Electroencephalographic (EEG) features of encephalopathy in the setting of Covid-19: A case series

COVID-19 and the brain: understanding the pathogenesis and consequences of neurological damage

SARS-CoV-2 has been known remarkably since December 2019 as a strain of pathogenic coronavirus. Starting from the earlier stages of the COVID-19 pandemic until now, we have witnessed many cases of neurological damage caused by SARS-CoV-2. There are many studies and research conducted on COVID-19-positive-patients that have found brain-related abnormalities with clear neurological symptoms, ranging from simple headaches to life-threatening strokes. For treating neurological damage, knowing the actual pathway or mechanism of causing brain damage via SARS-CoV-2 is very important. For this reason, we have tried to explain the possible pathways of brain damage due to SARS-CoV-2 with mechanisms and illustrations. The SARS-CoV-2 virus enters the human body by binding to specific ACE2 receptors in the targeted cells, which are present in the glial cells and CNS neurons of the human brain. It is found that direct and indirect infections with SARS-CoV-2 in the brain result in endothelial cell death, which alters the BBB tight junctions. These probable alterations can be the reason for the excessive transmission and pathogenicity of SARS-CoV-2 in the human brain. In this precise review, we have tried to demonstrate the neurological symptoms in the case of COVID-19-positive-patients and the possible mechanisms of neurological damage, along with the treatment options for brain-related abnormalities. Knowing the transmission mechanism of SARS-CoV-2 in the human brain can assist us in generating novel treatments associated with neuroinflammation in other brain diseases.

Clinical manifestations and EEG findings in children infected with COVID-19 and exhibiting neurological symptoms

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection has many neurological manifestations, and its effects on the nervous system are increasingly recognized. There has been no systematic analysis of electroencephalography (EEG) characteristics in children exhibiting neurological symptoms of Coronavirus disease 2019 (COVID-19). The primary aim of this study was to describe the EEG characteristics caused by COVID-19 infection in children who were showing neurological symptoms and to assess the relationship between COVID-19-related EEG changes and clinical features in these children.

METHOD

This study included 125 pediatric patients infected with SARS-CoV2 and showing neurological symptoms, and their continuous EEG was recorded. In addition, the demographic and clinical characteristics of these patients were analyzed and the correlation between the two was investigated.

RESULTS

Abnormal EEG findings were detected in 31.20% (N = 39) of the patients. Abnormal discharges (43.59%) were the most common EEG abnormalities, followed by background abnormalities (41.03%). The proportion of patients diagnosed with febrile seizure was higher in the normal EEG group than in the abnormal EEG group (P = 0.002), while the opposite was true for epilepsy and encephalitis/encephalopathy (P = 0.016 and P = 0.003, respectively). The independent associated factors of abnormal EEG were age and total length of stay (P < 0.001 and P = 0.003, respectively). Non-specific EEG abnormalities were found in COVID-19-related encephalitis/encephalopathy.

CONCLUSION

Our study corroborated that a small group of pediatric patients infected by COVID-19 and showing neurological symptoms may exhibit abnormal EEG. This study could help improve the understanding of clinical and EEG characteristics in children with COVID-19 and inform triage policies in other hospitals during the COVID-19 pandemic.

Impact of the COVID-19 Pandemic on Continuous EEG Utilization

PURPOSE

The coronavirus disease 2019 (COVID-19) has significantly impacted healthcare delivery and utilization. The aim of this article was to assess the impact of the COVID-19 pandemic on in-hospital continuous electroencephalography (cEEG) utilization and identify areas for process improvement.

METHODS

A 38-question web-based survey was distributed to site principal investigators of the Critical Care EEG Monitoring Research Consortium, and institutional contacts for the Neurodiagnostic Credentialing and Accreditation Board. The survey addressed the following aspects of cEEG utilization: (1) general center characteristics, (2) cEEG utilization and review, (3) staffing and workflow, and (4) health impact on EEG technologists.

RESULTS

The survey was open from June 12, 2020 to June 30, 2020 and distributed to 174 centers with 79 responses (45.4%). Forty centers were located in COVID-19 hotspots. Fifty-seven centers (72.1%) reported cEEG volume reduction. Centers in the Northeast were most likely to report cEEG volume reduction (odds ratio [OR] 7.19 [1.53-33.83]; P = 0.012). Additionally, centers reporting decrease in outside hospital transfers reported cEEG volume reduction; OR 21.67 [4.57-102.81]; P ≤ 0.0001. Twenty-six centers (32.91%) reported reduction in EEG technologist coverage. Eighteen centers had personal protective equipment shortages for EEG technologists. Technologists at these centers were more likely to quarantine for suspected or confirmed COVID-19; OR 3.14 [1.01-9.63]; P = 0.058.

CONCLUSIONS

There has been a widespread reduction in cEEG volume during the pandemic. Given the anticipated duration of the pandemic and the importance of cEEG in managing hospitalized patients, methods to optimize use need to be prioritized to provide optimal care. Because the survey provides a cross-sectional assessment, follow-up studies can determine the long-term impact of the pandemic on cEEG utilization.

