Título:	Avaliação cognitiva, olfativa e microestrutural cerebral após Covid-19
Autor(es):	Bispo, Diógenes Diego de Carvalho
Orientador(es):	Regattieri, Neysa Aparecida Tinoco
Coorientador(es):	Soares, Alexandre Anderson de Sousa Munhoz
Assunto:	Covid-19 Cognição Olfato Ressonância magnética Plasticidade neuronal
Data de publicação:	10-Jul-2024
Data de defesa:	13-Dez-2023
Referência:	BISPO, Diógenes Diego de Carvalho. Avaliação cognitiva, olfativa e microestrutural cerebral após Covid-19. 2023. 128 f., il. Tese (Doutorado em Ciências Médicas) — Universidade de Brasília, Brasília, 2023.
Abstract:	Fatigue, cognitive complaints, and olfactory disfunction are the most frequent persistent symptoms in patients after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aimed to assess fatigue and neuropsychological performance and investigate changes in the thickness and volume of gray matter and microstructural abnormalities in the white matter in a group of patients with mild-to-moderate coronavirus disease 2019 (COVID-19). Additionally, we aimed to investigate changes in olfactory bulb volume and brain network in the white matter in patients with persistent hyposmia following COVID-19. Methods. We studied 56 COVID-19 patients and 37 matched controls using magnetic resonance imaging (MRI). Cognition was assessed using Montreal Cognitive Assessment and Cambridge Neuropsychological Test Automated Battery, and fatigue was assessed using Chalder Fatigue Scale (CFQ-11). The Sniffin' Sticks smell identification test (SS-16) was used to evaluate participants' ability to identify odors. T1-weighted MRI was used to assess gray matter thickness and volume. The olfactory bulbs were manually segmented from T2-weighted MRI. Fiber-specific apparent fiber density (FD), free water index, and diffusion tensor imaging data were extracted using diffusion-weighted MRI (d-MRI). Network-Based Statistics (NBS) and graph theoretical analysis were used to explore the WM. d-MRI data were correlated with clinical, cognitive measures, and SS-16 score using partial correlations and general linear modeling. Results. COVID-19 patients had mild-to-moderate acute illness (95% nonhospitalized). The average period between real-time quantitative reverse transcription polymerase chain reaction-based diagnosis and clinical/MRI assessments was 93.3 (±26.4) days. The COVID-19 group had higher total CFQ-11 scores than the control group (p < 0.001). There were no differences in neuropsychological performance between groups. The COVID-19 group had lower FD in the association, projection, and commissural tracts, but no change in gray matter. The corona radiata, corticospinal tract, corpus callosum, arcuate fasciculus, cingulate, fornix, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, superior longitudinal fasciculus, and uncinate fasciculus were involved. CFQ-11 scores and performance in reaction time and visual memory tests correlated with microstructural changes in patients with COVID-19. The COVID-19 persistent hyposmia group had reduced olfactory bulb volume compared to controls. In NBS, COVID-19 patients showed increased structural connectivity in a subnetwork comprising parietal brain regions. Regarding global network topological properties, patients exhibited lower global and local efficiency and higher assortativity than controls. Concerning local network topological properties, patients had reduced local efficiency (left lateral orbital gyrus and pallidum), increased clustering (left lateral orbital gyrus), increased nodal strength (right anterior orbital gyrus), and reduced nodal strength (left amygdala). SS-16 test score was negatively correlated with clustering of whole-brain white matter in the COVID-19 group. Conclusions. Quantitative d-MRI detected changes in the white matter microstructure of patients recovering from COVID-19. This study suggests a possible brain substrate underlying the symptoms caused by SARS-CoV-2 during medium- to long-term recovery. Additionally, patients with olfactory disfunction after COVID-19 had relevant white matter network dysfunction with increased connectivity in the parietal sensory cortex. Reduced integration and increased segregation are observed within olfactoryrelated brain areas might be due to compensatory plasticity mechanisms devoted to recovering olfactory function.
Unidade Acadêmica:	Faculdade de Medicina (FM)
Informações adicionais:	Tese (doutorado) — Universidade de Brasília, Faculdade de Medicina, Programa de Pós-Graduação em Ciências Médicas, 2023.
Programa de pós-graduação:	Programa de Pós-Graduação em Ciências Médicas
Licença:	A concessão da licença deste item refere-se ao termo de autorização impresso assinado pelo autor com as seguintes condições: Na qualidade de titular dos direitos de autor da publicação, autorizo a Universidade de Brasília e o IBICT a disponibilizar por meio dos sites www.bce.unb.br, www.ibict.br, http://hercules.vtls.com/cgi-bin/ndltd/chameleon?lng=pt&skin=ndltd sem ressarcimento dos direitos autorais, de acordo com a Lei nº 9610/98, o texto integral da obra disponibilizada, conforme permissões assinaladas, para fins de leitura, impressão e/ou download, a título de divulgação da produção científica brasileira, a partir desta data.
Aparece nas coleções:	Teses, dissertações e produtos pós-doutorado UnB - Covid-19

Os itens no repositório estão protegidos por copyright, com todos os direitos reservados, salvo quando é indicado o contrário.