Characteristics of cognitive function in early and late stages of amnestic mild cognitive impairment

Aim: The detection of the early stages in amnesic mild cognitive impairment (aMCI) is considered important in diagnosing progression to Alzheimer's disease. The current study sought to investigate differences in cognitive function between control subjects with no memory loss (control), and subjects in the early stage of aMCI (EMCI) and late stage of aMCI (LMCI). Methods: A total of 100 community‐dwelling older adults aged 65 years and over were recruited from 1543 potential subjects. Subjects were classified into three groups based on the degree of objective memory impairment; control (n = 29), EMCI (n = 34) and LMCI (n = 37). Multiple neuropsychological tests were carried out to examine cognitive function. Results: The EMCI individuals showed lower cognitive function relative to controls; not only in logical memory, but also in letter fluency (P < 0.05). There were no significant differences in neuropsychological scores between the EMCI and LMCI groups, except for category fluency and logical memory. In addition, the EMCI subjects' logical memory score showed a significant relationship with letter fluency, category fluency and digit span backward test performance (P < 0.05). Conclusions: These results suggest that the application of multiple neuropsychological tests might be useful in diagnosing older adults with EMCI and LMCI. Geriatr Gerontol Int 2013; 13: 83–89 .     

Diabetes as a risk factor for dementia and mild cognitive impairment: a meta-analysis of longitudinal studies

This study examined the association of diabetes with the onset of dementia (including Alzheimer's disease (AD), vascular dementia (VD) and any dementia) and mild cognitive impairment (MCI) by using a quantitative meta-analysis of longitudinal studies. EMBASE and MEDLINE were searched for articles published up to December 2010. All studies that examined the relationship between diabetes and the onset of dementia or MCI were included. Pooled relative risks were calculated using fixed and random effects models. Nineteen studies met our inclusion criteria for this meta-analysis, and 6184 subjects with diabetes and 38 530 subjects without diabetes were included respectively. All subjects were without dementia or MCI at baseline. The quantitative meta-analysis showed that subjects with diabetes had higher risk for AD (relative risk (RR):1.46, 95% confidence interval (CI): 1.20-1.77), VD (RR: 2.48, 95% CI: 2.08-2.96), any dementia (RR: 1.51, 95% CI: 1.31-1.74) and MCI (RR: 1.21, 95% CI: 1.02-1.45) than those without. The quantitative meta-analysis showed that diabetes was a risk factor for incident dementia (including AD, VD and any dementia) and MCI.     

The GPCOG: a new screening test for dementia designed for general practice

OBJECTIVES: To design and test a brief, efficient dementia-screening instrument for use by general practitioners (GPs). DESIGN: The General Practitioner Assessment of Cognition (GPCOG) consists of cognitive test items and historical questions asked of an informant. The validity of the measure was assessed by comparison with the criterion standard of diagnoses of dementia derived from the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition). SETTING: Primary care doctors' offices. PARTICIPANTS: Sixty-seven GPs administered the GPCOG to 283 community-dwelling patients aged 50 to 74 with memory complaints or aged 75 and older. MEASUREMENTS: The Cambridge Mental Disorder of the Elderly Examination, the Abbreviated Mental Test (AMT), the Mini-Mental State Examination (MMSE), the 15-item Geriatric Depression Scale, and the 12-item Short-Form Health Survey. RESULTS: The GPCOG was reliable and superior to the AMT (and possibly to the MMSE) in detecting dementia. The two-stage method of administering the GPCOG (cognitive testing followed by informant questions if necessary)had a sensitivity of 0.85, a specificity of 0.86, a misclassification rate of 14%, and positive predictive value of 71.4%. Patient interviews took less than 4 minutes to administer and informant interviews less than 2 minutes. The instrument was reported by GPs to be practical to administer and was acceptable to patients. CONCLUSION: The GPCOG is a valid, efficient, well-accepted instrument for dementia screening in primary care.     

