Bilingualism delays the onset of behavioral but not aphasic forms of frontotemporal dementia.

Bilingualism has been found to delay onset of dementia and this has been attributed to an advantage in executive control in bilinguals. However, the relationship between bilingualism and cognition is complex, with costs as well as benefits to language functions. To further explore the cognitive consequences of bilingualism, the study used Frontotemporal dementia (FTD) syndromes, to examine whether bilingualism modifies the age at onset of behavioral and language variants of Frontotemporal dementia (FTD) differently. Case records of 193 patients presenting with FTD (121 of them bilingual) were examined and the age at onset of the first symptoms were compared between monolinguals and bilinguals. A significant effect of bilingualism delaying the age at onset of dementia was found in behavioral variant FTD (5.7 years) but not in progressive nonfluent aphasia (0.7 years), semantic dementia (0.5 years), corticobasal syndrome (0.4 years), progressive supranuclear palsy (4.3 years) and FTD-motor neuron disease (3 years). On dividing all patients predominantly behavioral and predominantly aphasic groups, age at onset in the bilingual behavioral group (62.6) was over 6 years higher than in the monolingual patients (56.5, p=0.006), while there was no difference in the aphasic FTD group (60.9 vs. 60.6 years, p=0.851). The bilingual effect on age of bvFTD onset was shown independently of other potential confounding factors such as education, gender, occupation, and urban vs rural dwelling of subjects. To conclude, bilingualism delays the age at onset in the behavioral but not in the aphasic variants of FTD. The results are in line with similar findings based on research in stroke and with the current views of the interaction between bilingualism and cognition, pointing to advantages in executive functions and disadvantages in lexical tasks.

Dementia in developing countries: does education play the same role in India as in the West? / Demência nos países em desenvolvimento: a edução desempenha o mesmo papel na Índia como no ocidente

Evidence suggests that education protects from dementia by enhancing cognitive reserve. However, this may be influenced by several socio-demographic factors. Rising numbers of dementia in India, high levels of illiteracy and heterogeneity in socio-demographic factors provide an opportunity to explore this relationship. OBJECTIVE: To study the association between education and age at dementia onset, in relation to socio-demographic factors. METHODS: Association between age at dementia onset and literacy was studied in relationship to potential confounding factors such as gender, bilingualism, place of dwelling, occupation, vascular risk factors, stroke, family history of dementia and dementia subtypes. RESULTS: Case records of 648 dementia patients diagnosed in a specialist clinic in a University hospital in Hyderabad, India were examined. All patients were prospectively enrolled as part of an ongoing longitudinal project that aims to evaluate dementia subjects with detailed clinical, etiological, imaging, and follow-up studies. Of the 648 patients, 98 (15.1%) were illiterate. More than half of illiterate skilled workers were engaged in crafts and skilled agriculture unlike literates who were in trade or clerical jobs. Mean age at onset in illiterates was 60.1 years and in literates 64.5 years (p=0.0002). Factors independently associated with age at dementia onset were bilingualism, rural dwelling and stroke, but not education. CONCLUSION: Our study demonstrates that in India, rural dwelling, bilingualism, stroke and occupation modify the relationship between education and dementia.

Evidências sugerem que a educação protége de demência pelo fortalecimento da reserva cognitiva. Todavia, pode ser influenciado por vários fatores socioeconômicos. O aumento no número de demência na Índia, altos índices de analfabetismo e heterogeneidade de fatores sociodemográficos fornecem uma oportunidade para explorar estas relações. OBJETIVO: Estudar a associação entre educação e idade no início da demência em relação aos fatores sociodemográficos. MÉTODOS: A associação entre idade de início da demência e alfabetismo foi estudado em relação aos potenciais fatores confundidores, como gênero, bilinguismo, local de moradia, ocupação, fatores de risco vasculares, acidente vascular cerebral (AVC), história familiar de demência e subtipos de demência. RESULTADOS: Arquivos de 648 pacientes com demência, diagnosticados numa clínica especializada no Hospital Universitário em Hyderabad, foram avaliados. Todos os pacientes foram prospectivamente incluídos num projeto de acompanhamento longitudinal cujo objetivo é avaliar indivíduos com demência através de estudo de detalhado de acompanhamento clínico, etiológico e de imagem. Dos 648 pacientes, 98 (15%) eram analfabetos. Mais da metade dos analfabetos estavam envolvidos em trabalhos manuais ao contrário dos alfabetizados, envolvidos em comércio ou escritórios. A idade média de início em analfabetos foi de 60,1 anos e entre alfabetizados 64,5 anos de idade (p=0,0002). Os fatores independentemente associados à idade de início da demência foram bilinguismo, AVC, moradia rural, mas não educação. CONCLUSÃO: Nosso estudo demonstra que na Índia, moradia rural, bilinguismo, AVC e ocupação modificam a relação entre educação e demência.

