Prevalence and associated factors of mild cognitive impairment among middle-aged and older adults: Results of the first phase of Ardakan Cohort Study on Aging

Background and Aims

Data on mild cognitive impairment (MCI) in low- to middle-income countries are still being determined, despite the fact that most future older adults are expected to reside in these regions. This study aimed to investigate the prevalence and associated factors of MCI in Iran.

Methods

A cross-sectional study was conducted on 4938 community-dwelling subjects aged 50 years or above in the first wave of the Ardakan Cohort Study on Aging. MCI was evaluated using the Mini-Mental State Examination (MMSE) and the Abbreviated Mental Test Score (AMTS) in literate and illiterate individuals. The relationship between factors associated with the odds of MCI was assessed through logistic regression.

Results

The prevalence of MCI among all participants, the literates and illiterates, was 15.8%, 6.3%, and 36.4%, respectively. It was found that failure to accomplish any of the MMSE or AMTS items was significantly related to MCI (p < 0.001). Age ([odds ratio (OR): 1.05; p < 0.001 in the literates], [OR: 1.06; p < 0.001 in the illiterates]), sex (OR: 0.13; p < 0.001 in the illiterates), history of stroke ([OR: 2.86; p = 0.006 in the literates], [OR: 2.04; p = 0.045 in the illiterates]), and depression ([OR: 1.87; p < 0.001 in the literates], [OR: 1.41; p = 0.008 in the illiterates]) were significantly associated with MCI.

Conclusion

This study highlights the significant associations between age, education, depression, stroke, and MCI in Iranian participants. These findings emphasize the need for targeted interventions in low-literacy populations, mental health screening, and stroke prevention strategies to mitigate the burden of MCI and enhance cognitive health.

Calcified carotid artery atheromas in individuals with cognitive dysfunction

OBJECTIVE

The aim of this case-control study was to investigate whether cognitively impaired individuals have a higher burden of calcified carotid artery atheroma (CCAA) than controls without cognitive impairment.

MATERIAL AND METHODS

The study included 154 cases with Alzheimer's disease (n = 52), mild cognitive impairment (n = 51), or subjective cognitive decline (n = 51) diagnosed at a university memory clinic. Seventy-six cognitively healthy controls were sampled through the Swedish population register. All participants underwent clinical oral and panoramic radiographic examinations. Two oral and maxillofacial radiologists performed blinded analyses of the panoramic radiographs for signs of CCAA, which was registered as absent or present and, if present, unilateral or bilateral. Consensus assessment was used for all statistical analyses.

RESULTS

CCAA was common (40%) in this middle-aged and older Swedish population. We found no differences in the prevalence of CCAA between cases and controls (40% vs. 42%).

CONCLUSION

Cognitively impaired patients do not have a higher burden of CCAA than matched controls without cognitive impairment.

Decreased Electroencephalography Global Field Synchronization in Slow-Frequency Bands Characterizes Synaptic Dysfunction in Amnestic Subtypes of Mild Cognitive Impairment

Background

Mild cognitive impairment (MCI) is highly prevalent in a memory clinic setting and is heterogeneous regarding its clinical presentation, underlying pathophysiology, and prognosis. The most prevalent subtypes are single-domain amnestic MCI (sd-aMCI), considered to be a prodromal phase of Alzheimer’s disease (AD), and multidomain amnestic MCI (md-aMCI), which is associated with multiple etiologies. Since synaptic loss and dysfunction are the closest pathoanatomical correlates of AD-related cognitive impairment, we aimed to characterize it in patients with sd-aMCI and md-aMCI by means of resting-state electroencephalography (EEG) global field power (GFP), global field synchronization (GFS), and novel cerebrospinal fluid (CSF) synaptic biomarkers.

Methods

We included 52 patients with sd-aMCI (66.9 ± 7.3 years, 52% women) and 30 with md-aMCI (63.1 ± 7.1 years, 53% women). All patients underwent a detailed clinical assessment, resting-state EEG recordings and quantitative analysis (GFP and GFS in delta, theta, alpha, and beta bands), and analysis of CSF biomarkers of synaptic dysfunction, neurodegeneration, and AD-related pathology. Cognitive subtyping was based on a comprehensive neuropsychological examination. The Mini-Mental State Examination (MMSE) was used as an estimation of global cognitive performance. EEG and CSF biomarkers were included in a multivariate model together with MMSE and demographic variables, to investigate differences between sd-aMCI and md-aMCI.

Results

Patients with sd-aMCI had higher CSF phosphorylated tau, total tau and neurogranin levels, and lower values in GFS delta and theta. No differences were observed in GFP. The multivariate model showed that the most important synaptic measures for group separation were GFS theta, followed by GFS delta, GFP theta, CSF neurogranin, and GFP beta.

Conclusion

Patients with sd-aMCI when compared with those with md-aMCI have a neurophysiological and biochemical profile of synaptic damage, neurodegeneration, and amyloid pathology closer to that described in patients with AD. The most prominent signature in sd-aMCI was a decreased global synchronization in slow-frequency bands indicating that functional connectivity in slow frequencies is more specifically related to early effects of AD-specific molecular pathology.

Olfactory Measures as Predictors of Conversion to Mild Cognitive Impairment and Alzheimer's Disease

BACKGROUND

Early biomarkers of prodromal Alzheimer's disease (AD) are critical both to initiate interventions and to choose participants for clinical trials. Odor threshold, odor identification and odor familiarity are impaired in AD.

METHODS

We investigated the relative abilities of standard screening (MMSE) and olfactory measures to predict transitions from cognitively normal (CN) to mild cognitive impairment (MCI), from CN to AD, and MCI to AD. The archival sample of 497, from the UCSD ADRC, included participants who were CN, MCI, AD and converters to MCI or AD. Apoe ε4 status, a genetic risk factor, was available for 256 participants, 132 were ε4 carriers. A receiver operating characteristic curve (ROC) curve plots the trade-off between sensitivity and specificity. Area under the ROC curve (AUC) was used to determine diagnostic accuracy.

RESULTS

Different measures were better predictors at specific stages of disease risk; e.g., odor familiarity, odor identification and the combination showed higher predictive value for converting from MCI to AD in ε4 carriers than the MMSE. Combining odor familiarity and odor identification produced an AUC of 1.0 in ε4 carriers, MMSE alone was 0.58.

CONCLUSIONS

Olfactory biomarkers show real promise as non-invasive indicators of prodromal AD. The results support the value of combining olfactory measures in assessment of risk for conversion to MCI and to AD.

Communication and understanding of mild cognitive impairment diagnoses

BACKGROUND

Communication of mild cognitive impairment (MCI) diagnoses is challenging due to its heterogeneity and unclear prognosis.

AIM

To identify how MCI is communicated and to explore the relationship with patient and companion understanding.

METHOD

Conversation analysis identified whether MCI was named and explained in 43 video recorded diagnosis feedback meetings. Afterward, patients and companions were asked to name the diagnosis to assess understanding.

