Recently, much attention has been drawn to the importance of the impact of infectious disease on human cognition. Several theories have been proposed, to explain the cognitive decline following an ...infection as well as to understand better the pathogenesis of human dementia, especially Alzheimer’s disease. This article aims to review the state of the art regarding the knowledge about the impact of acute viral infections on human cognition, laying a foundation to explore the possible cognitive decline followed coronavirus disease 2019 (COVID-19). To reach this goal, we conducted a narrative review systematizing six acute viral infections as well as the current knowledge about COVID-19 and its impact on human cognition. Recent findings suggest probable short- and long-term COVID-19 impacts in cognition, even in asymptomatic individuals, which could be accounted for by direct and indirect pathways to brain dysfunction. Understanding this scenario might help clinicians and health leaders to deal better with a wave of neuropsychiatric issues that may arise following COVID-19 pandemic as well as with other acute viral infections, to alleviate the cognitive sequelae of these infections around the world.
Altered structural brain asymmetry in autism spectrum disorder (ASD) has been reported. However, findings have been inconsistent, likely due to limited sample sizes. Here we investigated 1,774 ...individuals with ASD and 1,809 controls, from 54 independent data sets of the ENIGMA consortium. ASD was significantly associated with alterations of cortical thickness asymmetry in mostly medial frontal, orbitofrontal, cingulate and inferior temporal areas, and also with asymmetry of orbitofrontal surface area. These differences generally involved reduced asymmetry in individuals with ASD compared to controls. Furthermore, putamen volume asymmetry was significantly increased in ASD. The largest case-control effect size was Cohen's d = -0.13, for asymmetry of superior frontal cortical thickness. Most effects did not depend on age, sex, IQ, severity or medication use. Altered lateralized neurodevelopment may therefore be a feature of ASD, affecting widespread brain regions with diverse functions. Large-scale analysis was necessary to quantify subtle alterations of brain structural asymmetry in ASD.
An early and persistent sign of Alzheimer's disease (AD) is glucose hypometabolism, which can be evaluated by positron emission tomography (PET) with
F-2-fluoro-2-deoxy-D-glucose (
FFDG). Cannabidiol ...has demonstrated neuroprotective and anti-inflammatory properties but has not been evaluated by PET imaging in an AD model. Intracerebroventricular (icv) injection of streptozotocin (STZ) is a validated model for hypometabolism observed in AD. This proof-of-concept study evaluated the effect of cannabidiol treatment in the brain glucose metabolism of an icv-STZ AD model by PET imaging. Wistar male rats received 3 mg/kg of STZ and
FFDG PET images were acquired before and 7 days after STZ injection. Animals were treated with intraperitoneal cannabidiol (20 mg/kg-STZ-cannabidiol) or saline (STZ-saline) for one week. Novel object recognition was performed to evaluate short-term and long-term memory.
FFDG uptake in the whole brain was significantly lower in the STZ-saline group. Voxel-based analysis revealed a hypometabolism cluster close to the lateral ventricle, which was smaller in STZ-cannabidiol animals. The brain regions with more evident hypometabolism were the striatum, motor cortex, hippocampus, and thalamus, which was not observed in STZ-cannabidiol animals. In addition, STZ-cannabidiol animals revealed no changes in memory index. Thus, this study suggests that cannabidiol could be an early treatment for the neurodegenerative process observed in AD.
•Post-stroke depression and cognitive impairment is reported in a developing country.•Cognitive impairment was associated with left-sided stroke, but not with depression.•Overall, biomarkers did not ...influence on post-stroke depression and cognition.
Post-stroke depression (PSD) and cognitive impairment (PCI) are common conditions. This study aims to describe the protocol and preliminary findings of an investigation into factors associated with PSD and PCI 1–3 months after stroke (subacute phase) in survivors from the Study of Stroke Mortality and Morbidity (EMMA study).
Stroke patients underwent to clinical and neurological evaluations on admission to hospital. Cerebral magnetic resonance and biomarkers (serotonin, BDNF, IL-6 and IL-18) were carried out in the subacute phase. DSM-IV major depression for the diagnosis of PSD, cognitive functioning for the diagnosis of PCI and functional disability were also recorded at same time.
Of the 103 eligible patients, 85.4% had ischemic stroke and 73.7% had first-ever stroke. In the subacute phase, 27.2% had PCI and 13.6% had current PSD (5.8% with ‘first episode’ and 7.8% with ‘recurrent’ depression). PCI was associated with low education (0–7 years of formal education: 75%) and ageing (median age: 70; interquartile range: 59–75 y-old). Left-sided stroke was more frequently associated with increased PCI than right-sided stroke (71.4% vs. 28.4%, p = 0.005). PSD was neither associated with stroke laterality nor tentorial area. Overall, biomarkers levels were not alterated in patients with PSD and PCI.