Mild cognitive impairment: clinical and imaging profile in a memory clinic setting in India.

BACKGROUND: Despite the increasing burden of dementia in developing countries, mild cognitive impairment (MCI) continues to be underexplored. MCI has conventionally been identified based on clinical profile, but recently, biomarkers suggestive of Alzheimer's disease pathology have been included in the revised National Institute on Aging and the Alzheimer's Association (NIA-AA) criteria. In this study, we evaluated the profile of MCI in a memory clinic in India and explored the applicability of the revised NIA-AA criteria in a limited resource setting. METHODS: Consecutive subjects evaluated at the memory clinic for mild memory complaints were included and underwent clinical and neuropsychological examination as well as standard brain imaging. A subset of patients was subjected to imaging biomarker studies as a part of routine clinical practice. RESULTS: Among the 1,190 patients evaluated during the study period, 226 (19.0%) presented with mild memory complaints. Cerebrovascular disease was a common secondary cause. Nearly half of the patients (109 of 226) had MCI according to the modified Petersen criteria. All MCI subjects were educated and the majority were male. A total of 12% of the cohort was classified by imaging biomarkers as having MCI with intermediate likelihood of AD according to the NIA-AA criteria. CONCLUSION: In the setting of urban India, MCI is an emerging problem; therefore, it was feasible to operationalise the revised NIA-AA criteria in identifying subjects with MCI with intermediate likelihood of AD.

Dementia in developing countries: Does education play the same role in India as in the West?

Evidence suggests that education protects from dementia by enhancing cognitive reserve. However, this may be influenced by several socio-demographic factors. Rising numbers of dementia in India, high levels of illiteracy and heterogeneity in socio-demographic factors provide an opportunity to explore this relationship. OBJECTIVE: To study the association between education and age at dementia onset, in relation to socio-demographic factors. METHODS: Association between age at dementia onset and literacy was studied in relationship to potential confounding factors such as gender, bilingualism, place of dwelling, occupation, vascular risk factors, stroke, family history of dementia and dementia subtypes. RESULTS: Case records of 648 dementia patients diagnosed in a specialist clinic in a University hospital in Hyderabad, India were examined. All patients were prospectively enrolled as part of an ongoing longitudinal project that aims to evaluate dementia subjects with detailed clinical, etiological, imaging, and follow-up studies. Of the 648 patients, 98 (15.1%) were illiterate. More than half of illiterate skilled workers were engaged in crafts and skilled agriculture unlike literates who were in trade or clerical jobs. Mean age at onset in illiterates was 60.1 years and in literates 64.5 years (p=0.0002). Factors independently associated with age at dementia onset were bilingualism, rural dwelling and stroke, but not education. CONCLUSION: Our study demonstrates that in India, rural dwelling, bilingualism, stroke and occupation modify the relationship between education and dementia.