RESULTS

Mild cognitive impairment was not named in 21% meetings. Symptoms were explained as (a) a result of vascular conditions (49%), (b) a stage between normal ageing and dementia (30%), or (c) caused by psychological factors (21%). Fifty-four percentage of prognosis discussions included mention of dementia. There was no association between symptom explanations and whether prognosis discussions included dementia. Fifty-seven percentage patients and 37% companions reported not having or not knowing their diagnosis after the meeting. They were more likely to report MCI when prognosis discussions included dementia.

CONCLUSIONS

Doctors offer three different explanations of MCI to patients. The increased risk of dementia was not discussed in half the diagnostic feedback meetings. This is likely to reflect the heterogeneity in the definition, cause and likely prognosis of MCI presentations. Clearer and more consistent communication, particularly about the increased risk of dementia, may increase patient understanding and enable lifestyle changes to prevent some people progressing to dementia.

Interventions for subjective cognitive decline: systematic review and meta-analysis

OBJECTIVES

This review provides a broad overview of the effectiveness of interventions for subjective cognitive decline (SCD) in improving psychological well-being, metacognition and objective cognitive performance.

METHODS

Databases including PubMed, Web of Science and Cochrane Systematic Reviews were searched up to August 2017 to identify randomised controlled trials evaluating interventions for SCD. Interventions were categorised as psychological, cognitive, lifestyle or pharmacological. Outcomes of interest included psychological well-being, metacognitive ability and objective cognitive performance. To assess the risk of bias, three authors independently rated study validity using criteria based on the Critical Appraisal Skills Programme. Random-effects meta-analyses were undertaken where three or more studies investigated similar interventions and reported comparable outcomes.

RESULTS

Twenty studies met inclusion criteria and 16 had sufficient data for inclusion in the meta-analyses. Of these, only seven were rated as being high quality. Group psychological interventions significantly improved psychological well-being (g=0.40, 95% CI 0.03 to 0.76; p=0.03) but the improvement they conferred on metacognitive ability was not statistically significant (g=0.26, 95% CI -0.22 to 0.73; p=0.28). Overall, cognitive training interventions led to a small, statistically significant improvement in objective cognitive performance (g=0.13, 95% CI 0.01 to 0.25; p=0.03). However, the pooled effect sizes of studies using active control groups (g=0.02, 95% CI -0.19 to 0.22; p=0.85) or reporting global cognitive measures (g=0.06, 95% CI -0.19 to 0.31; p=0.66) were non-significant.

CONCLUSIONS

There is a lack of high-quality research in this field. Group psychological interventions improve psychological well-being and may also improve metacognition. A large, high-quality study is indicated to investigate this further. There is no evidence to suggest that cognitive interventions improve global cognitive performance and the clinical utility of small improvements in specific cognitive domains is questionable. There is a lack of research considering lifestyle interventions and poor quality evidence for pharmacological interventions.

PROSPERO REGISTRATION NUMBER

CRD42017079391.

Is Mild Cognitive Impairment a Valid Target of Therapy

The status of Mild Cognitive Impairment (MCI) as a valid construct is controversial. The term encompasses people with heterogeneous clinical profiles, and invites sub-classifications that still require validation. Still, much evidence suggests that, properly selected, many people with MCI - especially Amnestic MCI - are at a high risk of dementia. This paper considers the validity of the construct of MCI as a high-risk state for progression and a target for treatment. We conclude that the status of MCI as an entity remains controversial. On the one hand, it can be argued that the careful section of cases at high risk of developing dementia means that it is a valid target, with the goal being the prevention of dementia. Advocates of this view see a linear progression that they are trying to arrest, but studies have yet to show that this can be done. On the other hand, it can be argued that the patients who progressed did not develop dementia: they actually had a very early form of it. By this view, people without the progressive form will be needlessly exposed to antidementia drugs, and the others should be treated anyway. Why some people progress and others do not is not clear, but the variable rates of progression - between clinic-based and population-based samples and between very similar clinical trials with slightly different inclusion criteria - suggests that MCI is a heterogeneous entity. The phenomenon of slowing or non-progression itself should be investigated, and such investigations likely should extend to people now classified as having mild dementia.

Cognitive predictors of medical decision-making capacity in mild cognitive impairment and Alzheimer's disease

OBJECTIVE

Impaired capacity to make decisions in everyday life and situations of medical treatment is an inevitable consequence of the cognitive decline in Alzheimer's disease (AD). The objective of this study was to identify the most powerful cognitive component(s) that best predicted medical decision-making capacity (MDMC) in patients with AD and mild cognitive impairment.

METHOD

Three groups of subjects participated in the study: patients with AD (n = 20), mild cognitive impairment (n = 21), and healthy control subjects (n = 33). MDMC was assessed by the linguistic instrument for medical decision-making (LIMD) and related to demographics and 27 cognitive test measures.

RESULTS

The cognitive tests were found to aggregate into four components using a principle component analysis. The four components, which correspond to verbal knowledge, episodic memory, cognitive speed, and working memory, accounted for 73% of the variance in LIMD according to a stepwise regression analysis. Verbal knowledge was the most powerful predictor of LIMD (beta = 0.66) followed by episodic memory (beta = 0.43), cognitive speed (beta = 0.32), and working memory (beta = 0.23). The best single test as shown by the highest correlation with LIMD was Reading speed (R = 0.77).

CONCLUSION

Multiple factors are involved in MDMC in subjects with cognitive impairment. The component of verbal knowledge was the best predictor of MDMC and Reading speed was the most important single cognitive test measurement, which assessed both rapid Reading and understanding of text.

Subjective cognitive impairment subjects in our clinical practice

Background

The clinical challenge in subjective cognitive impairment (SCI) is to identify which individuals will present cognitive decline. We created a statistical model to determine which variables contribute to SCI and mild cognitive impairment (MCI) versus Alzheimer's disease (AD) diagnoses.

Methods

A total of 993 subjects diagnosed at a memory clinic (2007-2009) were included retrospectively: 433 with SCI, 373 with MCI and 187 with AD. Descriptive statistics were provided. A logistic regression model analyzed the likelihood of SCI and MCI patients being diagnosed with AD, using age, gender, Mini-Mental State Examination score, the ratio of β-amyloid 42 divided by total tau, and phosphorylated tau as independent variables.

Results

The SCI subjects were younger (57.8 ± 8 years) than the MCI (64.2 ± 10.6 years) and AD subjects (70.1 ± 9.7 years). They were more educated, had less medial temporal lobe atrophy (MTA) and frequently normal cerebrospinal fluid biomarkers. Apolipoprotein E4/E4 homozygotes and apolipoprotein E3/E4 heterozygotes were significantly less frequent in the SCI group (6 and 36%) than in the AD group (28 and 51%). Within the regression model, cardiovascular risk factors, confluent white matter lesions, MTA and central atrophy increased the AD likelihood for SCI subjects.

