Hemorrhagic encephalopathy associated with COVID-19

COVID-19: Post infection implications in different age groups, mechanism, diagnosis, effective prevention, treatment, and recommendations

SARS-CoV-2 is a highly contagious pathogen that predominantly caused the COVID-19 pandemic. The persistent effects of COVID-19 are defined as an inflammatory or host response to the virus that begins four weeks after initial infection and persists for an undetermined length of time. Chronic effects are more harmful than acute ones thus, this review explored the long-term effects of the virus on various human organs, including the pulmonary, cardiovascular, and neurological, reproductive, gastrointestinal, musculoskeletal, endocrine, and lymphoid systems and found that SARS-CoV-2 adversely affects these organs of older adults. Regarding diagnosis, the RT-PCR is a gold standard method of diagnosing COVID-19; however, it requires specialized equipment and personnel for performing assays and a long time for results production. Therefore, to overcome these limitations, artificial intelligence employed in imaging and microfluidics technologies is the most promising in diagnosing COVID-19. Pharmacological and non-pharmacological strategies are the most effective treatment for reducing the persistent impacts of COVID-19 by providing immunity to post-COVID-19 patients by reducing cytokine release syndrome, improving the T cell response, and increasing the circulation of activated natural killer and CD8 T cells in blood and tissues, which ultimately reduces fever, nausea, fatigue, and muscle weakness and pain. Vaccines such as inactivated viral, live attenuated viral, protein subunit, viral vectored, mRNA, DNA, or nanoparticle vaccines significantly reduce the adverse long-term virus effects in post-COVID-19 patients; however, no vaccine was reported to provide lifetime protection against COVID-19; consequently, protective measures such as physical separation, mask use, and hand cleansing are promising strategies. This review provides a comprehensive knowledge of the persistent effects of COVID-19 on people of varying ages, as well as diagnosis, treatment, vaccination, and future preventative measures against the spread of SARS-CoV-2.

Cerebrospinal fluid cytokines in COVID-19: a review and meta-analysis

INTRODUCTION

Neurological involvement can occur in patients with SARS-CoV-2 infections, resulting in coronavirus disease 2019 (COVID-19). Cytokine alterations are associated with neurological symptoms in COVID-19. We performed a review of cytokines in the cerebrospinal fluid (CSF) of patients with COVID-19.

METHODS

Two reviewers independently searched PubMed for all relevant articles published prior to November 11, 2022. Active SARS-CoV-2 infection and CSF cytokine analyses were required for inclusion.

RESULTS

Three-hundred forty-six patients with COVID-19 and 356 controls from 28 studies were included. SARS-CoV-2 PCR was positive in the CSF of 0.9% (3/337) of patients with COVID-19. Thirty-seven different cytokines were elevated in the CSF of patients with COVID-19 when compared to controls and the standards set forth by individual assays used in each study. Of the 37 cytokines, IL-6 and IL-8 were most commonly elevated. CSF IL-6 is elevated in 60%, and CSF IL-8 is elevated in 51% of patients with COVID-19.

CONCLUSION

Levels of several inflammatory cytokines are elevated in the CSF of patients with COVID-19, and SARS-CoV-2 PCR is often not isolated in the CSF of patients with COVID-19. Many patients with COVID-19 have neurological symptoms and given the cytokine elevations in the absence of detectable viral RNA in cerebrospinal fluid; further study of the CSF cytokine profiles and pathogenesis of neurological symptoms in COVID-19 is needed.

Neurological manifestations of COVID-19: a systematic review and detailed comprehension

The current pandemic caused by severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) is accompanied with a rapid increase of reports and papers detailing its neurological effects and symptoms. The virus infection causes respiratory illness named by the world health organization as corona virus 19 (COVID-19).This systematic review aims to study and summarize the different neurological manifestations of this virus. All articles published and indexed via Pubmed, Medline and Google Scholar databases between January 1st 2020 and February 28th 2021 that reported neurological symptoms of SARS-CoV-2 are reviewed following the Preferred Reporting Items for Systemic review and Meta-Analysis (PRISMA) guidelines.We included data from 113 articles: eight prospective studies, 25 retrospective studies and the rest were case reports/series. COVID-19 can present with central nervous system manifestations, such as headache, encephalitis and encephalopathy, peripheral nervous system manifestations, such as anosmia, ageusia and Guillian Barre syndrome, and skeletal muscle manifestations, such as myalgia and myasthenia gravis. Our systematic review showed that COVID-19 can be manifested by a wide spectrum of neurological symptoms reported either in the early stage or within the course of the disease. However, a detailed comprehension of these manifestations is required and more studies are needed in order to improve our scientific knowledge and to develop preventive and therapeutic measures to control this pandemic.

