SARS-CoV-2 and Acute Cerebrovascular Events: An Overview

Neuroprotective Agents with Therapeutic Potential for COVID-19

COVID-19 patients can exhibit a wide range of clinical manifestations affecting various organs and systems. Neurological symptoms have been reported in COVID-19 patients, both during the acute phase of the illness and in cases of long-term COVID. Moderate symptoms include ageusia, anosmia, altered mental status, and cognitive impairment, and in more severe cases can manifest as ischemic cerebrovascular disease and encephalitis. In this narrative review, we delve into the reported neurological symptoms associated with COVID-19, as well as the underlying mechanisms contributing to them. These mechanisms include direct damage to neurons, inflammation, oxidative stress, and protein misfolding. We further investigate the potential of small molecules from natural products to offer neuroprotection in models of neurodegenerative diseases. Through our analysis, we discovered that flavonoids, alkaloids, terpenoids, and other natural compounds exhibit neuroprotective effects by modulating signaling pathways known to be impacted by COVID-19. Some of these compounds also directly target SARS-CoV-2 viral replication. Therefore, molecules of natural origin show promise as potential agents to prevent or mitigate nervous system damage in COVID-19 patients. Further research and the evaluation of different stages of the disease are warranted to explore their potential benefits.

An Increased Risk for Ischemic Stroke in the Short-Term Period following COVID-19 Infection: A Nationwide Population-Based Study

INTRODUCTION

The association disclosed between coronavirus disease 2019 (COVID-19) infection and ischemic stroke (IS) raises concern. The exact risk periods, which were not consistent between studies, require further investigation.

METHODS

We linked two national databases: the COVID-19 database and the Israeli National Stroke Registry. The self-controlled case series method was used to estimate the association between COVID-19 infection and a first IS. The study population included all Israeli residents who had both a first IS event and a first COVID-19 diagnosis during 2020. The date of the PCR test served to define the day of exposure, and the 28 days following it were categorized into three risk periods: days 1-7, 8-14, and 15-28. A relative incidence (RI) with a 95% confidence interval (95% CI) was calculated based on the incidence rate of events in a post-exposure period, compared to the incidence rate in a control period.

RESULTS

From January 1, 2020, to December 31, 2020, 308,015 Israelis aged 18+ were diagnosed with COVID-19 and 9,535 were diagnosed with a first IS. Linking the two databases, 555 persons had both diagnoses during 2020. The mean age of the study population was 71.5 ± 13.7, 55.1% were males, 77.8% had hypertension, 73.7% had hyperlipidemia, 51.9% had diabetes, and 28.5% had ischemic heart disease. Comparing the risk period and the control period, we found a very similar distribution of the cardiovascular risk factors. The risk for an acute IS was 3.3-fold higher in the first week following COVID-19 diagnosis, compared with a control period (RI = 3.3; 95% CI: 2.3-4.6). The RI among males (RI = 4.5; 95% CI: 2.9-6.8) was 2.2-fold higher compared to females. The increased risk did not last beyond the first week following exposure.

CONCLUSION

Physicians should be aware of the elevated risk for IS among patients experiencing COVID-19, particularly among men with high burden of cardiovascular risk factors.

Impact of COVID-19 on Neuropsychiatric Disorders

Since the Coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), many studies have shown that besides common COVID-19 symptoms, patients may develop various neuropsychiatric conditions including anxiety, mood disorders, psychosis, neurodegenerative diseases (e.g., dementia), insomnia, and even substance abuse disorders. COVID-19 can also worsen the patients underlying neuropsychiatric and neurodevelopmental conditions during or after the system phase of disease. In this review, we discuss the impact of SARS-CoV-2 infection on development or status of neuropsychiatric conditions during or following COVID-19.

Neurological effects of COVID-19 in infants and children

Neurological manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children are becoming increasingly apparent as the coronavirus disease (COVID-19) pandemic continues. While children manifest relatively milder features of the disease, accumulating evidence warrants concern that COVID-19 exacts both acute- and long-term effects on the developing central and peripheral nervous systems. This review focuses on the relatively underinvestigated topic of the effects of SARS-CoV-2 on the brain in infancy and childhood, concluding that clinicians should be attentive to both the acute effects and long-term consequences of COVID-19 from a neurological perspective.

