Israel Contador

Experimental evidence for improved neuroimaging interpretation using three-dimensional graphic models.

Three‐dimensional (3D) or volumetric visualization is a useful resource for learning about the anatomy of the human brain. However, the effectiveness of 3D spatial visualization has not yet been assessed systematically. This report analyzes whether 3D volumetric visualization helps learners to identify and locate subcortical structures more precisely than classical cross‐sectional images based on a two dimensional (2D) approach. Eighty participants were assigned to each experimental condition: 2D cross‐sectional visualization vs. 3D volumetric visualization. Both groups were matched for age, gender, visual‐spatial ability, and previous knowledge of neuroanatomy. Accuracy in identifying brain structures, execution time, and level of confidence in the response were taken as outcome measures. Moreover, interactive effects between the experimental conditions (2D vs. 3D) and factors such as level of competence (novice vs. expert), image modality (morphological and functional), and difficulty of the structures were analyzed. The percentage of correct answers (hit rate) and level of confidence in responses were significantly higher in the 3D visualization condition than in the 2D. In addition, the response time was significantly lower for the 3D visualization condition in comparison with the 2D. The interaction between the experimental condition (2D vs. 3D) and difficulty was significant, and the 3D condition facilitated the location of difficult images more than the 2D condition. 3D volumetric visualization helps to identify brain structures such as the hippocampus and amygdala, more accurately and rapidly than conventional 2D visualization. This paper discusses the implications of these results with regards to the learning process involved in neuroimaging interpretation. Anat Sci Educ.

Prediction of burden in family caregivers of patients with dementia: A perspective of optimism based on generalized expectancies of control

The aim of this study was to investigate the predictors of burden for informal caregivers of patients with dementia. Based on a multidimensional approach of the optimism model proposed by Palenzuela, we assessed the moderating role of generalized expectancies of control (GEC) between caregiver stress and burden. A total of 130 patients with dementia and their main family caregivers were assessed from different rural areas of the province of Salamanca (Spain). Patients with dementia underwent a protocol to assess dementia stage, cognitive–functional impairment and behavioural symptoms. Meanwhile, the 20-item Battery of Generalized Expectancies of Control Scales of Palenzuela was completed by the family caregivers. Clinical variables of patients with dementia (progression and behavioural disorders) and GEC (success, self-efficacy, contingency, helplessness and luck) were considered as potential predictors of burden in the hierarchical regression analysis. The Zarit Burden Interview (ZBI) Scale was used as an outcome measure. The results indicated that the clinical variables could not predict burden in caregivers significantly; however, beliefs in personal abilities (self-efficacy) and internal locus of control (contingency) explained up to 32% of the variance in the ZBI scores. Family caregivers with high expectancies of self-efficacy and contingency are less vulnerable to stress. This research supports a base for interventions with informal caregivers and further study.

The Mini-Mental-37 Test for Dementia Screening in the Spanish Population: An Analysis Using the Rasch Model

Our aim was to analyze the psychometric properties of the Mini-Mental State Examination-37 using the Rasch Model (RM) in order to identify the cognitive domains that optimize detection of dementia in the Spanish population. All participants (n = 3955) were part of the NEDICES (Neurological Disorders in Central Spain) cohort study designed to detect dementia in persons aged 65 years and older. Clinical diagnosis of dementia (n = 178) was established by consensus of expert neurologists according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria. Results indicate that the items on the MMSE-37 have a good fit with the assumptions of the RM. None of the items on the MMSE-37 exhibits differential item functioning in relation to the groups. The items that assess orientation, attention, and language (repetition and comprehension) are those that best enable us to discriminate between the group with dementia and the group without dementia. The implications of the education and other sociodemographic characteristics of the population are discussed.

Cause of death in mild cognitive impairment: a prospective study (NEDICES).

Previous studies have reported the occurrence of increased mortality rates among individuals with mild cognitive impairment (MCI), but possible links between MCI subtypes and cause‐specific mortality need to be explored. To examine short‐term mortality (5 years), long‐term mortality (13 years) and cause‐specific mortality of individuals over 65 years of age suffering from MCI compared with cognitively unimpaired individuals in the Neurological Disorders in Central Spain (NEDICES) cohort.