A Near-Global Slowing of Background Activity and Epileptic Discharges in Children With Mild to Moderately Symptomatic COVID-19 Infection: An Electro-Neurophysiological Study

Background. To assess the functional involvement of the central nervous system (CNS) via quantitative electroencephalography (EEG) analysis in children with mild to moderate COVID-19 infection who were otherwise previously healthy children. Methods. This prospective, case-control study was conducted between June and September 2020. Sleep EEG records of at least 40 min were planned for children who tested positive for COVID-19 using real-time PCR analysis and within 4-6 months post-recovery. All of the EEG analyses in this study were performed on an Ubuntu 20.04.2 LTS Operating System with the developed software using Python 3.7.6. The quantitative analysis of the epileptic discharges within the EEG records was performed using random forest after elimination of the artifacts with a model training accuracy of 98% for each sample data point. The frequency analysis was performed using the Welch method. Results. Among the age and sex-matched groups, the global mean frequency was significantly lower among the COVID-19 patients, with a P-value of 0.004. The spike slow-wave and sharp slow-wave indices were significantly higher in the patients when compared to the controls. The mean frequency values were significantly lower in almost all of the electrodes recording the frontal, central, and occipital areas. For the temporal and parietal areas, those significantly low mean frequencies were limited to the right hemisphere. Conclusion. A near-global involvement of background activity with decreased frequency, in addition to epileptic discharges, was recorded in mild to moderately COVID-19 infected children post-infection.

COVID-19 Continuous-EEG Case Series: A Descriptive Study

PURPOSE

Corona virus disease 2019 (COVID-19) refers to coronavirus disease secondary to SARS-CoV2 infection mainly affecting the human respiratory system. The SARS-CoV2 has been reported to have neurotropic and neuroinvasive features and neurological sequalae with wide range of reported neurological manifestations, including cerebrovascular disease, skeletal muscle injury, meningitis, encephalitis, and demyelination, as well as seizures and focal status epilepticus. In this case series, we analyzed the continuous video-EEGs of patients with COVID-19 infection to determine the presence of specific EEG features or epileptogenicity.

METHODS

All continuous video-EEG tracings done on SARS-CoV2-positive patients during a 2-week period from April 5, 2020, to April 19, 2020, were reviewed. The demographics, clinical characteristics, imaging, and EEG features were analyzed and presented.

RESULTS

Of 23 patients undergoing continuous video-EEG, 16 were COVID positive and were included. Continuous video-EEG monitoring was ordered for "altered mental status" in 11 of 16 patients and for "clinical seizure" in 5 of 16 patients. None of the patients had seizures or status epilepticus as a presenting symptom of COVID-19 infection. Instead, witnessed clinical seizures developed as results of COVID-19-related medical illness(es): anoxic brain injury, stroke/hemorrhage, lithium (Li) toxicity (because of kidney failure), hypertension, and renal disease. Three patients required therapeutic burst suppression because of focal nonconvulsive status epilepticus, status epilepticus/myoclonus secondary to anoxic injury from cardiac arrest, and one for sedation (and with concomitant EEG abnormalities secondary to Li toxicity).

CONCLUSIONS

In this observational case series of 16 patients with COVID-19 who were monitored with continuous video-EEG, most patients experienced a nonspecific encephalopathy. Clinical seizures and electrographic status epilepticus were the second most commonly observed neurological problem.

The Clinical Neurophysiology of COVID-19- Direct Infection, Long-Term Sequelae and Para-Immunization responses: A literature review

The COVID-19 pandemic resulting from the SARS-CoV-2 virus is in its third year. There is continuously evolving information regarding its pathophysiology and its effects on the nervous system. Clinical neurophysiology techniques are commonly employed to assess for neuroanatomical localization and/or defining the spectrum of neurological illness. There is an evolving body of literature delineating the effects of the SARS-CoV-2 virus on the nervous system as well as para-immunization responses to vaccination against this virus. This review focuses on the use of neurophysiological diagnostic modalities in the evaluation of potential acute and long-term neurological complications in patients that experience direct infection with SARS-CoV-2 and analyzes those reports of para-immunization responses to vaccination against the SARS-CoV-2 virus. The neurophysiological modalities to be discussed include electroencephalography (EEG), evoked potentials (EPs), nerve conduction studies and electromyography (EMG/NCV), autonomic function tests, transcranial magnetic stimulation (TMS) and Transcranial Doppler ultrasound (TCD).

COVID-19-Induced Seizures: A Meta-Analysis of Case Series and Retrospective Cohorts

The adverse events and complications of coronavirus disease 2019 (COVID-19) continue to challenge the medical profession despite the worldwide vaccination against the severe acute respiratory coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19. Other than typical respiratory manifestations, COVID-19 also presents a wide range of neurological manifestations. This article underlines the pooled incidence of COVID-19-induced seizures in patients with epilepsy and without epilepsy. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocols, we conducted a bibliographical search, and an initial search revealed 1,375 articles. In total, 21 articles were included in the final analysis by following the inclusion criteria. A total of 11,526 patients from 21 published articles that met the predetermined search criteria were included. The median age of the patients was 61.9 years, of whom 51.5% were males. A total of 255 patients presented with seizures as the first manifestation of COVID-19 with a prevalence of 2.2% (95% confidence interval = 0.05-0.24, p < 0.01) (I² = 97%), of which 71 patients had previously been diagnosed with epilepsy. Among patients with epilepsy, 49 patients had seizures as an initial presentation of SARA-CoV-2 with an incidence of 72% (0.54-0.85, p = 0.1) (I² = 34). Although the incidence of COVID-19-induced seizures is not high compared to other neurological manifestations, seizure incidence in epileptic patients with COVID-19 is remarkably high. New-onset seizures in any patient should be considered a presentation of COVID-19 in the absence of other causative factors.