Breathing Exercises for Improving Cognitive Function in Patients with Stroke

Patients with stroke may experience a certain degree of cognitive decline during the period of recovery, and a considerable number of such patients have been reported to show permanent cognitive damage. Therefore, the period of recovery and rehabilitation following stroke is critical for rapid cognitive functional improvements. As dysfunctional breathing has been reported as one of the factors affecting the quality of life post stroke, a number of studies have focused on the need for improving the breathing function in these patients. Numerous breathing exercises have been reported to enhance the respiratory, pulmonary, cognitive, and psychological functions. However, scientific evidence on the underlying mechanisms by which these exercises improve cognitive function is scattered at best. Therefore, it has been difficult to establish a protocol of breathing exercises for patients with stroke. In this review, we summarize the psychological, vascular, sleep-related, and biochemical factors influencing cognition in patients and highlight the need for breathing exercises based on existing studies. Breathing exercises are expected to contribute to improvements in cognitive function in stroke based on a diverse array of supporting evidence. With relevant follow-up studies, a protocol of breathing exercises can be developed for improving the cognitive function in patients with stroke.

Clinical features of thrombosis and bleeding in COVID-19

Infection with the SARS-CoV-2 virus, resulting in COVID-19 disease has presented a unique scenario associated with high thrombotic rates. The risk of venous thrombosis is some 3-6 fold higher than for patients admitted to hospital for other indications and for patients who have thrombosis, mortality appears increased. Thrombosis may be a presenting feature of COVID-19. Pulmonary thrombi are the most frequent events, some related to deep vein thrombosis, but also in situ micro- and macrovascular thrombosis. Other venous thromboses include catheter and circuit-associated in patients requiring haemofiltration and ECMO. Arterial thrombosis is less commonly documented, with 3% of ICU patients having major arterial strokes and up to 9% myocardial infarction, which is likely multifactorial. Risk factors for thrombosis above those already documented in hospital settings include duration of COVID-19 symptoms before admission to hospital. Laboratory parameters associated with higher thrombotic risk include higher D-dimer, low fibrinogen and low lymphocyte count, with higher FVIII and von Willebrand factor levels indicative of more severe COVID-19 infection. All patients should receive thromboprophylaxis when admitted with COVID-19 infection, but the dose and length of treatment still remain debated. Treatment for thrombosis remains as per standard VTE guidelines, but adjustments may be required depending on other factors relevant to the patient admission.

Acute Arterial Thrombosis of Lower Extremities in COVID-19 Patients

Clinical signs and symptoms of COVID-19 varied from asymptomatic forms to severe, life-threatening conditions that required treatment in intensive care units. These severe forms of illness are connected with a hypercoagulable state due to excessive inflammation, hypoxia, immobilisation, and altered angiotensin-converting enzyme 2 (ACE-2). In total, 17 COVID-19 positive patients were diagnosed with peripheral arterial thrombosis (AT), 13 of them had COVID-19 pneumonia. Laboratory findings in patients with X-ray confirmed pneumonia showed a four times higher neutrophil-to-lymphocyte ratio (NLR), C-reactive protein (CRP) and three times higher lactate dehydrogenase level (LDH) than patients without confirmed pneumonia. Patients with pneumonia had significantly more bilateral occlusions of the lower extremities and a significantly higher percentage with complete occlusion of the arteries than patients without pneumonia. The rate of limb loss was 35.3%. They were all from the group with COVID-19 pneumonia. Ten out of thirteen patients with pneumonia died due to acute respiratory distress syndrome (ARDS). All patients without pneumonia were discharged from the hospital. The aim of this retrospective study was to report the incidence of arterial thrombosis of lower extremities and their complications in the acute phase of the infection among COVID-19 patients admitted to the hospital for treatment.

Long-term side effects and lingering symptoms post COVID-19 recovery

Since the Coronavirus disease 2019 (COVID‐19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), our understanding regarding the pathophysiology and clinical manifestations of this disease have been improving. However, we still have limited data on long‐term effects and lingering symptoms of post COVID‐19 recovery. Despite predilection of COVID‐19 for lungs, multiple extra‐pulmonary manifestations appear in multiple organs and biological systems and with continued infection and recovery worldwide. It is necessary that clinicians provide patients with previous SARS‐CoV‐2 infection with expectations of long‐term effects during or after recovery from COVID‐19. Herein, we review the long‐term impact of COVID‐19 on different organ systems reported from different clinical studies. Understanding risk factors and signs and symptoms of long‐term consequences after recovery from COVID‐19 will allow for proper follow‐up and management of the disease post recovery.