Cognitive deficits 3 to 6 years before dementia onset in a population sample: the Honolulu-Asia aging study

OBJECTIVE: To determine the type of cognitive deficits occurring 3 to 6 years before onset of dementia in a population sample. DESIGN: A prospective study in which cognitive deficits in participants who had incident dementia at the 6-year follow-up were examined at baseline and 3 years. SETTING: Honolulu, Hawaii. PARTICIPANTS: Three thousand seven hundred thirty-four Japanese-American men aged 71 to 93 at baseline. At the 6-year follow-up, there were 52 incident cases of dementia, and 1,559 controls. MEASUREMENTS: The Cognitive Abilities Screening Instrument (CASI) and a questionnaire on subjective memory problems were administered at baseline. Dementia was assessed at baseline and at 3-year and 6-year follow-ups. RESULTS: Subjects who had incident dementia at 6-year follow-up, had showed deficits 3 to 6 years earlier in the CASI domain of episodic memory and in the questionnaire covering subjective memory problems. Up to 3 years before onset, there was worsening of the episodic memory deficit from baseline and new deficits in language, verbal fluency, and orientation. CONCLUSION: Cognitive deficits and awareness of memory problems are frequently present several years before dementia onset. The predictive value of these deficits is not large enough to allow earlier diagnosis of dementia, but information about such deficits may be useful as criteria for mild cognitive impairment.     

Implementing a screening and diagnosis program for dementia in primary care

BACKGROUND: Primary care physicians are positioned to provide early recognition and treatment of dementia. We evaluated the feasibility and utility of a comprehensive screening and diagnosis program for dementia in primary care. METHODS: We screened individuals aged 65 and older attending 7 urban and racially diverse primary care practices in Indianapolis. Dementia was diagnosed according to International Classification of Diseases (ICD)-10 criteria by an expert panel using the results of neuropsychologic testing and information collected from patients, caregivers, and medical records. RESULTS: Among 3,340 patients screened, 434 scored positive but only 227 would agree to a formal diagnostic assessment. Among those who completed the diagnostic assessment, 47% were diagnosed with dementia, 33% had cognitive impairment—no dementia (CIND), and 20% were considered to have no cognitive deficit. The overall estimated prevalence of dementia was 6.0% (95% confidence interval (CI) 5.5% to 6.6%) and the overall estimate of the program cost was $128 per patient screened for dementia and $3,983 per patient diagnosed with dementia. Only 19% of patients with confirmed dementia diagnosis had documentation of dementia in their medical record. CONCLUSIONS: Dementia is common and undiagnosed in primary care. Screening instruments alone have insufficient specificity to establish a valid diagnosis of dementia when used in a comprehensive screening program; these results may not be generalized to older adults presenting with cognitive complaints. Multiple health system and patient-level factors present barriers to this formal assessment and thus render the current standard of care for dementia diagnosis impractical in primary care settings. Supported by grant R01 HS10884-01 from the Agency for Healthcare Research and Quality.     

Home-based evaluation of executive function (Home-MET) for older adults with mild cognitive impairment

IntroductionExecutive function helps older adults maintain their activities of daily living by making plans, setting goals, and carrying them out successfully. It is important for their independence in community living.MethodsWith a carefully match-group of 80 mild cognitive impaired with 80 health control subjects. The home-based evaluation of executive function (Home-MET) was validated in subjects’ own living environment.ResultsThis Home-MET showed significant correlation in the assessment of attention control that was assessing by Test of Everyday Attention (TEA) (r = .86, p < .01), with working memory that was assessed with Trail Making Test (TMT) (r = .72, p < .01), with inhibitory control that was assessing with Stroop Test (r = .86, p < .01), with individuals’ functional disability was assessed by Chinese Disability Assessment of Dementia (CDAD) (r = .77, p < .01) and cognitive assessment was assessed by Hong Kong Montreal Cognitive Assessment (HK-MoCA) (r = .88, p < .01). By benchmarking with the validated performance-based executive function assessment, the Home-MET shows significant correlation (r = .92, p < .05) with the executive function test in a standard environment in hospital, i.e. the Chinese Multiple Errands Test (the Chinese-MET). The two-stage hierarchical linear regression model with backward method showed functional disability was a marginally significant predictor (p < .059) for the Home-MET with regression model showed with R² = .93.ConclusionResults indicated the Home-MET, can provide an objective measure of executive function for subjects with mild cognitive impairment in participants’ own home environment.     