Conclusions

SCI patients form a distinct group. In our model, factors suggesting cardiovascular risk, MTA and central atrophy increased the AD likelihood for SCI subjects.

Current management decisions in mild cognitive impairment

Efforts toward early detection of Alzheimer disease (AD) have focused on refinement and identification of diagnostic markers, with the goal of preventing or delaying disease progression. Mild cognitive impairment (MCI) has emerged as a potential precursor to dementia. Though not without controversy, MCI has been associated with an increased risk for conversion to AD. In this article, with emphasis on meta-analyses, randomized controlled trials, and extant literature reviews, considerations and recommendations for optimal clinical management of MCI are offered. Given the substantial heterogeneity of this patient population and inconsistent research methodologies, the need for informed, clinical judgment is critical.

Exploring the experiences of people with mild cognitive impairment and their caregivers with particular reference to healthcare - a qualitative study

BACKGROUND

The aim of this study was to investigate the experiences of people with mild cognitive impairment (MCI; PWMCI) and their "advocates," particularly within healthcare services.

METHODS

Semi-structured interviews were conducted with 23 PWMCI diagnosed ≤6 months ago and 20 advocates recruited via patients. The resulting data were content-analyzed.

RESULTS

PWMCI interviewed rarely reported negative impressions of their general practitioner (GP). Reports regarding memory services were more mixed: positive impressions related to finding the service to be "well run" and the staff "pleasant," negative ones to the assessment process or a perceived lack of feedback. Aside from improved information provision, most PWMCI had no suggestions for improvements to their healthcare. However, these results should be interpreted with caution as many of the PWMCI interviewed displayed evidence of impaired recall and/or insight relating to their condition and healthcare. Advocates generally reported more negative impressions of both contact with the PWMCI's GP (most commonly reporting a "dismissive" attitude) and memory services (with common complaints relating to the assessments used in clinics and lengthy waiting times). This group generally had suggestions for improvements to services - particularly regarding information provision, changes in the assessment process, and improvements in communication by services.

CONCLUSIONS

To our knowledge, this is the first in-depth study of the difficulties experienced by PWMCI and their advocates which includes the context of healthcare provision. The specific needs of these groups, as described here, as well as those of people with dementia, should be considered when designing memory clinics and other related services.

The development and validation of a patient-reported quality of life measure for people with mild cognitive impairment

BACKGROUND

No validated patient-reported outcome measure (PROM) exists specifically to assess quality of life in mild cognitive impairment (MCI); we report a study conducted to develop such a measure.

METHODS

Semi-structured in-depth interviews were carried out with 23 people with MCI in order to determine items for a draft questionnaire. These interviews were audio-recorded, transcribed, and content analyzed. The draft questionnaire was refined following feedback from a focus group. 280 questionnaires were posted to subjects recruited from memory clinics and research databases, the response rate was 56% i.e. 146 questionnaires were included in the final analysis. The completed questionnaires were analyzed using factor analytic techniques to produce the final measure; construct validity was assessed by correlation with a generic patient-reported outcome measure, the SF-12v2.

RESULTS

Factor analysis produced a 13-item measure tapping two domains of patient-reported quality of life ("Emotional Effects" and "Practical Concerns"). Internal consistency reliability was high for both domains (α was 0.91 and 0.85 respectively). Both dimensions were highly and significantly correlated with the Mental Component Summary score of the SF-12v2 ("emotional effects" ρ = -0.43, p < 0.001 and "practical concerns" ρ = -0.56, p < 0.001).

CONCLUSIONS

The Mild Cognitive Impairment Questionnaire (MCQ) is a 13-item measure developed specifically to measure patient-reported outcomes in people with MCI. It was created on the basis of patient report and has been shown to have good psychometric properties. It is likely to prove valuable in the evaluation of treatment regimes in this patient group.

Mild cognitive impairment and mood: a systematic review

This systematic review, with meta-analyses conducted where data were available, aimed to investigate the prevalence of symptoms of depression and anxiety in mild cognitive impairment (MCI), and to establish how symptoms of depression and anxiety relate to the progression from no cognitive impairment to MCI, and from MCI to dementia. Sixty studies were included in the review. Meta-analyses indicated that symptoms of depression and anxiety were more prevalent in people with MCI than in people with normal cognitive function, and increased the risk of progression from no cognitive impairment to MCI. There were mixed results regarding the effect of such symptoms on progression from MCI to dementia. The findings highlight the need for more research in this area, which can inform attempts to slow or halt the progression of cognitive impairment in later life, with resulting benefits for quality of life.

Neuropsychiatric symptoms in mild cognitive impairment: An analysis and its impact on caregiving

BACKGROUND

Neuropsychiatric impairments play a significant role throughout the course of cognitive decline. Many psychological and behavioral symptoms are present in patients of mild cognitive impairment (MCI) similar to that seen in individuals with dementia.

AIMS AND OBJECTIVES

To study the relevance of neuropsychiatric symptoms of MCI and the impact it has on caregivers of these patients.

MATERIALS AND METHODS

This cross-sectional study was done on 90 patients (30 MCI, 30 dementia and 30 controls) above the age of 50 years. The scales used were Hindi-Mental Status Examination, Global deterioration scale and Neuropsychiatric inventory (NPI). Statistical analysis was done using SPSS 16 software.

RESULTS

73.33% (22) of the subjects in MCI group, 90% (27) of subjects in dementia group and 53.33% (16) of subjects having normal cognition had neuropsychiatric complaints. 73.33% (22) relatives of subjects in the MCI group, 90% (27) relatives of subjects in dementia group and 46.67% (14) relatives of subjects in the normal group (i.e. control group) experienced some distress. The differences in the mean NPI severity, frequency, distress and total scores of the three groups were statistically significant. Severity and frequency of neuropsychiatric symptoms significantly predicted the caregiver's distress.

CONCLUSIONS

Neuropsychiatric symptoms increase both in frequency and severity with increasing cognitive decline, and they cause distress both to the patient as well as the caregiver; and hence their early recognition is a must. The NPI appears to be a useful tool in that regard.

Dementia diagnosis differs in men and women and depends on age and dementia severity: data from SveDem, the Swedish Dementia Quality Registry

AIMS

We examine the dementia assessment with focus on age and gender differences.

METHODS

Data from the national quality database, Swedish Dementia Registry (SveDem), including 6,937 dementia patients diagnosed during 2007-2009 at memory clinics were used. We have studied the use of investigations for dementia diagnostics such as cognitive tests, blood and cerebrospinal fluid analyses, electroencephalography, radiological examinations and assessments of functions. Severity of cognitive impairment was assessed with the Mini Mental State Examination (MMSE).

RESULTS

There was a significant decrease in the number of total tests used in the elderly group (>75 years) when compared with the middle-aged group (65-75 years) and younger patients (<65 years). The oldest group was examined with 4 of 11 possible tests, the middle-aged group had 5/11 tests performed and the youngest age group 6/11 tests. There was also a significant gender difference in the diagnostic workup, however, mostly attributable to age. The number of tests positively correlated with the level of cognition assessed by the MMSE.