Role of aging in Blood-Brain Barrier dysfunction and susceptibility to SARS-CoV-2 infection: impacts on neurological symptoms of COVID-19

COVID-19, which is caused by Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2), has resulted in devastating morbidity and mortality worldwide due to lethal pneumonia and respiratory distress. In addition, the central nervous system (CNS) is well documented to be a target of SARS-CoV-2, and studies detected SARS-CoV-2 in the brain and the cerebrospinal fluid of COVID-19 patients. The blood-brain barrier (BBB) was suggested to be the major route of SARS-CoV-2 infection of the brain. Functionally, the BBB is created by an interactome between endothelial cells, pericytes, astrocytes, microglia, and neurons, which form the neurovascular units (NVU). However, at present, the interactions of SARS-CoV-2 with the NVU and the outcomes of this process are largely unknown. Moreover, age was described as one of the most prominent risk factors for hospitalization and deaths, along with other comorbidities such as diabetes and co-infections. This review will discuss the impact of SARS-CoV-2 on the NVU, the expression profile of SARS-CoV-2 receptors in the different cell types of the CNS and the possible role of aging in the neurological outcomes of COVID-19. A special emphasis will be placed on mitochondrial functions because dysfunctional mitochondria are also a strong inducer of inflammatory reactions and the "cytokine storm" associated with SARS-CoV-2 infection. Finally, we will discuss possible drug therapies to treat neural endothelial function in aged patients, and, thus, alleviate the neurological symptoms associated with COVID-19.

SARS-CoV-2-associated haemorrhagic encephalitis mimicking Herpes encephalitis

Although acute encephalopathy is quite commonly seen in patients of SARS-CoV-2 infection, encephalitis characterised by brain inflammation is relatively rare. Encephalitis caused by Herpes simplex type 1 is the most common cause of identified sporadic encephalitis, and early diagnosis and prompt treatment can prevent the devastating outcome. In this brief communication, we report a case of SARS-CoV-2 associated haemorrhagic encephalitis mimicking herpes encephalitis. In today's pandemic era, it is especially important to distinguish herpes encephalitis from SARS-CoV-2-associated encephalitis as treatment and prognosis of both the conditions differ greatly. This case highlights the importance of suspecting SARS-CoV-2 infection in a patient presenting with clinical symptoms and brain imaging suggestive of Herpes encephalitis.

Cerebrospinal fluid analysis in patients with COVID-19-associated central nervous system manifestations: a systematic review

ABSTRACT Background: Central nervous system (CNS) symptoms may occur in patients with acute COVID-19. The role of CSF examination in these patients remains to be established. Objective: A systematic review of CSF findings relating to COVID-19 was carried out. Methods: CSF parameters, including cytological and biochemical analyses, SARS-CoV-2 RT-PCR and other CSF markers, were recorded and analyzed among patients with acute COVID-19 and one of the following CNS syndromes: stroke, encephalopathy, encephalitis, inflammatory syndromes, seizure, headache and meningitis. Results: Increased white blood cells and/or increased protein concentration were found in 52.7% of the patients with encephalitis, 29.4% of the patients with encephalopathy and 46.7% of the patients with inflammatory syndromes (P < 0.05). CSF RT-PCR for SARS-CoV-2 was positive in 17.35% of the patients with encephalitis and less than 3.5% of the patients with encephalopathy or inflammatory syndromes (P < 0.05). Intrathecal production of immunoglobulins was found in only 8% of the cases. More than 85% of the patients had increased CSF cytokines and chemokines. Increased CSF neurofilament light chain (NfL) and CSF Tau were found in 71% and 36% of the cases, respectively. Conclusion: Non-specific inflammatory CSF abnormalities were frequently found in patients with COVID-19 CNS syndromes. The increase in neurodegeneration biomarkers suggests that neuronal damage occurs, with long-term consequences that are still unknown.

