Altered structural connectivity in olfactory disfunction after mild COVID-19 using probabilistic tractography.

We aimed to investigate changes in olfactory bulb volume and brain network in the white matter (WM) in patients with persistent olfactory disfunction (OD) following COVID-19. A cross-sectional study evaluated 38 participants with OD after mild COVID-19 and 24 controls, including Sniffin' Sticks identification test (SS-16), MoCA, and brain magnetic resonance imaging. Network-Based Statistics (NBS) and graph theoretical analysis were used to explore the WM. The COVID-19 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 WM in the COVID-19 group. Thus, patients with OD after COVID-19 had relevant WM network dysfunction with increased connectivity in the parietal sensory cortex. Reduced integration and increased segregation are observed within olfactory-related brain areas might be due to compensatory plasticity mechanisms devoted to recovering olfactory function.

Parkinson's Disease-Cognitive Rating Scale (PD-CRS): Normative Data and Mild Cognitive Impairment Assessment in Brazil.

Background: The Parkinson's Disease-Cognitive Rating Scale (PD-CRS) assesses posterior-cortical and frontal-subcortical cognitive functioning and distinguishes mild cognitive impairment in Parkinson's disease (PD-MCI); however, it was not evaluated in Brazil. Objectives: To investigate PD-CRS's reliability, validity, normative data, and accuracy for PD-MCI screening in Brazil. Methods: The effects of age, education, and sex on PD-CRS scores were explored. The instrument was tested in 714 individuals (53% female, 21-94 years), with a broad range of education and no neurodegenerative disorder. Trail Making, Consonant Trigrams, Five-Point, and semantic fluency tests were administered for comparison. A second study enrolled patients with PD and intact cognition (n = 44, 59.75 ± 10.79 years) and with PD-MCI (n = 25, 65.76 ± 10.33 years) to investigate criterion validity. PD-CRS subtests were compared with the Cambridge Automated Neuropsychological Battery memory and executive tasks. Results: PD-CRS was unidimensional and reliable (McDonald's ω = 0.83). Using robust multiple regressions, age, and education predicted the total and derived scores in the normative sample. At the 85-point cutoff, PD-MCI was detected with 68% sensitivity and 86% specificity (area under the curve = 0.870). PD-CRS scores strongly correlated with executive and verbal/visual memory tests in both normative and clinical samples. Conclusions: This study investigated the applicability of PD-CRS in the Brazilian context. The scale seems helpful in screening for PD-MCI, with adequate internal consistency and construct validity. The PD-CRS variance is influenced by age and educational level, a critical issue for cognitive testing in countries with educational and cultural heterogeneity.

Brain microstructural changes and fatigue after COVID-19.

Background: Fatigue and cognitive complaints 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 (GM) and microstructural abnormalities in the white matter (WM) in a group of patients with mild-to-moderate coronavirus disease 2019 (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). T1-weighted MRI was used to assess GM thickness and volume. Fiber-specific apparent fiber density (FD), free water index, and diffusion tensor imaging data were extracted using diffusion-weighted MRI (d-MRI). d-MRI data were correlated with clinical and cognitive measures using partial correlations and general linear modeling. Results: COVID-19 patients had mild-to-moderate acute illness (95% non-hospitalized). 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 GM. 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, performance in reaction time, and visual memory tests correlated with microstructural changes in patients with COVID-19. Conclusions: Quantitative d-MRI detected changes in the WM 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.

Importance of computed tomography angiography in acute/hyperacute ischemic stroke.

OBJECTIVE: To evaluate the importance of computed tomography and computed tomography angiography (CTA) in stroke protocols, as well as their impact on endovascular treatment and on the determination of the etiology. MATERIALS AND METHODS: Were evaluated 28 patients with acute/hyperacute stroke in the anterior circulation who underwent intracranial and cervical CTA between April 2018 and August 2019. The parameters evaluated were the degree of stenosis, plaque characteristics, type of infarct, treatment, etiology, and the Alberta Stroke Program Early CT Score (ASPECTS). RESULTS: Of the 28 patients evaluated, 16 (57.1%) had an ASPECTS of 10 (the maximum score, indicative of normality). Four patients (14.3%) underwent thrombolytic treatment, and seven (25.0%) underwent mechanical thrombectomy. The etiology was atherosclerosis in 32.1% of the patients, cerebral small-vessel disease in 7.1%, cardioembolic in 7.1%, and undetermined in 53.6%. Regarding plaque, 17.9% of the patients presented stenosis ≥ 50%, 21.4% presented stable plaques, and 42.9% presented vulnerable plaques. Patients with a lower ASPECTS were more likely to have relevant stenosis and were more likely to have a total infarct. CONCLUSION: In the evaluation of patients with acute/hyperacute strokes, CTA provides important information, identifying occlusion, as well as helping define the etiology and inform decisions regarding treatment.