CONCLUSION

We show here for the first time the impact of age, gender and MMSE score on the dementia diagnostic workup in a large memory clinic patient population in one country.

Absence of a relationship between subjective memory complaint and objective memory impairment in mild cognitive impairment (MCI): is it time to abandon subjective memory complaint as an MCI diagnostic criterion?

BACKGROUND

Subjective memory complaints are a requirement in the diagnosis of mild cognitive impairment (MCI) as they are thought to indicate a decline in objective memory performance. However, recent research suggests that the relationship between subjective memory complaint and objective memory impairment is less clear. Thus, it is possible that many people without subjective memory complaints who develop Alzheimer's disease are precluded from a diagnosis of MCI.

METHODS

The present study examined the relationship between subjective memory complaint assessed using the Multifactorial Memory Questionnaire (MMQ) and objective memory impairment assessed using standard neuropsychological measures in cases of amnestic MCI (n = 48), non-amnestic MCI (n = 27), and unimpaired healthy participants (n = 64).

RESULTS

Correlational and regression analyses indicated that subjective memory complaints displayed a poor relationship with objective memory performance. A subsequent discriminant function analysis indicated that subjective memory complaints failed to improve the diagnostic accuracy of MCI and resulted in increased rates of false negative and false positive diagnoses.

CONCLUSION

The results of the present study suggest that a diagnostic criterion of subjective memory complaint reduces the accuracy of MCI diagnosis, resulting in an elevated rate of false positive and false negative diagnoses. The results of this study in conjunction with recent research indicate that a criterion of subjective memory complaint should be discarded from emerging diagnostic criteria for MCI.

Self- and informant ratings of personality in mild cognitive impairment, reviewed

AIMS

To examine the degree of agreement between self- and informant ratings of personality in relation to cognitive function in patients with mild cognitive impairment (MCI), subjective cognitive impairment (SCI) and healthy controls (HC).

METHODS

Thirty-two patients and informants with MCI, 23 with SCI and 22 HC completed the Swedish universities Scales of Personality (SSP). Correlations and incongruence between self- and informant ratings were calculated. The Mini Mental State Examination (MMSE) was used to assess cognitive function.

RESULTS

The correlations between self- and informant ratings were fair-to-moderate on a majority of SSP scales and significant in 44%. The incongruence between patients and informants was significantly larger in MCI than in HC across SSP scales. There was a significant negative correlation between the incongruence index and the MMSE for all subjects.

CONCLUSIONS

Self-informant agreement on ratings of patients' personality was reasonable. Incongruence between patients and their informants was associated with MCI but not SCI or HC. Disagreement between patients and informants indicates cognitive impairment.

Accuracy of estimation of time-intervals in psychogeriatric outpatients

BACKGROUND

Accuracy of estimation of time-intervals has received marginal attention in psychogeriatrics. We examined presumed differences in this time measure in participants with dementia (PWD) versus participants without dementia (PWoutD), further subdivided into specific diagnoses and performance subgroups. We also studied its demographic, clinical, and cognitive correlates and predictors. A diagnostic role was hypothesized.

METHODS

Forty-three individuals (27 PWD: 16 dementia of the Alzheimer's type (DAT), 11 vascular dementia (VaD); 16 PWoutD: 10 major depressive disorder (MDD), 6 normal) were interviewed with the Cambridge Examination for Mental Disorders of the Elderly - Revised (CAMDEX-R) that permits the registration of this time measure. Demographic, clinical, and cognitive data were obtained.

RESULTS

Neither absolute accuracy of estimation of duration of interview nor its transformed logarithm were significantly different between PWD and PWoutD, or between DAT and VaD participants. MDD participants performed significantly poorer than normal and did not differ from PWD, and the PWD relatively better performing subgroup. The logarithm of absolute accuracy of estimation correlated with some clinical and cognitive variables. Only a measure of depression and of impaired judgment could significantly predict it.

CONCLUSIONS

The absolute accuracy of estimation of time-intervals did not differ between the major groups and the main diagnoses subgroups. It was associated with a variety of clinical and cognitive measures, and was predicted by the composite constructs of depression and impaired judgment. The diagnostic value of this measure in the psychogeriatric clinic is questionable, and limited to "worried" well individuals.

Identifying and characterizing trajectories of cognitive change in older persons with mild cognitive impairment

BACKGROUND

Mild cognitive impairment (MCI) represents a state of high risk for dementia but is heterogeneous in its course. To date, the trajectories reflecting distinct developmental courses of cognition among patients with MCI have not been well defined.

AIM

To identify the developmental trajectory of groups with distinct cognitive change patterns among a cohort of MCI patients.

METHODS

187 MCI patients from 2 geriatric outpatient clinics were evaluated serially with the Mini-Mental State Examination (MMSE) for up to 3.5 years. Group-based trajectory analysis was applied to identify distinct trajectories. Estimates of decline for each group were compared with the mean rate of decline obtained from mixed modeling of the entire sample.

RESULTS

5 trajectories were identified and labeled based on their baseline MMSE score and course: (1) 29/stable (6.5%); (2) 27/stable (53.9%); (3) 25/slow decline (23.8%); (4) 24/slow decline (11.6%); (5) 25/rapid decline (4.2%). Annual rate of change in the MMSE score for these 5 groups was 0.09, -0.43, -1.23, -1.84, and -4.6 points, respectively. None corresponded to the mean rate of -0.82 points estimated for the group as a whole. A majority of MCI patients (60.4%) follow stable cognitive trajectories over time. Within the 3 groups with declining trajectories, cognitive decline occurs slowly in a vast majority of MCI patients (98.5%).

CONCLUSIONS

Results provide direct evidence for the heterogeneous course of cognitive decline that has been suggested by the variable prognosis for patients with MCI.

Category cued recall following controlled encoding as a neuropsychological tool in the diagnosis of Alzheimer's disease: a review of the evidence

Aim of the present review paper was to evaluate the hypothesis (included in the proposal of new research criteria for Alzheimer's disease; Dubois et al., Lancet Neurology, 6, 734-746, 2007) that a neuropsychological tool which provides support for the semantic encoding of memorandum at the time of study and supplies category cues at the time of retrieval (i.e. the Grober-Buschke paradigm) is more effective than traditional measures of free recall in 1) differentiating patients affected by the amnestic form of Mild Cognitive Impairment (MCI) or by mild to moderate forms of Alzheimer's disease (AD) from healthy matches, 2) predicting the conversion of individuals with MCI to AD, and 3) differentiating AD patients from individuals affected by other forms of dementia. Results of the review are controversial regarding the superiority of the Grober-Buschke procedure in differentiating individuals affected by AD or MCI from healthy individuals. The only study that evaluated this issue directly found that the Grober-Buschke procedure was more sensitive and specific than more traditional memory tests in predicting the conversion of MCI patients to AD. Finally, two studies reported that patients affected by AD or other forms of dementia showed different performance patterns in the free and cued recall tasks of the Grober-Buschke procedure. In conclusion, although encouraging results are reported in the few studies that investigated the ability of this procedure to predict the evolution of individuals with amnestic MCI and to differentiate AD patients from patients with other forms of cortical and subcortical dementia, more experimental work is needed to confirm these positive findings.

