Acute Neurologic Complications of COVID-19 and Postacute Sequelae of COVID-19

A Case Report of a Boy With Clinically Mild Encephalopathy and a Reversible Splenial Lesion Associated With Severe Acute Respiratory Syndrome-Coronavirus 2 Infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with a high frequency of central nervous system abnormalities, particularly acute encephalopathy, in children. We report the case of a nine-year-old boy with SARS-CoV-2-associated clinically mild encephalopathy with a reversible splenial lesion. The patient was admitted to our hospital with fever, vomiting, and poor speech. The patient tested positive for SARS-CoV-2 by polymerase chain reaction of a nasal swab sample. The cerebrospinal fluid cell count was normal. The patient had a low serum sodium level upon admission. Computed tomography of the brain revealed mild cerebral edema. Diffusion-weighted magnetic resonance imaging (MRI) revealed transient abnormally high signal intensity in the splenium of the corpus callosum. Electroencephalography revealed generalized high-voltage slow waves. The patient was clinically diagnosed with mild encephalopathy and a reversible splenial lesion associated with SARS-CoV-2 infection. The patient was discharged without any neurological sequelae. In conclusion, it is useful to perform MRI evaluations in children with SARS-CoV-2 infection and impaired consciousness, poor speech, and behavior, considering the possibility that they may be in the early stages of encephalopathy.

The influence of COVID-19 on short-term mortality in acute ischemic stroke: A systematic review and meta-analysis

OBJECTIVE

To evaluate the differences in short-term mortality risk between acute ischemic stroke (AIS) patients with and without SARS-CoV-2 infection.

METHODS

PubMed, EMBASE, Scopus, and Cochrane Databases were systematically searched from December 1, 2019 to May 20, 2022 using the keywords coronavirus disease 2019 (COVID-19), COVID-19, SARS-CoV-2, and ischemic stroke. A random-effects model was estimated, and subgroup analysis and meta-regressions were performed. The quality of eligible studies was assessed using the Newcastle-Ottawa Scale.

RESULTS

A total of 26 eligible studies with 307,800 patients were included in this meta-analysis. The overall results show that in-hospital and 90-day mortality was 3.31-fold higher in AIS with SARS-CoV-2 patients compared with those without SARS-CoV-2. When matched for age and National Institutes of Health Stroke Scale score at admission, the risk ratio of in-hospital mortality from AIS among patients with SARS-CoV-2 versus without decreased to 2.83. Reperfusion therapy and endovascular thrombectomy may further reduce the risk of death in patients to some extent but do not increase the incidence of symptomatic intracerebral hemorrhage. Meta-regression showed that in-hospital mortality decreased with increasing National Institutes of Health Stroke Scale score in AIS with SARS-CoV-2 compared to those without SARS-CoV-2 and that the difference in mortality risk between the 2 was independent of age and sex.

CONCLUSIONS

The results of this study suggest that AIS patients with SARS-CoV-2 have higher short-term mortality compared to AIS patients without SARS-CoV-2, and reperfusion and endovascular thrombectomy therapy may reduce the risk of short-term mortality to some extent. The differences in in-hospital mortality risk were similar across ages and sexes. Focused attention is therefore needed on AIS patients with SARS-CoV-2 to control mortality.

Amantadine in unvaccinated patients with early, mild to moderate COVID-19: A randomized, placebo-controlled, double-blind trial

BACKGROUND AND PURPOSE

Adamantanes were listed as an interesting option as an early intervention against COVID-19. We aimed to evaluate the effectiveness of amantadine in preventing the progression of COVID-19 and its neurological sequelae.

METHODS

Unvaccinated patients with confirmed SARS-CoV-2 infection within 5 days were enrolled. Subjects were randomized (50:50) to amantadine (AMD; 100 mg twice daily) or placebo (PLB) for 14 days. The Ordinal Scale for Clinical Improvement of the World Health Organization (OSCI-WHO) was the primary measure. Secondary endpoints included assessment for fatigue; depression, disorders of smell and taste, and sleepiness on Days 1 and 15.

RESULTS

We enrolled 99 patients (49 AMD and 50 PLB). Disease progression (OSCI-WHO = 4) was observed in 6% (AMD) and 8% (PLB) patients (p > 0.05) with further deterioration (OSCI-WHO〉4) in 0% (AMD) and 8% (PLB) patients (p > 0.05). Complete recovery on Day 15 was 60% higher in the AMD compared with the PLB group (p = 0.025). There was improvement in taste (AMD: p = 0.003; PLB: p = 0.0001) and smell (AMD: p = 0.005; PLB: p = 0.0004) but not in fatigue in both groups. Improvement was observed in the AMD (p = 0.010) but not in the PLB group (p = 0.058) when assessing depression as well as sleepiness (AMD: p = 0.0002; PLB: p = 0.341). There was one death in the PLB group (2.0%) and none in the AMD group (p > 0.05) until Day 210. Overall, the drug was well tolerated.

CONCLUSION

The central effects of amantadine on the nervous system with reduction of sleepiness and depression might have had a supportive effect on faster recovery in early COVID-19 patients.