Decisional capacity for research participation in individuals with mild cognitive impairment

OBJECTIVES: To assess decisional capacity performance and the neuropsychological correlates of such performance to better understand higher-level instrumental activities of daily living in individuals with mild cognitive impairment (MCI).
DESIGN: Cross-sectional.
SETTING: Research center, medical center, or patient's home.
PARTICIPANTS: Forty participants with MCI and 40 cognitively normal older controls (NCs) aged 60 to 90 (mean age±standard deviation 73.3±6.6; 54% female).
MEASUREMENTS: Capacity to provide informed consent for a hypothetical, but ecologically valid, clinical trial was assessed using the MacArthur Competence Assessment Tool for Clinical Research. Neuropsychological functioning was assessed using a comprehensive protocol.
RESULTS: Adjusted between-group comparisons yielded significant differences for most decisional capacity indices examined, including Understanding ( P =.001; NC>MCI) and Reasoning ( P =.002; NC>MCI). Post hoc analyses revealed that participants with MCI who were categorized as capable of providing informed consent according to expert raters had higher levels of education than those who were categorized as incapable.
CONCLUSION: The findings suggest that many individuals with MCI perform differently on a measure of decisional capacity than their NC peers and that participants with MCI who are incapable of providing informed consent on a hypothetical and complex clinical trial are less educated. These findings are consistent with prior studies documenting functional and financial skill difficulties in individuals with MCI.     

轻度认知障碍与非痴呆型血管性认知功能障碍患者屏气指数的研究

目的评价轻度认知障碍（McI）患者与非痴呆型血管性认知功能障碍（VICND）患者的屏气指数（BHI）与认知功能的关系。方法 150例受试者分为正常对照组、MCI组及VICND组,应用经颅多普勒（TCD）屏气试验计算BHI,并应用蒙特利尔认知评估量表（MoCA）进行认知功能评分,分析BHI与认知功能的关系。结果MCI组和VCIND组高血压、高血糖、高血脂的患病率均显著高于对照组（P〈0．05）,MCI组与VCIND组间比较无显著差异。MCI组和VCIND组BHI,分别为（0．90±0．16）％／s、（0．87±0．19）％／s,均明显低于对照组的（1．37±0．22）％／s。MoCA评分与BHI呈正相关（r=0．803,P〈0．01）结论高血压、糖尿病及高血脂可能与MCI患者及VCIND患者的认知功能下降有关,BHI与认知功能具有一定的相关性。     

Associations between dementia/mild cognitive impairment and cognitive performance and activity levels in youth

OBJECTIVES: To study the associations between dementia/mild cognitive impairment (MCI) and cognitive performance and activity levels in youth. DESIGN: Retrospective cohort study. SETTING: Research volunteers living throughout the United States. PARTICIPANTS: A total of 396 persons (mean age 75) who were graduates of the same high school in the mid-1940s. MEASUREMENTS: Adolescent intelligence quotient (IQ) scores were gathered from archived student records, and activity levels were determined from yearbooks. A two-stage telephone screening procedure (Modified Telephone Interview for Cognitive Status or Informant Questionnaire on Cognitive Decline in the Elderly followed by Dementia Questionnaire) was used to determine adult cognitive status. Data were analyzed using logistic regression to model the risk of cognitive impairment (dementia/MCI) versus no cognitive impairment as a function of IQ and activity level, adjusting for sex and education. RESULTS: High adolescent IQ and greater activity level were each independently associated with a lower risk for dementia/MCI (odds ratio (OR) for a 1-standard deviation increase in IQ=0.51, 95% confidence interval (CI)=0.32-0.79; OR for a unit increase in activity=0.32, 95% CI=0.12-0.84). No association was found between sex or education and adult cognitive status in this model. CONCLUSION: High IQ and greater activity levels in youth reduce the risk for cognitive impairments in aging. The mechanism(s) underlying these associations are unknown, but intelligence may be a marker for cognitive/neurological "reserve," and involvement in activities may contribute to "reserve." Early neuropathology and ascertainment bias are also possible explanations for the observed associations.     