Neuropsychological profiles in MCI and in depression: Differential cognitive dysfunction patterns or similar final common pathway disorder?

The concept of "mild cognitive impairment" (MCI) refers to alterations in cognition in the transition between normal aging and dementia. However, from a neuropsychological point of view the conventional diagnostic criteria appear not sufficiently valid. In particular, it is still difficult to differentiate between subjects with MCI and subjects with depression plus cognitive deficits on the basis of their neuropsychological profiles. The aim of this study is to compare cognitive deficit patterns of subjects with MCI and with depression. 24 subjects with MCI, 50 subjects with depression (DEP) and 20 healthy control subjects were included (age: 55-74years). The neuropsychological assessment consisted of standardized tests to assess attention, memory, and executive functions. Compared to healthy controls both subject groups showed significantly lower performance in all cognitive domains. However, we did not find significant differences in cognitive performance between MCI and DEP subjects, neither at baseline nor at follow-up. In addition, preliminary results of follow-up assessments after 2 (DEP) and 6months (MCI), respectively, revealed no significant changes in cognition in subjects with depression, regardless of whether depressive symptoms had improved. Subjects with MCI also showed no changes in cognition at follow-up. The comparable neuropsychological patterns identified in the two subject groups may be understood as a consequence of similar alterations in cognitive systems, supporting the idea of a final common pathway disorder. Thus, the cognitive deficits present in a subgroup of subjects with depression may possibly better be understood in the context of MCI.

Verbal cued recall as a predictor of conversion to Alzheimer's disease in Mild Cognitive Impairment

OBJECTIVE

This study was set up to investigate whether neuropsychological tests are able to predict conversion to AD among Mild Cognitive Impairment (MCI) patients.

METHODS

At baseline the cognitive part of the Cambridge Examination for Mental Disorders of the Elderly (CAMCOG), the Mini Mental Status Examination (MMSE), the Geriatric Depression Scale (GDS), a Dutch variation of Rey's Auditory Verbal Learning Test, the Memory Impairment Screen plus (MISplus) and the Visual Association Test (VAT) were administered to 40 patients diagnosed with MCI. After 18 months, MCI-patients were reassessed and a follow-up diagnosis was established. Of those who were seen for follow-up (n = 31), seven fulfilled (NINCDS-ADRDA) criteria of probable AD, while 24 did not convert.

RESULTS

A binary logistic regression analysis showed that the MISplus contributed most to the prediction of conversion (OR = 0.28, 95% CI 0.099-0.790). With a cut-off of 2 out of 6, a positive predictive value of 71.5%, a negative predictive value of 91.5% and an overall diagnostic accuracy of 87.0% were achieved.

CONCLUSIONS

This prospective, longitudinal study shows that a score of 0 or 1 out of 6 on the MISplus may be a good indicator of future (within 18 months) progression to AD among MCI-patients.

The Clock Drawing Test--Modified and Integrated Approach (CDT-MIA) as an instrument for detecting mild cognitive impairment in a specialized outpatient setting

This study examined the accuracy of the Clock Drawing Test--Modified and Integrated Approach (CDT-MIA) alone and combined with the Mini-Mental State Examination (MMSE) to detect Mild Cognitive Impairment (MCI) in patients with suspected MCI. For comparison, the accuracy of the Cambridge Cognitive Examination-Revised (CAMCOG-R) was tested. A total of 65 elderly outpatients with suspected MCI underwent a comprehensive evaluation. Following assessment, the entire sample was classified into: dementia (mild)--24 participants, MCI--22 participants, no cognitive impairment (NCI)--19 participants. CDT-MIA and the MMSE alone failed to appropriately discriminate demented from nondemented (MCI and NCI) and MCI from NCI. The best acceptable diagnostic accuracy to discriminate between demented and nondemented was obtained with CDT-MIA/MMSE combined and with CAMCOG-R. CDT-MIA/MMSE combined failed to appropriately discriminate MCI from NCI. The best diagnostic accuracy in this regard was obtained with CAMCOG-R.

Stability in the clinical characteristics of patients with memory complaints

The objectives of this study were to examine potential clinical and neuropsychological changes over time in non-demented patients with subjective memory complaints (<or=70 years) and to compare the patients with objective memory impairment (OMI) with those who suffer from subjective memory impairment (SMI). OMI and SMI patients did not differ regarding duration of memory problems, age or education. At baseline no differences were revealed between the OMI and SMI patients regarding self-reported cognitive deficits, self-reported worry about deficits, and symptoms of anxiety or depression. None of the patients had converted to dementia at follow-up. Eighty percent of the OMI patients and 61% of the SMI patients reported cognitive deficits to the same degree at follow-up as at baseline. Despite a significant reduction of depressive symptoms in the OMI patients, a considerable portion of both OMI and SMI patients scored above the cut off score on both anxiety and depression subscales at baseline as well as at follow-up. Our study reveals close points of similarity between patients with memory complaints, verified by test, and patients with memory complaints, not verified by test, as well as stability over time regarding important clinical aspects.

Evidence-based evaluation of diagnostic accuracy of resting EEG in dementia and mild cognitive impairment

Cognitive impairment is the most frequent chronic condition in the elderly, and dementia is the most disabling form of cognitive impairment in elderly. In the absence of specific and reliable markers of etiologically different dementia syndromes and their preclinical stages, diagnosis in living patients is probabilistic and based on standardized clinical diagnostic criteria. There is still not enough information on the validity of the EEG method in dementia work-up, and an updated evidence-based consensus on appropriateness of this method in the initial evaluation of patients with suspected cognitive disorder and dementia is missing. Using an evidence-based technique we searched for articles on diagnostic accuracy of spontaneous EEG in dementia disorders published from 1980 until June 2008. Inclusion criteria were: original article published in English with 10 or more subjects per diagnostic group, diagnosed according to the established consensus clinical diagnostic criteria used as a "gold standard." In addition, it should have been possible to calculate from the reported results indexes of diagnostic test accuracy: sensitivity, specificity, likelihood ratios and diagnostic odds ratios. Forty-six articles were retrieved that satisfied eligibility criteria. Thirty-four (74%) studies employed case-control design where study population was recruited from consecutive patients at specialist clinic settings, 12 (26%) were prospective in terms of reported clinical followup of study population. Four (9%) studies used population-based samples and 5 (11%) studies stated in methods the recruitment procedures for patients and healthy subjects. Number of patients included in diagnostic groups and healthy subjects varied in included studies between 10 and 180 and 10 and 171, respectively. Figures on sensitivity and specificity across the studies varied widely. Positive likelihood ratio in studies reporting classification accuracies between Alzheimer's disease and controls ranged between 2.3 and 38.5, and diagnostic odds ratios consequently showed large variations between 7 and 219. In conclusion, despite the wealth of published research and reported high indexes of diagnostic accuracy of EEG, and qEEG in particular, in individual studies, evidence of diagnostic utility of resting EEG in dementia and mild cognitive impairment (MCI) is still not sufficient to establish this method for the initial evaluation of subjects with cognitive impairment in the routine clinical practice. Joint effort of preferably multicenter studies using uniform standards should develop optimized methods, investigate added diagnostic value of EEG in clinically established dementia diagnosis and predictive utility of EEG in MCI and questionable dementia.