COVID-19-Associated Encephalopathy—Case Series and Clinical Considerations

Neurological manifestations of the SARS-CoV-2 infection are present in up to 80% of the affected patients. While the majority of them is benign, in certain patients, viral replication in the central nervous system results in a severe disruption in cognitive function as well as basic life functions. In this case series, the authors present a detailed description of the three SARS-CoV-2 infection cases, which were all complicated by severe encephalopathy. Consecutive neurological status changes were described for each patient with detailed imaging and clinical sequelae. In the discussion, the authors highlight similarities in the course of the disease in presented patients, as well as common features in test results. An effective causal treatment could not be introduced in any of the patients, nor could the progression of the central nervous system (CNS) damage be stopped. The authors hope that the experiences they gathered will help to accelerate the diagnostic and therapeutic process in other patients with COVID-19-associated encephalopathy and can result in introducing an effective treatment.

Severe placental lesions due to maternal SARS-CoV-2 infection associated to intrauterine fetal death

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can cause severe placental lesions leading rapidly to intrauterine fetal death (IUFD). From August 2020 to September 2021, in the pathology department of Toulouse Oncopole, we analyzed 50 placentas from COVID-19–positive unvaccinated mothers.

The purpose of our study is to describe the clinicopathological characteristics of these placental damages and to understand the pathophysiology.

Ten of them (20%) showed placental lesions with positive immunohistochemistry for SARS-CoV-2 in villous trophoblasts. In five cases (10%), we observed massive placental damage associating trophoblastic necrosis, fibrinous deposits, intervillositis, as well as extensive hemorrhagic changes due to SARS-CoV-2 infection probably responsible of IUFD by functional placental insufficiency. In five other cases, we found similar placental lesions but with a focal distribution that did not lead to IUFD but live birth.

These lesions are independent of maternal clinical severity of COVID-19 infection because they occur despite mild maternal symptoms and are therefore difficult to predict. In our cases, they occurred 1–3 weeks after positive SARS-CoV-2 maternal real-time polymerase chain reaction testing and were observed in the 2nd and 3rd trimesters of pregnancies. When these lesions are focal, they do not lead to IUFD and can be involved in intrauterine growth restriction.

Our findings, together with recent observations, suggest that future pregnancy guidance should include stricter pandemic precautions such as screening for a wider array of COVID-19 symptoms, enhanced ultrasound monitoring, as well as newborn medical surveillance.

Encephalopathy as a prognostic factor in adults with acute disseminated encephalomyelitis following COVID-19

Numerous reports support the possible occurrence of acute disseminated encephalomyelitis (ADEM) following COVID-19. Herein, we report a case of ADEM in a 53-year-old man 2 weeks after SARS-CoV-2 infection. We reviewed the reports of adult cases of ADEM and its variant acute necrotizing hemorrhagic leukoencephalitis (ANHLE) to check for possible prognostic factors and clinical/epidemiological peculiarities. We performed a descriptive analysis of clinical and cerebrospinal fluid data. Ordinal logistic regressions were performed to check the effect of clinical variables and treatments on ADEM/ANHLE outcomes. We also compared ADEM and ANHLE patients. We identified a total of 20 ADEM (9 females, median age 53.5 years) and 23 ANHLE (11 females, median age 55 years). Encephalopathy was present in 80% of ADEM and 91.3% of ANHLE patients. We found that the absence of encephalopathy predicts a better clinical outcome in ADEM (OR 0.027, 95% CI 0.001–0.611, p = 0.023), also when correcting for the other variables (OR 0.032, 95% CI 0.001–0.995, p = 0.05). Conversely, we identified no significant prognostic factor in ANHLE patients. ANHLE patients showed a trend towards a worse clinical outcome (lower proportion of good/complete recovery, 4.5% vs 16.7%) and higher mortality (36.4% vs 11.1%) as compared to ADEM. Compared to pre-pandemic ADEM, we observed a higher median age of people with post-COVID-19 ADEM and ANHLE, a shorter interval between infection and neurological symptoms, and a worse prognosis both in terms of high morbidity and mortality. Despite being affected by the retrospective nature of the study, these observations provide new insights into ADEM/ANHLE following SARS-CoV-2 infection.