Effects of education and word reading on cognitive scores in a community-based sample of Spanish elders with diverse socioeconomic status

Introduction. The influence of education and oral word-reading ability on cognitive performance was examined in a sample of 1510 nondemented elders differing in socioeconomic status (SES) from three Spanish communities. Method. All individuals were enrolled in the Neurological Disorders in Central Spain, a population-based epidemiological study in central Spain. They completed a detailed demographic survey and a short standardized neuropsychological battery assessing psychomotor speed, attention, language, and memory. The Word Accentuation Test (WAT) was used as measure of oral reading ability. The influence of education and oral reading on cognitive performance was determined by multiple linear regression models, first controlling for demographics (age and sex), and subsequently for the WAT score and education. The contribution of socioeconomic conditions was addressed by stratifying the sample into groups of high and low SES. Results. The WAT showed a significant independent effect on cognitive scores, generally greater than that predicted by demographics. The higher predictive power of oral word reading on cognitive scores compared to education was consistent across the three communities. Although the variance explained by WAT was very similar in areas with diverse SES (low vs. high), WAT scores accounted for slightly more variance in naming and memory tasks in low SES areas. In contrast, the variance explained by WAT was higher for verbal fluency and the Trail-Making Test in areas with high SES. Conclusion. Oral word-reading ability predicts cognitive performance better than years of education across individuals with different SES. The influence of WAT may be modulated by SES and cognitive task properties.

Improvement pattern in the clock drawing test in early Alzheimer's disease.

Objective: The aim of this paper was to compare the performance of a group of patients with early Alzheimer’s disease (EAD) against a control group of healthy control (HC) subjects in the Clock Drawing Test (CDT), i.e. verbal command versus copying of a clock model presented to the subject. Patients and Methods: The authors have studied 140 subjects; 70 patients with probable EAD, with a mean age of 76.4 ± 7.64 years and a clinical dementia rating stage 1 (mild dementia), and70 HC with a mean age of 75.16 ± 6.34 years. Results: Patients in the EAD group obtained significantly higher scores on the copy command mode than on the verbal command mode (Z = –7.129, p < 0.001) – improvement pattern of the CDT – whereas no statistically significant differences were found in the HC group (Z = –2.001, p < 0.080). Within the group of EAD patients, we have noticed that there is a correlation between the copy command mode and the visual-constructive functions of the Cambridge Cognitive Examination (CAMCOG) (r = 0.607, p < 0.01), while the memory functions of the CAMCOG correlate with the verbal command mode (r = 0.704, p < 0.01). Conclusions: In our study, the EAD patients show an improvement pattern in the execution of the CDT copy command in comparison with the execution of the CDT verbal command, which we did not observe in the HC group. Such results might be associated with a greater deterioration of the memory functions when compared with the visual-constructive ones in the patients with EAD.

Childhood and Adulthood Rural Residence Increases the Risk of Dementia: NEDICES Study

OBJECTIVE This research aims to determine whether residence (rural vs. urban) at different life stages (childhood, adulthood, and late life) is associated with increased risk of incident dementia in a population-based cohort of older Spaniards. METHODS In this prospective study, 2,711 participants aged 65 years and older were assessed at baseline and 3 years later. All cases of incident dementia were diagnosed using DSM-IV criteria. The relationship between residence and the relative risk of dementia was analysed using Coxs regression models. Demographics, comorbidity index, consumption (tobacco / alcohol) and doubtful dementia diagnosis were considered as possible confounders. RESULTS At the three-year follow-up, 91 cases of dementia were detected. Lower education and occupational attainment were associated with a higher incidence of dementia three years later. Rural residence in adulthood was associated with a significantly higher risk of dementia at the follow-up. Childhood rural residence revealed a marked trend for risk of dementia (p = 0.08), but it was nonsignificant in later life. The risk of dementia was considerably higher for the rural/low-education group than for the urban/high-education group, for both childhood and adulthood residence. Finally, people from areas with the lowest socio- economic status Arévalo (rural, blue-collar) and Margaritas (urban, blue-collar) showed higher risk of dementia than people from Lista (urban, mixed white/blue collar). CONCLUSION In this cohort, early and mid-life stages rural residence was a risk factor for dementia, but not later-life rural residence. The rural residence effect was noticeably higher in people with a lower educational level.