Findings are based on small sample and less disabled stroke participants, e.g. those without aphasia and deafness.
Findings reinforce the need of early recognition and rehabilitation of PCI and PSD, mainly among those less educated and with left-sided stroke. PSD might occur through a pathophysiological pathway other than classical depression.
•32% of the patients visited an emergency room after COVID-19 hospitalization.•The rate of hospital readmission after COVID-19 hospitalization is high, in the present sample 10% of patients needed a ...second hospitalization in 6-months•Patients with persistent diarrhea after COVID-19 discharge had two times more chance to have another hospitalization in the next 6-months.
The aim of this study was to describe the incidence and risk factors for hospital readmission and infection during the months after COVID-19 hospital admission.
This prospective study included adult patients who were hospitalized due to COVID-19 and had been discharged from April 2020 to August 2020. All patients had a medical evaluation with a structured questionnaire 6 to 11 months after hospital admission. The authors included only patients with confirmed COVID-19 by RT-PCR. Patients with pregnant/postpartum women, with a proven COVID-19 reinfection or incapable of answering the questionnaire were excluded.
A total of 822 patients completed the follow-up assessment, and 68% reported at least one recurrent symptom related to COVID-19. The most frequent symptom was myalgia (42%). Thirty-two percent of patients visited an emergency room after COVID-19 hospitalization, and 80 (10%) patients required re-hospitalization. Risk factors for hospital readmission were orotracheal intubation during COVID-19 hospitalization (p = 0.003, OR = 2.14), Charlson score (p = 0.002, OR = 1.21), congestive heart failure (p = 0.005, OR = 2.34), peripheral artery disease (p = 0.06, OR = 2.06) and persistent diarrhea after COVID-19 hospitalization discharge (p = 0.02, OR = 1.91). The main cause of hospital readmission was an infection, 43 (54%). Pneumonia was the most frequent infection (29%).
The presence of symptoms after six months of COVID-19 diagnosis was frequent, and hospital readmission was relatively high.
People with Alzheimer's disease (AD) dementia have impaired sleep. However, the characteristics of sleep in the early stages of AD are not well known, and studies with the aid of biomarkers are ...lacking. We assessed the subjective sleep characteristics of non-demented older adults and compared their amyloid profiles.
We enrolled 30 participants aged ≥ 60 years, with no dementia or major clinical and psychiatric diseases. They underwent 11CPiB-PET-CT, neuropsychological evaluations, and completed two standardized sleep assessments (Pittsburgh Sleep Quality Inventory and Epworth Sleep Scale).
Comparative analysis of subjective sleep parameters across the two groups showed longer times in bed (p = 0.024) and reduced sleep efficiency (p = 0.05) in individuals with positive amyloid. No differences in other subjective sleep parameters were observed. We also found that people with multiple-domain mild cognitive impairment (MCI) had shorter self-reported total sleep times (p = 0.034) and worse overall sleep quality (p = 0.027) compared to those with single-domain MCI.
Older adults testing positive for amyloid had a longer time in bed and lower sleep efficiency, regardless of cognitive status. In parallel, individuals with multiple-domain MCI reported shorter sleep duration and lower overall sleep quality.
Brain magnetic resonance imaging studies have not investigated the cortical surface comprehensively in schizophrenia subjects by assessing thickness, surface area and gyrification separately during ...the first-episode of psychosis (FEP) or chronic schizophrenia (ChSch).
We investigated cortical surface abnormalities in 137 FEP patients and 240 ChSch subjects compared to 297 Healthy Controls (HC) contributed by five cohorts. Maps showing results of vertexwise between-group comparisons of cortical thickness, area, and gyrification were produced using T1-weighted datasets processed using FreeSurfer 5.3, followed by validated quality control protocols.
FEP subjects showed large clusters of increased area and gyrification relative to HC in prefrontal and insuli cortices (Cohen's d: 0.049 to 0.28). These between-group differences occurred partially beyond the effect of sample. ChSch subjects displayed reduced cortical thickness relative to HC in smaller fronto-temporal foci (d: −0.73 to −0.35), but not beyond the effect of sample. Differences between FEP and HC subjects were associated with male gender, younger age, and earlier illness onset, while differences between ChSch and HC were associated with treatment-resistance and first-generation antipsychotic (FGA) intake independently of sample effect.
