The effects of Baduanjin exercise on the subjective memory complaint of older adults: A randomized controlled trial

This study aimed to explore the efficacy of Baduanjin exercise on promoting memory function, executive function and general self-efficacy, decreasing the level of subjective memory complaints of older adults.In this randomized controlled trial, 80 patients were randomly allocated in a 1:1 ratio to 12-week Baduanjin exercise group or 12-week control group. Subjective memory complaint questionnaire, Auditory verbal learning test, Trail Making Test and General Self-Efficacy Scale was used to assess the subjective memory complaint level, memory function, executive function and general self-efficacy level at three times (baseline, after intervention and follow up at 3 months). One-way repeated measures analysis of variance was used to compare the outcome variables of the two groups.There were no significant differences between the Baduanjin exercise and the control group at baseline in demographic, SMCQ, MoCA, and GDS-15. Compared to participants in the control group, participants in the Baduanjin group had a significantly improvement in memory function (F = 46.93, P < .00), executive function (F = 317.83, P < .00) and general self-efficacy (F = 38.72, P < .00) at the end of 12-week intervention period and after 3months follow-up period (P < .01). At the same time, participants in the Baduanjin group had a significantly greater decrease in subjective memory complaint scores at the end of 12-week intervention period and after 3months follow-up period (F = 24.53, P < 0.00).Baduanjin exercise appears to be a feasible and acceptable intervention to improve subjective memory complaint among older adults.

Clinical relevance of brain atrophy subtypes categorization in memory clinics

INTRODUCTION

The clinical relevance of brain atrophy subtypes categorization in non-demented persons without a priori knowledge regarding their amyloid status or clinical presentation is unknown.

METHODS

A total of 2083 outpatients with either subjective cognitive complaint or mild cognitive impairment at study entry were followed during 4 years (MEMENTO cohort). Atrophy subtypes were defined using baseline magnetic resonance imaging (MRI) and previously described algorithms.

RESULTS

Typical/diffuse atrophy was associated with faster cognitive decline and the highest risk of developing dementia and Alzheimer's disease (AD) over time, both in the whole analytic sample and in amyloid-positive participants. Hippocampal-sparing and limbic-predominant atrophy were also associated with incident dementia, with faster cognitive decline in the limbic predominant atrophy group. Lewy body dementia was more frequent in the hippocampal-sparing and minimal/no atrophy groups.

DISCUSSION

Atrophy subtypes categorization predicted different subsequent patterns of cognitive decline and rates of conversion to distinct etiologies of dementia in persons attending memory clinics.

Usefulness of investigating error profiles in diagnosis of naming impairments

BACKGROUND

Word-retrieval difficulties are commonly experienced by people with aphasia (PwA) and also by typically ageing persons. Differentiation between true naming impairments and naming difficulties found in healthy persons may, therefore, be challenging.

AIMS

To investigate the extent to which the Maltese adaptation of the Boston Naming Test (BNT) can identify people with lexical retrieval difficulties and to differentiate them from people with unimpaired word finding.

METHODS & PROCEDURES

Naming performance of a group of PwA was compared with the performance of a control group. Performance on the Maltese adaptation of the BNT was investigated in terms of scores, range of scores and error profiles of the two groups.

OUTCOMES & RESULTS

All PwA scored below the mean score of the controls, indicating that persons who scored above the mean score may be considered as unimpaired. However, a number of the controls obtained very low scores that overlapped with the scores obtained by the PwA. This indicated that scores alone cannot be used to differentiate between impaired and unimpaired people. Some types of errors were only produced by people with impaired naming, and did not appear at all in error profiles of unimpaired individuals.

CONCLUSIONS & IMPLICATIONS

Mild-moderate anomic impairments may be missed if naming impairment is assessed and diagnosed using a cut-off score. In order to differentiate between people with impaired and unimpaired naming, it is necessary to look at error profiles, apart from the number of errors, as the presence of atypical errors may be an important indicator of naming impairments.

Memory dysfunction

PURPOSE OF REVIEW

This article highlights the dissociable human memory systems of episodic, semantic, and procedural memory in the context of neurologic illnesses known to adversely affect specific neuroanatomic structures relevant to each memory system.

RECENT FINDINGS

Advances in functional neuroimaging and refinement of neuropsychological and bedside assessment tools continue to support a model of multiple memory systems that are distinct yet complementary and to support the potential for one system to be engaged as a compensatory strategy when a counterpart system fails.

SUMMARY

Episodic memory, the ability to recall personal episodes, is the subtype of memory most often perceived as dysfunctional by patients and informants. Medial temporal lobe structures, especially the hippocampal formation and associated cortical and subcortical structures, are most often associated with episodic memory loss. Episodic memory dysfunction may present acutely, as in concussion; transiently, as in transient global amnesia (TGA); subacutely, as in thiamine deficiency; or chronically, as in Alzheimer disease. Semantic memory refers to acquired knowledge about the world. Anterior and inferior temporal lobe structures are most often associated with semantic memory loss. The semantic variant of primary progressive aphasia (svPPA) is the paradigmatic disorder resulting in predominant semantic memory dysfunction. Working memory, associated with frontal lobe function, is the active maintenance of information in the mind that can be potentially manipulated to complete goal-directed tasks. Procedural memory, the ability to learn skills that become automatic, involves the basal ganglia, cerebellum, and supplementary motor cortex. Parkinson disease and related disorders result in procedural memory deficits. Most memory concerns warrant bedside cognitive or neuropsychological evaluation and neuroimaging to assess for specific neuropathologies and guide treatment.

[Mental disorders due to brain lesions in the DSM-5 in the light of the previous versions]

The DSM-5 introduces major modifications in the category of mental disorders due to brain lesions compared to the previous DSM versions, which are reviewed in this paper. The description of the category Major neurocognitive disorder, as a substitute for dementia, seems to fit better for patients and families, and more adapted to many neurodegenerative cognitive disorders for which memory impairment is not predominant. Similarly, the introduction of the category of Mild neurocognitive disorder appears to be an improvement although some difficulty still remains for distinguishing mild cognitive disorder from normal aging. The addition of new etiological categories such as fronto-temporal NCD or NCD with Lewy bodies should also to be considered as a significant improvement. Despite these advances, to circumscribe the mental disorders due to brain lesions to cognitive deficits and biological mechanisms remains highly questionable, and does not provide an adequate care for the patients and families if not complemented by a psychological and environmental approach.

