Review of Neurological Manifestations of SARS-CoV-2

Latent class analysis of post-acute sequelae of SARS-CoV-2 infection

Symptoms post-SARS-CoV-2 infection may persist for months and cause significant impairment and impact to quality of life. Acute symptoms of SARS-CoV-2 infection are well studied, yet data on clusters of symptoms over time, or post-acute sequelae of SARS-CoV-2 infection (PASC), are limited. We aim to characterize PASC phenotypes by identifying symptom clusters over a six-month period following infection in individuals vaccinated (boosted and not) and those unvaccinated. Subjects with ≥1 self-reported symptom and positive RT-PCR for SARS-CoV-2 at CVS Health US test sites were recruited between January and April 2022. Patient-reported outcomes symptoms, health-related quality of life (HRQoL), work productivity and activity impairment (WPAI) were captured at 1 month, 3 months, and 6 months post-acute infection. Phenotypes of PASC were determined based on subject matter knowledge and balanced consideration of statistical criteria (lower AIC, lower BIC, and adequate entropy) and interpretability. Generalized estimation equation approach was used to investigate relationship between QoL, WPAI and number of symptoms and identified phenotypes, and relationship between phenotypes and vaccination status as well. LCA identified three phenotypes that are primarily differentiated by number of symptoms. These three phenotypes remained consistent across time periods. Subjects with more symptoms were associated with lower HRQoL, and worse WPAI scores. Vaccinated individuals were more likely to be in the low symptom burden latent classes at all time points compared to unvaccinated individuals.

Brain magnetic resonance imaging findings in children with neurological complications of coronavirus disease 2019 (Omicron variant): a multicenter retrospective observational study

BACKGROUND

An increasing rate of encephalopathy associated with coronavirus disease 2019 (COVID-19) has been observed among children. However, the literature on neuroimaging data in children with COVID-19 is limited.

OBJECTIVE

To analyze brain magnetic resonance imaging (MRI) of pediatric COVID-19 patients with neurological complications.

MATERIALS AND METHODS

This multicenter retrospective observational study analyzed clinical (n=102, 100%) and neuroimaging (n=93, 91.2%) data of 102 children with COVID-19 infections and comorbid acute neurological symptoms. These children were hospitalized at five pediatric intensive care units (PICUs) in China between December 1, 2022, and January 31, 2023.

RESULTS

All patients were positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as detected via reverse transcriptase polymerase chain reaction. About 75.7% of the children were infected with the Omicron variant BF.7 strain. Brain MRI was performed 1-12 days following the onset of neurological symptoms, which revealed acute neuroimaging findings in 74.2% (69/93) of cases, including evidence of acute necrotizing encephalopathy (33/69, 47.8%), encephalitis (31/69, 44.9%), reversible splenial lesion syndrome (3/69, 4.3%), reversible posterior leukoencephalopathy (1/69, 1.4%), and hippocampal atrophy (1/69, 1.4%).

CONCLUSIONS

Overall, these data highlighted five neuroimaging patterns associated with the outbreak of the SARS-CoV-2 Omicron variant, with acute necrotizing encephalopathy being the most common of these neuroimaging findings. Rarely, the brain MRI of these pediatric COVID-19 patients also demonstrate hippocampal atrophy.

Retinal response to systemic inflammation differs between sexes and neurons

Background

Neurological dysfunction and glial activation are common in severe infections such as sepsis. There is a sexual dimorphism in the response to systemic inflammation in both patients and animal models, but there are few comparative studies. Here, we investigate the effect of systemic inflammation induced by intraperitoneal administration of lipopolysaccharide (LPS) on the retina of male and female mice and determine whether antagonism of the NLRP3 inflammasome and the extrinsic pathway of apoptosis have protective effects on the retina.

Methods

A single intraperitoneal injection of LPS (5 mg/kg) was administered to two months old C57BL/6J male and female mice. Retinas were examined longitudinally in vivo using electroretinography and spectral domain optical coherence tomography. Retinal ganglion cell (RGC) survival and microglial activation were analysed in flat-mounts. Retinal extracts were used for flow cytometric analysis of CD45 and CD11b positive cells. Matched plasma and retinal levels of proinflammatory cytokines were measured by ELISA. Retinal function and RGC survival were assessed in animals treated with P2X7R and TNFR1 antagonists alone or in combination.

Results

In LPS-treated animals of both sexes, there was transient retinal dysfunction, loss of vision-forming but not non-vision forming RGCs, retinal swelling, microglial activation, cell infiltration, and increases in TNF and IL-1β. Compared to females, males showed higher vision-forming RGC death, slower functional recovery, and overexpression of lymphotoxin alpha in their retinas. P2X7R and TNFR1 antagonism, alone or in combination, rescued vision-forming RGCs. P2X7R antagonism also rescued retinal function. Response to treatment was better in females than in males.

Conclusions

Systemic LPS has neuronal and sex-specific adverse effects in the mouse retina, which are counteracted by targeting the NLRP3 inflammasome and the extrinsic pathway of apoptosis. Our results highlight the need to analyse males and females in preclinical studies of inflammatory diseases affecting the central nervous system.