Separate assessments of FEP and ChSch revealed abnormalities that differed in regional distribution, phenotypes affected and effect size. In FEP, associations of greater cortical area and gyrification abnormalities with earlier age of onset suggest an origin on anomalous neurodevelopment, while thickness reductions in ChSch are at least partially explained by treatment-resistance and FGA intake. Associations of between-group differences with clinical variables retained statistical significance beyond the effect of sample.
Positron emission tomography (PET) allows in vivo evaluation of molecular targets in neurodegenerative diseases, such as Alzheimer's disease. Mild cognitive impairment is an intermediate stage ...between normal cognition and Alzheimer-type dementia. In vivo fibrillar amyloid-beta can be detected in PET using 11C-labeled Pittsburgh compound B (11C-PiB). In contrast, 18Ffluoro-2-deoxy-d-glucose (18F-FDG) is a neurodegeneration biomarker used to evaluate cerebral glucose metabolism, indicating neuronal injury and synaptic dysfunction. In addition, early cerebral uptake of amyloid-PET tracers can determine regional cerebral blood flow. The present study compared early-phase 11C-PiB and 18F-FDG in older adults without cognitive impairment, amnestic mild cognitive impairment, and clinical diagnosis of probable Alzheimer's disease.
We selected 90 older adults, clinically classified as healthy controls, with amnestic mild cognitive impairment, or with probable Alzheimer's disease, who underwent an 18F-FDG PET, early-phase 11C-PiB PET and magnetic resonance imaging. All participants were also classified as amyloid-positive or -negative in late-phase 11C-PiB. The data were analyzed using statistical parametric mapping.
We found that the probable Alzheimer's disease and amnestic mild cognitive impairment group had lower early-phase 11C-PiB uptake in limbic structures than 18F-FDG uptake. The images showed significant interactions between amyloid-beta status (negative or positive). However, early-phase 11C-PiB appears to provide different information from 18F-FDG about neurodegeneration.
Our study suggests that early-phase 11C-PiB uptake correlates with 18F-FDG, irrespective of the particular amyloid-beta status. In addition, we observed distinct regional distribution patterns between both biomarkers, reinforcing the need for more robust studies to investigate the real clinical value of early-phase amyloid-PET imaging.
Animal and human studies indicate that cannabidiol (CBD), a major constituent of cannabis, has anxiolytic properties. However, no study to date has investigated the effects of this compound on human ...pathological anxiety and its underlying brain mechanisms. The aim of the present study was to investigate this in patients with generalized social anxiety disorder (SAD) using functional neuroimaging. Regional cerebral blood flow (rCBF) at rest was measured twice using (99m)Tc-ECD SPECT in 10 treatment-naïve patients with SAD. In the first session, subjects were given an oral dose of CBD (400 mg) or placebo, in a double-blind procedure. In the second session, the same procedure was performed using the drug that had not been administered in the previous session. Within-subject between-condition rCBF comparisons were performed using statistical parametric mapping. Relative to placebo, CBD was associated with significantly decreased subjective anxiety (p < 0.001), reduced ECD uptake in the left parahippocampal gyrus, hippocampus, and inferior temporal gyrus (p < 0.001, uncorrected), and increased ECD uptake in the right posterior cingulate gyrus (p < 0.001, uncorrected). These results suggest that CBD reduces anxiety in SAD and that this is related to its effects on activity in limbic and paralimbic brain areas.
Voxel-based morphometry (VBM) is a useful approach for investigating neurostructural brain changes in dementia. We systematically reviewed VBM studies of Alzheimer's disease (AD) and mild cognitive ...impairment (MCI), specifically focusing on grey matter (GM) atrophy in the frontal lobe.
Two searches were performed on the Pubmed database. A set of exclusion criteria was applied to ensure the selection of only VBM studies that directly investigated GM volume abnormalities in AD and/or MCI patients compared to cognitively normal controls.
From a total of 46 selected articles, 35 VBM studies reported GM volume reductions in the frontal lobe. The frontal subregions, where most of the volume reductions were reported, included the inferior, superior and middle frontal gyri, as well as the anterior cingulate gyrus. We also found studies in which reduced frontal GM was detected in MCI patients who converted to AD. In a minority of studies, correlations between frontal GM volumes and behavioural changes or cognitive deficits in AD patients were investigated, with variable findings.
Results of VBM studies indicate that the frontal lobe should be regarded as an important brain area when investigating GM volume deficits in association with AD. Frontal GM loss might not be a feature specific to late AD only. Future VBM studies involving large AD samples are warranted to further investigate correlations between frontal volume deficits and both cognitive impairment and neuropsychiatric symptoms.
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