Education effects on cognitive function in a healthy aged Arab population

Mini-mental state examination (MMSE) scores in elderly Jordanian population

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Key findings: MMSE score in Jordanians above age of 50 was positively related to level of education and negatively related to age.

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What his adds to what is known: no such data is available in Jordan or the nearby Arabic countries in the Middle East.

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Implications: these data can be used by doctors interested in screening for cognitive function in Jordan and other Arab Middle East countries.

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What should change now: we can better use MMSE in these countries based on local data.

Background

The Mini-Mental State Examination (MMSE) is a simple informative and validated screening test of cognitive functions. No data of MMSE scores has been published about elderly Jordanian population. Objective: To study the MMSE scores in the elderly Jordanian population (defined as age of 50 years or more).

Methods

This was a cross sectional study. A 250 healthy elderly Jordanians were interviewed and tested for their MMSE score. Their scores were analyzed and the effect of age, gender, education, marital status, diabetes mellitus (DM), hypertension (HTN), smoking, dyslipidemia, heart disease (HD), and family history of dementia (FHD) on the score was studied.

Results

MMSE scores of 236 elderly subjects, aged 63±8.4 years (range 50–86 years) were analyzed. There were 111 (47%) males. There was a direct correlation between MMSE score and education level. People with a higher education (college) had the highest scores in comparison with people who are illiterates or have a high school level. The score correlated negatively with age (Pearson correlation r = -0.23, p = 0.00). Other studied variables did not correlate with score on multivariate analysis.

Conclusion

Jordanians ≥50 years old with no previous brain disease scored 26.7 ± 3.2. Education was the most important determining factor of this score. the score showed also a negative correlation with age. We suggest that in this population a cut off score of 24 for those with high education beyond high school and 21 for those with up to high school education and it is not appropriate for illiterate.

An Arabic Version of the Mini-Mental State Examination for the Lebanese Population: Reliability, Validity, and Normative Data

BACKGROUND

The Mini-Mental State Examination (MMSE) has not been validated in the Lebanese population and no normative data exist at the national level.

OBJECTIVE

To evaluate the reliability and validity of an Arabic version of MMSE developed by the "Groupe de Travail sur les Démences de l'Université Saint Joseph" (A-MMSE(GTD-USJ)) and to provide normative data by gender, age, and education in adults over 55.

METHODS

Study design: national cross-sectional survey.

STUDY POPULATION

1,010 literate community-dwelling Lebanese residents aged 55 and above.

OUTCOMES

reproducibility, internal consistency, sensitivity, specificity, predictive values, and area under the curve of the A-MMSE(GTD-USJ) for the detection of cognitive impairment using the Clinical Dementia Rating (CDR) as the gold standard. Normative data were established from 720 healthy adults. A-MMSE(GTD-USJ) scores corresponding to the 5th, 10th, 15th, and 50th percentiles were identified according to gender, age, and education.

RESULTS

Intra-rater and inter-rater test-retest score correlations were 0.89 and 0.72, respectively. Cronbach alpha coefficient for internal consistency of the A-MMSE(GTD-USJ) was 0.71. A threshold value of 23 provided a sensitivity of 80% and a specificity of 89.4%. The area under the curve was 0.92. A-MMSE(GTD-USJ) scores increased with education and decreased with age. Women had significantly lower scores than men. Normative data for A-MMSE(GTD-USJ) stratified by gender, age, and education were generated.

CONCLUSION

In reference to the CDR, the A-MMSE(GTD-USJ) is a valid tool to assess cognitive status among Lebanese subjects aged 55 and above. Normative data will help clinicians in detecting cognitive impairment in this population.

[Influence of occupation on cognitive impairment with no dementia in a sample population over 55 years from Zaragoza]

INTRODUCTION

The prevalence of cognitive impairment with no dementia (CIND) varies between 5.1% and 35.9%, increasing between 65 and 85 years. The CIND increases the risk of dementia. Factors such as education, occupation, and social activities are associated with the risk of cognitive impairment. The main objective of this study was to analyse the association between the main occupation developed throughout life and CIND in a general population sample of over 55 years.