[Prospective memory - concepts, methods of assessment, neuroanatomical bases and its deficits in mental disorders]

In the last two decades of the last century there has been a shift in the studies on memory. In psychology of memory the criticism of the laboratory approach resulted in development of the ecological approach. One of the effects of this change was to initiate researches on memory that includes plans for the future, which has resulted in the distinction of the concept of prospective memory. Prospective memory is used in many aspects of everyday life. It deals with remembering intentions and plans, it is connected with remembering about specific task or activity in the future. There are three types of PM: event-based prospective memory, time-based prospective memory and activity-based prospective memory. Current research in this field have already established its own paradigm and tools measuring PM and there is still increasing scientific interest in this issue. Prospective memory assessment may be carried out in various ways. Among them, the most frequently used are: a) questionnaires, b) psychological tests, c) experimental procedures. Within the latter, the additional distinction can be introduced for: the experiments conducted under natural conditions and the laboratory procedures. In Polish literature, there are only a few articles on PM. The aim of this work is to review studies on assessment methods of PM. Its neuroanatomical bases and its functioning in different mental disorders are analyzed. The work is aimed to focus clinicians attention on prospective memory as an area which is important for complex diagnosis of cognitive processes.

Confabulations (I): concept, classification and neuropathology

INTRODUCTION

A working definition of confabulation could be that of describing them as false memories due to a retrieval problem, where the patient is unaware that he/she is confabulating, and has the belief that the memory is true. Several types of confabulations have been described, according to a broad variety of criteria. Confabulations can be seen in very different neurological conditions, which have lead to a controversy on their pathophysiological mechanisms.

OBJECTIVE

To obtain an updated revision in Spanish of the definitions, types, brain regions involved and neuropsychological correlates of the confabulations.

DEVELOPMENT

After reviewing the concept and several types of confabulations, the damaged brain regions associated to two conditions where confabulations occur, such as Korsakoff syndrome and patients with anterior communicating artery aneurysm, are described. The neuropsychological correlates associated to them are then reviewed.

CONCLUSIONS

Confabulations are a difficult-to-define complex phenomenon. Probably, the most accepted classification, in accordance with how they appear, would be that which distinguishes spontaneous from provoked confabulations, although the validity of this distinction is not clear. Regarding to crucial cerebral regions involved in the confabulations, it seems that prefrontal cortex lesions, specifically in ventromedial and orbitofrontal areas, are necessary. Neuropsychological evidence suggests the presence in most of the cases of executive dysfunction and at least some degree of memory dysfunction as an underlying mechanism of confabulation. Nevertheless, the specific characteristics of these neuropsychological dysfunctions are not well-known.

Patterns of cognitive decline, conversion rates, and predictive validity for 3 models of MCI

Our objective was to compare the predictive ability of different models of mild cognitive impairment (MCI) as a marker of incipient dementia in a longitudinal population-based Canadian sample. We examined the use of existing, well-documented MCI criteria using data from persons who underwent a clinical examination in the second wave of the Canadian Study of Health and Aging (CSHA). Demographic characteristics, average neuropsychological test performance, and sample frequencies and conversion rates were calculated for each classification. Receiver operating characteristic (ROC) analyses were employed to assess the predictive power of each cognitive classification. The highest sample frequencies and conversion rates were associated with case definitions of multiple-domain MCI. The only diagnostic criteria to significantly predict dementia 5 years later was the cognitive impairment no dementia (CIND)-2 case definition. More restrictive MCI case definitions fail to address the varying temporal increases in decline across different cognitive domains in the progression from normal cognitive functioning and dementia.

[Memory and its dysfunction]

In the last decades interdisciplinary research of memory takes place and it connects regions as cognitive psychology and neuroscience. Learning and memory are theoretical concepts, which enable to explain the fact that personal experience influences the behavior of the particular person. Memory has neuronal representation, which enables recollection of obtained experiences and information, and subsequently enables changes in behavior. The review describes events as registration, formation of memory trace as well as memory retrieval. Memory classification is possible according to many criteria, e.g. according to the length, its conscious recollection and the character of deposited information. Main types of memories are episodic memory (for facts and events), semantic memory (for general knowledge) and procedural memory (the ability to learn behavioral and cognitive abilities and algorithms). At present it is generally accepted that memory is a complicated process, which utilizes several brain structures at the same time that are called memory systems; according to the type of memory the experiences and information are deposited in various brain regions. The present research enables many approaches for determination of the sites of memory deposition. In the present period important role in memory localization have the brain imaging techniques. Together with the study of memory under physiological conditions, in the center of interest there is the study of memory during various life periods, under pathological conditions and diseases. The review is closed by the list of most important diseases in which we observe memory dysfunctions, including the retrograde and anterograde amnesias.

Clusters of cognitive and behavioral disorders clearly distinguish primary progressive aphasia from frontal lobe dementia, and Alzheimer's disease

BACKGROUND/AIMS

Frontal lobe dementia (FLD) and primary nonfluent progressive aphasia (PnPA) are two forms of frontotemporal lobe degeneration. The relationship between these conditions remains unclear. Our study aimed to better define the behavioral and cognitive clusters characterizing PnPA patients.

METHODS

We cognitively and behaviorally evaluated three groups of newly diagnosed patients affected by Alzheimer's disease (AD, n=20), FLD (n=22) and PnPA (n=10), in order to assess the cognitive-behavioral pattern of PnPA, compared to both FLD and AD.

RESULTS

We found, as expected, worse performances in episodic memory in AD, of both the verbal fluency and naming tasks in PnPA, while FLD mainly showed behavioral disorders associated with an unremarkable deficit in the executive tasks. PnPA was not characterized by any significant behavioral disorders. Factor analysis-extracted three main factors ('mnesic', 'behavioral' and 'linguistic') clearly correlated to each group. A discriminant analysis based on the extracted factors correctly classified 84.6% of all patients.

CONCLUSION

The evidence of a characteristics cognitive profile, without any significant behavioral changes, highlights that PnPA is different from other forms of frontotemporal lobe degeneration regarding both the cognitive and behavioral patterns; thus, it should be considered independently in further studies.

