Seizures and COVID-19
Initially thought to be mainly a respiratory infection, it is now clear that COVID-19 is associated with neurological involvement in more than 30% of patients, with approximately 25% having symptoms indicating CNS dysfunction. Fortunately, the incidence of seizures appears to be low (0.5%).3 Although there are case reports of seizures at onset in both adults and children, new-onset seizures and status epilepticus (SE) are rarely described. In a recent multicenter, retrospective study of 304 people with no known history of epilepsy in China, neither acute symptomatic seizures nor SE was observed.4 Two people had seizure-like symptoms during hospitalization that were thought to be related to acute stress reaction and hypocalcemia. There was no evidence suggesting an additional risk of acute symptomatic seizures in people with COVID-19. About a third (30%) of respondents in the current survey reported seeing COVID-19 patients with new-onset seizures. This high rate, which is much higher than we might expect given the reported rate of new-onset seizures in the literature (0.5%), is likely reflective of the population surveyed, namely epilepsy specialists.3
A number of mechanisms of neuropathogenesis related to COVID-19 have been described, including manifestations of systemic disease including hypoxia, metabolic derangements, and multi-organ failure; direct invasion of the nervous system (meningitis/encephalitis); and a postinfection immune-mediated process.5,6 All of these may lead to seizures, but the specific contribution of each mechanism is unclear, and in some cases the cause may be multifactorial. Meningoencephalitis associated with COVID 19 with transient seizures has been described in one patient.7 The responses in the AES survey reflected similar uncertainty of possible mechanisms causing seizures.
There are very few data regarding the type of new-onset seizures seen in patients with COVID-19 in the literature. There is a single case report of focal SE as a presenting manifestation in a patient with underlying postencephalitic epilepsy.8 A small case series of 7 patients with COVID-19 presenting with seizures, of which 4 had new-onset seizures, has been reported.9 A patient with COVID-19 related meningoencephalitis was reported to have generalized seizures lasting about a minute.7 One EEG-based case series demonstrates abnormalities seen in encephalopathic patients with COVID-19, including generalized slowing, generalized epileptiform discharges and focal seizures, although many of the patients in the series had preexisting epilepsy.10 In this study, there were 2 patients with focal seizures, 1 was new onset and 1 was in a PWE. Additionally, in this study several patients had generalized periodic discharges of triphasic morphology. Other patients with COVID-19 related new onset seizures and SE have also been described.11,12
Respondents in the current survey did not notice an increase in susceptibility of PWE to COVID-19. This is supported by a consensus statement which finds no increased risk of acquiring COVID-19 in most PWE.13 Exceptions include PWE who are being treated with immunosuppressant medications or those particularly sensitive to fever. However, a recent study that reported on EEG findings in 8 patients with COVID-19 related neurologic problems found 5 (63%) had a history of epilepsy.10 These authors raised the concern that PWE may be at increased risk developing neurologic manifestations if they acquire COVID-19.