The value of EEG attenuation in the prediction of outcome in COVID-19 patients

Introduction

During the COVID-19 pandemic, electroencephalography (EEG) proved to be a useful tool to demonstrate brain involvement. Many studies reported non-reactive generalized slowing as the most frequent pattern and epileptiform activity in a minority of patients.

Objective

To investigate the prevalence of diffuse unreactive background attenuation or suppression and its correlation with outcome in a cohort of COVID-19 patients.

Methods

The EEGs recorded during the first year of the COVID-19 pandemic were retrospectively evaluated to identify the main pattern and focus on the occurrence of a low-voltage background, either attenuated (10–20 μV) or suppressed (< 10 μV). We sought a correlation between in-hospital mortality and low-voltage EEG. In a subsample of patients, biomarkers of inflammation, hypoxemia and organ failure were collected. Brain imaging was also evaluated.

Results

Among 98 EEG performed in 50 consecutive patients, diffuse unreactive slowing was the most prevalent pattern (54%), followed by unreactive attenuation or suppression pattern (26%), being the latter significantly correlated with an unfavourable outcome (p = 0.0004). Survivors showed significantly lower interleukine-6 values compared to non-survivors. Patients with attenuated EEG and non-survivors also showed lower PaO₂/FiO₂ values. Neuroradiological findings were very heterogeneous with a prevalence of lesions suggestive of a microangiopathic substrate.

Conclusions

EEG attenuation or suppression may be more frequent than previously reported and significantly associated with a poor outcome. SARS-CoV-2 infection may result in encephalopathy and reduced EEG voltage through mechanisms that are still unknown but deserve attention given its negative impact on prognosis.

Database and AI Diagnostic Tools Improve Understanding of Lung Damage, Correlation of Pulmonary Disease and Brain Damage in COVID-19

The COVID-19 pandemic caused a sharp increase in the interest in artificial intelligence (AI) as a tool supporting the work of doctors in difficult conditions and providing early detection of the implications of the disease. Recent studies have shown that AI has been successfully applied in the healthcare sector. The objective of this paper is to perform a systematic review to summarize the electroencephalogram (EEG) findings in patients with coronavirus disease (COVID-19) and databases and tools used in artificial intelligence algorithms, supporting the diagnosis and correlation between lung disease and brain damage, and lung damage. Available search tools containing scientific publications, such as PubMed and Google Scholar, were comprehensively evaluated and searched with open databases and tools used in AI algorithms. This work aimed to collect papers from the period of January 2019-May 2022 including in their resources the database from which data necessary for further development of algorithms supporting the diagnosis of the respiratory system can be downloaded and the correlation between lung disease and brain damage can be evaluated. The 10 articles which show the most interesting AI algorithms, trained by using open databases and associated with lung diseases, were included for review with 12 articles related to EEGs, which have/or may be related with lung diseases.

Retrospective Analysis of EEG in Patients With COVID-19: EEG Recording in Acute and Follow-up Phases

Background. Interest in electroencephalographic (EEG) coronavirus disease 2019 (COVID-19) findings has been growing, especially in the search for a specific-features EEG of encephalopathy. Methods. We made a retrospective analysis of 29 EEGs recorded in 15 patients with COVID-19 and neurological symptoms. We classified the EEGs as "Acute EEG" and "follow-up EEG." We did a statistical analysis between voltage and respiratory status of the patient, stay or not in the intensive care unit (ICU), days of stay in the ICU, sedative drugs, pharmacological treatment, type of symptoms predominating, and outcome. Results. We found EEG abnormalities in all patients studied. We observed the amplitude of background <20 µV at 93% of "acute EEG," versus only 21.4% of "follow-up EEG." The average voltage went from 12.33 ± 5.09 µV in the acute EEGs to 32.8 ± 20.13 µV in the follow-up EEGs. A total of 60% of acute EEGs showed an intermittent focal rhythmic. We have not found a statistically significant association between voltage of acute EEG and nonneurological clinical status (including respiratory) that may interfere with the EEG findings. Conclusions. Nonspecific diffuse slowing EEG pattern in COVID-19 is the most common finding reported, but we found in addition to that, as a distinctive finding, low voltage EEG, that could explain the low prevalence of epileptic activity published in these patients. A metabolic/hypoxic mechanism seems unlikely on the basis of our EEG findings. This pattern in other etiologies is reminiscent of severe encephalopathy states associated with poor prognosis. However, an unreactive low voltage pattern in COVID-19 patients is not necessarily related to poor prognosis.

COVID-19-Associated Encephalopathy: Systematic Review of Case Reports

Background and Purpose

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) primarily attacks the respiratory system, but there are also several reports of the involvement of the central nervous system, with one of the manifestations being encephalopathy. The relatively new emergence of COVID-19 means that few studies have investigated the clinical profile of encephalopathy associated with this disease. This study aimed to determine the clinical profile, laboratory, and imaging results of encephalopathy associated with COVID-19.

Methods

Three databases, namely PubMed/MEDLINE, Embase, and Scopus, were systematically searched for case reports and case series related to COVID-19-associated encephalopathy published from January 1, 2019 to July 20, 2020.

Results

This review included 24 studies involving 33 cases. The most-reported neurological symptoms were disorientation/confusion (72.72%), decreased consciousness (54.54%), and seizures (27.27%). Laboratory examinations revealed increases in the C-reactive protein level (48.48%), the lactate dehydrogenase level (30.30%), and lymphopenia (27.27%). Brain imaging did not produce any pathological findings in 51.51% of the cases. Electroencephalography showed generalized slowing in 45.45% of the cases. Elevated protein (42.42%) and lymphocytosis (24.24%) were found in the cerebrospinal fluid. Fifteen patients were reportedly discharged from the hospital in a stable condition, while four cases of mortality were recorded.