Arbeitsgedächtnisstörungen bei psychiatrischen Erkrankungen

Working memory disturbances occur in various psychiatric disorders and play a major role for general cognitive ability in everyday life and thus social integration of the patients. In schizophrenia and bipolar disorder, working memory deficits have been found to be associated with certain genotypes and clinical symptoms. This makes them promising endophenotypes, i.e., mediators between genotype and phenotype. Furthermore recent studies indicate that the identification of selective deficits in working memory may be useful in order to define patient subgroups that are more homogenous with respect to the functional integrity or dysfunction of neural systems underlying working memory subcomponents. This scientific approach may ultimately lead to better understanding of the pathophysiologic mechanisms underlying working memory dysfunctions in psychiatric disorders and may provide clinicians with additional information for diagnostic and therapeutic decisions.

Selective impairment in the retrieval of family relationships in person identification: A case study of delusional misidentification

We describe a 74-year-old, right-handed woman who exhibited a peculiar form of delusional misidentification due to Alzheimer's disease (AD) combined with idiopathic normal pressure hydrocephalus (iNPH). The patient's most distinctive symptom was that she often misidentified her daughters as her sisters. She had severe atrophy of the bilateral medial temporal lobe and right-hemisphere-dominant hypoperfusion in the fronto-temporo-parietal cortices. Detailed tests revealed that she had a selective deficit in retrieving the family relationships between herself and her daughters/husband (i.e., she misidentified her daughters as her sisters and her husband as her father), despite being able to retrieve the names and faces of her family members, and some person-specific semantic information (e.g., occupation) related to them. We speculate that this specific type of misidentification can be elicited by failure to update semantic memory through the encoding of new episodic memory due to right-hemisphere-dominant fronto-temporal dysfunction.

The Semantic Object Retrieval Test (SORT) in Normal Aging and Alzheimer Disease

OBJECTIVE

To characterize performance on a test of semantic object retrieval (Semantic Object Retrieval Test-SORT) in healthy, elderly subjects and patients with Alzheimer disease (AD).

BACKGROUND

Although the initial presentation of patients with AD often reflects impairment in delayed recall for verbally encoded memory, common complaints of patients with early AD are actually related to semantic memory impairment.

DESIGN

Thirty-eight AD patients and 121 healthy aging controls enrolled in an Alzheimer's Disease Center received a battery of standard neuropsychologic tests including the SORT.

RESULTS

Compared with normal controls, AD patients had SORT memory impairments with significantly more false positive memory errors, fewer correctly produced names, and more substitutions in the name production aspect of the test. SORT had robust test-retest reliability in normals.

CONCLUSIONS

The SORT task provides a direct, specific assessment of semantic memory, and has now been administered to 121 healthy, aging controls for normative ranges of performance, and to AD patients. The task detected semantic memory deficits in approximately half of patients with mild-moderate AD, which is comparable to other studies assessing semantic deficits in AD with less specific measures.

Evidence for a double dissociation between spatial-simultaneous and spatial-sequential working memory in visuospatial (nonverbal) learning disabled children

The paper describes the performance of three children with specific visuospatial working memory (VSWM) impairments (Study 1) and three children with visuospatial (nonverbal) learning disabilities (Study 2) assessed with a battery of working memory (WM) tests and with a number of school achievement tasks. Overall, performance on WM tests provides evidence of a double dissociation between spatial-simultaneous processes, underpinning the memorization item positioning in a spatial configuration, and spatial-sequential processes, which allow memorization of the presentation order. In both groups of children of the two studies, a selective impairment either on spatial-sequential or on spatial-simultaneous working memory tasks was observed. These data support the existence of -simultaneous and -sequential modality-dependent processes in visuospatial working memory and confirm the importance of distinguishing between different subtypes of visuospatial (nonverbal) learning-disabled children.

Patterns of verbal memory performance in mild cognitive impairment, Alzheimer disease, and normal aging

OBJECTIVE

Individuals with mild cognitive impairment (MCI) typically demonstrate memory loss that falls between normal aging (NA) and Alzheimer disease (AD), but little is known about the pattern of memory dysfunction in MCI.

METHOD

To explore this issue, California Verbal Learning Test (CVLT) performance was examined across groups of MCI, AD, and NA.

RESULTS

MCI subjects displayed a pattern of deficits closely resembling that of AD, characterized by reduced learning, rapid forgetting, increased recency recall, elevated intrusion errors, and poor recognition discriminability with increased false-positives. MCI performance was significantly worse than that of controls and better than that of AD patients across memory indices. Although qualitative analysis of CVLT profiles may be useful in individual cases, discriminant function analysis revealed that delayed recall and total learning were the best aspects of learning/memory on the CVLT in differentiating MCI, AD, and NA.

CONCLUSIONS

These findings support the position that amnestic MCI represents an early point of decline on the continuum of AD that is different from normal aging.

Spontaneous verbal labeling: visual memory and reading ability in children with cleft

OBJECTIVE

The purpose of this study was to examine different types of short-term memory deficits (visual versus verbal) of children with cleft and to determine what type of memory deficits were associated with reading disorders.

DESIGN

The study examined memory and reading in 48 consecutive cases of children with cleft, aged 7 to 9 years. A memory test designed to assess memory modalities (verbal-visual) was administered, along with tests of reading ability.

RESULTS

Visual and verbal memory were examined with a one-way analysis of variance (ANOVA). The memory pattern indicated greatest deficit in visual memory. Two subgroups were formed, according to whether or not there was evidence of visual memory impairment. A hit rate predicting reading disability based on group membership was calculated to be 65%. Visual memory was significantly correlated with reading ability (r = .48).

CONCLUSION

A brief visual memory test was almost as good as Full Scale IQ in predicting reading disability.

What is the locus of the errorless-learning advantage?

In two experiments involving word-stem completion, an advantage was found for errorless over errorful-learning conditions, for both severely and moderately memory-impaired participants. This advantage did not depend on the implicit/explicit nature of the question asked. Additional tests showed that subsequent recognition of target items was good for both groups, but only in the absence of lures derived from participants' prior errors. Source-memory was shown to be virtually absent in the severely impaired group and only weakly present in the moderately impaired group. This combination of results suggests that preserved implicit memory, in the absence of explicit memory, is sufficient for an errorless-learning advantage to accrue.