Effect of unawareness on rehabilitation outcome in a randomised controlled trial of multicomponent intervention for patients with mild Alzheimer's disease

Unawareness of deficit has been shown to affect the outcome of targeted cognitive intervention programmes applied to patients with Alzheimer’ disease (AD), but the effects on multimodal therapeutic approaches have not yet been explored. This research investigated the efficacy of the Multi-Intervention Programme (MIP) approach on improving cognitive, functional, affective, and behavioural symptoms in people with mild AD. In addition, we examined whether the presence of unawareness influences the MIP outcomes. Sixty-one mild stage AD patients were randomly assigned to either an experimental group which carried out an MIP individually (48 sessions, 16 weeks duration), combining diverse cognitive tasks, training in daily life and recreational activities, or a waiting list group which did not receive any treatment for the same time period. The efficacy of MIP (vs. waiting list) was tested using various standardised neuropsychological, functional, and behavioural outcome measures. Planned analyses were carried out to determine the effect of unawareness versus awareness on such outcomes. The results showed that patients overall benefited from the MIP in terms of both cognitive and non-cognitive symptoms. AD patients with awareness of deficits showed positive effects on all outcome measures in comparison with the waiting list group, while AD patients with unawareness showed improvements in non-cognitive symptoms only. In conclusion, the presence of unawareness reduces the cognitive and functional effects of MIP in patients with mild AD.

Prognostic Significance of Mild Cognitive Impairment Subtypes for Dementia and Mortality: Data from the NEDICES Cohort

BACKGROUND The predictive value of diverse subtypes of mild cognitive impairment (MCI) for dementia and death is highly variable. OBJECTIVE To compare the predictive value of several MCI subtypes in progression to dementia and/or mortality in the NEDICES (Neurological Disorders in Central Spain) elderly cohort. METHODS Retrospect algorithmic MCI subgroups were established in a non-dementia baseline NEDICES cohort using Spanish adaptations of the original Mini-Mental State Examination (MMSE-37) and Pfeffers Functional Activities Questionnaire (Pfeffer-11). The presence of MCI was defined according two cognitive criteria: using two cut-offs points on the total MMSE-37 score. Five cognitive domains were used to establish the MCI subtypes. Functional capacity (Pfeffer-11) was preserved or minimally impaired in all MCI participants. The incident dementia diagnoses were established by specialists and the mortality data obtained from Spanish official registries. RESULTS 3,411 participants without dementia were assessed in 1994-5. The baseline prevalence of MCI varied according to the MCI definition (4.3%-31.8%). The follow-up was a mean of 3.2 years (1997-8). The dementia incidence varied between 14.9 and 71.8 per 1,000/person-years. The dementia conversion rate was increased in almost all MCI subgroups (p >  0.01), and mortality rate was raised only in four MCI subtypes. The amnestic-multi-domain MCI (aMd-MCI) had the best dementia predictive accuracy (highest positive likelihood ratio and highest clinical utility when negative). CONCLUSIONS Those with aMd-MCI were at greatest risk of progression to dementia, as in other surveys and might be explored with increased attention in MCI research and in dementia preventive trials.

The 37 item Version of the Mini-Mental State Examination: Normative Data in a Population-Based Cohort of Older Spanish Adults (NEDICES)

The 37-item version of the Mini-Mental State Examination (MMSE-37) is an extended version of the original test for individuals with low education, which was adapted for different cultures. Despite its favorable psychometric properties, there is a lack of normative data for this instrument. We provide normative data for the MMSE-37 stratified by age, sex, and education in a large population-based cohort of older Spanish adults. The sample consisted of 3,777 participants without dementia (age range: 65-97 years) from different socioeconomic areas of central Spain. Normative data are presented in percentile ranks and divided into nine overlapping age tables with different midpoints, using the overlapping cell procedure. A hierarchical regression was performed to evaluate the effects of sociodemographic variables on MMSE-37 performance. Results showed that age, sex, and education affect test score. The norms presented herein are important for the correct interpretation of MMSE-37 scores when assessing older adults in Spain.