Conclusions

The clinical, laboratory, and imaging findings in this review support the hypothesis that cerebral damage in COVID-19-associated encephalopathy is caused by cytokine-immune-mediated inflammation rather than by direct invasion.

Severe and long-lasting neuropsychiatric symptoms after mild respiratory symptoms caused by COVID-19: A case report

Background

Coronavirus disease 2019 (COVID‐19) is known to cause not only respiratory but also neuropsychiatric symptoms, which are assumed to be derived from a cytokine storm and its effects on the central nervous systems. Patients with COVID‐19 who develop severe respiratory symptoms are known to show severe neuropsychiatric symptoms such as cerebrovascular disease and encephalopathy. However, the detailed clinical courses of patients with neuropsychiatric symptoms caused by mild or asymptomatic COVID‐19 remain poorly understood. Here, we present a case of COVID‐19 who presented with severe and prolonged neuropsychiatric symptoms subsequent to mild respiratory symptoms.

Case presentation

A 55‐year‐old female with COVID‐19 accompanied by mild respiratory symptoms showed delusion, psychomotor excitement, and poor communication ability during quarantine outside the hospital. Considering her diminished respiratory symptoms, her neuropsychiatric symptoms were initially regarded as psychogenic reactions. However, as she showed progressive disturbance of consciousness accompanied by an abnormal electroencephalogram, she was diagnosed with post‐COVID‐19 encephalopathy. Although her impaired consciousness and elevated cytokine level improved after steroid pulse therapy, several neuropsychiatric symptoms, including a loss of concentration, unsteadiness while walking, and fatigue, remained.

Conclusions

This case suggests the importance of both recognizing that even apparently mild COVID‐19‐related respiratory symptoms can lead to severe and persistent neuropsychiatric symptoms, and elucidating the mechanisms, treatment, and long‐term course of COVID‐19‐related neuropsychiatric symptoms in the future.

A 55‐year‐old female with COVID‐19 accompanied by mild respiratory symptoms was diagnosed with post‐COVID‐19 encephalopathy. Although her impaired consciousness and elevated cytokine level improved after steroid pulse therapy, several neuropsychiatric symptoms remained. This case suggests the importance of both recognizing that even apparently mild COVID‐19‐related respiratory symptoms can lead to severe and persistent neuropsychiatric symptoms.

Elektroenzephalografische (EEG) Merkmale der Enzephalopathie bei Covid-19

Mit dem Fortschreiten der Covid-19-Pandemie wurde eine Reihe von neurologischen Störungen erkannt, die sowohl die zentralen wie die peripheren Komponenten des Nervensystems betreffen. Die Autoren beschreiben anhand von Fallbeispielen die Elektroenzephalografie-(EEG)-Befunde, die bei Patienten mit schwerem Covid-19 typischerweise beobachtet wurden.

Intermittent Frontal Rhythmic Discharges as an Electroencephalogram Biomarker of Acute SARS-CoV-2 Infection-Associated Encephalopathy in Children

Data on neurological sequelae of COVID-19 infection in children are sparse. Neurotropic and neuroinvasive potentials of the SARS-CoV-2 virus are a matter of ongoing scientific debate and not yet well understood. Most of the reported symptoms are nonspecific including headache, encephalopathy, weakness, and as a part of multisystem inflammatory response syndrome. Few observational studies have reported acute encephalopathy to be one of the neurological manifestations of COVID-19 infection, mostly in adults. A little is known about epileptogenesis or electroencephalogram (EEG) findings in this limited cohort of pediatric patients. We report a 17-year-old female with type 1 diabetes mellitus (DM), who presented with two weeks history of intermittent headaches, followed by a one-day history of acute change in behavior in the form of prolonged staring, decreased speech, confusion, and alternating periods of agitation and sleepiness. No fever or respiratory symptoms. Her blood glucose was normal. Brain MRI was unremarkable. Cerebrospinal fluid (CSF) studies showed 1000 RBCs, no WBCs, normal glucose/protein, negative culture, and negative infectious PCR, and autoimmune panels. She was found to be positive for SARS-CoV-2 PCR with negative IgG. Her EEG showed remarkable background slowing and frequent frontal intermittent rhythmic discharges. She was managed with high-dose steroids with the full clinical recovery of all symptoms at discharge, as well as normalization of subsequent EEG studies. We hypothesize there may be some specific seizure characteristics or EEG patterns in patients with pediatric COVID-19 infection and concomitant acute encephalopathy. It is perhaps reasonable to obtain EEG studies in children who test positive for SARS-CoV-2 and report central neurological symptoms. Long-term follow-up of this cohort of patients will be helpful to understand the clinical significance and implications of such neurophysiological studies.