Anatomical functional and cognitive determinants of semantic memory disorders

Contemporary debates on the 'semantic memory' construct revolve around three main topics: (1) the functional and anatomical relationships between episodic and semantic memory; (2) the format of semantic representations and their relationships with the underlying sensory-motor processes; (3) the categorical organization of semantic memory. The aim of the present review is to demonstrate that there is a common thread linking these different aspects of semantic memory. This thread is represented by the interdependence of mechanisms involved in the construction of semantic memory and the content of semantic representations. In particular, I suggest there is a continuity between: (a) the mechanisms of acquisition of episodic and semantic memory; (b) semantic representations and sensory-motor processes preliminary to the acquisition of these representations. This continuity has important implications for the format of semantic representations and the brain structures subserving the organisation of various categories of knowledge.

Patterns of impairment in autobiographical memory in the degenerative dementias constrain models of memory

Detailed study of the autobiographical memory (ABM) impairments seen in different forms of degenerative dementia, in particular Alzheimer's disease (AD) and semantic dementia (SD) can inform neuropsychological models of memory. A modified ABM questionnaire which allowed more detailed analysis of episodic and semantic ABM was used to study the pattern of deficits in patients with minimal to mild Alzheimer's disease (AD) and in two patients with mild and moderate semantic dementia (SD). The questionnaire tested both cued and free recall. A group of healthy elderly was also tested. AD patients differed from controls in all measures. There was no clear temporal gradient for episodic ABM, but a modest gradient was observed for semantic ABM. The mild SD patient performed at control level for episodic ABM but showed a deficit within the range of the AD patients for semantic ABM except for the most recent life period. In contrast the moderate SD patient was impaired within the range of the AD patients for both episodic and semantic ABM. The evidence for differential impairment of episodic and semantic ABM retrieval in AD and SD is interpreted as supporting the multiple trace model of memory.

Variability in the Impairment of Recognition Memory in Patients with Frontal Lobe Lesions

Fourteen patients with frontal lobe lesions and 14 normal subjects were tested on a recognition memory task that required discriminating between target words, new words that are synonyms of the targets and unrelated distractors. A deficit was found in 12 of the patients. Moreover, three different patterns of recognition impairment were identified: (I) poor memory for targets, (II) normal hits but increased false recognitions for both types of distractors, (III) normal hit rates, but increased false recognitions for synonyms only. Differences in terms of location of the damage and behavioral characteristics between these subgroups were examined. An encoding deficit was proposed to explain the performance of patients in subgroup I. The behavioral patterns of the patients in subgroups II and III could be interpreted as deficient post-retrieval verification processes and an inability to recollect item-specific information, respectively.

[What is a mild cognitive impairment?]

The concept of mild cognitive impairment (MCI) has been proposed by Petersen et al. (1997, 1999) as a nosologic entity referring to elderly persons with mild cognitive deficit without dementia. MCI is being widely used in studies as an intermediate stage between cognitive normalcy and dementia. However, MCI appears to be a heterogeneous clinical entity. Multiple sources of heterogeneity have been described: heterogeneity in aetiological factors (various types of degenerative lesions, vascular risk factors, psychiatric features, association of pathological conditions), heterogeneity in clinical symptoms, and heterogeneity in clinical course with decliners and non decliners presenting stable or reversible cognitive impairment. Thus new criteria of MCI are proposed for use in research but also in clinical practice. MCI may henceforth correspond to the following: (1.) Cognitive complaint emanating from the patient and/or his/her family; (2.) the subject and/or notifying party report a decline in cognitive and/or functional performance relative to previous abilities; (3.) cognitive disorders evidenced by clinical evaluation: impairment in memory and/or another cognitive domain; (4.) cognitive impairment does not have any repercussions on daily life, the subject may report difficulties concerning complex day-to-day activities; (5.) no dementia.

Disorders of memory

The understanding of the neuroanatomic substrates and cognitive processes underlying memory functioning has improved dramatically during the past several decades. Animal studies and observations of patients who have brain diseases show that memory is not a unitary factor but instead can be parsed into overlapping but dissociable constructs; that encoding, retention, and retrieval processes depend on the integrity of several distinct brain regions; and that the creation of new memories depends on structural and functional changes within the neuronal systems of those brain regions. Much remains to be learned, however, regarding the specific biologic,genetic, and information-processing mechanisms underlying many features of this complex cognitive construct. As this knowledge base grows, new and improved pharmacologic and behavioral treatments for patients who have memory disorders may be realized.

Usefulness of P300 in Subjective Memory Complaints

The existing studies about the utility of P300 latency for diagnostically classifying patients in preclinical stages of dementia are cross-sectional rather than longitudinal in design, and their results are inconclusive. The authors investigated the P300 value in a series of patients with subjective memory complaints using a prospective design. The study was performed in a consecutive series of 116 outpatients with subjective memory complaints as the predominant symptom. P300 (auditory oddball task) was performed immediately after the first clinical evaluation, and at 12 and 24 months. Final cognitive syndrome diagnosis (mean follow-up period, 27.7 months) was then made by a neurologist who was blinded to the neurophysiologic results. Diagnosis at the end of follow-up was 30 cases of normal cognition, 30 cases of mild cognitive impairment, 28 cases of dementia of Alzheimer's type (DAT), five cases of vascular dementia, and one case of frontotemporal dementia; 22 patients were lost to follow-up. P300 latency was significantly higher for the DAT group (analysis of variance: P=0.023) throughout the study. The diagnostic value of P300 latency at baseline examination for DAT had a sensitivity of 52.9% and a specificity of 76.9%; the odds ratio was 3.75 (95% confidence interval, 1.23-11.41). Findings from the present study suggest that assessment of evoked related potentials may contribute to the early detection of DAT.

Alzheimer's disease and models of computation: Imaging, classification, and neural models

Prediction or early-stage diagnosis of Alzheimer's disease (AD) requires a comprehensive understanding of the underlying mechanisms of the disease and its progression. Researchers in this area have approached the problem from multiple directions by attempting to develop (a) neurological (neurobiological and neurochemical) models, (b) analytical models for anatomical and functional brain images, (c) analytical feature extraction models for electroencephalograms (EEGs), (d) classification models for positive identification of AD, and (e) neural models of memory and memory impairment in AD. This article presents a state-of-the-art review of research performed on computational modeling of AD and its markers. The review covers the following approaches: computer imaging, classification models, connectionist neural models, and biophysical neural models. It is concluded that a mixture of markers and a combination of novel computational techniques such as neural computing, chaos theory, and wavelets can increase the accuracy of algorithms for automated detection and diagnosis of AD.

