COVID-19, caused by the SARS-CoV-2 virus, is primarily known as a respiratory illness, yet it can also lead to various neurological symptoms. These can range from common complaints like headaches and loss of smell or taste to more serious conditions. The possibility of seizures occurring in individuals with COVID-19, whether directly or indirectly linked to the infection, has been a subject of ongoing research. Understanding this relationship is important for affected individuals and healthcare providers.
Does COVID-19 Directly Cause Seizures?
Whether the SARS-CoV-2 virus directly triggers seizures involves its potential to invade the central nervous system. While the virus can indeed reach the brain, this direct neuroinvasion is considered less common than indirect pathways for seizure induction. Researchers have observed the presence of SARS-CoV-2 RNA and viral proteins in the brain tissue of some deceased COVID-19 patients.
The virus may enter the central nervous system through several routes, including the olfactory nerve pathway or by crossing the blood-brain barrier. Once inside the brain, the virus could potentially cause inflammation of the brain tissue, known as encephalitis, or lead to direct damage to neurons. However, studies suggest that new-onset seizures directly caused by SARS-CoV-2 neuroinvasion are relatively rare. For instance, one review found that only 0.25% of hospitalized COVID-19 patients experienced seizures, with an incidence of new-onset seizures in severely ill individuals being around 3.6%.
Indirect Pathways to Seizure Activity
Seizures in COVID-19 are more frequently linked to indirect mechanisms than direct viral invasion. A common indirect trigger is high fever, which can lead to febrile seizures, particularly in children. The inflammatory response, often referred to as a “cytokine storm,” also contributes to seizure activity. Pro-inflammatory molecules released during this process can increase neuronal excitability, lowering the seizure threshold.
Systemic complications of severe COVID-19 can also induce seizures. Hypoxia, or a lack of oxygen to the brain due to severe respiratory distress, can cause brain damage that results in seizures. Metabolic disturbances, such as electrolyte imbalances (e.g., low sodium levels), are another indirect cause, as these can disrupt normal brain function and trigger seizures. Complications like strokes or blood clots, which are known to occur in some COVID-19 patients, can also lead to new-onset seizures by causing brain tissue injury.
Who is More Susceptible?
Certain groups face an increased likelihood of seizures with COVID-19. People with pre-existing neurological conditions, such as epilepsy or a history of stroke, may be more vulnerable. For those with epilepsy, a COVID-19 infection, particularly with fever, can sometimes increase seizure frequency, though the overall risk appears low.
The severity of COVID-19 also plays a role, with seizures more common in individuals with severe or critical disease. Older adults and those with multiple underlying health conditions are at higher risk. Children, especially those under 16, have also shown a higher relative risk of developing seizures or epilepsy after COVID-19 compared to influenza.
What to Do About Seizures and COVID-19
If a seizure occurs during or after a COVID-19 infection, seek immediate medical attention. Contact emergency services for evaluation and management. Avoid self-diagnosing the cause, as many COVID-19 related factors can contribute.
Consult with healthcare professionals for accurate diagnosis and appropriate treatment. Inform them about the COVID-19 infection and any pre-existing medical conditions. For new-onset seizures or a worsening of an existing seizure disorder, follow-up care with a neurologist is recommended to determine the underlying cause and establish a long-term management plan.