METHODS

In wave I of the ZARADEMP Project, a sample (n=4803) of people over 55 years was interviewed. CIND measurement was obtained through the Mini Mental State Examination. Occupational activity data were recoded into white collar, blue collar, homemakers, and farmers. The association between the occupation variables and CIND was estimated using the odds ratio, and 95% confidence intervals using logistic regression equations.

RESULTS

The prevalence of CIND in the sample was 28.2%. As regards white collar workers, the CIND diagnosis odds was 53% higher for blue collar workers, 77% higher for women who were homemakers and almost twice for farmers, after controlling for socio-demographic, behavioural and clinical variables. All results were statistically significant.

CONCLUSIONS

CIND frequency is influenced by the previous occupation of the subjects. An occupation with higher intellectual requirements can help keep cognitive functions intact for longer.

Brain Training Games Enhance Cognitive Function in Healthy Subjects

Background

Brain training games (BTG) are believed to play a major role in improving cognitive functions. The current study evaluated if BTG showed positive impact on attention and memory functions compared with baseline visit in healthy subjects.

Material/Methods

The study was carried out from October 2015 until April 2016 in the Department of Physiology, College of Medicine, King Saud University and in King Khalid University Hospital (KKUH), Riyadh, Saudi Arabia.

We enrolled 51 normal healthy subjects to use a computerized cognitive training game (Lumosity) for exercises that target a range of cognitive functions, including attention, processing speed, visual memory, and executive functions for about 15 min per day, at least 7 days per week, for 3 weeks. The control (n=21) group did not perform the training. Both groups took the CANTAB test before and 3 weeks after training for various cognitive functions (flexibility, memory, attention, speed, and problem solving). Serum samples were used to study the brain-derived growth factor (BDNF) and apolipoprotein (Apo) E (APOE) levels.

Results

A significant improvement in Lumosity performance index was observed in the active group compared to the control group by the end of training (p-value 0.001). After the training, a statistically significant difference in most of the CANTAB measures, such as attention-switching task (AST), mean correct latency, AST switching cost, AST mean correct latency (congruent), AST mean correct latency (incongruent), AST mean correct latency (blocks 3 and 5) [non-switching blocks], AST mean correct latency (block 7) [switching block], and MOT mean correct latency (all P=0.000). However, in the control group, significant improvements were not observed. A positive correlation between pattern recognition memory (PRM) and APOE was found and people who had higher ApoE levels had faster response.

Conclusions

An improvement in different cognitive domains was noted, including attention and motor speed. However, this study warrants further research to determine the long-term effect on other cognitive functions and in different groups (e.g., elderly vs. adults).

Depression Reduces Accuracy While Parkinsonism Slows Response Time for Processing Positive Feedback in Patients with Parkinson's Disease with Comorbid Major Depressive Disorder Tested on a Probabilistic Category-Learning Task

Major depressive disorder (MDD) is the most common non-motor manifestation of Parkinson's disease (PD) affecting 50% of patients. However, little is known about the cognitive correlates of MDD in PD. Using a computer-based cognitive task that dissociates learning from positive and negative feedback, we tested four groups of subjects: (1) patients with PD with comorbid MDD, (2) patients with PD without comorbid MDD, (3) matched patients with MDD alone (without PD), and (4) matched healthy control subjects. Furthermore, we used a mathematical model of decision-making to fit both choice and response time data, allowing us to detect and characterize differences between the groups that are not revealed by cognitive results. The groups did not differ in learning accuracy from negative feedback, but the MDD groups (PD patients with MDD and patients with MDD alone) exhibited a selective impairment in learning accuracy from positive feedback when compared to the non-MDD groups (PD patients without MDD and healthy subjects). However, response time in positive feedback trials in the PD groups (both with and without MDD) was significantly slower than the non-PD groups (MDD and healthy groups). While faster response time usually correlates with poor learning accuracy, it was paradoxical in PD groups, with PD patients with MDD having impaired learning accuracy and PD patients without MDD having intact learning accuracy. Mathematical modeling showed that both MDD groups (PD with MDD and MDD alone) were significantly slower than non-MDD groups in the rate of accumulation of information for stimuli trained by positive feedback, which can lead to lower response accuracy. Conversely, modeling revealed that both PD groups (PD with MDD and PD alone) required more evidence than other groups to make responses, thus leading to slower response times. These results suggest that PD patients with MDD exhibit cognitive profiles with mixed traits characteristic of both MDD and PD, furthering our understanding of both PD and MDD and their often-complex comorbidity. To the best of our knowledge, this is the first study to examine feedback-based learning in PD with MDD while controlling for the effects of PD and MDD.