Evidence for impaired encoding and retrieval memory profiles in Parkinson disease

OBJECTIVE

The purpose of the study was to determine whether patients with Parkinson disease (PD) demonstrate different memory profiles. Specifically, we sought to ascertain whether the memory performance of PD patients can be categorized as fitting an unimpaired, an impaired retrieval, or an impaired encoding memory profile.

BACKGROUND

Cognitive impairment in PD is usually described as subcortical-frontal in nature. However, neuropathophysiological changes consistent with diffuse cortical disease are also reported. Establishing memory subtypes in PD could potentially assist in reducing the observed heterogeneity of disease presentation, establishing prognosis, making clinical decisions, and defining endpoints in clinical trials.

METHODS

: A sample of 63 PD patients was evaluated with the Hopkins Verbal Learning Test-Revised (HVLT-R). Cluster analysis was used to classify patients into three memory subgroups based on performance on free recall, intrusion errors, and recall enhancement with recognition. Subgroup comparisons were made for demographic and clinical characteristics.

RESULTS

An "unimpaired" group (n = 30) demonstrated intact free recall and few intrusion errors. "Impaired retrieval" (n = 22) and "impaired encoding" (n = 11) subgroups with similar impairment on free recall were also identified, but the impaired retrieval group demonstrated greater memory improvement with recognition (P < 0.001) and had fewer intrusion errors (P < 0.001) than the impaired encoding group.

CONCLUSIONS

A majority of PD patients demonstrate memory impairment, which can be categorized as either a primary retrieval or a primary encoding deficit. Further research is needed to confirm memory subtypes in PD and determine their diagnostic, prognostic, and therapeutic significance.

[Optimised neuro-psychological tests on different stages of dementia diagnostics]

OBJECTIVE

We postulated three level of dementia diagnostics: the general practitioner, the neuro-psychiatrist and the memory clinic. For each level, definite diagnostic questions were defined as the main diagnostic focus. The aim was to establish a staged process in dementia diagnostics, proposing for each diagnostic level a specific test battery suitable for the respective diagnostic focus. On each level, the test battery can be supplemented by other tests proposed on the subsequent diagnostic level.

METHOD

159 patients were examined clinically, neuropsychologically, and neuroradiologically. Discriminant analyses were computed to find out which tests out of a comprehensive test battery are most suitable in differentiating between several diagnostic groups.

RESULTS

The diagnostic accuracy of the test batteries proposed for general practitioners and neuro-psychiatrists were maximally 3 % below that of the complete test battery which we suggest for memory clinics.

CONCLUSION

Depending on the diagnostic level, a definite short form of a comprehensive test battery can be implemented without unacceptably reducing diagnostic accuracy.

A positive emotional bias in confabulatory false beliefs about place

Some neurological patients with medial frontal lesions exhibit striking confabulations. Most accounts of the cause of confabulations are cognitive, though the literature has produced anecdotal suggestions that confabulations may not be emotionally neutral, having a ('wish-fulfilment') bias that shapes the patient's perception of reality in a more affectively positive direction. The present study reviewed every case (N = 16) of false beliefs about place reported in the neuroscientific literature from 1980 to 2000, with blind raters evaluating the 'pleasantness' of the patient's actual and confabulated locations. In each case the confabulated location was evaluated as more pleasant. This striking finding supports the claim that there may be a systematic affective bias in the false beliefs held by neurological patients with confabulation.

Stability and functional correlates of memory-based classification in older schizophrenia patients

OBJECTIVE

There is an increasing interest in the usefulness of neurocognitive subtyping of schizophrenia. The classification of schizophrenia patients with cortical versus subcortical impairments has recently been validated with both neuropsychological and neurobiological measures. The authors examined the stability and correlations of these classifications with longitudinal assessments in older, chronically ill schizophrenia patients.

METHODS

Older, chronically ill patients (N=589) were classified on the basis of their baseline profile, and a subset (N=243) was followed for periods up to 8 years, with data analyses conducted to evaluate the stability of these profiles, to determine whether classification into cortical or subcortical impairment at baseline predicts changes in self-care and social functioning at endpoint, up to 8 years later.

RESULTS

Cortical profiles were most common and most stable over time, with the majority of patients with a subcortical profile at baseline found to have a cortical profile at follow-up. Those patients whose subcortical impairment profile was stable over time had less severe cognitive and functional impairments at baseline than those whose profile was found to be cortical at follow-up.

DISCUSSION

Cortical profiles of memory impairment were associated with substantial cognitive impairments at baseline and did not predict risk for subsequent cognitive decline, whereas subcortical profiles were associated with worsening of cognitive impairments in about half of the cases. Those patients with more severe negative symptoms and cognitive and functional impairments within the subcortical group were most likely to decline.

The fuzzy frontier between subjective memory complaints and early dementia. A survey of patient management in German memory clinics

BACKGROUND

Mild cognitive decline is frequent in the elderly population. Whether it is related to normal aging or an early phase of evolving dementia is difficult to ascertain with confidence, and accordingly there is a lack of consensus guidelines for diagnosis and therapy in such patients. We assessed the variability with which memory clinics deal with this problem in everyday practice.

METHODS

We sent three fictitious case histories to all 85 German memory clinics that contained the results of clinical examination and neuropsychological test scores and asked for diagnosis and patient management. Patient 1 presented with complaints of mental decline but normal neuropsychological and neurological evaluation and normal daily living activities. Patient 2 came in as a control subject for a study and had impaired test scores but preserved daily living activities, and patient 3 was brought in by relatives with slight impairment of daily living activities and decline in some neuropsychological test scores but relatively spared memory scores.

RESULTS

Most of the 51 respondents agreed in recommending further neuropsychological testing, a basic laboratory work-up, brain imaging, and a re-examination after 3-6 months. Yet, there was a high variability in the diagnostic terms used, in the additional diagnostic procedures proposed, and in the recommendations concerning therapeutic intervention and driving.

