Screening of mild cognitive impairment in Chinese older adults--a multistage validation of the Chinese abbreviated mild cognitive impairment test

Tai Chi versus conventional exercise for improving cognitive function in older adults: a pilot randomized controlled trial

Studies have shown that Tai Chi and conventional exercise can modify the brain through distinct mechanisms, resulting in different brain adaptations. Therefore, it is conceivable to speculate that these two exercise modalities may have different effects on improving cognitive function. This study was a parallel group, assessor-blinded, pilot randomized controlled trial comparing the effects of Tai Chi and conventional exercise on improving cognitive function in older persons with mild cognitive impairment (MCI). A total of 34 adults aged ≥ 50 years with MCI were randomized (1:1:1) to the Tai Chi group (TC, n = 10, 3 sessions of 60-min Yang-style Tai Chi training per week for 24 weeks), conventional exercise group (EX: n = 12, 3 sessions of 60-min fitness training per week for 24 weeks), or control group (CON: n = 12, no intervention). Global cognitive function assessed by the Hong Kong version of the Montreal Cognitive Assessment (MoCA-HK) and performance in various cognitive domains were examined at baseline, and 12 and 24 weeks of the intervention. Both exercise groups showed improved global cognitive function as measured by MoCA-HK compared with the control group after 12 and 24 weeks of the intervention, (all P < 0.001). Only TC achieved clinically relevant improvement on global cognitive function at week 12. Both exercise groups achieved clinically relevant improvements at the end of the interventions at week 24. Compared with EX, TC exhibited greater improvements on global cognitive function indicated by MoCA-HK after 12 weeks of the intervention (P < 0.001) and cognitive flexibility indicated by part B/A ratio score of the Trail Making Test throughout the study (all P < 0.05). Both interventions were equally effective in improving the other examined cognitive domains. Further studies are needed to substantiate the superior long-term benefits of Tai Chi on global cognitive function compared with conventional exercise, and dissect the underlying mechanisms of the two exercises on improving cognitive domains and the corresponding brain adaptations. Trial registration: This study was registered at clinicaltrials.gov (Trial registration number: NCT04248400; first registration date: 30/01/2020).

Cognitive Impairment and Its Associated Factors in Older Adults Living in High and Low Altitude Areas: A Comparative Study

BACKGROUND

Cognitive impairment is a major health concern in older adults. Few studies have examined the association between environmental factors and cognitive impairment, especially in high altitude areas. In this study, the prevalence of cognitive impairment in older adults living in high altitude was compared with those living in low altitude areas.

METHODS

This was a comparative study conducted at Qinghai (high altitude group), and Guangzhou (low altitude group), China. Cognition, depressive symptoms and quality of life (QOL) were assessed using the Montreal Cognitive Assessment (MoCA), Patient Health Questionnaire (PHQ-9) and WHO Quality of Life brief version-WHOQOL-BREF, respectively.

RESULTS

Altogether, 644 older adults (207 in Qinghai and 437 in Guangzhou) completed the assessment. The prevalence rate of cognitive impairment was 94.7% (95% CI: 91.6-97.7%) in older adults living in the high altitude area, while the corresponding figure was 89.2% (95% CI: 86.3-92.1%) in the low altitude area. After controlling for covariates, the high altitude group appeared more likely to have cognitive impairment (OR = 2.92, 95% CI: 1.23-6.91, P = 0.015) compared with the low altitude group. Within the high altitude group sample, multinomial logistic regression analysis revealed that older age (aged 74 and above) was significantly associated with higher risk of severe cognitive impairment (OR = 3.58, 95%CI: 1.44-8.93, P = 0.006), while higher education level (secondary school and above) was associated with decreased risk of moderate cognitive impairment (OR = 0.43, 95%CI: 0.22-0.85, P = 0.006). Within the high altitude group, QOL did not differ significantly between normal/mild, moderate and severe cognitive impairment subgroups across physical [F _{(1, 207)} = 1.83, P = 0.163], psychological [F _{(1, 207)} = 1.50, P = 0.225], social [F _(1,207) = 2.22, P = 0.111] and environmental domains [F _(1,207) = 0.49, P = 0.614].

CONCLUSION

This study found that cognitive impairment was more common among older adults living in the high altitude area. Regular screening and appropriate interventions should be provided to older adults in need.