Estimating the risk for conversion from mild cognitive impairment to Alzheimer's disease in an elderly Arab community

BACKGROUND

Vascular risk factors and lack of formal education may increase the risk of Alzheimer's disease (AD).

OBJECTIVE

To determine the contribution of vascular risk factors and education to the risk of mild cognitive impairment (MCI) and AD and to estimate the risk for conversion from MCI to AD.

METHODS

This door-to-door survey was performed by an Arab-speaking team in Wadi Ara villages in Israel. All consenting residents aged ≥ 65 years were interviewed for medical history and underwent neurological and cognitive examinations. Individuals were cognitively classified as normal (CN), MCI, AD, vascular dementia, or unclassifiable. MCI patients were re-examined at least one year later to determine conversion to AD. The contributions of age, gender, school years, and vascular risk factors to the probability of conversion were estimated using logistic regression models.

RESULTS

Of the 906 participants, 297 (33%) had MCI and 95 (10%) had AD. Older age (p = 0.0008), female gender (p = 0.023), low schooling (p < 0.0001), and hypertension (p = 0.0002) significantly accounted for risk of MCI versus CN, and diabetes was borderline (p = 0.051). The risk of AD versus CN was significantly associated with age (p < 0.0001), female gender (p < 0.0001), low schooling (p = 0.004) and hypertension (p = 0.049). Of the 231 subjects with MCI that were re-examined, 65 converted to AD.

CONCLUSIONS

In this population, age, female gender, lack of formal education, and hypertension are risk factors for both AD and MCI. Conversion risk from MCI to AD could be estimated as a function of age, time interval between examinations, and hypertension.

Alzheimer's disease and the elderly in Israel: are we paying enough attention to the topic in the Arab population?

With the continuing rise in the elderly population, Alzheimer’s disease (AD) and dementia represent an increasing public health concern worldwide. In recent years, research has focused on the relationship between AD and ethnicity. Israel, a multiethnic society, provides a natural laboratory for research on ethnicity and health. The largest ethnic group is that of Israeli Jews, followed by Arab citizens, mostly Arab Muslims, with smaller numbers of Arab Christians in addition to Druze, Circassians, and others. The aim of this review is to clarify ethnic differences in prevalence and risk factors for Alzheimer’s disease. We review available literature on ethnic differences in epidemiologic and risk factors for Alzheimer’s disease, including genetic differences as well as disparities in health access and quality of health services. We will conclude with research and policy implications.

Practice effects distort translational validity estimates for a Neurocognitive Battery

INTRODUCTION

With the globalization of biomedical research and the advent of "precision medicine," there is increased need for translation of neuropsychological tests, such as computerized batteries that can be incorporated in large-scale genomic studies. Estimates of translational validity are obtained by administering the test in the original and the translated versions to bilingual individuals. We investigated the translation of a neuropsychological battery from English to Arabic and how practice effects influence translational validity estimates.

METHODS

The Penn computerized neurocognitive battery (Penn CNB) includes tests that were validated with functional neuroimaging and provides measures of accuracy and speed of performance in several cognitive domains. To develop an Arabic version of the CNB, the English version was translated into Arabic, then back translated and revised. The Arabic and the original English versions were administered in a randomized crossover design to bilingual participants (N = 22).

RESULTS

Performance varied by cognitive domain, but generally improved at the second session regardless of the language of the initial test. When performance on the English and Arabic version was compared, significant positive correlations were detected for accuracy in 8/13 cognitive domains and for speed in 4/13 domains (r = .02 to .97). When the practice estimates using linear models were incorporated, the translational validity estimates improved substantially (accuracy, r = .50-.96, speed, r = .63-.92, all correlations, p = .05 or better).