CONCLUSIONS

The results reveal a need of practice guidelines for the use of diagnostic terms, therapeutic interventions and driving recommendations in patients between subjective memory complaints and early dementia.

Psychometric analysis of the Revised Memory and Behavior Problems Checklist: factor structure of occurrence and reaction ratings

A modified version of the Revised Memory and Behavior Problems Checklist (RMBPC; L. Teri et al., 1992) was administered across 6 different sites to 1,229 family caregivers of community-dwelling adults with dementia. The total sample was divided randomly into 2 subsamples. Principal components analyses on occurrence responses and reaction ratings from the first subsample resulted in a 3-factor solution that closely resembled the originally proposed dimensions (memory-related problems, disruptive behaviors, and depression). Confirmatory factor analyses on data from the second subsample indicated adequate fit for the 3-factor model. Correlations with other caregiver and care-recipient measures supported the convergent and discriminant validity of the RMBPC measures. In addition, female caregivers and White caregivers reported more problems, on average, than male caregivers and African American caregivers, respectively.

Comparison of Predicted-difference, Simple-difference, and Premorbid-estimation methodologies for evaluating IQ and memory score discrepancies

Discrepancies between WAIS-III and WMS-III scores for a group of 39 males and 48 females with a history of TBI were examined using three methodologies: Predicted-difference, Simple-difference, and Premorbid-estimation methods. Overall, the Predicted-difference method tended to classify the fewest individuals as impaired based on statistical rarity of discrepancies (11-16% classified as impaired), while the regression-based Premorbid method tended to classify the fewest individuals as impaired based on clinical rarity of discrepancies (4-8% classified as impaired). Degree of agreement is reported and was substantial. The only comparison between methods to reach statistical significance was the Predicted-difference method classifying subjects as impaired at a higher rate than other methods for Auditory Delayed memory index (Cochran's Q = 7.00, P < .05). Findings suggest a combination of estimates of premorbid functioning and regression-based predicted scores is optimal for interpreting IQ/memory score discrepancies. Clinical implications are discussed.

[Memory. An introduction to the study of the cognitive disorders in normal and pathological aging]

INTRODUCTION

As the life expectancy of the population rises, there is also an increase in the frequency of the diseases that appear in the elderly. Aging can be healthy or pathological, but the borderline between the two is still a bit fuzzy.

DEVELOPMENT

With the increase in the longevity of the population, Alzheimer's Disease (AD) and other illnesses linked to the aging process have become more common, above all in people between 65 and 85 years of age. The cognitive aspects that, in clinical practice, are most frequently seen to be involved are memory, attention, executive functions and the speed at which information is processed; these are the most common in these patients but the most severe and insidious as well as the first to appear are problems affecting memory. The physiological mechanism behind memory has still not been wholly explained. The modulation of many of the cognitive processes given by the cerebellum expands the borders in the study of the different mnemonic processes. The prefrontal cortex plays an essential role in controlling attention and in the mnemonic filing system required to supervise and modulate sensory motor processing and the basic complex actions of cognition, emotion and human behaviour.

CONCLUSIONS

The neuroanatomical, psychological and neurophysiological foundations of memory are very complex and involve the intervention of a number of structures that, within a single integrated context, each contribute to the overall functioning.

Prevalence and Classification of Mild Cognitive Impairment in the Cardiovascular Health Study Cognition Study

OBJECTIVE

To examine the prevalence of mild cognitive impairment (MCI) and its diagnostic classification in the Cardiovascular Health Study (CHS) Cognition Study.

DESIGN

The CHS Cognition Study is an ancillary study of the CHS that was conducted to determine the presence of MCI and dementia in the CHS cohort.

SETTING

Multicenter population study.

PATIENTS

We examined 3608 participants in the CHS who had undergone detailed neurological, neuropsychological, neuroradiological, and psychiatric testing to identify dementia and MCI.

MAIN OUTCOME MEASURES

The prevalence of MCI was determined for the whole cohort, and specific subtypes of MCI were examined in detail only at the Pittsburgh, Pa, center (n = 927). Mild cognitive impairment was classified as either MCI amnestic-type or MCI multiple cognitive deficits-type.

RESULTS

The overall prevalence of MCI was 19% (465 of 2470 participants); prevalence increased with age from 19% in participants younger than 75 years to 29% in those older than 85 years. The overall prevalence of MCI at the Pittsburgh center was 22% (130 of 599 participants); prevalence of the MCI amnesic-type was 6% and of the MCI multiple cognitive deficits-type was 16%.

CONCLUSIONS

Twenty-two percent of the participants aged 75 years or older had MCI. Mild cognitive impairment is a heterogeneous syndrome, where the MCI amnestic-type is less frequent than the MCI multiple cognitive deficits-type. Most of the participants with MCI had comorbid conditions that may affect their cognitive functions.

Mild cognitive impairment: directions for future research

Mild cognitive impairment (MCI), an intermediate state between normal aging and dementia, is characterized by acquired cognitive deficits, without significant decline in functional activities of daily living. Studies conducted on MCI have introduced new concepts regarding the possible distinctions between normal and pathologic aging of the brain. Neuroimaging and genetic testing have aided in the identification of individuals at increased risk for dementia. The measurement of change in cognitive and functional status in MCI remains challenging, because it requires instruments that are more sensitive and specific than those considered adequate for research in dementia. The authors provide an overview of the many methods that have been used to study MCI and directions that may help achieve greater uniformity in methodology. Considerable heterogeneity exists in research methodology used to study the epidemiology, thresholds for cognitive and functional impairment, rate of progression, risk factors, and defining subtypes of MCI. This article emphasizes the need for uniformity in the use of 1) appropriate and sensitive neuropsychological and functional measures to diagnose MCI, 2) reliable methods to determine progression or improvement of cognitive impairment, and 3) instruments in epidemiologic studies to establish population estimates for diverse ethnic and cultural groups. Greater consensus is needed to standardize definitions and research methodology for MCI, so as to make future studies more comparable and more useful for designing effective treatment strategies.

