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.

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.

Transient Elastography and Controlled Attenuation Parameter (CAP) in the Assessment of Liver Steatosis in Severe Adult Growth Hormone Deficiency.

Non-alcoholic fatty liver disease (NAFLD) is common in patients with growth hormone deficiency (GHD). Some noninvasive techniques have been used to quantify liver fat, such as the controlled attenuation parameter (CAP). Objective: To evaluate CAP as a tool to identify liver steatosis and its relationship with different clinical and biochemical metabolic parameters in a group of patients with severe adult growth hormone deficiency (AGHD), and to compare the evolution of metabolic profiles after 6 months of human growth hormone (rhGH) replacement therapy in a subgroup of patients. Methods: Cross-sectional observational study at baseline of naive rhGH multiple pituitary hormonal deficiency (MPHD) hypopituitarism patients. A 6-month intervention clinical trial in a selected group of a non-randomized, non-controlled cohort was also applied. Results: Liver stiffness measurement (LSM) was normal in severe AGHD patients. CAP evaluation showed steatosis in 36.3% of baseline patients (8/22), associated with higher BMI, waist circumference, insulin, and alanine aminotransferase (ALT) levels. According to steatosis degree by CAP, child-onset growth hormone deficiency (CO-GHD) was graded as 68.75% (11/16) S0, 12.5% (2/16) S1, and 18.75% (3/16) S3, whereas AO-GHD was graded as 50% (3/6) S0, 16.66% (1/6) S2, and 33.33% S3. After 6 months of hrGH replacement, CAP measurements did not change significantly, neither on group without hepatic steatosis at baseline (194.4 ± 24.3 vs. 215.4 ± 51.3; p = 0.267) nor on the group with hepatic steatosis (297.2 ± 32.3 vs. 276.4 ± 27.8; p = 0.082). A significant improvement of body composition was observed only in the first group. Conclusions: We have demonstrated the importance of CAP as a non-invasive tool in the liver steatosis identification on hypopituitary patients. This method may be an important indicator of the severity of metabolic disorders in MPHD patients. In our study, no liver health modification in LSM at baseline or after 6 months of rhGH replacement was found. Longer studies can help to establish the potential repercussions of growth hormone replacement therapy on liver steatosis.

External vascular compression by hyaluronic acid filler documented with high-frequency ultrasound.

We present a case report of a hyaluronic acid filler-induced complication documented using high-frequency ultrasound. We regard the scientific value of the case as indicating the benefit that ultrasound provides for the management and documentation of this complication. This technology has been becoming increasingly widespread in the care of patients who experience unwanted effects of hyaluronic acid filler because it can be used for the high-resolution visualization of skin layers as well as the differentiation of filler types and their relationships with adjacent tissues (via gray scale or B-mode ultrasound) and blood vessels (via color Doppler ultrasound). In addition, it was possible to conclude that external vascular compression causes clinical repercussions, a fact that is often questioned by some dermatologists. This questioning is based on the vast vascularization and anastomosis of arteries of the face, which should permit compensation for vascular compression. However, in this case, there was no doubt that compression caused a region of low output with the clinical manifestation of peri-oral pallor. Ultrasound was used to document the compression of a vessel by the filler; after application of hyaluronidase, increased vessel lumen and clinical reversal of hypoperfusion in the affected area were observed.

Anatomia arterial intracraniana: avaliação por angiotomografia computadorizada: [revisão] / Intracranial arterial anatomy: evaluation by computed tomography angiography: [review]

Durante muitos anos, o estudo arterial intracraniano foi realizado, exclusivamente, por meio daangiografia convencional, em que há cateterização seletiva das artérias. Hoje em dia, com a evoluçãotecnológica da tomografia computadorizada por meio de multidetectores permitindo aquisições com fatias de corte cada vez mais finas, maior velocidade e melhor resolução espacial, surgiucomo nova modalidade de investigação a angiotomografia, menos invasiva e com menor morbidade que a arteriografia convencional. Muitos estudos na literatura vêm analisando a sensibilidade deste novo método na detecção de aneurismas intracranianos e comparando seus resultados com aqueles obtidos pela arteriografia convencional. Para tal, percebe-se a necessidade doreconhecimento da anatomia arterial intracraniana normal e suas variações a partir de imagenscom reformações multiplanares, objetivando o fornecimento de importantes informações paradefinição de estratégias nas abordagens cirúrgicas, tais como calcificações parietais, posição docolo aneurismático e relações com estruturas anatômicas circundantes.

By many decades, the intracranial arteries study was realized exclusively by angiography through selective arterial catheterization.Nowadays, with the technologic evaluation of computerized tomography devices with multidetectors allowing acquisitions with even more thinner slices, higher speed and better resolution, it had appeared a new modality of investigation: the computed tomography angiography, less invasive and with minor morbidity than conventional arteriography. Many studies in the literature have been analyzing the sensibility of the new method for the detection ofintracranial aneurisms and comparing them with the conventional arteriography. There is a necessity to recognize the normal intracranial arterial anatomy and its variations using images obtainedfrom multiplanar reformations, in order to give important informationfor surgeries strategies, such as wall calcifications, aneurismatic neck position and relationships with surrounding anatomical structures.