CONCLUSION

While crossover designs control for order effects on average performance, practice effects, regardless of language, still need to be removed to obtain estimates of translational validity. When practice effect is controlled for, the Arabic and English versions of the Penn-CNB are well correlated, and the Arabic version is suitable for use in research.

Performance of the 16-Item Informant Questionnaire on Cognitive Decline for the Elderly (IQCODE) in an Arabic-Speaking Older Population

BACKGROUND/AIM

The North African and Middle Eastern region has high illiteracy rates among older people, making direct cognitive testing challenging. Validated screening instruments for dementia in Arabic are lacking. We aimed to validate the Arabic version of the 16-item Informant Questionnaire on Cognitive Decline for the Elderly (A-IQCODE 16) for screening for dementia through an informant.

METHODS

236 Lebanese participants older than 65 years, 143 with normal cognition and 93 with mild-to-moderate dementia according to the DSM-IV criteria, and their informants were recruited. Half of the participants had no formal education. Interviewers blinded to the cognitive status of the participants administered the A-IQCODE 16 to the informants. The ability of the A-IQCODE 16 to screen for dementia was evaluated against the DSM-IV diagnoses.

RESULTS

The A-IQCODE 16 had excellent overall predictive power (area under the receiver operator characteristic curve = 0.96). A cutoff point of >3.34 yielded the best sensitivity (92.5%) and specificity (94.4%) for dementia screening. At this cutoff point, the discriminatory ability of the A-IQCODE 16 was comparable between participants with and those without formal education.

CONCLUSION

The A-IQCODE 16 is not biased by education and is therefore useful as a brief screening tool for dementia among Arabic-speaking older adults with low education.

Depression impairs learning, whereas the selective serotonin reuptake inhibitor, paroxetine, impairs generalization in patients with major depressive disorder

To better understand how medication status and task demands affect cognition in major depressive disorder (MDD), we evaluated medication-naïve patients with MDD, medicated patients with MDD receiving the selective serotonin reuptake inhibitors (SSRI) paroxetine, and healthy controls. All three groups were administered a computer-based cognitive task with two phases, an initial phase in which a sequence is learned through reward-based feedback (which our prior studies suggest is striatal-dependent), followed by a generalization phase that involves a change in the context where learned rules are to be applied (which our prior studies suggest is hippocampal-region dependent). Medication-naïve MDD patients were slow to learn the initial sequence but were normal on subsequent generalization of that learning. In contrast, medicated patients learned the initial sequence normally, but were impaired at the generalization phase. We argue that these data suggest (i) an MDD-related impairment in striatal-dependent sequence learning which can be remediated by SSRIs and (ii) an SSRI-induced impairment in hippocampal-dependent generalization of past learning to novel contexts, not otherwise seen in the medication-naïve MDD group. Thus, SSRIs might have a beneficial effect on striatal function required for sequence learning, but a detrimental effect on the hippocampus and other medial temporal lobe structures is critical for generalization.

Prayer at midlife is associated with reduced risk of cognitive decline in Arabic women

Midlife habits may be important for the later development of Alzheimer's disease (AD). We estimated the contribution of midlife prayer to the development of cognitive decline. In a door-to-door survey, residents aged ≥65 years were systematically evaluated in Arabic including medical history, neurological, cognitive examination, and a midlife leisure-activities questionnaire. Praying was assessed by the number of monthly praying hours at midlife. Stepwise logistic regression models were used to evaluate the effect of prayer on the odds of mild cognitive impairment (MCI) and AD versus cognitively normal individuals. Of 935 individuals that were approached, 778 [normal controls (n=448), AD (n=92) and MCI (n=238)] were evaluated. A higher proportion of cognitively normal individuals engaged in prayer at midlife [(87%) versus MCI (71%) or AD (69%) (p<0.0001)]. Since 94% of males engaged in prayer, the effect on cognitive decline could not be assessed in men. Among women, stepwise logistic regression adjusted for age and education, showed that prayer was significantly associated with reduced risk of MCI (p=0.027, OR=0.55, 95% CI 0.33-0.94), but not AD. Among individuals endorsing prayer activity, the amount of prayer was not associated with MCI or AD in either gender. Praying at midlife is associated with lower risk of mild cognitive impairment in women.