Specific memory deficits in ecstasy users? The results of a meta-analysis

A meta-analysis was carried out on the possible functional neurotoxic effects of ecstasy use in humans on verbal short-term memory (STM), verbal long-term memory (LTM), processing speed (RT) and % errors (attention). To that end studies were found on the effect of ecstasy that fulfilled the criteria for a meta-analysis (number of subjects, means and standard deviations of the dependent variables). Ten studies were included on STM, ten on LTM, eight on RT and eight on % errors (attention). In addition meta-regression analyses were carried out on the effect sizes with total lifetime ecstasy consumption (TLEC) as predictor. It was found that in all four meta-analyses the mean effect size (ES) was significant: ecstasy users had lower verbal STM and LTM scores, reacted slower and made more errors. The meta-regression coefficients were not significant, indicating no support for a linear relationship between the mean ES values and TLEC, leaving open the possibility for a stepwise relationship. Additional meta-analyses on ecstasy groups that did not differ in lifetime cannabis consumption showed that only the ES for LTM became insignificant. This suggests that ecstasy use does not decrease LTM, but the number of studies on which this conclusion is based was very low.

[Memory and brain--neurobiological correlates of memory disturbances]

A differentiation of memory is possible on the basis of chronological and contents-related aspects. Furthermore, it is possible to make process-specific subdivisions (encoding, transfer, consolidation, retrieval). The time-related division on the one hand refers to the general differentiation into short-term and long-term memory, and, on the other, to that between anterograde and retrograde memory ("new" and "old memory"; measured from a given time point, usually that when brain damage occurred). Anterograde memory means the successful encoding and storing of new information; retrograde the ability to retrieve successfully acquired and/or stored information. On the contents-based level, memory can be divided into five basic long-term systems--episodic memory, the knowledge system, perceptual, procedural and the priming form of memory. Neural correlates for these divisions are discussed with special emphasis of the episodic and the knowledge systems, based both on normal individuals and brain-damaged subjects. It is argued that structures of the limbic system are important for encoding of information and for its transfer into long-term memory. For this, two independent, but interacting memory circuits are proposed--one of them controlling and integrating primarily the emotional, and the other primarily the cognitive components of newly incoming information. For information storage principally neocortical structures are regarded as important and for the recall of information from the episodic and semantic memory systems the combined action of portions of prefrontal and anterior temporal regions is regarded as essential. Within this fronto-temporal agglomerate, a moderate hemispheric-specificity is assumed to exist with the right-hemispheric combination being mainly engaged in episodic memory retrieval and the left-hemispheric in that of semantic information. Evidence for this specialization comes from the results from focally brain-damaged patients as well as from that functional brain imaging in normal human subjects. Comparing results from imaging studies in memory disturbed patients with brain damage and from patients with a psychiatric diagnosis (e. g., psychogenic amnesia) revealed that both patient groups demonstrate comparable metabolic changes on the brain level. It can therefore be concluded that in neurological patients distinct, identifiable tissue damage is existent, while in psychiatric patients changes in the brain's biochemistry (release of stress hormones, and transmitters) constitute the physiological bases for the memory disturbances.

Disorders of memory

This paper reviews disorders of memory. After a brief survey of the clinical varieties of the amnesic syndrome, transient and persistent, selected theoretical issues will be considered by posing a series of questions. (i) What is impaired and what is spared in anterograde amnesia? (ii) Do temporal lobe, diencephalic and frontal lobe amnesias differ? (iii) How independently semantic is semantic memory? (iv) What determines the pattern and extent of retrograde memory loss? (v) Can retrograde amnesia ever be "isolated"? (vi) Does psychogenic amnesia involve the same mechanisms as organic amnesia? (vii) How and when do false memories arise? Commonalities as well as differences across separate literatures will be emphasized, and the case for a more "dynamic" (interactionist) approach to the investigation of amnesia will be advocated.

Classification accuracy of the portland digit recognition test in traumatic brain injury

This study examined the classification accuracy of the Portland Digit Recognition Test (PDRT) in traumatic brain injury (TBI). It differs from past studies in assigning patients to malingering and control groups on the basis of compensation-seeking status and the presence of external markers for malingering. Sensitivity and Specificity were.77 and 1.00, respectively. Past research comparing compensation-seekers to noncompensation-seekers reported Sensitivities of.33 or lower (Specificity is always high). This study demonstrates that past research has seriously underestimated the Sensitivity of the PDRT and raises questions about the true Sensitivity of other malingering techniques as well.

Interobserver disagreements on clinical dementia rating assessment: interpretation and implications for training

The Clinical Dementia Rating (CDR) is a widely used semiobjective instrument for staging dementia severity. A global CDR score is reported that is derived from individual scores in six domains. In this study, we examined both agreement and disagreement, among raters and with a gold standard, to identify domain-specific and global dementia severity level ratings that would most benefit from further training or greater emphasis in future training. We found that raters-in-training experienced the most difficulty with rating normal and questionable dementia. They also had the most trouble scoring the memory domain. When they disagreed with the gold standard, they nearly always gave higher ratings. A third, extremely experienced group of raters were uniform in their high levels of agreement on each domain and the global CDR and tended to give lower ratings if they disagreed with the gold standard. Analysis of the agreement and disagreement patterns suggested that greater emphasis on the memory, home and hobbies, and orientation domains during CDR training, and increasing the information provided for the judgment and problem solving domain on the standardized CDR worksheets, could improve the consistency of raters and increase the efficiency with which they are trained to use the CDR.

[Clinical history in the study of a patient with dementia]

OBJECTIVES

To carry out a detailed review of the keys to diagnosis of different types of dementia whilst taking a clinical history.

DEVELOPMENT

Dementia is a syndrome with many different aetiologies. Correct diagnosis depends on recording data of the history of the dementia, particularly of complaints regarding cognition and behavior. The keys to the clinical history should be based on questions about cognitive disorders, with emphasis on how they started, their evolution and particular form of dysfunction, Although Alzheimer's dementia is the most frequent, this diagnosis should only be made when the other forms of dementia have been ruled out. In this article we describe some of the keys to a good clinical history to facilitate the etiological and differential diagnosis of dementia.

CONCLUSIONS

Establishment of a full clinical history is the first and most important step in the diagnosis of dementia and cognitive disorders. On this will depend the plan to be followed to study the aetiology and most suitable treatment. Success or failure in the study of a patient with dementia depends on the quality of the clinical history obtained.

Do subgroups of patients with Alzheimer's disease exhibit asymmetric deficits on memory tests?