Neuropsychiatric manifestations of COVID-19, potential neurotropic mechanisms, and therapeutic interventions

The coronavirus disease 2019 (COVID-19) pandemic has caused large-scale economic and social losses and worldwide deaths. Although most COVID-19 patients have initially complained of respiratory insufficiency, the presence of neuropsychiatric manifestations is also reported frequently, ranging from headache, hyposmia/anosmia, and neuromuscular dysfunction to stroke, seizure, encephalopathy, altered mental status, and psychiatric disorders, both in the acute phase and in the long term. These neuropsychiatric complications have emerged as a potential indicator of worsened clinical outcomes and poor prognosis, thus contributing to mortality in COVID-19 patients. Their etiology remains largely unclear and probably involves multiple neuroinvasive pathways. Here, we summarize recent animal and human studies for neurotrophic properties of severe acute respiratory syndrome coronavirus (SARS-CoV-2) and elucidate potential neuropathogenic mechanisms involved in the viral invasion of the central nervous system as a cause for brain damage and neurological impairments. We then discuss the potential therapeutic strategy for intervening and preventing neuropsychiatric complications associated with SARS-CoV-2 infection. Time-series monitoring of clinical-neurochemical-radiological progress of neuropsychiatric and neuroimmune complications need implementation in individuals exposed to SARS-CoV-2. The development of a screening, intervention, and therapeutic framework to prevent and reduce neuropsychiatric sequela is urgently needed and crucial for the short- and long-term recovery of COVID-19 patients.

Encephalopathy in COVID-19 Patients

The clinical presentation of coronavirus disease 2019 (COVID-19) has a wide spectrum, ranging from asymptomatic patients to severe presentations with acute respiratory distress syndrome (ARDS), kidney injury, stroke, electrolyte imbalance, and multi-organ failure. Encephalopathy and encephalitis are devastating severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) virus‐associated central nervous system complications.

We reported a case of a 67-year-old male who was admitted to the hospital for the management of COVID-19 pneumonia. Due to worsening hypoxia, the patient was transferred to ICU and was intubated. On examination, he was aphasic and noted to have right-sided hemiplegia with left-sided hemiparesis on day 4. CT scan of the head without contrast and MRI findings were suggestive of acute necrotizing encephalopathy secondary to intracranial cytokine storm caused by viral infection. The patient was treated with intravenous immunoglobulin (IVIG), and high dose corticosteroids, with clinical improvement in the right-sided hemiparesis on day 5. A repeat MRI brain revealed decreased edema.

The pathogenesis of encephalopathy associated with COVID-19 may be multifactorial. Postulated mechanisms include hypoxic/metabolic changes produced by the intense inflammatory response due to cytokine storm and neurotropism. Cytokine storm causes hypoxia and metabolic insults that result in global dysfunction of the brain. Altered consciousness, ranging from mild confusion, delirium, to deep coma, are some of the cardinal clinical features. The most common imaging finding on MRI T2-weighted fluid-attenuated inversion recovery (MRI T2/FLAIR) includes symmetric, multifocal lesions with invariable thalamic involvement. Other commonly involved locations include the brainstem, cerebral white matter, cortical and subcortical white matter, and cerebellum. In a few case reports, cerebrospinal fluid (CSF) analysis has shown the presence of the virus. Management of encephalopathy in COVID-19 patients involves supportive care including supplemental oxygen therapy and immune modulators. Immune modulation therapy including high-dose corticosteroids and IVIG have been shown to improve outcomes in these patients.

Etiologies of Delirium in Consecutive COVID-19 Inpatients and the Relationship Between Severity of Delirium and COVID-19 in a Prospective Study With Follow-Up

OBJECTIVE

The investigators aimed to describe delirium etiologies and clinical characteristics, as well as the relationship between COVID-19 and delirium severities, at baseline and follow-up after delirium improvement among patients with SARS-CoV-2 infection.

METHODS

A longitudinal study of 20 consecutive critically ill, delirious COVID-19 inpatients, assessed with the Charlson Comorbidity Index-Short Form (CCI-SF), COVID-19 Clinical Severity Scale (CCSS), Delirium Etiology Checklist, Delirium Motor Subtype Scale-4, and Delirium Diagnostic Tool-Provisional (DDT-Pro), was conducted. Correlational analysis of delirium severity (DDT-Pro) with each measure of clinical severity (CCI-SF and CCSS) and comparison of baseline DDT-Pro scores between patients who were living and those who were deceased at follow-up were conducted.

RESULTS

Participants were 50-90 years old (male, 75%; hypertension, 60%). The prevalence of preexisting medical comorbidities (CCI-SF) was low and not correlated with delirium severity (p=0.193). Eighteen patients were on mechanical or high-flow noninvasive ventilation at baseline in the intensive care unit (ICU; CCSS scores 2-4). Delirium severity (DDT-Pro scores 0-6) correlated with COVID-19 severity (0.459, p=0.021). Delirium motor subtype was hyperactive in 75% of patients. There were three to four etiologies for delirium in each patient, most commonly organ insufficiency (100%), systemic infection (100%), and metabolic and endocrine disturbances (95%). The baseline DDT-Pro score was ≤4 for five (25%) patients who died before the final assessment, with a trend of being lower than that for survivors (χ²=3.398, p=0.065).

CONCLUSIONS

Among inpatients with COVID-19, at least three different etiological categories were identified for delirium. ICU staff treating patients with severe cases of COVID-19 should anticipate a greater severity of delirium. Although multivariate analyses with larger study samples are needed, more severe delirium may herald greater risk of death among COVID-19 patients.

Electroencephalographic findings among inpatients with COVID-19 in a tertiary hospital from a middle-income country

BACKGROUND

In 2019, the world witnessed the emergence of a new type of coronavirus - the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The spectrum of coronavirus disease 2019 (COVID-19) is variable, and amongst its manifestations are neurological implications.

OBJECTIVE

This report aimed to describe electroencephalographic findings in COVID-19 patients from a general tertiary hospital in São Paulo, Brazil.

METHODS

It was a retrospective, observational, and non-interventional study. Data were collected anonymously, comprising inpatients from Mar 1 to Jun 30, 2020, either confirmed (positive RT-PCR) or probable cases (CO-RADS 4/5) who had performed EEG during hospitalization.

