Letter: Neurological Implications of COVID-19 and Lessons Learned From Prior Epidemics and Pandemics

Abstract

To the Editor:We performed a literature review on viral epidemics and pandemics, including the severe acute respiratory syndrome (SARS), the Middle East respiratory syndrome (MERS), influenza H1N1, and the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with the goal of identifying the neurological symptoms, signs, and complications of these infections within the context of the COVID-19 pandemic (Figure).Of 16 articles that included 8042 patients with H1N1, neurological involvement was reported in 1286 patients (15.99%). Excluding headaches, 771 patients had neurological involvement (9.6%) (Table 1). Of 8 articles consisting of 1128 patients with MERS, 323 patients (28.6%) had neurological findings and 170 patients (15.07%) without headache. Of 5 articles with 1251 patients with SARS, 187 patients (14.95%) were reported to have neurological involvement and 6.2% (n = 78) with the exclusion of headache. Of 17 articles on 5335 patients with COVID-19, 744 patients were reported to have neurological signs, symptoms, FIGURE. Flow diagram of study selection criteria and results.or sequelae (13.9%) to date, with a rate of 2.47% when headache was excluded (n = 132) (Table 2).At this time, the neurological complications of COVID-19 are not fully understood, but reports of prominent neurological symptoms and complications are beginning to emerge. 1 The current incidence of neurological findings with COVID-19 is relatively low, but as data from prior epidemics show, particularly prior coronavirus-related epidemics, the rate is likely to further increase. Neurological manifestations, including headache, dizziness, altered level of consciousness, focal neurological deficits, cranial nerve involvement, 2 seizures, and to a lesser extent meningoencephalitis, 3 more severe necrotizing encephalopathy, 4 cerebral edema, and stroke, 5 have been reported with the recent viral epidemics. Importantly, with prior epidemics (Table 3), there are also several reports of patients developing neurological sequelae months to weeks later, including cerebellitis, 6,7 neuropathy, 8 Guillain-Barré syndrome, 9 postinfluenza myositis, 10 and postviral Parkinsonism. 11 Coronaviruses are thought to disseminate to the central nervous system (CNS) through either hematogenous spread, retrograde neuronal dissemination, or direct invasion of the olfactory epithelium. 12

Characteristics, onset, and evolution of neurological symptoms in patients with COVID-19

“…In our study, headache was the most frequent neurological symptom (41.1% of the cases). It was also reported as one of the most common complaints in participants with COVID-19 in several other studies where its prevalence ranged between 11.7 and 64.8% of the cases [9,11,15]. As yet, a detailed description of headache characteristics and timeline of its occurrence compared to other COVID-19 symptoms have not been undertaken.…”

“…This study shows the prevalence of neurological manifestations in COVID-19 occurs in 72.1% of participants. In previous studies, neurological symptoms were noted in 13.9 to 57.4% of the cases [ 9 , 11 , 12 ] and up to 84% in a series of patients hospitalized in intensive care units [ 10 ]. Headache, chemosensory impairment, and myalgia were the most frequently observed neurological symptoms in our series.…”

The influence of the COVID-19 pandemic on traumatic brain injuries in Tyrol: experiences from a state under lockdown

“…Additionally, we have to keep in mind that that prior coronavirus-related pandemics have reported high numbers of neurological sequelae such as large vessel stroke and infectious complications [21]. The influence of COVID-19 on TBI patients is currently unknown.…”

Cytokine storm induced by SARS-CoV-2 infection: The spectrum of its neurological manifestations

“…Headache is one of the most common neurological symptoms in patients with COVID-19. Neurological symptoms were found in 13.9% of 5335 COVID-19 patients, while headache was seen in 11.74% of patients, followed by dizziness and altered consciousness observed in 1.17% and 1.17% of patients respectively [29] . A meta-analysis including over 40,000 patients from 60 studies estimated that the incidence of headache is high as 12% [30] .…”