Neuropsychiatric symptoms associated with the COVID-19 and its potential nervous system infection mechanism: the role of imaging in the study

The epidemic of coronavirus disease 2019 (COVID-19) has broken the normal spread mode of respiratory viruses, namely, mainly spread in winter, resulting in over 230 million confirmed cases of COVID-19. Many studies have shown that severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) can affect the nervous system by varying degrees. In this review, we look at the acute neuropsychiatric impacts of COVID-19 patients, including acute ischemic stroke, encephalitis, acute necrotizing encephalopathy, dysosmia, and epilepsy, as well as the long-term neuropsychiatric sequelae of COVID-19 survivors: mental disorder and neurodegenerative diseases. In particular, this review discusses long-term changes in brain structure and function associated with COVID-19 infection. We believe that the traditional imaging sequences are important in the acute phase, while the nontraditional imaging sequences are more meaningful for the detection of long-term neuropsychiatric sequelae. These long-term follow-up changes in structure and function may also help us understand the causes of neuropsychiatric symptoms in COVID-19 survivors. Finally, we review previous studies and discuss some potential mechanisms of SARS-CoV-2 infection in the nervous system. Continuous focus on neuropsychiatric sequelae and a comprehensive understanding of the long-term impacts of the virus to the nervous system is significant for formulating effective sequelae prevention and management strategies, and may provide important clues for nervous system damage in future public health crises.

Relevance of CSF, Serum and Neuroimaging Markers in CNS and PNS Manifestation in COVID-19: A Systematic Review of Case Report and Case Series

BACKGROUND

The data on neurological manifestations in COVID-19 patients has been rapidly increasing throughout the pandemic. However, data on CNS and PNS inflammatory disorders in COVID-19 with respect to CSF, serum and neuroimaging markers is still lacking.

METHODS

We screened all articles resulting from a search of PubMed, Google Scholar and Scopus, using the keywords "SARS-CoV-2 and neurological complication", "SARS-CoV-2 and CNS Complication" and "SARS-CoV-2 and PNS Complication" looking for transverse myelitis, vasculitis, acute disseminated encephalomyelitis, acute hemorrhagic necrotizing encephalitis (AHNE), cytotoxic lesion of the corpus callosum (CLOCC) and Guillain-Barré syndrome (GBS), published between 1 December 2019 to 15 July 2021.

RESULTS

Of the included 106 CNS manifestations in our study, CNS inflammatory disorders included transverse myelitis (17, 14.7%), AHNE (12, 10.4%), ADEM (11, 9.5%), CLOCC/MERS (10, 8.6%) and vasculitis (4, 3.4%). Others were nonspecific encephalopathy, encephalitis, seizures and stroke. Most patients were >50 years old (75, 70.8%) and male (64, 65.3%). Most (59, 63.4%) were severe cases of COVID-19 and 18 (18%) patients died. Of the included 94 PNS manifestations in our study, GBS (89, 92.7%) was the most common. Most of these patients were >50 years old (73, 77.7%) and male (59, 64.1%). Most (62, 67.4%) were non-severe cases of COVID-19, and ten patients died.

CONCLUSION

Our comprehensive review of the clinical and paraclinical findings in CNS and PNS manifestations of COVID-19 provide insights on the pathophysiology of SARS-CoV-2 and its neurotropism. The higher frequency and severity of CNS manifestations should be noted by physicians for increased vigilance in particular COVID-19 cases.

Acute Neurologic Manifestations of Respiratory Viruses

PURPOSE OF REVIEW

Understanding the pathophysiology of COVID-19 and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus that causes the disease has demonstrated the complexity of acute respiratory viruses that can cause neurologic manifestations. This article describes the most common respiratory viruses that have neurologic manifestations, with a focus on SARS-CoV-2 and COVID-19.

RECENT FINDINGS

In vitro and in vivo studies have better elucidated the neurotropism of various respiratory viruses. Understanding host cell receptors that mediate viral binding and entry not only demonstrates how viruses enter host cells but also provides possible mechanisms for therapeutic interventions. Elucidation of SARS-CoV-2 binding and fusion with host cells expressing the angiotensin-converting enzyme 2 (ACE2) receptor may also provide greater insights into its systemic and neurologic sequelae. Respiratory virus neurotropism and collateral injury due to concurrent inflammatory cascades result in various neurologic pathologies, including Guillain-Barré syndrome, encephalopathy, encephalitis, ischemic stroke, intracerebral hemorrhage, and seizures.

SUMMARY

Numerous respiratory viruses can infect the cells of the peripheral and central nervous systems, elicit inflammatory cascades, and directly and indirectly cause various neurologic manifestations. Patients with neurologic manifestations from respiratory viruses are often critically ill and require mechanical ventilation. Neurologists and neurointensivists should be familiar with the common neurologic manifestations of respiratory viruses and the unique and still-evolving sequelae associated with COVID-19.

