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

Geoffroy Vellieux,Pierre Jaquet,Sérafima Vledouts,Romain Sonneville,Anny Rouvel-Tallec,Marie-Pia D’Ortho

doi:10.3389/fphys.2020.622466

Abstract

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.

Highlights

The coronavirus infectious disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, was initially recognized as a respiratory tract disease which could lead to an acute respiratory distress syndrome
While the volume of COVID-19-related case studies is still growing, we present the spectrum of EEG findings published at the moment, allowing physicians to be cognizant of this new and emerging literature while dealing with COVID-19 patients
We considered all studies with EEG findings at the acute phase in COVID-19 patients with neurological manifestations

Summary

Introduction

The coronavirus infectious disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, was initially recognized as a respiratory tract disease which could lead to an acute respiratory distress syndrome. EEG in COVID-19 Patients reported central nervous system (CNS) manifestations, as anosmia referring to olfactory tract involvement. Other critical presentations, including meningoencephalitis, seizures, status epilepticus (SE), encephalopathy, and altered mental status were described (Ellul et al, 2020). Neurological complications, such as encephalopathy and seizures/SE, and electroencephalographic (EEG) abnormalities, mainly diffuse slowing and epileptiform discharges, have already been described in past viral pandemics such as influenza A H1N1 (Ekstrand et al, 2010; Kedia et al, 2011; Ibrahim and Haddad, 2014). >Epileptiform findings and seizures Bilateral frontal sharp waves, n=6 Unilateral frontal sharp waves, n=2 Temporal or hemispheric sharp waves, n=2 Seizures, n=0 >Background activity Nonspecific changes, n=8 Diffuse bifrontal slowing, n=1.

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Discussion

Conclusion