RESULTS

Twenty-eight patients were enrolled, 17 (60.7%) women and 11 men, with a median age of 58 (minimum and maximum: 18-86; IQR 23.5). COVID-19 diagnosis was confirmed in 22 (78.5%). Twenty-one patients (75%) had severe disease, requiring mechanical ventilation due to acute respiratory distress syndrome (ARDS); 16 (57.1%) patients developed adjunct sepsis throughout hospitalization. There was no specific pattern found for COVID-19 in EEG. No patients presented with status epilepticus or electrographic events; most patients developed an encephalopathic pattern, as seen in most studies, with a high prevalence of altered mental status as an indication for EEG. Adjunct sepsis was associated with higher mortality.

CONCLUSIONS

EEG presents as a useful tool in the context of COVID-19, as in other conditions, to differentiate nonconvulsive status epilepticus (NCSE) from encephalopathy and other causes of mental status alterations. Further studies are required to analyze whether there might be a specific EEG pattern to the disease.

Cerebrospinal fluid findings in patients with seizure in the setting of COVID-19: A review of the literature

We reviewed the literature on cerebrospinal fluid (CSF) studies in patients who had a seizure in the setting of COVID-19 infection to evaluate for evidence of viral neuroinvasion. We performed a systematic review of Medline and Embase to identify publications that reported one or more patients with COVID-19 who had a seizure and had CSF testing preformed. The search ranged from December 1st 2019 to November 18th 2020. We identified 56 publications which described 69 unique patients who met our inclusion criteria. Of the 54 patients whose past medical history was provided, 2 (4%) had epilepsy and 1 (2%) had a prior seizure in the setting of hyperglycemia, but the remaining 51 (94%) had no history of seizures. Seizure was the initial symptom of COVID-19 for 15 (22%) patients. There were 26 (40%) patients who developed status epilepticus. SARS-CoV-2 PCR testing was performed in the CSF for 45 patients; 6 (13%) had a positive CSF SARS-CoV-2 PCR, only 1 (17%) of whom had status epilepticus. The cycle thresholds were not reported. Evaluation for CSF SARS-CoV-2 antibodies (directly or indirectly, via testing for CSF oligoclonal bands or immunoglobulins) was performed in 26 patients, only 2 (8%) of whom had evidence of intrathecal antibody synthesis. Of the 11 patients who had CSF autoimmune antibody panels tested, 1 had NMDA antibodies and 1 had Caspr-2 antibodies. Detection of SARS-CoV-2 in the CSF of patients with seizures who have COVID-19 is uncommon. Our review suggests that seizures in this patient population are not likely due to direct viral invasion of the brain.

Outcomes of seizures, status epilepticus, and EEG findings in critically ill patient with COVID-19

OBJECTIVE

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has a myriad of neurological manifestations and its effects on the nervous system are increasingly recognized. Seizures and status epilepticus (SE) are reported in the novel coronavirus disease (COVID-19), both new onset and worsening of existing epilepsy; however, the exact prevalence is still unknown. The primary aim of this study was to correlate the presence of seizures, status epilepticus, and specific critical care EEG patterns with patient functional outcomes in those with COVID-19.

METHODS

This is a retrospective, multicenter cohort of COVID-19-positive patients in Southeast Michigan who underwent electroencephalography (EEG) from March 12th through May 15th, 2020. All patients had confirmed nasopharyngeal PCR for COVID-19. EEG patterns were characterized per 2012 ACNS critical care EEG terminology. Clinical and demographic variables were collected by medical chart review. Outcomes were divided into recovered, recovered with disability, or deceased.

RESULTS

Out of the total of 4100 patients hospitalized with COVID-19, 110 patients (2.68%) had EEG during their hospitalization; 64% were male, 67% were African American with mean age of 63 years (range 20-87). The majority (70%) had severe COVID-19, were intubated, or had multi-organ failure. The median length of hospitalization was 26.5 days (IQR = 15 to 44 days). During hospitalization, of the patients who had EEG, 21.8% had new-onset seizure including 7% with status epilepticus, majority (87.5%) with no prior epilepsy. Forty-nine (45%) patients died in the hospital, 46 (42%) recovered but maintained a disability and 15 (14%) recovered without a disability. The EEG findings associated with outcomes were background slowing/attenuation (recovered 60% vs recovered/disabled 96% vs died 96%, p < 0.001) and normal (recovered 27% vs recovered/disabled 0% vs died 1%, p < 0.001). However, these findings were no longer significant after adjusting for severity of COVID-19.

CONCLUSION

In this large multicenter study from Southeast Michigan, one of the early COVID-19 epicenters in the US, none of the EEG findings were significantly correlated with outcomes in critically ill COVID-19 patients. Although seizures and status epilepticus could be encountered in COVID-19, the occurrence did not correlate with the patients' functional outcome.

Association of Clinical, Biological, and Brain Magnetic Resonance Imaging Findings With Electroencephalographic Findings for Patients With COVID-19

Importance

There is evidence of central nervous system impairments associated with coronavirus disease 2019 (COVID-19) infection, including encephalopathy. Multimodal monitoring of patients with COVID-19 may delineate the specific features of COVID-19-related encephalopathy and guide clinical management.

Objectives

To investigate clinical, biological, and brain magnetic resonance imaging (MRI) findings in association with electroencephalographic (EEG) features for patients with COVID-19, and to better refine the features of COVID-19-related encephalopathy.