记忆与执行筛查量表鉴别血管性痴呆与阿尔茨海默病的作用

目的探讨记忆与执行筛查量表(MES)鉴别诊断皮质下缺血性血管性痴呆(SIVD)与阿尔茨海默病(AD)的价值。方法回顾性纳入2012年6月至2013年11月首都医科大学附属复兴医院神经内科门诊和病房收治的SIVD和AD患者各50例。选取同期于复兴医院月坛社区体格检查健康者50名为对照组。3组受试者的年龄、性别和教育程度匹配。以简易精神状态量表(MMSE)和MES检测全部受试者并加以比较;记忆与执行评分比值(MES-R)对于SIVD与AD区分度的分析采用受试者工作特征曲线。结果 (1)SIVD组与AD组的MMSE总分差异无统计学意义[(20.6±5.5)分比(20.6±3.3)分,P0.05]。(2)3组患者MES各指标差异均有统计学意义(均P0.01)。SIVD组句子记忆1、3、4、5评分均明显高于AD组,差异均有统计学意义(均P0.05)。执行部分指标:SIVD组左、右手连续动作及指令与动作矛盾刺激评分均低于AD组[(5.1±3.1)分比(7.3±2.1)分,(5.2±3.0)分比(7.7±1.9)分,(3.5±4.4)分比(6.2±4.3)分],差异均有统计学意义(均P0.01)。SIVD组MES-R值高于AD组(1.2±0.7比0.5±0.2),差异有统计学意义(P0.01)。(3)MES-R≥0.7时,区分SIVD与AD的敏感度76.7%,特异度为83.3%;而MMSE总分区分SIVD与AD的敏感度为40.0%,特异度仅为0.7%。结论对SIVD与AD患者进行MES测定,反映句子记忆和执行部分的差异,可以较好地区分两种疾病。     

The Montreal Cognitive Assessment, MoCA: a brief screening tool for mild cognitive impairment

OBJECTIVES: To develop a 10-minute cognitive screening tool (Montreal Cognitive Assessment, MoCA) to assist first-line physicians in detection of mild cognitive impairment (MCI), a clinical state that often progresses to dementia. DESIGN: Validation study. SETTING: A community clinic and an academic center. PARTICIPANTS: Ninety-four patients meeting MCI clinical criteria supported by psychometric measures, 93 patients with mild Alzheimer's disease (AD) (Mini-Mental State Examination (MMSE) score > or =17), and 90 healthy elderly controls (NC). MEASUREMENTS: The MoCA and MMSE were administered to all participants, and sensitivity and specificity of both measures were assessed for detection of MCI and mild AD. RESULTS: Using a cutoff score 26, the MMSE had a sensitivity of 18% to detect MCI, whereas the MoCA detected 90% of MCI subjects. In the mild AD group, the MMSE had a sensitivity of 78%, whereas the MoCA detected 100%. Specificity was excellent for both MMSE and MoCA (100% and 87%, respectively). CONCLUSION: MCI as an entity is evolving and somewhat controversial. The MoCA is a brief cognitive screening tool with high sensitivity and specificity for detecting MCI as currently conceptualized in patients performing in the normal range on the MMSE.     

Caring for individuals with dementia and cognitive impairment, not dementia: findings from the aging, demographics, and memory study