Neuroimaging differences between older adults with maintained versus declining cognition over a 10-year period

BACKGROUND

Maintaining cognitive function protects older adults from developing functional decline. This study aims to identify the neuroimaging correlates of maintenance of higher global cognition as measured by the Modified Mini Mental State Test (3 MS) score.

METHODS

Repeated 3 MS measures from 1997-98 through 2006-07 and magnetic resonance imaging with diffusion tensor in 2006-07 were obtained in a biracial cohort of 258 adults free from dementia (mean age 82.9 years, 56% women, 42% blacks). Participants were classified as having shown either maintenance (3 MS slope>0) or decline (3 MS slope<1 SD below the mean) of cognition using linear mixed models. Measures of interest were white matter hyperintensity volume (WMHv) from total brain, volume of the gray matter (GMv) and microstructure (mean diffusivity, MD) for total brain and for brain areas known to be related to memory and executive control function: medial temporal area (hippocampus, parahippocampus and entorhinal cortex), cingulate cortex, dorsolateral prefrontal and posterior parietal cortex.

RESULTS

Differences between cognitive maintainers (n=153) and non-maintainers (n=107) were significant for GMv of the medial temporal area (35.8%, p=0.004) and lower MD of the cingulate cortex (37.9%, p=0.008), but not for other neuroimaging markers. In multivariable regression models adjusted for age, race, WMHv and GMV from the total brain and vascular conditions, each standard deviation of GMv of the medial temporal area and each standard deviation of MD of the cingulate cortex were associated with a nearly 4 times greater probability (odds ratio [standard deviation]: 3.80 [1.16, 12.44]) and a 34% lower probability (0.66, [0.46, 0.97]) of maintaining cognitive function, respectively. In these models neither WMHv nor GMv from total brain were significantly associated with probability of maintaining cognitive function.

CONCLUSIONS

Preserving the volume of the medial temporal area and the microstructure of the cingulate cortex may contribute to maintaining cognitive function late in life.

Beliefs about medications predict adherence to antidepressants in older adults

BACKGROUND

Adherence to treatment is a complex and poorly understood phenomenon. This study investigates the relationship between older depressed patients' adherence to antidepressants and their beliefs about and knowledge of the medication.

METHODS

Assessment was undertaken of 108 outpatients over the age of 55 years diagnosed with depressive disorder and treated for at least four weeks with antidepressants. Adherence was assessed using two self-report measures: the Medication Adherence Rating Scale (MARS) and a Global Adherence Measure (GAM). Potential predictors of adherence investigated included sociodemographic, medication and illness variables. In addition, 33 carers were interviewed regarding general medication beliefs.

RESULTS

56% of patients reported 80% or higher adherence on the GAM. Sociodemographic variables were not associated with adherence on the MARS. Specific beliefs about medicines, such as "my health depends on antidepressants" (necessity) and being less worried about becoming dependant on antidepressants (concern) were highly correlated with adherence. General beliefs about medicines causing harm or being overprescribed, experiencing medication side-effects and severity of depression also correlated with poor adherence. Linear regression with the MARS as the dependent variable explained 44.3% of the variance and showed adherence to be higher in subjects with healthy specific beliefs who received more information about antidepressants and worse with depression severity and autonomic side-effects.

CONCLUSIONS

Our findings strongly support a role for specific beliefs about medicines in adherence. Challenging patients' beliefs, providing information about treatment and discussing side-effects could improve adherence. Poor response to treatment and medication side-effects can indicate poor adherence and should be considered before switching medications.