Design, Setting, and Participants

This retrospective cohort study conducted in Pitié-Salpêtrière Hospital, Paris, France, enrolled 78 hospitalized adults who received a diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-Cov2) and underwent EEG between March 30 and June 11, 2020.

Exposures

Detection of SARS-CoV-2 from a nasopharyngeal specimen using a reverse transcription-polymerase chain reaction assay or, in the case of associated pneumonia, on a computed tomography scan of the chest.

Main Outcomes and Measures

Data on the clinical and paraclinical features of the 78 patients with COVID-19 were retrieved from electronic patient records.

Results

Of 644 patients who were hospitalized for COVID-19, 78 (57 men [73%]; mean [SD] age, 61 [12] years) underwent EEG. The main indications for EEG were delirium, seizure-like events, and delayed awakening in the intensive care unit after stopping treatment with sedatives. Sixty-nine patients showed pathologic EEG findings, including metabolic-toxic encephalopathy features, frontal abnormalities, periodic discharges, and epileptic activities. Of 57 patients who underwent brain MRI, 41 showed abnormalities, including perfusion abnormalities, acute ischemic lesions, multiple microhemorrhages, and white matter-enhancing lesions. Fifty-five patients showed biological abnormalities, including dysnatremia, kidney failure, and liver dysfunction, the same day as the EEG. The results of cerebrospinal fluid analysis were negative for SARS-Cov-2 for all tested patients. Nine patients who had no identifiable cause of brain injury outside COVID-19 were further isolated; their brain injury was defined as COVID-19-related encephalopathy. They represented 1% (9 of 644) of patients with COVID-19 requiring hospitalization. Six of these 9 patients had movement disorders, 7 had frontal syndrome, 4 had brainstem impairment, 4 had periodic EEG discharges, and 3 had MRI white matter-enhancing lesions.

Conclusions and Relevance

The results from this cohort of patients hospitalized with COVID-19 suggest there are clinical, EEG, and MRI patterns that could delineate specific COVID-19-related encephalopathy and guide treatment strategy.

COVID-19-Associated Neurological Manifestations: An Emerging Electroencephalographic Literature

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide since the end of year 2019 and is currently responsive for coronavirus infectious disease 2019 (COVID-19). The first reports considered COVID-19 as a respiratory tract disease responsible for pneumonia, but numerous studies rapidly emerged to warn the medical community of COVID-19-associated neurological manifestations, including encephalopathy at the acute phase and other postinfectious manifestations. Using standard visual analysis or spectral analysis, recent studies reported electroencephalographic (EEG) findings of COVID-19 patients with various neurological symptoms. Most EEG recordings were normal or revealed non-specific abnormalities, such as focal or generalized slowing, interictal epileptic figures, seizures, or status epilepticus. Interestingly, novel EEG abnormalities over frontal areas were also described at the acute phase. Underlying mechanisms leading to brain injury in COVID-19 are still unknown and matters of debate. These frontal EEG abnormalities could emphasize the hypothesis whereby SARS-CoV-2 enters the central nervous system (CNS) through olfactory structures and then spreads in CNS via frontal lobes. This hypothesis is reinforced by the presence of anosmia in a significant proportion of COVID-19 patients and by neuroimaging studies confirming orbitofrontal abnormalities. COVID-19 represents a new viral disease characterized by not only respiratory symptoms but also a systemic invasion associated with extra-respiratory signs. Neurological symptoms must be the focus of our attention, and functional brain evaluation with EEG is crucial, in combination with anatomical and functional brain imaging, to better understand its pathophysiology. Evolution of symptoms together with EEG patterns at the distance of the acute episode should also be scrutinized.

Cerebrospinal fluid in COVID-19: A systematic review of the literature

OBJECTIVE

We sought to review the literature on cerebrospinal fluid (CSF) testing in patients with COVID-19 for evidence of viral neuroinvasion by SARS-CoV-2.

METHODS

We performed a systematic review of Medline and Embase between December 1, 2019 and November 18, 2020 to identify case reports or series of patients who had COVID-19 diagnosed based on positive SARS-CoV-2 polymerase chain reaction (PCR) or serologic testing and had CSF testing due to a neurologic symptom.

RESULTS

We identified 242 relevant documents which included 430 patients with COVID-19 who had acute neurological symptoms prompting CSF testing. Of those, 321 (75%) patients had symptoms that localized to the central nervous system (CNS). Of 304 patients whose CSF was tested for SARS-CoV-2 PCR, there were 17 (6%) whose test was positive, all of whom had symptoms that localized to the central nervous system (CNS). The majority (13/17, 76%) of these patients were admitted to the hospital because of neurological symptoms. Of 58 patients whose CSF was tested for SARS-CoV-2 antibody, 7 (12%) had positive antibodies with evidence of intrathecal synthesis, all of whom had symptoms that localized to the CNS. Of 132 patients who had oligoclonal bands evaluated, 3 (2%) had evidence of intrathecal antibody synthesis. Of 77 patients tested for autoimmune antibodies in the CSF, 4 (5%) had positive findings.

CONCLUSION

Detection of SARS-CoV-2 in CSF via PCR or evaluation for intrathecal antibody synthesis appears to be rare. Most neurological complications associated with SARS- CoV-2 are unlikely to be related to direct viral neuroinvasion.

Meta-analysis of EEG findings in patients with COVID-19

OBJECTIVE

To perform a systematic review and meta-analysis to summarize and quantitatively evaluate the electroencephalogram (EEG) findings in patients with coronavirus disease 2019 (COVID-19).