OBJECTIVES: To compare the characteristics and outcomes of caregivers of adults with dementia with those of caregivers of adults with cognitive impairment, not dementia (CIND). DESIGN: Cross‐sectional. SETTING: In‐home assessment for cognitive impairment and self‐administered caregiving questionnaire. PARTICIPANTS: One hundred sixty‐nine primary family caregivers of participants in the Aging, Demographics, and Memory Study (ADAMS). ADAMS participants were aged 71 and older drawn from the nationally representative Health and Retirement Study. MEASUREMENTS: Neuropsychological testing, neurological examination, clinical assessment, and medical history were used to assign a diagnosis of normal cognition, CIND, or dementia. Caregiving measures included caregiving time, functional limitations, depressive symptoms, physical and emotional strain, caregiving rewards, caregiver health, and demographic characteristics. RESULTS: Dementia caregivers spent approximately 9 hours per day providing care, compared with 4 hours per day for CIND caregivers (P=.001). Forty‐four percent of dementia caregivers exhibited depressive symptoms, compared with 26.5% of CIND caregivers (P=.03). Physical and emotional strains were similar in both groups of caregivers. Regardless of the strains, nearly all caregivers reported some benefits from providing care. Behavioral problems (P=.01) and difficulty with instrumental activities of daily living (P=.01) in persons with CIND partially explained emotional strain experienced by CIND caregivers. For those with dementia, behavioral problems predicted caregiver emotional strain (P<.001) and depressive symptoms (P=.01). CONCLUSION: Although support services are available to dementia caregivers, CIND caregivers also expend considerable time and experience strains. The real caregiver burden of cognitive impairment in the U.S. population may therefore be greatly underestimated if people who have reached the diagnostic threshold for dementia are focused on exclusively.     

Depressive symptoms and incidence of mild cognitive impairment and probable dementia in elderly women: the Women's Health Initiative Memory Study

OBJECTIVES: To examine whether significant depressive symptoms in postmenopausal women increases the risk of subsequent mild cognitive impairment (MCI) and dementia. DESIGN: Prospective cohort study. SETTING: Thirty nine of the 40 Women's Health Initiative (WHI) clinical centers that participated in a randomized clinical trial of hormone therapy. PARTICIPANTS: Six thousand three hundred seventy‐six postmenopausal women without cognitive impairment aged 65 to 79 at baseline. MEASUREMENTS: Depressive disorders were assessed using an eight‐item Burnam algorithm and followed annually for a mean period of 5.4 years. A central adjudication committee classified the presence of MCI and probable dementia based on an extensive neuropsychiatric examination. RESULTS: Eight percent of postmenopausal women in this sample reported depressive symptoms above a 0.06 cut point on the Burnam algorithm. Depressive disorder at baseline was associated with greater risk of incident MCI (hazard ratio (HR)=1.98, 95% confidence interval (CI)=1.33–2.94), probable dementia (HR=2.03, 95% CI=1.15–3.60), and MCI or probable dementia (HR=1.92, 95% CI=1.35–2.73) after controlling for sociodemographic characteristics, lifestyle and vascular risk factors, cardiovascular and cerebrovascular disease, antidepressant use, and current and past hormone therapy status. Assignment to hormone therapy and baseline cognitive function did not affect these relationships. Women without depression who endorsed a remote history of depression had a higher risk of developing dementia. CONCLUSION: Clinically significant depressive symptoms in women aged 65 and older are independently associated with greater incidence of MCI and probable dementia.     

Amnestic behavior in dementia: symptoms to assist in early detection and diagnosis

OBJECTIVES: This study evaluated two amnestic behavior changes (repetitive questioning and repetitive actions) to determine their utility in screening for early dementia. DESIGN: Patient data were collected through a retrospective chart review. Comparison data from nondemented older people were collected prospectively from acquaintances of clinic patients. SETTING: The setting was a hospital-based outpatient memory disorder clinic. PARTICIPANTS: Participants were older individuals with no cognitive impairment (n = 25), undetermined dementia (n = 50), and definite dementia (n = 25). The undetermined cases were followed for at least 1 year to assess for conversion to dementia. MEASUREMENTS: Amnestic behaviors were assessed using informant-report for all participants. The behaviors were examined for their ability to distinguish between definite dementia cases and noncases. They were further evaluated for the ability to differentiate undetermined cases that eventually converted to definite dementia from cases that did not convert. RESULTS: Results indicated that repetitive behaviors were common in early and more-severe dementia cases. Repetitive behaviors were relatively uncommon in cognitively intact older participants. In analyses of the full study sample, engagement in repetitive behaviors had high sensitivity (0.97) in identifying dementia cases. CONCLUSIONS: Assessing repetitive behaviors in patients may be a useful means for family members and primary care physicians to screen for early cognitive impairment. The assessment can help to identify individuals that should be evaluated further for dementia.