OBJETIVO: Avaliar a importância da tomografia computadorizada e angiotomografia computadorizada (ATC) no protocolo de acidente vascular encefálico (AVE) e o seu impacto no tratamento endovascular e na determinação da etiologia.Materiais e Métodos: Foram avaliados 28 pacientes com AVE agudo/hiperagudo da circulação anterior que realizaram ATC intracraniana e cervical, no período de abril de 2018 a agosto de 2019. Os parâmetros avaliados foram grau de estenose, placa, tipo do infarto, tratamento, etiologia e classificação Alberta Stroke Program Early CT Score (ASPECTS). RESULTADOS: A maioria dos casos (16; 57,1%) apresentou ASPECTS de 10. Quatro pacientes (14,3%) realizaram tratamento trombolítico e sete (25%) foram submetidos a trombectomia mecânica. A etiologia foi aterosclerose em 32,1% dos pacientes, doença de pequenas artérias em 7,1%, cardioembólico em 7,1% e indeterminada em 53,6%. Em relação à placa, 17,9% apresentaram estenose maior que 50%, 21,4% apresentaram placas estáveis e 42,9%, placas instáveis. Pacientes com ASPECTS mais baixo apresentavam maior probabilidade de ter estenose relevante e apresentavam maior chance de ocorrência de infarto total. CONCLUSÃO: A ATC fornece informações importantes na avaliação do paciente com AVE agudo/hiperagudo, identificando a oclusão e auxiliando na definição da etiologia e no direcionamento do tratamento.

Importance of computed tomography angiography in acute/hyperacute ischemic stroke / Importância da angiotomografia computadorizada no acidente vascular encefálico isquêmico agudo/hiperagudo

Abstract Objective: To evaluate the importance of computed tomography and computed tomography angiography (CTA) in stroke protocols, as well as their impact on endovascular treatment and on the determination of the etiology. Materials and Methods Were evaluated 28 patients with acute/hyperacute stroke in the anterior circulation who underwent intracranial and cervical CTA between April 2018 and August 2019. The parameters evaluated were the degree of stenosis, plaque characteristics, type of infarct, treatment, etiology, and the Alberta Stroke Program Early CT Score (ASPECTS). Results: Of the 28 patients evaluated, 16 (57.1%) had an ASPECTS of 10 (the maximum score, indicative of normality). Four patients (14.3%) underwent thrombolytic treatment, and seven (25.0%) underwent mechanical thrombectomy. The etiology was atherosclerosis in 32.1% of the patients, cerebral small-vessel disease in 7.1%, cardioembolic in 7.1%, and undetermined in 53.6%. Regarding plaque, 17.9% of the patients presented stenosis ≥ 50%, 21.4% presented stable plaques, and 42.9% presented vulnerable plaques. Patients with a lower ASPECTS were more likely to have relevant stenosis and were more likely to have a total infarct. Conclusion: In the evaluation of patients with acute/hyperacute strokes, CTA provides important information, identifying occlusion, as well as helping define the etiology and inform decisions regarding treatment.

Resumo Objetivo: Avaliar a importância da tomografia computadorizada e angiotomografia computadorizada (ATC) no protocolo de acidente vascular encefálico (AVE) e o seu impacto no tratamento endovascular e na determinação da etiologia. Materiais e Métodos: Foram avaliados 28 pacientes com AVE agudo/hiperagudo da circulação anterior que realizaram ATC intracraniana e cervical, no período de abril de 2018 a agosto de 2019. Os parâmetros avaliados foram grau de estenose, placa, tipo do infarto, tratamento, etiologia e classificação Alberta Stroke Program Early CT Score (ASPECTS). Resultados: A maioria dos casos (16; 57,1%) apresentou ASPECTS de 10. Quatro pacientes (14,3%) realizaram tratamento trombolítico e sete (25%) foram submetidos a trombectomia mecânica. A etiologia foi aterosclerose em 32,1% dos pacientes, doença de pequenas artérias em 7,1%, cardioembólico em 7,1% e indeterminada em 53,6%. Em relação à placa, 17,9% apresentaram estenose maior que 50%, 21,4% apresentaram placas estáveis e 42,9%, placas instáveis. Pacientes com ASPECTS mais baixo apresentavam maior probabilidade de ter estenose relevante e apresentavam maior chance de ocorrência de infarto total. Conclusão: A ATC fornece informações importantes na avaliação do paciente com AVE agudo/hiperagudo, identificando a oclusão e auxiliando na definição da etiologia e no direcionamento do tratamento.