Update on Central Nervous System Effects of the Intersection of HIV-1 and SARS-CoV-2

PURPOSE OF REVIEW

Research has shown myriad neurologic and mental health manifestations during the acute and subsequent stages of COVID-19 in people with HIV (PWH). This review summarizes the updates on central nervous system (CNS) outcomes following SARS-CoV-2 infection in PWH and highlight the existing knowledge gaps in this area.

RECENT FINDINGS

Studies leveraging electronic record systems have highlighted the excess risk of developing acute and lingering neurological complications of COVID-19 in PWH compared to people without HIV (PWoH). However, there is a notable scarcity of neuroimaging as well as blood and cerebrospinal fluid (CSF) marker studies that can confirm the potential synergy between these two infections, particularly in PWH receiving suppressive antiretroviral therapy. Considering the unclear potential interaction between SARS-CoV-2 and HIV, clinicians should remain vigilant regarding new-onset or worsening neurological symptoms in PWH following COVID-19, as they could be linked to either infection.

Neurological risks of COVID-19 in women: the complex immunology underpinning sex differences

The COVID-19 pandemic has uncovered many mysteries about SARS-CoV-2, including its potential to trigger abnormal autoimmune responses. Emerging evidence suggests women may face higher risks from COVID-induced autoimmunity manifesting as persistent neurological symptoms. Elucidating the mechanisms underlying this female susceptibility is now imperative. We synthesize key insights from existing studies on how COVID-19 infection can lead to immune tolerance loss, enabling autoreactive antibodies and lymphocyte production. These antibodies and lymphocytes infiltrate the central nervous system. Female sex hormones like estrogen and X-chromosome mediated effects likely contribute to dysregulated humoral immunity and cytokine profiles among women, increasing their predisposition. COVID-19 may also disrupt the delicate immunological balance of the female microbiome. These perturbations precipitate damage to neural damage through mechanisms like demyelination, neuroinflammation, and neurodegeneration - consistent with the observed neurological sequelae in women. An intentional focus on elucidating sex differences in COVID-19 pathogenesis is now needed to inform prognosis assessments and tailored interventions for female patients. From clinical monitoring to evaluating emerging immunomodulatory therapies, a nuanced women-centered approach considering the hormonal status and immunobiology will be vital to ensure equitable outcomes. Overall, deeper insights into the apparent female specificity of COVID-induced autoimmunity will accelerate the development of solutions mitigating associated neurological harm.

SARS-CoV-2 Omicron (B.1.1.529) shows minimal neurotropism in a double-humanized mouse model

Although severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) initially infects the respiratory tract, it also directly or indirectly affects other organs, including the brain. However, little is known about the relative neurotropism of SARS-CoV-2 variants of concern (VOCs), including Omicron (B.1.1.529), which emerged in November 2021 and has remained the dominant pathogenic lineage since then. To address this gap, we examined the relative ability of Omicron, Beta (B.1.351), and Delta (B.1.617.2) to infect the brain in the context of a functional human immune system by using human angiotensin-converting enzyme 2 (hACE2) knock-in triple-immunodeficient NGC mice with or without reconstitution with human CD34+ stem cells. Intranasal inoculation of huCD34+-hACE2-NCG mice with Beta and Delta resulted in productive infection of the nasal cavity, lungs, and brain on day 3 post-infection, but Omicron was surprisingly unique in its failure to infect either the nasal tissue or brain. Moreover, the same infection pattern was observed in hACE2-NCG mice, indicating that antiviral immunity was not responsible for the lack of Omicron neurotropism. In independent experiments, we demonstrate that nasal inoculation with Beta or with D614G, an ancestral SARS-CoV-2 with undetectable replication in huCD34+-hACE2-NCG mice, resulted in a robust response by human innate immune cells, T cells, and B cells, confirming that exposure to SARS-CoV-2, even without detectable infection, is sufficient to induce an antiviral immune response. Collectively, these results suggest that modeling of the neurologic and immunologic sequelae of SARS-CoV-2 infection requires careful selection of the appropriate SARS-CoV-2 strain in the context of a specific mouse model.

Warmer ambient air temperatures reduce nasal turbinate and brain infection, but increase lung inflammation in the K18-hACE2 mouse model of COVID-19

Warmer climatic conditions have been associated with fewer COVID-19 cases. Herein we infected K18-hACE2 mice housed at the standard animal house temperature of ∼22 °C, or at ∼31 °C, which is considered to be thermoneutral for mice. On day 2 post infection, RNA-Seq analyses showed no significant differential gene expression lung in lungs of mice housed at the two temperatures, with almost identical viral loads and type I interferon responses. There was also no significant difference in viral loads in lungs on day 5, but RNA-Seq and histology analyses showed clearly elevated inflammatory signatures and infiltrates. Thermoneutrality thus promoted lung inflammation. On day 2 post infection mice housed at 31 °C showed reduced viral loads in nasal turbinates, consistent with increased mucociliary clearance at the warmer ambient temperature. These mice also had reduced virus levels in the brain, and an ensuing amelioration of weight loss and a delay in mortality. Warmer air temperatures may thus reduce infection of the upper respiratory track and the olfactory epithelium, resulting in reduced brain infection. Potential relevance for anosmia and neurological sequelae in COVID-19 patients is discussed.