Influence of education on the pattern of cognitive deterioration in AD patients: the cognitive reserve hypothesis.
ABSTRACT The cognitive reserve hypothesis proposes that a high educational level could delay the clinical expression of Alzheimer's disease (AD) although neuropathologic changes develop in the brain. Therefore, some studies have reported that when the clinical signs of the disease emerge, high-educated patients may decline more rapidly than low-educated patients because the neuropathology is more advanced. However, these studies have only investigated the decline of global cognition or an isolated cognitive process. To study the differential deterioration pattern of several cognitive processes according to education, the performance of 20 AD patients with a high educational level and a low educational level were compared with the performance of 20 control subjects on a neuropsychological battery. The results showed that cognitive deterioration of AD patients is different according to education, although the global performance was similar in AD patients. The high-educated patients exhibited greater impairment of abstract thinking whereas the low-educated patients showed greater impairment of memory and attentional function. This confirms that some cognitive processes, such as abstract thinking, decline more rapidly in high-educated patients whereas others seem to evolve more slowly if compared to low-educated patients. In this latter case, high-educated patients may still benefit from cognitive reserve after the diagnosis of the dementia.
- SourceAvailable from: Charitomeni Piperidou[show abstract] [hide abstract]
ABSTRACT: We sought to longitudinally evaluate the potential association of educational level with performance on verbal and nonverbal tasks in individuals with mild cognitive impairment (MCI). We evaluated patients with MCI, age >50 years, no medication intake, absent vascular risk factors, and no lesions on brain magnetic resonance imaging (MRI). Each patient underwent a clinical assessment packet and a series of neuropsychological tests of the language and constructional praxis subtests of Cambridge Cognitive Examination (CAMGOG) and the Boston naming test (BNT), at baseline, 6 months, and 12 months. Educational levels were defined taking into account the total years of education, the school level, and diplomas. MCI patients with low education level showed a stepwise reduction in scores of naming objects (NO; P = 0.009), definition (DF; P = 0.012), language (LT; P = 0.021), constructional praxis (CD; P = 0.022), confrontation naming skills (BXB; P = 0.033), phonemic help (BFB; P = 0.041), and BNT (P = 0.002). Analysis of covariance, controlling for baseline scores, showed that education was associated with NO score (P = 0.002), DF score (P = 0.005), LT (P = 0.008), CD score (P = 0.008), BXB score (44.36 ± 1.84, P = 0.0001), BFB (P = 0.022), and BNT (P = 0.004). Our findings indicate that education appeared to affect verbal and nonverbal task performance in MCI patients. Despite the fact that higher educated patients are more acquainted with the tasks, slower deterioration in consecutive follow-up examinations could be explained by the cognitive reserve theory. The potential association of this protective effect with delayed onset of symptoms deserves further investigation.Brain and behavior. 09/2012; 2(5):620-7.
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ABSTRACT: Some authors suggest that besides the fundamental components, cognitive reserve (CR) also reflects the influence of a combination of factors that improve mental health. After obtaining the sociodemographic profile of each participant and evaluating their neurologic and neuropsychologic abilities, first, homogeneity analysis was used as a technique to select variables and reduce the number of categories with similar behavior; then CR construct was identified through a latent class analysis model. It was then possible to categorize participants according to their level in this construct and compare the neuropsychological performance of the subgroups that emerged, using a t test of differences of means for independent samples. Participants with Alzheimer's disease with low CR scores exhibited significantly greater deficits in measures of memory, attention, and language than patients with high CR. Our results ratify the effect of higher education, higher professional performance, and ludic activities on CR.American Journal of Alzheimer s Disease and Other Dementias 11/2011; 26(7):542-54. · 1.52 Impact Factor
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ABSTRACT: The present study aims to investigate the protective effect of formal education on age-related changes in different cognitive domains with the hypothesis that it may attenuate the rate of decline. Individuals aged 50 years or older attending primary care physicians without known brain disease (431 participants, mostly [60.3%] female with 66.3 [±9.1] years of age and 7.7 [±4.1] years of education, on average), were evaluated with a neuropsychological battery including 28 cognitive measures. Cognitive domains identified by factor analysis were subject to repeated multiple regression analyses to determine the variance explained by age and education controlling for gender, depressive symptoms, and vascular risk factors. The slope of the regression equation was compared between two educational groups with an average of 4 years and 11 years of education, respectively. Factors identified corresponded to processing ability (Factor 1), memory (Factor 2), and acquired knowledge (Factor 3). Although education improved performance in Factors 1 and 3, it did not change the slope of age-related decline in any factor. This study suggests that in culturally heterogeneous groups, small increments in education enhance cognition but do not modify the rate of decline of executive functioning with age. These results contradict some clinical findings and need to be confirmed in longitudinal studies.Applied Neuropsychology 10/2012; 19(4):287-98. · 1.32 Impact Factor