied words according to their associations and by varying the associative strength between studied and nonstudied words at test. Both associative blocking and associative strength had smaller effects on false recognition in AD patients than in control participants, consistent with gist memory impairments. However, unlike the case with control participants, blocking influenced true and false recognition equally in AD patients, demonstrating an overdependence on gist when making memory decisions. AD also impaired item-specific recollections, relative to control participants, as true recognition of studied words was reduced even when the two groups were equated on gist-based false recognition. We propose that the overdependence on degraded gist memory in AD is caused by even larger impairments in item-specific recollections. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Amnestic mild cognitive impairment: Difference of memory profile in subjects who converted or did not convert to Alzheimer's disease.

Episodic long-term, short-term, and implicit memory were investigated in 79 elderly subjects who fulfilled criteria for the amnestic form of mild cognitive impairment (a-MCI; i.e., by having an idiopathic amnestic disorder with absence of impairment in cognitive areas other than memory and without confounding medical or psychiatric conditions) and who developed Alzheimer's disease (AD) after 2 years as well as in 111 subjects affected by a-MCI who did not develop dementia. Results document a memory profile in a-MCI subjects characterized by preserved short-term and implicit memory and extensive impairment of episodic long-term memory. In virtually all episodic memory indexes examined (learning, forgetting, recognition abilities), a-MCI subjects who converted to AD were more severely impaired than were subjects who did not become demented. This memory profile, which closely resembles that exhibited by amnestic patients with bilateral mesial-temporal lobe lesions, confirms a precocious phase in preclinical AD characterized by selective involvement of mesial-temporal areas and worsening of the memory impairment as atrophic changes progress in hippocampal structures. In this context of pervasive episodic memory impairment, tests assessing the free recall of verbal material following a delay interval demonstrated the greater sensitivity to memory deficits of a-MCI subjects who developed AD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Patterns of prospective and retrospective memory impairment in preclinical Alzheimer's disease.

Forty-six preclinical Alzheimer's disease (AD) participants and 188 nondemented control persons from the Kungsholmen Project (L. B?ckman et al., 2004) were compared on prospective memory (ProM) and retrospective memory (RetM) tasks 3 years before dementia diagnosis. The preclinical AD participants showed deficits in both ProM and RetM. Most interestingly, logistic regression analyses revealed that ProM made an independent contribution to the prediction of AD over and above that of RetM. This finding suggests that ProM and RetM tap partly different cognitive operations. Furthermore, within the ProM task, both the retrospective and prospective components were similarly impaired in preclinical AD. Within RetM, the preclinical AD participants were impaired on indices of encoding, storage (forgetting), and retrieval of information. Hence, the findings indicate a rather global episodic memory impairment in preclinical AD that cuts across type of memory assessed (ProM and RetM) as well as across different components of both the ProM and RetM tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hippocampal sclerosis contributes to dementia in the elderly

OBJECTIVE: To assess the relevance of hippocampal sclerosis (HS) to dementia in the elderly. BACKGROUND: HS is a prominent pathologic finding in some demented elderly, but the anatomic substrate and cognitive profiles of this dementia have not been well established. DESIGN/METHODS: An autopsy series, including dot-immunobinding assay to estimate neocortical synaptic density, of eight patients (three men, five women) with HS on whom extensive antemortem neuropsychological testing was available. RESULTS: Mean age at onset was 72.0 (+/-9.8) (range, 59 to 89) with a mean duration of symptoms of 6.5 (+/-2.9) years. Patients were only mildly impaired with a mean MMSE of 20.9 (+/-4.9) and a mean DRS of 103.1 (+/-12.5) at presentation. Cardiovascular disease was present in 88%, with a mean Hachinski score of 3.4 (+/-2.2). No patient had a history of seizures. Sixty-three percent had depression or depressive symptoms. Neuropsychologically, most patients presented with prominent memory and language deficits and became progressively demented. Neuropathologically, isolated HS was a rare finding; many patients had either very mild or neocortical "plaque only or plaque predominant" Alzheimer's disease (AD) in addition to HS changes. Midfrontal neocortical synaptophysin counts were significantly reduced in all HS patients compared with controls (p = 0.0006). CONCLUSIONS: In the elderly, HS can be a neuropathologic substrate of dementia. Clinically, it can be associated with a course that is difficult to distinguish from AD although cardiac disease and depression are frequent concomitants. Deterioration of cognitive function in these subjects may relate to other pathologic features such as neocortical synapse loss.     

The Dementia Rating Scale in Alzheimer's disease, Huntington's disease and progressive supranuclear palsy

The Dementia Rating Scale (DRS) comprises a series of five subtests which assess attention, memory, initiation/preservation, construction, and conceptualisation. It can be delivered in full in approximately 30 min, making it a useful test for the detection and estimation of the overall level of dementia. We analysed the pattern of subscale test scores in patients with cortical and subcortical dementias, who were matched for their overall level of dementia on this scale. Patients with dementia of Alzheimer's type were more impaired than patients with Huntington's disease (HD) and progressive supranuclear palsy (PSP) on the memory subtest, whereas patients with HD and PSP were more impaired on the initiation/perseveration subtest. This is evidence in favour of the concept of cortical and subcortical dementias as separate, although overlapping, entities. Qualitative differences in the pattern of cognitive impairment in these disorders can be detected with a brief cognitive status examination.     

Working memory in mild cognitive impairment and Alzheimer's disease: Contribution of forgetting and predictive value of complex span tasks.

Objective: This study examines working memory (WM) in mild cognitive impairment (MCI) and Alzheimer's disease (AD). Method: Performances on sentence span and operation span were measured in individuals meeting criteria for MCI (n = 20) and AD (n = 16) as well as in healthy older adults (n = 20). In addition, the effect of retention interval was assessed by manipulating the length of first and last items of trials (long-short vs. short-long), as forgetting might contribute to impaired performance in AD and MCI. Results: Results show a group effect (p