Neurologic Manifestations of Severe Acute Respiratory Syndrome Coronavirus 2 Infection

PURPOSE OF REVIEW

This article describes the spectrum of neurologic complications associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, their underlying pathology and pathogenic mechanisms, gaps in knowledge, and current therapeutic strategies.

RECENT FINDINGS

COVID-19 is the clinical syndrome caused by the novel coronavirus SARS-CoV-2. It can affect the entire neuraxis, and presentations in the acute phase are variable, although anosmia is a common manifestation. Encephalopathy is common in patients who are hospitalized and is often associated with multiorgan involvement. Immune-mediated encephalitis is probably underrecognized; however, viral encephalitis is rare. Other manifestations include stroke, seizures, myelitis, and peripheral neuropathies, including Guillain-Barré syndrome, which sometimes has atypical manifestations. Treatment is symptomatic, and immunotherapies have been used successfully in some patients. Long-term complications include dysautonomia, exercise intolerance, malaise, sleep disturbances, cognitive impairment, and mood disorders.

SUMMARY

Neurologic manifestations of COVID-19 may occur in the acute setting and may be independent of respiratory manifestations. Immune-mediated syndromes and cerebrovascular complications are common. Large populations of patients are expected to have long-term neurologic complications of COVID-19, many of which may emerge only after recovery from the acute illness.

Neurological complications in COVID-19 - a diagnostic challenge

With the exponential growth of COVID-19 cases, the neurological complications reported during or after the infection became more common. There is limited knowledge regarding the pathophysiological mechanisms that are responsible for these complications. Recent data provides compelling evidence for the neurotropic nature of SARS-CoV-2, based on neurological manifestations reported during the current pandemic, as well as on previous experience with other coronaviruses. We present the case of a patient who developed headaches, motor deficit and dysphasia after respiratory COVID-19. Imaging tests showed heterogeneous central nervous system lesions (multiple subarachnoid hemorrhages and two ischemic strokes). Given the plethora of atypical neurological complications of COVID-19 described in the current literature, establishing a positive diagnosis and deciding on a treatment plan proved to be particularly challenging. We set to discuss some of the possible pathologies, hypothesized to be associated with COVID-19, that could lead to concomitant neurological lesions, similar to those noticed in our patient.

Heterogeneity in Regional Damage Detected by Neuroimaging and Neuropathological Studies in Older Adults With COVID-19: A Cognitive-Neuroscience Systematic Review to Inform the Long-Term Impact of the Virus on Neurocognitive Trajectories

Background: Other than its direct impact on cardiopulmonary health, Coronavirus Disease 2019 (COVID-19) infection affects additional body systems, especially in older adults. Several studies have reported acute neurological symptoms that present at onset or develop during hospitalisation, with associated neural injuries. Whilst the acute neurological phase is widely documented, the long-term consequences of COVID-19 infection on neurocognitive functioning remain unknown. Although an evidence-based framework describing the disease chronic phase is premature, it is important to lay the foundations for future data-driven models. This systematic review aimed at summarising the literature on neuroimaging and neuropathological findings in older over-60 patients with COVID-19 following a cognitive neuroscientific perspective, to clarify the most vulnerable brain areas and speculate on the possible cognitive consequences. Methods: PubMed and Web of Science databases were searched to identify relevant manuscripts published between 1st March 2020 and 31th December 2020. Outputs were screened and selected by two assessors. Relevant studies not detected by literature search were added manually. Results: Ninety studies, mainly single cases and case series, were included. Several neuroimaging and neuropathological findings in older patients with COVID-19 emerged from these studies, with cerebrovascular damage having a prominent role. Abnormalities (hyperintensities, hypoperfusion, inflammation, and cellular damage) were reported in most brain areas. The most consistent cross-aetiology findings were in white matter, brainstem and fronto-temporal areas. Viral DNA was detected mainly in olfactory, orbitofrontal and brainstem areas. Conclusion: Studies on COVID-19 related neural damage are rich and diverse, but limited to description of hospitalised patients with fatal outcome (i.e., in neuropathological studies) or severe symptoms (i.e., in neuroimaging studies). The damage seen in this population indicates acute and largely irreversible dysfunction to neural regions involved in major functional networks that support normal cognitive and behavioural functioning. It is still unknown whether the long-term impact of the virus will be limited to chronic evolution of acute events, whether sub-clinical pathological processes will be exacerbated or whether novel mechanisms will emerge. Based on current literature, future theoretical frameworks describing the long-term impact of COVID-19 infection on mental abilities will have to factor in major trends of aetiological and topographic heterogeneity.