METHODS

The MEDLINE, CENTRAL, and ClinicalTrials.Gov databases were comprehensively assessed and searched for observational studies with EEG findings in patients with COVID-19. Pooled proportions of EEG findings with 95% confidence intervals (CIs) were assessed using a random effects model. The quality of assessment for each study, heterogeneity between the studies, and publication bias were also evaluated.

RESULTS

In total, 12 studies with 308 patients were included in the meta-analysis. Abnormal background activity and generalized slowing in the pooled proportions were common findings among the patients with COVID-19 (96.1% [95% CI: 89.4-99.9]; I² = 60%; p < 0.01 and 92.3% [95% CI: 81.2-99.3]; I² = 74%; p < 0.01, respectively). The proportion of patients with epileptiform discharges (EDs) was 20.3% ([95% CI: 9.85-32.9]; I² = 78%; p < 0.01). The proportion of EDs varied between patients with a history of epilepsy or seizures (59.5% [95% CI: 33.9-83.2]; I² = 0%; p = 0.49) and patients without them (22.4% [95% CI: 10.4-36.4]; I² = 46%; p = 0.07). The findings of seizures and status epilepticus on EEG were observed in 2.05% ([95% CI: 0.02-6.04]; I² = 39%; p = 0.08) and 0.80% ([95% CI: 0.00.-3.69]; I² = 28%; p = 0.17) of the patients, respectively.

CONCLUSION

The proportion of abnormal background activity in patients with COVID-19 was high (96.1%). Epileptiform discharges were present in 20.3% of the cases and the proportion varied between people who had a history of epilepsy/seizure and those who did not. However, the proportion of seizures and status epilepticus on EEG was low (2.05% and 0. 80%, respectively).

Electroencephalographic Abnormalites in SARS-CoV-2 Patients

Viral infection with SARS-CoV-2 has a neurological tropism that may induce an encephalopathy. In this context, electroencephalographic exploration (EEG) is indicated as a diagnostic argument correlated with lumbar puncture, biology, and imaging. We performed a retrospective analysis of 42 patients explored by EEG and infected by COVID-19, according to the EEG abnormalities and clinical signs that motivated the examination. Confusion and epileptic seizures were the most common clinical indications, with 64% of the patients displaying these symptoms. The EEG was altered in 85% of the cases of confusion, in 57% of the cases of epileptic symptoms (general or focal seizure or prolonged loss of contact) and 20% of the cases of malaise or brief loss of consciousness. Nine EEG (21%) were in favor of an encephalopathy, two had de novo alterations in persistent consciousness and two had alterations in general states of confusion; one was very agitated and without history of epilepsy and combined eyelids clonia while a second one exhibited unconsciousness with left hemicorpus clonus. Two were being investigated for delayed awakening without sedation for more than 24 h. All of these patients were diagnosed COVID-19, some of them with associated mild to severe respiratory disorders. This work shows the interest of the EEG in exploring COVID-19 patients suffering from neurological or general symptoms looking for cerebral alteration.

EEG findings and clinical prognostic factors associated with mortality in a prospective cohort of inpatients with COVID-19

Purpose

Our objective is to describe the most prevalent electroencephalographic findings in COVID-19 hospitalized patients, and to determine possible predictors of mortality including EEG and clinical variables.

Methods

A multicentric prospective observational study in patients with COVID-19 requiring EEG during hospitalization.

Results

We found 94 EEG from 62 patients (55 % men, mean age 59.7 ± 17.8 years) were analyzed. Most frequent comorbidity was cardiac (52 %), followed by metabolic (45 %) and CNS disease (39 %). Patients required ICU management by 60 %, with a mortality of 27 % in the whole cohort. The most frequent EEG finding was generalized continuous slow-wave activity (66 %). Epileptic activity was observed in 19 % including non-convulsive status epilepticus, seizures and interictal epileptiform discharges. Periodic patterns were observed in 3 patients (3.2 %). Multivariate analysis found that cancer comorbidity and requiring an EEG during the third week of evolution portended a higher risk of mortality

Conclusion

We observed that the most prevalent EEG finding in this cohort was generalized continuous slow-wave activity, while epileptic activity was observed in less than 20 % of the cases. Mortality risk factors were comorbidity with cancer and requiring an EEG during the third week of evolution, possibly related to the hyperinflammatory state.

Electroencephalographic findings in COVID-19 patients: A systematic review

Background

Growing evidence of neurologic involvement seen in COVID-19 infection necessitates the pooling of neurodiagnostic findings like electroencephalography (EEG) that may guide clinical management. The objective of this study was to review the EEG findings in patients diagnosed with COVID-19 infection through a systematic review of published articles.

Methods

We systematically searched until July 25, 2020 for published articles that reported on descriptive EEG findings in patients diagnosed with COVID-19 in PUBMED by Medline, EMBASE, and CENTRAL by the Cochrane Library.

Results

From a total of 94 identified records, 29 relevant articles were included in this review. A total of 177 patients with COVID-19 with descriptive EEG reports were analyzed. The most common indication for EEG was unexplained altered mental status. Disturbances of background activity such as generalized and focal slowing were seen as well epileptiform abnormalities and rhythmic or periodic discharges. There were no consistent EEG findings specific to COVID-19 infection.

Conclusion

The EEG findings in COVID-19 appear to be non-specific. Further research on the relationship of the EEG findings to the clinical state and short- or long-term prognosis of COVID-19 patients may be conducted to help clinicians discern which patients would necessitate an EEG procedure and would eventually require treatment.