Neuroimaging research on dementia in Brazil between 2010‐2020

Abstract

AbstractBackgroundIn low‐ and middle‐income countries, studies involving structural and functional neuroimaging are challenging due to low investments and heterogeneous populations. Outstanding the importance of an accurate diagnosis of dementia, and the contribution that neuroimaging can provide in this field, we aimed to offer an overview of neuroimaging dementia researches developed in Brazil in the last ten years.MethodPubmed was queried to select research papers that (a) had a Brazilian author, (b) presented some kind of neuroimaging result, (c) concerned a neurodegenerative disease presenting a dementia syndrome, and (d) were published from 2010 to 2020.Result65 original papers were included. Referred pathologies were mainly Alzheimer’s disease (54%, n=35) and MCI (48%, n=31), followed by vascular dementia (4.6%, n=3). Besides, the most utilized methods were morphometrics (58%, n=38), fMRI (23%, n=15), and DTI (18%, n= 12). There was no trend toward increasing or decreasing the number of publications per year between 2010‐2020 (Spearman ρ=0.13, p=0.70). The median of the citations for each paper was 5 (IQR 2‐18). Journal impact factor was available for 55/65 papers, with a median of 2.94 (IQR 1.90‐4.35). The vast majority of studies were set in the state of São Paulo (65%), with others from Rio de Janeiro (20%), Minas Gerais (7.6%), Rio Grande do Sul (4.5%), Pernambuco, and Goiás (each with 1.5%).ConclusionDementia neuroimaging research in Brazil is highly focused on AD. Surprisingly, only 4.6% of the studies are about vascular dementia, although Brazilians may have more cerebrovascular damage than other populations. Despite difficulties, Brazilians are studying and refining new neuroimaging methods, such as functional and structural connectivity, DTI, and surface‐based morphometry. However, neuroimaging research in Brazil is far from being developed and widespread across the country. The trend towards a highly concentrated scientific production in the Southeast region along with average‐to‐low research impact reflects the national tendency. Researches in Brazil are also particularly affected by spatial restriction in the national territory, as the cultural, ethnic, and socioeconomic diversity. Therefore, neuroimaging researches with the Brazilian population in this field are an urgent matter to better improve the diagnosis of dementia in Brazil.