Cognitive reserve and the severity of Alzheimer’s disease

Abstract

Alzheimer's disease (AD) is the most common form of dementia in the elderly 1 and a clinical syndrome caused by neurodegeneration and characterized by a progressive deterioration in cognitive ability and capacity for independent living. The course of AD is not the same in every person, but symptoms seem to develop over the same general stages. Cognitive reserve (CR) is a hypothetical construct that has been used to inform of cognitive aging and describes the capacity of the adult brain to deal with the effects of the neurodegenerative process and to minimize the clinical manifestation of pathology of dementia that is probably the result of innate intelligence or life experience 2 . The CR hypothesis suggests that individual differences in the ability to cope with AD pathology 2,3 are consistent with the prediction that people with more reserve can cope with advancing AD pathology longer before it is expressed clinically 3,4,5 . CR is not fixed, but continues to evolve across the lifespan 5 . Variables pertaining to lifetime experience (education, occupation attainment and leisure activities) 4,5 are the most commonly used proxies for CR and help retain cognitive function in old age. Epidemiological studies suggest that lifelong experiences, including educational, occupational attainment and leisure activities (LA) in later life, can increase reserve 4 . Greater understanding of the concept of CR could lead to ABSTRACTAlzheimer´s disease (AD) is a clinical syndrome caused by neurodegeneration and characterized by a progressive deterioration in cognitive ability and capacity for independent living. Cognitive reserve (CR) describes the capacity of the adult brain to cope with the effects of the neurodegenerative process and to minimize the clinical manifestation of pathology of dementia. The aim of this study was to evaluate the association of CR and the severity of AD. Method: This study was cross-sectional. Functional and neuropsychological abilities of 75 outpatients with probable AD diagnosis were evaluated. Patients completed two questionnaires, "Participation in leisure activities throughout life" and CR Questionnaire. Result: The relationship between Clinical Dementia Rating (CDR) and the level of CR was statistically significant (likelihood ratio (LR), p = 0.015). Conclusion: The level of CR influenced the severity of dementia. This study suggests that AD patients with higher CR may benefit against cognitive decline after diagnosis of AD.Keywords: Alzheimer´s disease, cognitive reserve, education, leisure activities, lifelong occupation. RESUMODoença de Alzheimer (DA) é uma síndrome neurodegenerativa caracterizada por uma deterioração progressiva das capacidades cognitivas e das competências para uma vida independente. A reserva cognitiva (RC) descreve a capacidade do cérebro adulto em lidar com os efeitos deste processo neurodegenerativo e minimizar a manifestação clínica da patologia de demência. O objetivo deste trabalho foi avaliar a associação entre RC e a severidade da DA. Método: Este estudo foi tra...

Measuring Cognitive Reserve (CR) – A systematic review of measurement properties of CR questionnaires for the adult population

“…Rami et al [3] found associations between the CRQ and Tests of Attentional Performance (r = 0.62 p<0.001 in healthy adults and r = 0.75 p<0.001 in adults with AD). In patients with probable AD, Sobral et al [53] reported a relationship between the Clinical Dementia Rating and the CRQ (p = 0.02, no effect estimate provided). A comparative study of participants with different degrees of cognitive impairment showed that CRQ was positively associated with underlying brain pathology, measured with amyloid deposition (Aβ1–42) (ρ = 0.42, p<0.05) [54].…”

Avaliação neuropsicológica de idosos em investigação para demência

“…Acrescenta-se aí, o fato de que a maioria eram analfabetos ou possuíam baixa escolaridade, fator esse que se mostrou associado ao pior desempenho nos testes. Estudos anteriores [7][8]22 , já haviam indicado que a maior escolaridade influencia para a manutenção das funções cognitivas em idosos, assim como, que a escolarização precoce, contribui de forma importante para a criação de uma reserva cognitiva, que minimiza o impacto das lesões cerebrais 7,8,23,24 .…”

“…De acordo com o DSM-5, para o diagnóstico de transtorno neurocognitivo é preciso que exista comprometimento da memória em conjunto com déficit em pelo menos um dos seguintes domínios cognitivos: linguagem, praxia, gnosia ou funções executivas 4 . Essas patologias prejudicam a independência funcional e criam a dependência de um cuidador externo para os idosos [5][6][7][8] .…”

Mild cognitive impairment and structural brain abnormalities in a sexagenarian with a history of childhood traumatic brain injury

“…Standard contributors to CR include education and IQ (Carnero Pardo & del Ser, ; Elkana et al, ; Kowoll et al, ), including literacy, occupational attainment, engagement in leisure activities, and the integrity of social networks (Cheng, ; Henderson, ; Sakka, ; Moussard, Bermudez, Alain, Tays, & Moreno, ). Most research on BRC and CR has taken place in aging and degenerative disease (Sobral, Pestana, & Paul, ), but these concepts likely apply to the effects of TBI, especially with regard to recovery (Bigler, ; Miller, Colella, Mikulis, Maller, & Green, ; Scheibel et al, ; Schneider et al, ; Sumowski, Chiaravalloti, Krch, Paxton, & Deluca, ). Because increased incidence of TBI occurs in those under age 35, both CR and BRC factors likely relate to how the individual copes with TBI over the life span.…”