High prevalence of mild cognitive impairment and Alzheimer's disease in arabic villages in northern Israel: impact of gender and education

The prevalence of mild cognitive impairment (MCI) and Alzheimer's disease (AD) have not been well been studied in Arab populations. In a door-to-door study of all residents aged ≥ 65 years in Wadi-Ara, an Arab community in northern Israel, we estimated the prevalence of AD, MCI, and the risk of conversion to AD. Subjects were classified as cognitively normal, MCI, AD, or other based on neurological and cognitive examination (in Arabic). MCI subjects were re-examined (interval ≥ 1 year) to determine conversion to AD and contributions of age, gender, and education to the probability of conversion. Of the 944 participants (96.6% of those approached; 49.4% men), 92 (9.8%) had AD. An unusually high prevalence of MCI (n = 303, 32.1%) was observed. Since the majority of women (77.2%) had no schooling, we estimated the effect of gender on the risk of AD and MCI among subjects without schooling and of school years among men. Among subjects with no schooling (n = 452), age (p = 0.02) and female gender (p < 0.0001) were significant predictors of AD, whereas risk of MCI increased only with age (p = 0.0001). Among men (n = 318), age increased the risk (p < 0.0001), school years reduced the risk of AD (p = 0.039) and similarly for MCI [age (p = 0.0001); school years (p = 0.0007)]. Age (p = 0.013), but not gender or school years, was a significant predictor of conversion from MCI to AD (annual rate 5.7%). The prevalence of MCI and AD are unusually high in Wadi Ara, while the rate of conversion from MCI to AD is low. Yet unidentified genetic factors might underlie this observation.

Mild cognitive impairment is associated with mild parkinsonian signs in a door-to-door study

Mild cognitive impairment (MCI) and healthy aging have been shown to be associated with mild parkinsonian signs (MPS). We performed a door-to-door observational and follow-up study amongst consenting residents of Wadi Ara Arab villages in northern Israel aged ≥65 years (n=687) to examine whether MPS represent a risk factor for MCI and/or conversion from MCI to Alzheimer's disease (AD). In Phase 1, 223 cognitively normal (CN) and 173 MCI subjects were assessed by interview for medical history, neurological examination, motor part of the Unified Parkinson Disease Rating Scale (mUPDRS) (divided into item-clusters: axial, limb bradykinesia, tremor and rigidity) and cognitive tests. MCI subjects (n=111) were re-evaluated in Phase 2 for conversion to AD at least one year after initial assessment. MCI subjects had a higher frequency of axial dysfunction (8.7% vs. 1.3%) and limb bradykinesia (10.4% vs. 1.3%) than CN subjects (p<0.001, both). Stepwise logistic regression analysis estimating the probability of MCI vs. CN revealed higher mUPDRS (OR =1.19, 95% CI, 1.05 to 1.35, p=0.006) and higher limb bradykinesia scores (OR=1.75, 95% CI, 1.2 to 2.56, p=0.003) and not age as explanatory variables. Presence of MPS did not predict conversion to AD after adjustment for age and time-interval. These results suggest that axial and bradykinetic parkinsonian signs represent risk factors for MCI but MPS may not predict conversion from MCI to AD.

Identification of novel candidate genes for Alzheimer's disease by autozygosity mapping using genome wide SNP data

Alzheimer's disease (AD) is highly prevalent in Wadi Ara despite the low frequency of apolipoprotein E ε4 in this genetically isolated Arab community in northern Israel. We hypothesized that the reduced genetic variability in combination with increased homozygosity would facilitate identification of genetic variants that contribute to the high rate of AD in this community. AD cases (n = 124) and controls (n = 142) from Wadi Ara were genotyped for a genome-wide set of more than 300,000 single nucleotides polymorphisms (SNPs) which were used to calculate measures of population stratification and inbreeding, and to identify regions of autozygosity. Although a high degree of relatedness was evident in both AD cases and controls, controls were significantly more related and contained more autozygous regions than AD cases (p = 0.004). Eight autozygous regions on seven different chromosomes were more frequent in controls than the AD cases, and 116 SNPs in these regions, primarily on chromosomes 2, 6, and 9, were nominally associated with AD. The association with rs3130283 in AGPAT1 on chromosome 6 was observed in a meta-analysis of seven genome-wide association study (GWAS) datasets. Analysis of the full Wadi Ara GWAS dataset revealed 220 SNP associations with AD at p ≤ 10⁻⁵, and seven of these were confirmed in the replication GWAS datasets (p < 0.05). The unique population structure of Wadi Ara enhanced efforts to identify genetic variants that might partially explain the high prevalence of AD in the region. Several of these variants show modest evidence for association in other Caucasian populations.