Identification of susceptibility loci for cognitive impairment in a cohort of Han Chinese patients with Parkinson's disease

Parkinson's disease (PD) is one of the most common neurodegenerative diseases. Identifying PD cognitive impairment (PDCI) in the early stage will help slow or prevent PD dementia. Susceptibility loci for PDCI are inconsistent in different studies. The aim of this study is to determine susceptibility loci for PDCI in the Han Chinese population. A total of 24 single nucleotide polymorphisms (SNPs) associated with PDCI were genotyped by Massarray system and Sanger sequencing in 158 PD patients and 275 healthy controls. Two SNPs (rs34778348 in LRRK2, rs78973108 in GBA) had different genotype distribution between PD and controls. None of risk SNPs was identified between PDCI and PD with normal cognition (PDNC). Aging and high Unified Parkinson's Disease Rating Scale (UPDRS) score were the independent risk factors for PDCI, rather than sex and SNPs. Our study showed that none of risk SNPs was identified to be significantly associated with cognitive decline of PD patients, indicating the effect of susceptibility loci on PDCI is subtle in the Han Chinese population.

Screening for Cognitive Impairment in Older Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Early identification of cognitive impairment may improve patient and caregiver health outcomes.

OBJECTIVE

To systematically review the test accuracy of cognitive screening instruments and benefits and harms of interventions to treat cognitive impairment in older adults (≥65 years) to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed, PsycINFO, and Cochrane Central Register of Controlled Trials through January 2019, with literature surveillance through November 22, 2019.

STUDY SELECTION

Fair- to good-quality English-language studies of cognitive impairment screening instruments, and pharmacologic and nonpharmacologic treatments aimed at persons with mild cognitive impairment (MCI), mild to moderate dementia, or their caregivers.

DATA EXTRACTION AND SYNTHESIS

Independent critical appraisal and data abstraction; random-effects meta-analyses and qualitative synthesis.

MAIN OUTCOMES AND MEASURES

Sensitivity, specificity; patient, caregiver, and clinician decision-making; patient function, quality of life, and neuropsychiatric symptoms; caregiver burden and well-being.

RESULTS

The review included 287 studies with more than 280 000 older adults. One randomized clinical trial (RCT) (n = 4005) examined the direct effect of screening for cognitive impairment on patient outcomes, including potential harms, finding no significant differences in health-related quality of life at 12 months (effect size, 0.009 [95% CI, -0.063 to 0.080]). Fifty-nine studies (n = 38 531) addressed the accuracy of 49 screening instruments to detect cognitive impairment. The Mini-Mental State Examination was the most-studied instrument, with a pooled sensitivity of 0.89 (95% CI, 0.85 to 0.92) and specificity of 0.89 (95% CI, 0.85 to 0.93) to detect dementia using a cutoff of 23 or less or 24 or less (15 studies, n = 12 796). Two hundred twenty-four RCTs and 3 observational studies including more than 240 000 patients or caregivers addressed the treatment of MCI or mild to moderate dementia. None of the treatment trials were linked with a screening program; in all cases, participants were persons with known cognitive impairment. Medications approved to treat Alzheimer disease (donepezil, galantamine, rivastigmine, and memantine) improved scores on the ADAS-Cog 11 by 1 to 2.5 points over 3 months to 3 years. Psychoeducation interventions for caregivers resulted in a small benefit for caregiver burden (standardized mean difference, -0.24 [95% CI, -0.36 to -0.13) over 3 to 12 months. Intervention benefits were small and of uncertain clinical importance.

CONCLUSIONS AND RELEVANCE

Screening instruments can adequately detect cognitive impairment. There is no empirical evidence, however, that screening for cognitive impairment improves patient or caregiver outcomes or causes harm. It remains unclear whether interventions for patients or caregivers provide clinically important benefits for older adults with earlier detected cognitive impairment or their caregivers.

Randomized controlled trial of TDCS on cognition in 201 seniors with mild neurocognitive disorder

OBJECTIVE

To examine the efficacy and safety of combined transcranial direct current stimulation (tDCS) and working memory training (WMT) in enhancing the cognitive functions for individuals with mild neurocognitive disorder due to AD (NCD-AD).

METHODS

In this double-blind, sham-controlled randomized clinical trial (RCT), 201 patients with NCD-AD were randomly assigned for a 4-week intervention of either a combination of tDCS and WMT, sham tDCS and WMT, or tDCS and control cognitive training (CCT). Global cognition and domain-specific cognitive function were assessed before and after the intervention with Alzheimer's disease assessment scale-cognitive subscale (ADAS-Cog), category verbal fluency test, logical memory, digit, and visual span tests.