Intracerebral hemorrhage in COVID-19: A narrative review

Coronavirus Disease 19 (COVID-19) pandemic affects the worldwide healthcare system and our understanding of this disease grows rapidly. Although COVID-19 is a mainly respiratory disease, neurological manifestations are not uncommon. The aim of this review is to report on the etiology, clinical profile, location, and outcome of patients with intracerebral hemorrhage (ICH) and COVID-19. This review includes 36 studies examining ICH in the clinical presentation of COVID-19. Overall, 217 cases with intracranial hemorrhage, of which 188 ICHs, were reported. Generally, a low incidence of both primary and secondary ICH was found in 8 studies [106 (0.25%) out of 43,137 hospitalized patients with COVID-19]. Available data showed a median age of 58 years (range: 52–68) and male sex 64%, regarding 36 and 102 patients respectively. Furthermore, 75% of the patients were on prior anticoagulation treatment, 52% had a history of arterial hypertension, and 61% were admitted in intensive care unit. Location of ICH in deep structures/basal ganglia was ascertained in only 7 cases making arterial hypertension an improbable etiopathogenetic mechanism. Mortality was calculated at 52.7%. Disease related pathophysiologic mechanisms support the hypothesis that SARS-CoV2 can cause ICH, however typical ICH risk factors such as anticoagulation treatment, or admission to ICU should also be considered as probable causes. Physicians should strongly suspect the possibility of ICH in individuals with severe COVID-19 admitted to ICU and treated with anticoagulants. It is not clear whether ICH is related directly to COVID-19 or reflects expected comorbidity and/or complications observed in severely ill patients.

Covid-19: Involvement of the nervous system. Identifying neurological predictors defining the course of the disease

The main objective of this study was to analyse neurological symptoms during a Covid-19 infection and determine the pattern of symptoms by comparing outpatients with inpatients. A further goal was to identify possible predictors, such as pre-existing conditions and neurological symptoms.

We recorded the clinical data of 40 inpatients and 42 outpatients in this retrospective, cross sectional study. Of them, 68 patients (83%), evenly distributed between the two groups, suffered from neurological symptoms. We identified the onset of neurological symptoms and the related time ranges in 41 patients (36 outpatients and 5 inpatients). Of these, 63.4% reported neurological symptoms on the first or second day of illness. 49 patients (72%) showed combinations of at least two to a maximum of seven different neurological symptoms. A more severe course of disease was correlated with age and male sex, but age was not identified as a predictor for the occurrence of neurological symptoms. Women suffered from central and neuromuscular symptoms more often than men (p = 0,004). The most common symptoms were fatigue (54%), headache (31%), loss of taste (31%), and loss of smell (27%).

Pre-existing dementia was associated with increased lethality; similarly, pre-existing stroke was associated with a more severe course of Covid-19 infection. Hallucinations and confusion were related to an increased likelihood of death.

The present data demonstrate the importance of comprehensive neurological support of inpatients and outpatients affected by Covid-19.

CNS implications of COVID-19: a comprehensive review

COVID-19 was first reported in December 2019 in the Wuhan city of China, and since then it has spread worldwide taking a heavy toll on human life and economy. COVID-19 infection is commonly associated with symptoms like coughing, fever, and shortness of breath, besides, the reports of muscle pain, anosmia, hyposmia, and loss of taste are becoming evident. Recent reports suggest the pathogenic invasion of the SARS-CoV-2 into the CNS, that could thereby result in devastating long term complications, primarily because some of these complications may go unnoticed for a long time. Evidence suggest that the virus could enter the CNS through angiotensin-converting enzyme-2 (ACE-2) receptor, neuronal transport, haematogenous route, and nasal route via olfactory bulb, cribriform plate, and propagates through trans-synaptic signalling, and shows retrograde movement into the CNS along nerve fiber. COVID-19 induces CNS inflammation and neurological degenerative damage through a diverse mechanism which includes ACE-2 receptor damage, cytokine-associated injury or cytokine storm syndrome, secondary hypoxia, demyelination, blood-brain barrier disruption, neurodegeneration, and neuroinflammation. Viral invasion into the CNS has been reported to show association with complications like Parkinsonism, Alzheimer's disorder, meningitis, encephalopathy, anosmia, hyposmia, anxiety, depression, psychiatric symptoms, seizures, stroke, etc. This review provides a detailed discussion of the CNS pathogenesis of COVID-19. Authors conclude that the COVID-19 cannot just be considered as a disorder of the pulmonary or peripheral system, rather it has a significant CNS involvement. Therefore, CNS aspects of the COVID-19 should be monitored very closely to prevent long term CNS complications, even after the patient has recovered from COVID-19.