Impact of sociodemographic and health variables on mini-mental state examination in a community-based sample of older people

The mini-mental state examination (MMSE) has been widely used as a screening instrument for cognitive disorders. Age, schooling and many other sociodemographic and health variables may be associated with a worse performance on the MMSE. The objectives of this study were to investigate the distribution of MMSE percentiles in a large Brazilian community-based elderly sample, divided according to age and schooling, and to evaluate the impact of sociodemographic and health variables on groups of elderly people with lower cognitive performance. The MMSE was applied to a sample of 2,708 adults, aged 60 years and older. Of this population, 1,563 individuals were living in the city of São Paulo, while 1,145 were living in the city of Ribeirão Preto. The subjects were divided into six groups according to the amount of schooling that they had received (no formal education, 1-4 and ≥5 years) and age (<75 and ≥75 years old). To each one of the subgroups a stepwise logistic regression was applied, considering the following dependent variable: subjects who scored under or above the 15th percentile on MMSE. High scores on a depression scale, high scores on a memory complaints scale and low socio-economic levels were associated with poorer performance on the MMSE. Being currently employed and being married were related to higher scores on the test. Many sociodemographic and health variables can influence MMSE performance, with impacts depending on age and schooling. Clinicians and primary care physicians should pay attention to variables that may be associated with worse cognitive performance.

Depression impairs learning whereas anticholinergics impair transfer generalization in Parkinson patients tested on dopaminergic medications

In a study of acquired equivalence in Parkinson disease (PD), in which patients were tested on normal dopaminergic medication, we found that comorbid clinical depression impairs initial acquisition, whereas the use of anticholinergic therapy impairs subsequent transfer generalization. In addition, this study provides a replication of the basic finding of Myers et al (2003) that patients with PD on dopaminergic therapy are impaired at initial acquisition, but normal at subsequent transfer generalization, generalizing these results to an Arabic-speaking population including many participants with no formal education. These results are consistent with our past computational modeling, which argues that acquisition of incrementally acquired, feedback-based learning tasks is dependent on cortico-striatal circuits, whereas transfer generalization is dependent on medial temporal (MT) structures. They are also consistent with prior computational modeling, and with empiric work in humans and animals, suggesting that anticholinergic drugs may particularly impair cognitive abilities that depend on the MT lobe.

Meta-analysis confirms CR1, CLU, and PICALM as alzheimer disease risk loci and reveals interactions with APOE genotypes

OBJECTIVES

To determine whether genotypes at CLU, PICALM, and CR1 confer risk for Alzheimer disease (AD) and whether risk for AD associated with these genes is influenced by apolipoprotein E (APOE) genotypes.

DESIGN

Association study of AD and CLU, PICALM, CR1, and APOE genotypes.

SETTING

Academic research institutions in the United States, Canada, and Israel.

PARTICIPANTS

Seven thousand seventy cases with AD, 3055 with autopsies, and 8169 elderly cognitively normal controls, 1092 with autopsies, from 12 different studies, including white, African American, Israeli-Arab, and Caribbean Hispanic individuals.

RESULTS

Unadjusted, CLU (odds ratio [OR], 0.91; 95% confidence interval [CI], 0.85-0.96 for single-nucleotide polymorphism [SNP] rs11136000), CR1 (OR, 1.14; 95% CI, 1.07-1.22; SNP rs3818361), and PICALM (OR, 0.89; 95% CI, 0.84-0.94, SNP rs3851179) were associated with AD in white individuals. None were significantly associated with AD in the other ethnic groups. APOE ε4 was significantly associated with AD (ORs, 1.80-9.05) in all but 1 small white cohort and in the Arab cohort. Adjusting for age, sex, and the presence of at least 1 APOE ε4 allele greatly reduced evidence for association with PICALM but not CR1 or CLU. Models with the main SNP effect, presence or absence of APOE ε4, and an interaction term showed significant interaction between presence or absence of APOE ε4 and PICALM.

CONCLUSIONS

We confirm in a completely independent data set that CR1, CLU, and PICALM are AD susceptibility loci in European ancestry populations. Genotypes at PICALM confer risk predominantly in APOE ε4-positive subjects. Thus, APOE and PICALM synergistically interact.