RESULTS

Study participants did not show intervention group differences in baseline demographics, or cognitive characteristics (ANOVA). Cognitive enhancement was found across three groups after 4 weeks intervention. Combined tDCS-WMT group showed significantly greater improvement compared with single-modality groups in delayed recall (P = 0.043, η²  = 0.036) and working memory capacity (P = 0.04, η²  = 0.038) at 4th week, and logical memory at 12th week (P = 0.042, η²  = 0.037). Adverse events, including skin lesions (2.2%), were similar between groups.

INTERPRETATION

tDCS or WMT could be a safe, feasible, and effective intervention for individuals with NCD-AD. A combination of tDCS and WMT presents greater cognitive enhancement, which may highlight the potential synergistic effects of combined modality intervention on cognition.

Would transcranial direct current stimulation (tDCS) enhance the effects of working memory training in older adults with mild neurocognitive disorder due to Alzheimer's disease: study protocol for a randomized controlled trial

BACKGROUND

There has been longstanding interesting in cognitive training for older adults with cognitive impairment. In this study, we will investigate the effects of working memory training, and explore augmentation strategies that could possibly consolidate the effects in older adults with mild neurocognitive disorder. Transcranial direct current stimulation (tDCS) has been demonstrated to affect the neuronal excitability and reported to enhance memory performance. As tDCS may also modulate cognitive function through changes in neuroplastic response, it would be adopted as an augmentation strategy for working memory training in the present study.

METHODS/DESIGN

This is a 4-week intervention double-blind randomized controlled trial (RCT) of tDCS. Chinese older adults (aged 60 to 90 years) with mild neurocognitive disorder due to Alzheimer's disease (DSM-5 criteria) would be randomized into a 4-week intervention of either tDCS-working memory (DCS-WM), tDCS-control cognitive training (DCS-CC), and sham tDCS-working memory (WM-CD) groups. The primary outcome would be working memory test - the n-back task performance and the Chinese version of the Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-Cog). Secondary outcomes would be test performance of specific cognitive domains and mood. Intention-to-treat analysis would be carried out. Changes of efficacy indicators with time and intervention would be tested with mixed effect models.

DISCUSSION

This study adopts the theory of neuroplasticity to evaluate the potential cognitive benefits of non-invasive electrical brain stimulation, working memory training and dual stimulation in older adults at risk of cognitive decline. It would also examine the tolerability, program adherence and adverse effects of this novel intervention. Information would be helpful for further research of dementia prevention studies.

TRIAL REGISTRATION

ChiCTR-TRC- 14005036 Date of registration: 31 July 2014.

Electroacupuncture for older adults with mild cognitive impairment: study protocol for a randomized controlled trial

BACKGROUND

Mild cognitive impairment is an intermediary state between normal aging and clinical Alzheimer's disease. Early intervention of mild cognitive impairment may be an important strategy in the management of Alzheimer's disease. The proposal aims to evaluate if electroacupuncture would optimize cognitive function in subjects with mild cognitive impairment and understand the role of electroacupuncture in the treatment of Alzheimer's disease.

METHODS/DESIGN

A randomised patient- and assessor-blind sham-controlled trial is designed to assess whether electroacupuncture intervention decreases the rate of cognitive decline amongst older adults with mild cognitive impairment. One hundred and fifty subjects aged 65 years of age or over with a diagnosis of mild cognitive impairment are recruited from the community and elderly centre in Hong Kong. All subjects are randomly allocated into two groups (75 subjects each group): the electroacupuncture group and sham control. Participants in the electroacupuncture group receive electroacupuncture stimulation by sterile, disposable acupuncture needles inserted to the acupoints with a depth of 1 to 3 cm. The acupuncture needles are subjected to 2 Hz electroacupuncture with an intensity of 5 to 10 mA. Each participant receives electroacupuncture for 8 weeks (once a day, 3 days a week) and the treatment lasts for 30 minutes each time. For sham electroacupuncture, needles are inserted to a depth of 1 to 2 mm, and connected to the electroacupuncture device without any current passing through. Outcome measures (including primary and secondary outcome measures) are collected at baseline, at the end day of intervention, and months 4 and 6 after intervention. The primary outcome is measured by the Alzheimer Disease Assessment Scale-Cognitive subscale. Secondary outcomes are measured by the mini-mental state examination, category fluency text and the Short Form 12.

DISCUSSION

The study will provide evidence for evaluating and understanding the role of electroacupuncture in the treatment of Alzheimer's disease.