Evidências sugerem que a educação protége de demência pelo fortalecimento da reserva cognitiva. Todavia, pode ser influenciado por vários fatores socioeconômicos. O aumento no número de demência na Índia, altos índices de analfabetismo e heterogeneidade de fatores sociodemográficos fornecem uma oportunidade para explorar estas relações. OBJETIVO: Estudar a associação entre educação e idade no início da demência em relação aos fatores sociodemográficos. MÉTODOS: A associação entre idade de início da demência e alfabetismo foi estudado em relação aos potenciais fatores confundidores, como gênero, bilinguismo, local de moradia, ocupação, fatores de risco vasculares, acidente vascular cerebral (AVC), história familiar de demência e subtipos de demência. RESULTADOS: Arquivos de 648 pacientes com demência, diagnosticados numa clínica especializada no Hospital Universitário em Hyderabad, foram avaliados. Todos os pacientes foram prospectivamente incluídos num projeto de acompanhamento longitudinal cujo objetivo é avaliar indivíduos com demência através de estudo de detalhado de acompanhamento clínico, etiológico e de imagem. Dos 648 pacientes, 98 (15%) eram analfabetos. Mais da metade dos analfabetos estavam envolvidos em trabalhos manuais ao contrário dos alfabetizados, envolvidos em comércio ou escritórios. A idade média de início em analfabetos foi de 60,1 anos e entre alfabetizados 64,5 anos de idade (p=0,0002). Os fatores independentemente associados à idade de início da demência foram bilinguismo, AVC, moradia rural, mas não educação. CONCLUSÃO: Nosso estudo demonstra que na Índia, moradia rural, bilinguismo, AVC e ocupação modificam a relação entre educação e demência.

Bilingualism delays age at onset of dementia, independent of education and immigration status.

OBJECTIVES: The purpose of the study was to determine the association between bilingualism and age at onset of dementia and its subtypes, taking into account potential confounding factors. METHODS: Case records of 648 patients with dementia (391 of them bilingual) diagnosed in a specialist clinic were reviewed. The age at onset of first symptoms was compared between monolingual and bilingual groups. The influence of number of languages spoken, education, occupation, and other potentially interacting variables was examined. RESULTS: Overall, bilingual patients developed dementia 4.5 years later than the monolingual ones. A significant difference in age at onset was found across Alzheimer disease dementia as well as frontotemporal dementia and vascular dementia, and was also observed in illiterate patients. There was no additional benefit to speaking more than 2 languages. The bilingual effect on age at dementia onset was shown independently of other potential confounding factors such as education, sex, occupation, and urban vs rural dwelling of subjects. CONCLUSIONS: This is the largest study so far documenting a delayed onset of dementia in bilingual patients and the first one to show it separately in different dementia subtypes. It is the first study reporting a bilingual advantage in those who are illiterate, suggesting that education is not a sufficient explanation for the observed difference. The findings are interpreted in the context of the bilingual advantages in attention and executive functions.

Lost and forgotten? Orientation versus memory in Alzheimer's disease and frontotemporal dementia.

Recent studies suggest that significant memory problems are not specific to Alzheimer's disease (AD) but can be also observed in other neurodegenerative conditions, such as behavioral variant frontotemporal dementia (bvFTD). We investigated whether orientation (spatial & temporal) information is a better diagnostic marker for AD compared to memory and whether their atrophy correlates of orientation and memory differ. A large sample (n = 190) of AD patients (n = 73), bvFTD patients (n = 54), and healthy controls (n = 63) underwent testing. A subset of the patients (n = 72) underwent structural imaging using voxel-based morphometry analysis of magnetic resonance brain imaging. Orientation and memory scores from the Addenbrooke's Cognitive Examination showed that AD patients had impaired orientation and memory, while bvFTD patients performing at control level for orientation but had impaired memory. A logistic regression showed that 78% of patients could be classified on the basis of orientation and memory scores alone at clinic presentation. Voxel-based morphometry analysis was conducted using orientation and memory scores as covariates, which showed that the neural correlates for orientation and memory also dissociated with posterior hippocampus cortex being related to orientation in AD, while the anterior hippocampus was associated with memory performance in the AD and bvFTD patients. Orientation and memory measures discriminate AD and bvFTD to a high degree and tap into different hippocampal regions. Disorientation and posterior hippocampus appears therefore specific to AD and will allow clinicians to discriminate AD patients from other neurodegenerative conditions with similar memory deficits at clinic presentation.