COVID-19 and Cerebrovascular Diseases: A Systematic Review and Perspectives for Stroke Management

Importance: Reported cerebrovascular events in patients with COVID-19 are mainly ischemic, but hemorrhagic strokes and cerebral venous sinus thrombosis (CSVT), especially in critically ill patients, have also been described. To date, it is still not clear whether cerebrovascular manifestations are caused by direct viral action or indirect action mediated by inflammatory hyperactivation, and in some cases, the association may be casual rather than causal. Objective: To conduct a systematic review on the cerebrovascular events in COVID-19 infection. Evidence review: A comprehensive literature search on PubMed was performed including articles published from January 1, 2020, to July 23, 2020, using a suitable keyword strategy. Additional sources were added by the authors by reviewing related references. The systematic review was conducted in accordance with the PRISMA guidelines. Only articles reporting individual data on stroke mechanism and etiology, sex, age, past cardiovascular risk factors, COVID symptoms, admission NIHSS, D-dimer levels, and acute stroke treatment were selected for the review. Articles that did not report the clinical description of the cases were excluded. A descriptive statistical analysis of the data collected was performed. Finding: From a total of 1,210 articles published from January 1, 2020, to July 23, 2020, 80 articles (275 patients), which satisfied the abovementioned criteria, were included in this review. A total of 226 cases of ischemic stroke (IS), 35 cases of intracranial bleeding, and 14 cases of CVST were found. Among patients with IS, the mean age was 64.16 ±14.73 years (range 27-92 years) and 53.5% were male. The mean NIHSS score reported at the onset of stroke was 15.23 ±9.72 (range 0-40). Primary endovascular thrombectomy (EVT) was performed in 24/168 patients (14.29%), intravenous thrombolysis (IVT) was performed in 17/168 patients (10.12%), and combined IVT+EVT was performed in 11/168 patients (6.55%). According to the reported presence of large vessel occlusion (LVO) (105 patients), 31 patients (29.52%) underwent primary EVT or bridging. Acute intracranial bleeding was reported in 35 patients: 24 patients (68.57%) had intracerebral hemorrhage (ICH), 4 patients (11.43%) had non-traumatic subarachnoid hemorrhage (SAH), and the remaining 7 patients (20%) had the simultaneous presence of SAH and ICH. Fourteen cases of CVST were reported in the literature (50% males), mean age 42.8 years ±15.47 (range 23-72). Treatment was reported only in nine patients; seven were treated with anticoagulant therapy; one with acetazolamide, and one underwent venous mechanical thrombectomy. Conclusion: Cerebrovascular events are relatively common findings in COVID-19 infection, and they could have a multifactorial etiology. More accurate and prospective data are needed to better understand the impact of cerebrovascular events in COVID-19 infection.

COVID-19-Associated Neurological Disorders: The Potential Route of CNS Invasion and Blood-Brain Relevance

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel human coronavirus that has sparked a global pandemic of the coronavirus disease of 2019 (COVID-19). The virus invades human cells through the angiotensin-converting enzyme 2 (ACE2) receptor-driven pathway, primarily targeting the human respiratory tract. However, emerging reports of neurological manifestations demonstrate the neuroinvasive potential of SARS-CoV-2. This review highlights the possible routes by which SARS-CoV-2 may invade the central nervous system (CNS) and provides insight into recent case reports of COVID-19-associated neurological disorders, namely ischaemic stroke, encephalitis, encephalopathy, epilepsy, neurodegenerative diseases, and inflammatory-mediated neurological disorders. We hypothesize that SARS-CoV-2 neuroinvasion, neuroinflammation, and blood-brain barrier (BBB) dysfunction may be implicated in the development of the observed disorders; however, further research is critical to understand the detailed mechanisms and pathway of infectivity behind CNS pathogenesis.