Several studies have reported asymmetric cognitive profiles in patients with Alzheimer's disease (AD), but these results have almost exclusively been found using non-memory cognitive instruments. The present study investigated whether AD patients who display lateralized profiles on non-memory cognitive instruments also exhibit asymmetric deficits on verbal versus spatial memory tests. Sixty-eight AD patients participated in the study: 36 with a "High Verbal" cognitive profile, and 32 with a "High Spatial" profile. The results indicated that the High Verbal AD patients performed significantly better than the High Spatial AD patients on verbal memory tests, but the two subgroups failed to differ on spatial memory tests. Implications of these findings for understanding the heterogeneous nature of cognitive profiles in AD patients are discussed.

Higher basal cortisol predicts verbal memory loss in postmenopausal women: Rancho Bernardo Study

BACKGROUND

In animals, higher endogenous or exogenous corticosteroids cause neuronal dysfunction, damage, and loss, especially in the hippocampus. In humans, high cortisol levels have been linked to memory impairment.

OBJECTIVE

To prospectively examine the relation between morning basal cortisol level and change in cognitive performance during an average follow-up of 2 years.

DESIGN

Longitudinal cohort.

SETTING

Geographic community in southern California.

MEASUREMENTS

Between 1984 and 1987, blood for basal morning cortisol was obtained along with pertinent medical, behavioral, and physical covariates from 749 post-menopausal women, mean age 72 years, who were not taking corticosteroids or postmenopausal hormones. Cognitive function was assessed in 502 women in the period from 1988 to 1991 and repeated in 136 women in the period from 1991 to 1993.

RESULTS

In both age- and multiply adjusted linear regression models, higher baseline cortisol was a significant predictor of worsened category fluency. No other cognitive domain tested was related to cortisol.

CONCLUSIONS

These results support the hypothesis that subtle dysregulation of cortisol axis is related to memory loss. Interventions that block this pathway may provide new therapeutic options to prevent cognitive decline.

The dependence of span and delayed-response performance on prefrontal cortex

Theoretical and empirical research on the cognitive functions of the prefrontal cortex have established that this region mediates what have been called 'executive' processes that can influence working and long-term memory. Despite the accumulation of such empirical evidence, the dependence of purely mnemonic portions of memory tasks on PFC remains unresolved. To address this issue, we performed an analysis of reports of performance on tests of working memory of patients with lesions of the dorsolateral prefrontal cortex, focusing on published reports in the literature of simple span and delayed-response tasks. We found that none of the eleven studies of forward verbal and spatial span in patients with prefrontal cortical lesions that we reviewed (reflecting the performance of 166 individual patients) demonstrated a statistically significant deficit relative to normal controls. In contrast, our review of the delayed-response literature indicated that there are conditions under which PFC lesions disrupt delayed-response performance. Based on the results of our review of the literature, we present testable hypotheses about the working memory functions of the PFC.

Memory and metamemory functioning among depressed patients

Memory and metamemory functioning were studied among 30 adult patients suffering from major depression. The results indicate that, besides showing signs of cognitive slowing, the patients were especially vulnerable to visual memory impairment, whereas verbal, short-term memory, and recall by recognition were more often unaffected. The patients whose depression was characterized by physiological symptoms, such as loss of appetite and sleep disturbances, showed impairment in traditional short-term memory measures, whereas there was no firm connection between cognitive or behavioral depressive symptoms and memory functioning. The depressive patients' generalized view of their memory capability was strongly underestimated, whereas online metamemory accuracy by which one perceives and makes inferences about one's performance was adequate.

Memory versus intelligence in dementia screening--MMSE

The Mini-Mental State exam is a widely used screening instrument for dementia. Recent research has suggested that errors in classification reported for this instrument may be due to premorbid levels of intelligence and education, Thirty-one ambulatory patients diagnosed with Alzheimer's disease were administered a standard neuropsychological testing battery. MMSE scores and intelligence are significantly correlated. However when memory ability is partialed out, the covariance of MMSE and intellectual abilities does not add any further information to that already provided by the memory scores.

Cognitive decline in ageing: are AAMI and AACD distinct entities?

BACKGROUND

Two sets of research diagnostic criteria, age-associated memory impairment (AAMI) and ageing-associated cognitive decline (AACD), are widely used to describe mild cognitive decline in ageing. However, the extent to which the nosological entities they represent are similar or distinct is unclear.

METHODS

A sample of 111 participants without dementia but with informant evidence of cognitive decline were drawn from the EUGERIA Study of Cognitive Ageing, a population-based study in southern France. These participants were classified as either normal or with AAMI according to the criteria of Crook et al. (1986), then reclassified as normal or with AACD according to criteria recommended by Levy et al. (1994). Neuropsychological test scores were then compared in these two pairs of groups.

RESULTS

Particpants were classified as either normal (N=74) or with AAMI (N=37), then reclassified as normal (N=72) or with AACD (N=39). Only 20 (54%) of participants with AAMI simultaneously met criteria for AACD, and those with AACD showed more extensive cognitive impairment than those with AAMI.

CONCLUSIONS

Although there is a large overlap between AAMI and AACD, these findings suggest that AAMI and AACD refer to distinct clinical entities, the latter delineating a more severe state of impairment. This may be largely because AAMI is defined as impairment with reference to young normals, whereas AACD refers to impairment with respect to normal contemporaries.

[Cognitive changes in normal aging: nosology and current status]

INTRODUCTION AND OBJECTIVES

During the last 15 years several diagnostic categories have appeared to describe a group of adults with cognitive impairment compared to their age-matched standardized norms but without dementia. In this work, the main studies relating to these categories are reviewed and compared in order to establish if they define similar or different aged populations.

DEVELOPMENT

Differences in prevalence or in prognostic values among studies are probably due to the selection of diagnostic categories or the differences in the application of inclusion/exclusion criteria. Genetic and neuroimaging data have contributed to reinforce the validity of the proposed classifications to identify the age related cognitive decline.

CONCLUSIONS

The criteria used seems to be very important in the inclusion of subjects closer to normal aging or to dementia. In this respect further longitudinal studies and a consensus from previous described categories are need to reliably identify aged population with lower cognitive function compared to their age norms but different from patients in the initial stages of dementia.