The clinical significance of subjective memory complaints in the diagnosis of mild cognitive impairment and dementia: a meta-analysis

BACKGROUND

Subjective memory complaints (SMC) are frequently reported by individuals with objective evidence of cognitive decline although the exact rate of complaints and their diagnostic value is uncertain.

METHOD

A meta-analysis was conducted for all studies examining SMC and either concurrent dementia or mild cognitive impairment (MCI).

RESULTS

Eight studies reported the rate of SMC in dementia, seven studies reported the rate of SMC in MCI and of these four compared the rate of SMC in dementia and MCI head-to-head. SMC were present in 42.8% of those with dementia and 38.2% of those with MCI. Across all levels of cognitive impairments 39.8% of people had SMC compared with 17.4% in healthy elderly controls (Relative Risk 2.3). In head-to-head studies there was a significantly higher rate of SMC in dementia vs MCI (48.4% vs 35.1%). Examining the diagnostic value of SMC in dementia, the meta-analytic pooled sensitivity was 43.0% and specificity was 85.8%. For MCI, meta-analytic pooled sensitivity was 37.4% and specificity was 86.9%. In community studies with a low prevalence the positive and negative predictive values were 18.5% and 93.7% for dementia and 31.4% and 86.9% for MCI. The clinical utility index which calculates the value of a diagnostic method suggested 'poor' value for ruling in a diagnosis of dementia but 'good' value for ruling out a diagnosis.

CONCLUSIONS

When assessed by simple questions, SMC appear to be present in the minority of those with mild cognitive impairment and dementia. In cross-sectional community settings, even when people agree that they have SMC there is only a 20% or 30% chance that dementia or MCI are present, respectively. Despite this, the absence of SMC may be a reasonable method of excluding dementia and MCI and could be incorporated into short screening programs for dementia and MCI but replication is required in clinical settings.

Increasing CSF phospho-tau levels during cognitive decline and progression to dementia

BACKGROUND

Little is known about longitudinal changes of cerebrospinal fluid (CSF) biomarkers during cognitive decline in neurodegenerative disease progression.

OBJECTIVE

To investigate longitudinal changes in CSF biomarkers--total-tau (T-tau), phospho-tau (P-tau) and beta-amyloid (Abeta42)--during cognitive decline.

METHODS

Forty memory clinic patients (47.5% females), aged 61.3+/-7.6 (S.D.) years, non-demented at baseline, underwent lumbar puncture and neuropsychological testing at two occasions. Baseline mean MMSE-score was 28.3+/-1.8. Patients were divided into three groups based on baseline memory functioning; severely impaired (SIM), moderately impaired (MIM) and no impairment (NIM).

RESULTS

There was a significant increase in P-tau in the SIM-group during follow-up, while P-tau in MIM and NIM did not change. Eighty-three percent of the SIM-patients converted to dementia (80% AD), while most MIM- and NIM-patients remained non-demented. T-tau- and Abeta42-levels did not change in any of the memory groups during follow-up.

CONCLUSION

Increasing P-tau levels during cognitive decline and conversion to dementia suggest that P-tau may be useful as a longitudinal marker of the neurodegenerative process.

Hippocampal atrophy and EEG markers in subjects with mild cognitive impairment

OBJECTIVE

The present study evaluates the potential relationship between hippocampal atrophy and EEG brain rhythmicity, as assessed by relative band power and alpha frequency indices in a cohort of subjects with mild cognitive impairment (MCI).

METHODS

Eighty-eight subjects falling within the definition of MCI patients were enrolled. All subjects underwent EEG recording and magnetic resonance imaging (MRI). Volumetric morphometry estimates of the hippocampal region were computed. Individual EEG frequencies were indexed by the theta/alpha transition frequency (TF) and the individual alpha frequency (IAF). The relative power was separately computed for delta, theta, alpha1, alpha2 and alpha3 frequency bands. The MCI cohort was classified into four subgroups, based on the mean and standard deviations of the hippocampal volume of a normal elderly control sample.

RESULTS

The group with moderate hippocampal atrophy showed the highest increase in the theta power on frontal regions, and of the alpha2 and alpha3 powers on frontal and temporo-parietal areas. The analysis of the individual alpha frequency markers showed that the values for the alpha markers were highest in the group with the smallest hippocampal volume, whereas in the group with moderate hippocampal atrophy, these values were lower than in the group with severe atrophy.

CONCLUSIONS

The relationship between hippocampal atrophy and EEG activity changes in MCI subjects is not proportional to the hippocampal atrophy. Therefore, EEG markers could represent a new tool for differential diagnosis.

SIGNIFICANCE

The hippocampal atrophy induces different brain synchronization/desynchronization patterns. EEG changes model the brain activity induced by a discrete change of the hippocampal volume. The changes in the EEG rhythmicity differ greatly from those in MCI patients with subcortical vascular damage.

Reduced neuronal efficacy in progressive mild cognitive impairment: a prospective fMRI study on visuospatial processing

Mild cognitive impairment (MCI) often refers to the preclinical stage of dementia, where the majority develop Alzheimer's disease (AD). Given that neurodegenerative burden and compensatory mechanisms might exist before accepted clinical symptoms of AD are noticeable, the current prospective study aimed to investigate the functioning of brain regions in the visuospatial networks responsible for preclinical symptoms in AD using event-related functional magnetic resonance imaging (fMRI). Eighteen MCI patients were evaluated and clinically followed for approximately 3 years. Five progressed to AD (PMCI) and eight remained stable (SMCI). Thirteen age-, gender- and education-matched controls also participated. An angle discrimination task with varying task demands was used. Brain activation patterns as well as task demand-dependent and -independent signal changes between the groups were investigated by using an extended general linear model including individual performance (reaction time [RT]) of each single trial. Similar behavioral (RT and accuracy) responses were observed between MCI patients and controls. A network of bilateral activations, e.g. dorsal pathway, which increased linearly with increasing task demand, was engaged in all subjects. Compared with SMCI patients and controls, PMCI patients showed a stronger relation between task demand and brain activity in left superior parietal lobules (SPL) as well as a general task demand-independent increased activation in left precuneus. Altered brain function can be detected at a group level in individuals that progress to AD before changes occur at the behavioral level. Increased parietal activation in PMCI could reflect a reduced neuronal efficacy due to accumulating AD pathology and might predict future clinical decline in patients with MCI.