TRIAL REGISTRATION

This trial is registered with chictr.org (registration number: ChiCTR-TRC-12002414 . Registration date: 11 August 2012.

Mild cognitive impairment and its management in older people

Mild cognitive impairment (MCI) is a common condition in the elderly. It is characterized by deterioration of memory, attention, and cognitive function that is beyond what is expected based on age and educational level. MCI does not interfere significantly with individuals’ daily activities. It can act as a transitional level of evolving dementia with a range of conversion of 10%–15% per year. Thus, it is crucial to protect older people against MCI and developing dementia. The preventive interventions and appropriate treatments should improve cognitive performance, and retard or prevent progressive deficits. The avoidance of toxins, reduction of stress, prevention of somatic diseases, implementation of mental and physical exercises, as well as the use of dietary compounds like antioxidants and supplements can be protective against MCI. The modification of risk factors such as stopping smoking, as well as the treatment of deficiency in vitamins and hormones by correcting behaviors and lifestyle, can prevent cognitive decline in the elderly. The progressive increase in the growth rate of the elderly population can enhance the rate of MCI all over the world. There is no exact cure for MCI and dementia; therefore, further studies are needed in the future to determine causes of MCI and risk factors of progression from MCI to dementia. This will help to find better ways for prevention and treatment of cognitive impairment worldwide.

A review of amnestic MCI screening in east/southeast Asian older adults with low education: implications for early informant-clinician collaboration

OBJECTIVE

The aim of this study is to review the recent literature on established cognitive tests and appropriate screening methods for amnestic mild cognitive impairment (MCI) in East/Southeast Asian older adults with a focus on those with low education.

DESIGN

Peer-reviewed empirical studies conducted in Asia (China, Hong Kong, Japan, Korea, Singapore, and Taiwan) were identified using databases in psychology and medicine with combinations of the search terms "mild cognitive impairment," "dementia," "screening," "literacy," "illiteracy," "low education," "informant," "family," "cognitive test," "memory complaints," "activities of daily living," and "clinical dementia rating," limiting articles to those published in English since 1 January 2002. Of note, is that the term "amnestic mild cognitive impairment" was not used for searching the articles because the related cognitive impairment were often categorized non-specifically as MCI, but participants included those with amnestic cognitive challenges. Hence, the general term "MCI" has been used often throughout the text.

RESULTS

Twelve studies that examined MCI screens were identified. An integrative approach using a combination of cognitive test and informant-based measure may be more sensitive or accurate than using any single screening method alone.

CONCLUSION

MCI misdiagnosis may be prevalent, highlighting the need for early collaborative work between informants and clinicians to improve the accuracy of this diagnosis in older Asian adults with low education. Findings were suggestive, although restricted in generalizability even within similar cultural groups or neighboring regions. Clinical application is limited, but some findings provide guidance for future research.

Cognitive screening for dementia in primary care: a systematic review

BACKGROUND

Identifying dementia in primary care could minimize the impact of a late intervention; however, it shows high rates of misdiagnosis. One of the reasons seems to be the lack of knowledge of adequate cognitive screening instruments. This is a systematic review of the available instruments for the primary care context.

METHOD

For this systematic review, articles were collected according to the following combined key terms: "cognitive screening" and "dementia" and "primary care" and "review". Studies should be reviews focusing on cognitive screening instruments best used in primary care setting.

RESULTS

Thirteen reviews were selected. In total, it was considered 34 cognitive screening instruments. Half of the instruments can be applied in an adequate time-limit for primary care context. Memory is the most commonly assessed cognitive function (91%). Almost half of the tests are mentioned to have influence of education or cultural factors (44%).

CONCLUSION

Tests such as 6CIT, AMT, GPCOG, Mini-Cog, MIS, MoCA, and STMS seem to be good alternatives to the use of the Mini-Mental State Examination when considering factors such as application time, sensitivity, specificity, and number of studies. However, there is a wide range of tests with different characteristics, therefore it is recommended that the professional gets some expertise in a few number of instruments in order to be able to choose which to use, or use in combination, depending on the setting and the profile of the patient.

Bias in discriminating very mild dementia for older adults with different levels of education in Hong Kong

BACKGROUND

Education has a profound effect on older adults' cognitive performance. In Hong Kong, some dementia screening tasks were originally designed for developed population with, on average, higher education.