Hypertension increases the probability of Alzheimer's disease and of mild cognitive impairment in an Arab community in northern Israel

BACKGROUND

We aimed to determine whether vascular risk factors are associated with Alzheimer's disease (AD) and mild cognitive impairment (MCI) in an elderly Arab population.

METHODS

An Arabic-speaking team performed a door-to-door survey of consecutive residents aged > or =65 years. We estimated the odds of AD or MCI versus normal controls as a function of age, gender, education and presence of vascular factors by multinomial logistic regression with interactions.

RESULTS

Out of 767 subjects (54% men), 444 were cognitively normal, 234 had MCI and 89 had AD. AD was significantly associated with hypertension (p = 0.01; OR = 2.08; 95% CI: 1.18-3.65), age (p < 0.0001; OR = 1.19; 95% CI: 1.14-1.24), female gender (p = 0.0016; OR = 3.06; 95% CI: 1.53-6.15) and education (p = 0.0002; OR = 0.75; 95% CI: 0.65-0.88). MCI was significantly associated with hypertension (p = 0.0042; OR = 1.69; 95% CI: 1.25-2.44), age (p < 0.0001; OR = 1.06; 95% CI: 1.03-1.09) and education (p < 0.0001; OR = 0.76; 95% CI: 0.71-0.83), but not with gender.

CONCLUSIONS

Hypertension, older age and low education significantly increase the probability of AD and MCI. The effect of hypertension on the odds of AD versus controls is over and above the effects of age, gender and education. For MCI versus controls there is no gender effect, and the effect of hypertension is over and above the effects of age and education.

Essential tremor might be less frequent than Parkinson's disease in North Israel Arab villages

Essential tremor (ET) is much more prevalent than Parkinson's disease (PD) in Western countries. We estimated ET and PD prevalence in Wadi Ara Arabic villages in Northern Israel. In this door-to-door survey, all consenting residents aged >or=65 years were systematically examined by an Arabic speaking team. No prescreening questionnaires were used. A random sample of 900 subjects [437 males, mean age (SD) = 72.6 years (6.6)] of the 2,163 eligible residents were evaluated. Sixteen subjects had an action, intentional tremor. Tremor prevalence was estimated as 1.78% (95% CI 1.1-2.87). Nine of these had another likely cause of tremor. Only 7 patients were diagnosed as ET [prevalence 0.78% (95% CI 0.38-1.6)]. PD was diagnosed in 13 subjects. PD prevalence was 1.44% (95% CI 0.84-2.45). ET is unusually uncommon in this population and possibly even less frequent than PD. The PD prevalence in Wadi Ara is similar to that reported in Western countries.

Cross-cultural comparisons of the Mini-mental State Examination between Japanese and U.S. cohorts

BACKGROUND

The Mini-mental State Examination (MMSE) is widely used in Japan and the U.S.A. for cognitive screening in the clinical setting and in epidemiological studies. A previous Japanese community study reported distributions of the MMSE total score very similar to that of the U.S.A.

METHODS

Data were obtained from the Monongahela Valley Independent Elder's Study (MoVIES), a representative sample of community-dwelling elderly people aged 65 and older living near Pittsburgh, U.S.A., and from the Tajiri Project, with similar aims in Tajiri, Japan. We examined item-by-item distributions of the MMSE between two cohorts, comparing (1) percentage of correct answers for each item within each cohort, and (2) relative difficulty of each item measured by Item Characteristic Curve analysis (ICC), which estimates log odds of obtaining a correct answer adjusted for the remaining MMSE items, demographic variables (age, gender, education) and interactions of demographic variables and cohort.

RESULTS

Median MMSE scores were very similar between the two samples within the same education groups. However, the relative difficulty of each item differed substantially between the two cohorts. Specifically, recall and auditory comprehension were easier for the Tajiri group, but reading comprehension and sentence construction were easier for the MoVIES group.

CONCLUSIONS

Our results reaffirm the importance of validation and examination of thresholds in each cohort to be studied when a common instrument is used as a dementia screening tool or for defining cognitive impairment.