The normal equilibrium between CSF and plasma amyloid beta levels is disrupted in Alzheimer's disease

Amyloid-beta (Abeta) with 40 (Abeta40) and 42 (Abeta42) amino acids, the main components of amyloid plaques in the Alzheimer's disease (AD) brain, can be measured in human cerebrospinal fluid (CSF) and plasma. Whereas CSF Abeta42 is decreased in AD, some studies have reported changed plasma Abeta levels in AD and in subjects with mild cognitive impairment (MCI). To this date it is unclear if and how CSF and plasma levels of Abeta correlate with each other in healthy individuals, albeit earlier studies on AD patients found no correlation between CSF and plasma Abeta. We have measured Abeta40 and Abeta42 in paired CSF and plasma samples from patients with AD (n=39), MCI (n=29) and healthy control subjects (n=18). We observed a clear correlation between CSF and plasma levels for both Abeta40 and Abeta42 in healthy individuals, whereas no such correlation could be seen for AD or MCI cases. Similarly to other studies we also found low levels of Abeta42 in AD CSF, whereas there were no significant differences in plasma Abeta levels between the diagnostic groups. Our findings suggest that the normal equilibrium between CSF and plasma Abeta may be disrupted with the initiation of amyloid deposition in the brain.

Levels of ApoE in cerebrospinal fluid are correlated with Tau and 24S-hydroxycholesterol in patients with cognitive disorders

Evidence was recently presented from in vitro studies that 24S-hydroxycholesterol acts as a signalling molecule inducing apoE-mediated cholesterol efflux from astrocytoma cells, and that there is a direct effect of the oxysterol on apoE transcription, protein synthesis and secretion. Consistent with this mechanism, a significant correlation is demonstrated here between levels of apoE and 24S-hydroxycholesterol in cerebrospinal fluid from patients with Alzheimer's disease and patients with mild cognitive impairment. Such a correlation was not found in control patients. There was no correlation between levels of apoE and cholesterol in cerebrospinal fluid from controls. The results are consistent with a close coupling between release of 24S-hydroxycholesterol and apoE secretion under conditions with neuronal degeneration. The levels of apoE in cerebrospinal fluid were also correlated to the levels of Tau and the possibility is discussed that the level of apoE in cerebrospinal fluid may be used as a marker of neurodegeneration.

Differential CSF biomarker levels in APOE-epsilon4-positive and -negative patients with memory impairment

OBJECTIVES

To investigate the relationships between episodic memory, APOE genotype, CSF markers (total tau, T-tau; phospho-tau, P-tau; beta-amyloid, Abeta42) and longitudinal cognitive decline.

METHODS

124 memory clinic patients were retrospectively divided into 6 groups based on (i) episodic memory function (Rey Auditory Verbal Learning Test, RAVLT): severe, moderate or no impairment (SIM, MIM or NIM), and (ii) APOE genotype (epsilon4+ or epsilon4-). CSF marker levels and cognitive decline were compared across groups.

RESULTS

Episodic memory function, according to RAVLT scores, was significantly correlated with CSF marker levels only among epsilon4+ subjects and not among epsilon4- subjects. When comparing the 6 subgroups, SIM epsilon4+ and MIM epsilon4+ groups showed significantly lower Abeta42 levels than the other groups. T-tau and P-tau levels were significantly increased in SIM epsilon4+ when compared to all the other groups, including the SIM epsilon4- group. However, both SIM epsilon4+ and SIM epsilon4- declined cognitively during the follow-up.

CONCLUSION

It remains to be determined whether APOE genotype affects the expression of biomarkers in CSF, or whether the different biomarker patterns reflect different types of disease processes in patients with progressive cognitive dysfunction.

A Temporal Lobe Factor in Verb Fluency

Verb fluency requires self-sustained verb retrieval. The brain correlates of this task are virtually unknown. We investigated the relations between verb and noun (semantic) fluency and regional brain perfusion in subjects with varying degrees of cognitive decline, ranging from very mild subjective impairment to Alzheimer's disease (AD). Data consisted of single-photon emission computed tomography (SPECT) data and temporally resolved verb and noun fluency scores from 93 participants. Impaired verb fluency was predicted by a temporal lobe hypoperfusion factor and low education, whereas high age and low perfusion in the parietotemporal-occipital region predicted impaired noun fluency. Analysis of perfusion within the temporal region indicated primary involvement of the temporal pole and medial temporal lobe in AD. This might reflect pathology of the anterior parahippocampal region, which appears early in neurodegenerative disease. Although temporal lobe structures have not usually been implicated in verb processing, early temporal pathology thus appears to contribute to impaired verb fluency in cognitive decline.

Mild cognitive impairment: deficits in cognitive domains other than memory

Patients with mild cognitive impairment (MCI) typically present with memory complaints, but may have mild deficits in other cognitive domains. We compared the neuropsychological profiles of a series of consecutive MCI patients (n = 116) with a control group of healthy elderly subjects (n = 63). The presence of a memory deficit on delayed recall was consistent in the MCI sample, as it was an inclusion criterion in the study. Impairment on immediate recall was present in 62.6% of the patients on paragraph recall of the logical memory test and in 63.1% of the patients on the word paired-associate learning test. Remarkably, patients with MCI frequently had deficits in cognitive domains beyond memory. As much as 68.7% of the patients had deficits in temporal orientation, 30.2% had deficits in semantic fluency, 33.7% in the Token test, 23.4% in calculation, and 23.9% in motor initiative. If detailed neuropsychological testing is performed, the majority of MCI patients will have deficits in cognitive domains other than memory.

Identifying patients at high and low risk of cognitive decline using Rey Auditory Verbal Learning Test among middle-aged memory clinic outpatients

OBJECTIVES

To investigate whether application of cutoff levels in an episodic memory test (Rey Auditory Verbal Learning Test, RAVLT) is a useful method for identifying patients at high and low risk of cognitive decline and subsequent dementia.

METHODS

224 patients with memory complaints (mean age = 60.7 years, mean MMSE = 28.2) followed-up at a memory clinic over approximately 3 years were assigned retrospectively to one of three memory groups from their baseline results in RAVLT [severe (SIM), moderate (MIM) or no impairment (NIM)]. These groups were investigated regarding cognitive decline.

RESULTS

Patients assigned to SIM showed significant cognitive decline and progressed to dementia at a high rate, while a normal performance in RAVLT at baseline (NIM) predicted normal cognition after 3 years. Patients with MIM constituted a heterogeneous group; some patients deteriorated cognitively, while the majority remained stable or improved.

CONCLUSIONS

The application of cutoff levels in RAVLT at baseline showed that patients with severely impaired RAVLT performance were at a high risk of cognitive decline and progression to dementia, while patients with normal RAVLT results did not show cognitive decline during 3 years. Furthermore, the initial degree of memory impairment was decisive in the cognitive prognosis 3 years later.