METHODS

We compared the screening power of these tasks for Chinese older adults with different levels of education. Community-dwelling older adults who were healthy (N = 383) and with very mild dementia (N = 405) performed the following tasks: Mini-Mental State Examination, Alzheimer's Disease Assessment Scale-Cognitive subscales, Verbal Fluency, Abstract Thinking, and Visual/Digit Span. Logistic regression was used to examine the power of these tasks to predict Clinical Dementia Rating (CDR 0.5 vs. 0).

RESULTS

Logistic regression analysis showed that while the screening power of the total scores in all tasks was similar for high and low education groups, there were education biases in some items of these tasks.

CONCLUSION

The differential screening power in high and low education groups was not identical across items in some tasks. Thus, in cognitive assessments, we should exercise great caution when using these potentially biased items for older adults with limited education.

Effects of education on very mild dementia among Chinese people in Hong Kong: potential mediators in the Cantonese Mini-Mental State Examination tasks

BACKGROUND

In Hong Kong, older Chinese adults generally have a low level of education. This study examined the effect of education on very mild Alzheimer's disease (AD), as quantified by Clinical Dementia Rating (CDR) scale (CDR 0.5 versus 0), in a Chinese community. The Cantonese version of the Mini-Mental State Examination (C-MMSE) was used to estimate cognitive abilities that were related to the level of education, and that in turn serve as protective factors for AD.

METHODS

A total of 788 community-dwelling older adults (383 CDR 0 and 405 CDR 0.5) were recruited in this cross-sectional study, which was derived from a population-based prevalence project. The participants' number of years of education and C-MMSE scores were used to predict their CDR scores using logistic regression and the mediation effects of C-MMSE scores were analyzed.

RESULTS

Consistent with previous studies, the chance of being rated as having very mild AD increased with age, but decreased with years of education, among the older adult community of Hong Kong. The effect of education on very mild dementia was weakened substantially when C-MMSE scores were included as mediating variables.

CONCLUSIONS

The findings indicate that the protective effects of education on dementia were mediated by an enhancement of older adults' performance on some C-MMSE items, including attention and orientation to time and place.

Cognitive predictors for five-year conversion to dementia in community-dwelling Chinese older adults

BACKGROUND

This study evaluates which cognitive measure is best for predicting incident dementia in a population-based random sample of Chinese older adults without dementia over a five-year period.

METHODS

A total of 787 community-dwelling Chinese older adults without dementia in Hong Kong were assessed at baseline (T0), at two years (T1), and at five years (T2).

RESULTS

The annual conversion rate to dementia was 1.6% and 6.3% for baseline normal participants and baseline mild cognitive impairment (MCI) participants, respectively. The Cantonese version of Mini-mental State Examination (CMMSE) scores declined significantly over time. In participants who progressed to dementia, Category Verbal Fluency Test (CVFT) scores dropped significantly from T0 to T1. A 1-SD drop of either CMMSE or CVFT in two years predicted dementia at five years with 91.5% sensitivity and 62.0% specificity. A stable CMMSE and CVFT at two years predicted a 91% chance of not progressing to clinical dementia at five years.

CONCLUSION

In this community sample of Chinese older adults, a decline in cognitive screening tests in short term (two years) offered useful information in predicting dementia conversion over a longer period.

A systematic review of screening tools for predicting the development of dementia

Early detection of dementia is essential to guide front-line health care practitioners in further clinical evaluations and treatments. There is a paucity of literature assessing the effectiveness of screening tools to predict the development of dementia, thus we conducted a systematic review to fill this gap. The purpose of the systematic review was to make recommendations to health care practitioners on which screening tool best predicts the development of dementia and is most feasible in the primary care setting. Ten databases were searched for relevant articles, yielding 751 papers. Of these, 12 met relevance criteria for inclusion. Screening tools were assessed for test accuracy, cognitive domain coverage, predictive ability, and feasibility. Four screening tools were recommended. Addenbrooke's Cognitive Examination (ACE) was considered to be the ideal tool. A revised version of this tool is now used in clinical practice but the psychometric properties of the ACE-R remain to be established.

Population-based distribution and psychometric properties of a short cognitive performance measure in the population-based Heinz Nixdorf Recall Study

BACKGROUND

Providing a valid and sensitive measure of different domains of cognitive performance in epidemiologic studies of early old-age populations presents a methodological challenge, given the broad range of variability in cognitive functioning in this age group.

OBJECTIVES

(1) To provide data on the distribution of cognitive performance scores in a representative sample of an early old-age population, and (2) to assess psychometric properties of a short cognitive performance measure developed within the framework of a cohort study.

DESIGN

Population-based cohort study.

