Epilepsy is a neurological condition marked by recurrent, unprovoked seizures. While COVID-19 is primarily a respiratory illness, it has been linked to various neurological manifestations. This article explores the scientific understanding of a potential connection between COVID-19 infection and the development of epilepsy, examining how the virus might contribute to seizure activity.
Is There a Link Between COVID and Epilepsy?
Research suggests seizures can occur with COVID-19, but a widespread causal link to new-onset, long-term epilepsy is still under investigation. Seizures are uncommon, affecting fewer than 1% of infected individuals. Studies are exploring how COVID-19 might lead to seizures in people with or without a prior history of epilepsy.
Large population studies offer insights. One 2022 study of 1.2 million COVID-19 patients found no overall increased epilepsy risk, but noted a moderate increase in those over 60. Another study comparing over 150,000 COVID-19 patients to influenza patients found COVID-19 linked to an increased risk of seizures and epilepsy within six months. COVID-19 patients were 55% more likely to develop seizures or be diagnosed with epilepsy (0.94% incidence) than flu patients (0.60%). This risk was more pronounced in children under 16 and in non-hospitalized individuals.
New-onset seizure risk is higher in severe COVID-19 cases, especially among ICU patients. A South Korean study showed 3.6% of severely ill COVID-19 patients needing intensive care developed new-onset seizures. Patients without a history of epilepsy who experienced new seizures often had longer hospital stays and higher mortality. Despite these findings, the overall absolute risk of developing seizures or epilepsy after COVID-19 remains low.
How COVID Might Affect Brain Activity
COVID-19 can influence brain activity through indirect mechanisms, potentially contributing to seizures. One pathway involves inflammation, where the virus triggers an excessive immune response known as a “cytokine storm.” These pro-inflammatory molecules can increase neuronal excitability and disrupt the blood-brain barrier, making the brain more susceptible to seizure activity.
Oxygen deprivation (hypoxia) is another mechanism, occurring in severe COVID-19 due to lung damage. Low oxygen can lead to encephalopathy, a brain dysfunction, and potentially trigger seizures. Blood clotting issues are also observed in some COVID-19 patients, which can result in strokes. Strokes are a known cause of new-onset seizures and epilepsy.
While SARS-CoV-2 is not highly neurotropic, it can still reach the brain and cause damage. This can happen through direct entry or by infecting immune cells that carry the virus across the blood-brain barrier. Fever, a common COVID-19 symptom, can also lower the seizure threshold, especially in children, leading to febrile seizures.
Understanding Seizures After COVID Infection
It is important to distinguish acute seizures during or shortly after COVID-19 from the long-term development of epilepsy. Acute seizures can be triggered by systemic effects like high fever, electrolyte imbalances, or metabolic disturbances. These seizures do not necessarily mean an individual has developed epilepsy, which is defined by recurrent, unprovoked seizures.
People with pre-existing neurological conditions or severe COVID-19 requiring intensive care may have an increased seizure risk. For individuals already diagnosed with epilepsy, COVID-19 infection, like any illness with fever or stress, can potentially increase seizure frequency. However, for most people with epilepsy, the risk of worsening seizures due to COVID-19 appears low.
Some studies indicate a delayed onset of seizures or epilepsy diagnoses after COVID-19, particularly in children and those with less severe infections. This suggests underlying mechanisms may involve slower processes, such as immune system changes, that manifest weeks after initial infection. While the overall incidence of new seizures or epilepsy after COVID-19 is low, it is notably higher than after influenza, even without hospitalization.
When to Seek Medical Help
If new neurological symptoms, particularly seizures, occur after a COVID-19 infection, seek prompt medical evaluation. Symptoms such as prolonged confusion, a seizure lasting more than five minutes, or seizures occurring in clusters warrant immediate medical attention. Difficulty breathing, persistent chest pain, or bluish lips or face are also signs to seek emergency care.
A healthcare provider will conduct a neurological examination and may recommend diagnostic tests. These could include an electroencephalogram (EEG) to measure brain activity or imaging scans like an MRI to look for structural brain changes. These evaluations help determine the cause of seizures and whether epilepsy has developed. Professional medical advice is essential; self-diagnosis is not appropriate for new or concerning neurological symptoms.