Modelling the Anatomical Distribution of Neurological Events in COVID-19 Patients: A Systematic Review

Background

Neuropathology caused by the coronavirus disease 2019 (COVID-19) has been reported across several studies. The characterisation of the spatial distribution of these pathology remains critical to assess long and short-term neurological sequelae of COVID-19. To this end, Mathematical models can be used to characterise the location and aetiologies underlying COVID-19-related neuropathology.

Method

We performed a systematic review of the literature to quantify the locations of small neurological events identified with magnetic resonance imaging (MRI) among COVID-19 patients. Neurological events were localised into the Desikan-Killiany grey and white matter atlases. A mathematical network diffusion model was then used to test whether the spatial distribution of neurological events could be explained via a linear spread through the structural connectome of the brain.

Findings

We identified 35 articles consisting of 123 patients that assessed the spatial distribution of small neurological events among COVID-19 patients. Of these, 91 patients had grey matter changes, 95 patients had white matter changes and 72 patients had confirmed cerebral microbleeds. White matter events were observed within 14 of 42 white matter bundles from the IIT atlas. The highest proportions (26%) of events were observed within the bilateral corticospinal tracts. The splenium and middle of the corpus callosum were affected in 14% and 9% of the cases respectively. Grey matter events were spatially distributed in the 41 brain regions within the Desikan-Killiany atlas. The highest proportions (∼10%) of the events were observed in areas including the bilateral superior temporal, precentral, and lateral occipital cortices. Sub-cortical events were most frequently identified in the Pallidum. The application of a mathematical network diffusion model suggested that the spatial pattern of the small neurological events in COVID-19 can be modelled with a linear diffusion of spread from epicentres in the bilateral cerebellum and basal ganglia (Pearson's r =0.41, p <0.001, corrected).

Interpretation

To our knowledge, this is the first study to systematically characterise the spatial distribution of small neurological events in COVID-19 patients and test whether the spatial distribution of these events can be explained by a linear diffusion spread model. The location of neurological events is consistent with commonly identified neurological symptoms including alterations in conscious state among COVID-19 patients that require brain imaging. Given the prevalence and severity of these manifestations, clinicians should carefully monitor neurological symptoms within COVID-19 patients and their potential long-term sequelae .

Rehabilitation and COVID-19: the Cochrane Rehabilitation 2020 rapid living systematic review. Update as of July 31st, 2020

INTRODUCTION

This paper is the first update of the second edition of the rapid living systematic review on the latest scientific literature informing rehabilitation of patients with COVID-19 and/or describing consequences of the disease and its treatment, as they relate to limitations in functioning of rehabilitation interest. The aim of this study was to report data of a systematic search performed on papers published in July 2020.

EVIDENCE ACQUISITION

The methodology described in the second edition of the rapid living systematic review was applied to search eligible papers included in the databases between July 1, 2020 and July 31, 2020.

EVIDENCE SYNTHESIS

Eight-hundred-ninety-two papers were identified through database searching (after removal of duplicates); of these, only 23 studies were included. According to OCEBM 2011 Levels of Evidence Table, they were level 3 in 30.5% cases and level 4 in 69.5%. No RCT was found. Nineteen papers studied COVID-19 patients, assessed in the acute (10 studies), post-acute (8 studies) and chronic phase (one study). Four studies reported data on the impact of COVID-19 on subjects with pre-existing health conditions.

CONCLUSIONS

The current literature production still focuses more on describing all the possible aspects and complications of the pathology than on interventions or new organization models to deal with it. Albeit evidence on handling COVID-19 from a rehabilitative point of view is improving each month, further studies are still mandatory to report the role of rehabilitation in this scenario.

Intracranial hemorrhage in critically ill patients hospitalized for COVID-19

In this study, we report three cases of spontaneous intracranial hemorrhage in patients who were initially hospitalized at our tertiary care center in Washington, DC with symptoms of COVID-19. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was diagnosed in all three patients, who were critically ill, requiring intubation and ventilatory support. During their protracted hospitalizations, subsequent imaging disclosed intracranial hemorrhages, including intracerebral and subarachnoid hemorrhages, in the context of anticoagulation and coagulopathy. We believe this is related to the tropism of SARS-CoV-2 to the endothelial lining of the cerebral vasculature via their angiotensin-converting enzyme (ACE) II receptors. Given our findings, we advocate heightened vigilance for intracerebral hemorrhage events, and scanning when practicable, in COVID-19 patients which have prolonged ventilatory support and depressed neurologic examinations.