SETTING AND PARTICIPANTS

As part of the second examination of the Heinz Nixdorf Recall Study, 4,145 participants aged 50-80 years underwent a short cognitive performance assessment composed of 5 subtests with a mean duration of 7.31 min. Additionally, a subsample of 656 participants had a detailed neuropsychological and neurological examination.

METHODS

Age- and education-specific cognitive performance scores in the total sample were calculated. Based on data from the subsample, concurrent validity was examined by comparing findings with a clinically validated neuropsychological assessment.

RESULTS

In the total sample, younger and more highly educated participants had higher scores of cognitive performance. In the subsample, a good accuracy [area under the curve (AUC) = 0.81 (0.74-0.87)] of the short cognitive performance assessment compared with results from a clinically established Alzheimer disease assessment scale and diagnosis of mild cognitive impairment [AUC = 0.82 (0.78-0.82)] was observed.

CONCLUSION

This brief, cognitive performance measure, documenting good psychometric properties, can be useful in future epidemiological investigations exploring different domains and overall cognitive functioning in early old-age populations.

Brain structure and cerebrovascular risk in cognitively impaired patients: Shanghai Community Brain Health Initiative-pilot phase

OBJECTIVE

To investigate the associations among brain morphologic changes as seen on magnetic resonance imaging (MRI), cerebrovascular risk (CVR), and clinical diagnosis and cognition in elderly patients with mild cognitive impairment and dementia living in urban Shanghai.

DESIGN

Cross-sectional study performed from May 1, 2007, to November 31, 2008.

SETTING

Memory Disorders Clinic of the Huashan Hospital and the Shanghai community.

PARTICIPANTS

Ninety-six older people: 32 with normal cognition (NC), 30 with amnestic mild cognitive impairment (aMCI), and 34 with dementia.

MAIN OUTCOME MEASURES

For each patient, we administered a neurologic and physical examination, neuropsychological evaluation, and brain MRI and genotyped the apolipoprotein E-ε4 (APOE-ε4) gene. The volumes determined by MRI were assessed using a semiautomatic method.

RESULTS

Brain volume was significantly smaller in the dementia patients compared with the NC (P < .001) and aMCI patients (P = .04). Hippocampal volume (HV) was lower and white matter hyperintensity (WMH) volume was higher in those with aMCI (HV: P = .03; WMH volume: P = .04) and dementia (HV: P < .001; WMH volume: P = .002) compared with NC participants. The presence of APOE-ε4 was significantly associated with reduced HV (P = .02). Systolic blood pressure was positively associated with CVR score (P = .04); diastolic blood pressure (P = .02) and CVR score (P = .04) were positively associated with WMH volume. The WMH volume (P = .03) and CVR score (P = .03) were higher among dementia patients compared with NC participants.

CONCLUSIONS

Brain structure changes seen on MRI were significantly associated with clinical diagnosis. In addition, blood pressure was highly associated with CVR score and WMH volume. These results suggest that MRI is a valuable measure of brain injury in a Chinese cohort and can serve to assess the effects of various degenerative and cerebrovascular diseases.

Screening for mild cognitive impairment: a systematic review

OBJECTIVE

Patients with mild cognitive impairment account for a significant number of referrals to old age psychiatry services and specialist memory clinics. The cognitive evaluation of such patients is commonly restricted to brief dementia screens, with no consideration to their suitability for assessing MCI. Here, we review the utility of such cognitive screens for MCI and provide an overview of validated instruments.

METHODS

We identified papers published after Petersen and colleagues 1999 MCI criteria (Petersen et al., 1999) and examining face-to-face cognitive screening for MCI from publication databases using combinations of the search terms 'mild cognitive impairment' and 'cognitive screening'. We also combined the former search with the names of 39 screening tests recently identified in a relevant review (Cullen et al., 2007).

RESULTS

Fifteen cognitive screening instruments were identified, 11 cover a restricted range of cognitive domains. High sensitivity and specificity for MCI relative to healthy controls were reported for two comprehensive and two noncomprehensive screening instruments, adequate test-retest and inter-rater reliability for only one of these. With the exception of three studies, sample sizes were universally small (i.e. n </= 100), and prognostic values were reported for only two of the identified 15 screening measures. Sensitivities of the full domain measures were universally high, but information about their specificity against psychiatric and non-progressive neurological conditions and predictive validity is lacking.

CONCLUSION

Several cognitive screening instruments afford the clinician the ability to detect MCI, early AD, and in some cases non-AD dementia, but they cannot currently be used to make reliable inferences about the course and eventual outcome of MCI.