Heterogeneity of mild cognitive impairment and other predementia syndromes in progression to dementia

Mild cognitive impairment (MCI) is thought to be a prodromal phase of Alzheimer's disease, but in population-based studies MCI classification is less consistent than in clinical series, suggesting that MCI is a heterogeneous descriptor and the outcome at follow-up depends on which population is studied and how MCI is defined. We discussed in the present paper the issue of the heterogeneity of MCI and other predementia syndromes, both in clinical presentation and progression to dementia, supported by the findings of the Italian Longitudinal Study on Aging (ILSA) and other population-based and clinical-based studies.

The significance of thyroid-stimulating hormone and homocysteine in the development of Alzheimer's disease in mild cognitive impairment: a 6-year follow-up study

Mild cognitive impairment (MCI) represents a transition between normal aging and Alzheimer's disease (AD). The aim of this study was to investigate the predictive value of vitamin B12/folate, homocysteine, standard laboratory parameters, and concomitant diseases for development of AD in persons with an MCI diagnosis. Development of dementia was followed for 6 years in 93 consecutively recruited MCI persons. Information concerning the above factors was obtained from medical journals. Thirty-four percent of participants converted to AD within 6 years. A forward stepwise logistic regression was performed. The odds ratio (OR) for the Mini-Mental State Examination (MMSE) was 0.777; for age, 1.084; and for thyroid stimulating hormone (TSH), 0.287. The OR for homocysteine was 1.287 at 60 years of age and 1.087 at 65 years of age. Lower TSH levels together with the more established factors lower MMSE, higher homocysteine levels, and age were found to be predictive factors of AD. This may have clinical implications with regard to monitoring TSH levels and thyroxin substitution in MCI patients.

Subjective memory complaints in Chinese subjects with mild cognitive impairment and early Alzheimer's disease

BACKGROUND

Mild cognitive impairment (MCI) represents a transitional state between normal aging and dementia. However, there is inconsistent opinion as to the validity of subjective memory complaints as a criterion for diagnosis.

OBJECTIVE

This study aimed to examine the potential significance of applying a short memory questionnaire in the assessment of Chinese subjects with MCI and early dementia.

METHODS

Three hundred and six ambulatory Chinese subjects were recruited. Each participant completed a short memory questionnaire. They were also assessed with the Chinese versions of the mini-mental state examination (CMMSE), Alzheimer's disease assessment scale-cognitive subscale (ADAS-Cog), category verbal fluency test (CVFT) and span tests. Severity of cognitive impairment was evaluated using the Clinical Dementia Rating (CDR); subjects with CDR 0.5 were further classified into MCI not demented (MCIND) and MCI possible incipient dementia (MCIID) depending on the subscale scores of CDR.

RESULTS

An increasing frequency of memory complaints with increasing CDR was observed (Kruskal Wallis test, chi square = 21.29, df 3, p < 0.001). With a cutoff of 3 or more memory complaints, the memory questionnaire demonstrated a sensitivity of 65.3% and 70.4% in identifying subjects with incipient and early dementia respectively. Significant associations between memory complaints and most cognitive test performance were found (Spearman's correlations, p < 0.01). Logistic regression analysis revealed that educational level, the memory questionnaire, ADAS-Cog total and delayed recall scores were significant predictors of MCIID status.

CONCLUSIONS

The findings suggested that a short memory questionnaire is useful in the screening of MCI, particularly in subjects who already present with subtle functioning disturbances. Subjective memory complaints were significant correlated with objective performance of memory functions, reflecting the usefulness of memory complaints in the assessment of MCI.

Association between global brain volume and the rate of cognitive change in elderly humans without dementia

Patients with mild cognitive deficits experience different types of evolution. They are at increased risk of developing dementia, but they have also a chance of remaining stable in cognition or of improving. We investigated whether global brain volume, callosal size and hippocampal size are associated with the rate of cognitive change in elderly without dementia. Volumetric MR images were recorded from 39 controls and 35 patients with questionable dementia who were followed up longitudinally for a mean of 2.3 years. The outcome measure was the annual change in the test score in the Structured Interview for the Diagnosis of Alzheimer's Dementia and Multi-Infarct Dementia, which includes all items of the Mini-Mental State Examination. Global brain volume, grey matter volume and white matter volume were the only significant independent predictors of the rate of cognitive change.

Neuropsychological evaluation of mild cognitive impairment: three case reports

Recent research on mild cognitive impairment (MCI) has focused on the description of the disorder, its biological markers, and conversion rates to dementia. Studies of cognitive deficits in individuals who present with memory decline but do not fulfill criteria for dementia have analyzed baseline group data according to outcome diagnosis. The application of these findings to the individual person remains problematic. The current article presents three cases with a relatively isolated deficit in memory for word lists but better performance on other memory tests. Questions arising with regards to the MCI criteria are discussed in light of these case reports.

Mild cognitive impairment in Parkinson's disease: the challenge and the promise

This review addresses the literature surrounding Parkinson's disease (PD) and mild cognitive impairment (MCI). It discusses the neuropsychological, pharmaceutical, and pathological overlap, the socioeconomic impact of PD and MCI, and the value of recognizing, understanding, and treating MCI in PD. It is concluded from this review that MCI in PD does exist and should be considered in clinical and research investigations. Due to the lack of accepted clinical criteria, an inclusive operating definition of MCI in PD is proposed. Research guidelines for studying the presence of MCI in PD and evaluating the efficacy of pharmaceutical interventions are also suggested.

Predictors of reversible mild cognitive impairment after stroke: a 2-year follow-up study

Many studies have investigated mild cognitive impairment (MCI) in the context of prodromal dementia, but few have investigated recovery from MCI. The aim of this study was to determine the prevalence of reversible MCI after stroke and to identify factors related to recovery.

METHODS

One hundred and eighteen patients with a first ever cerebral stroke were followed up for 2 years. Neuropsychological assessment was performed at 1, 6, 12, and 24 months poststroke. Possible predictors of reversible MCI were demographic variables, baseline MMSE scores, presence of stroke risk factors, and CT variables. Poststroke MCI was diagnosed when there was a deficit in at least one cognitive domain, without their being demented. Recovery was considered when MCI was no longer present.

RESULTS

Twenty-four (20.3%) patients were classified as having permanent reversible MCI and were compared with patients without recovery. Most patients recovered from MCI between the first and second assessments (19.7% versus 13.1% and 2.0% later on). Higher baseline MMSE scores and female sex were independent predictors of recovery (OR(High MMSE)=9.9; OR(female sex)=2.8). Neither stroke-related risk factors nor CT variables were predictors of favorable outcome.

CONCLUSION

About 20% of patients with poststroke MCI recover from MCI. Higher MMSE scores at baseline and female sex are independent predictors of this recovery.