Infectious diseases implicated in epilepsy
A broad range of peripheral infections, including those of the central nervous system (CNS), appears to be associated with a heightened risk of developing epilepsy, potentially due to inflammatory processes affecting the brain, according to a study.
In a Danish cohort of 1,938,555 individuals, 573,915 (53.9 percent male) had a hospital contact for infection during a median follow-up of 14.6 years. Meanwhile, 25,825 individuals (1.3 percent) developed epilepsy, of whom 8,235 (32 percent) had a previous hospital contact for infection.
Multivariable Cox proportional hazards analysis revealed that a hospital contact for infection was associated with a 78-percent increase in the risk of subsequently receiving an epilepsy diagnosis (hazard ratio [HR], 1.78; 95 percent CI, 1.73–1.83).
The highest risk of incident epilepsy was identified after CNS infections (HR, 4.97; 4.42–5.59), although substantial risk increases were observed across all infected organ systems and types of pathogens.
Furthermore, the risk of receiving an epilepsy diagnosis was associated with the temporal proximity of the infection (p<0.001), increasing with the number of hospital contacts for infection (p<0.001) and with the severity of infection (p<0.001).
Sensitivity analyses for specific types of epilepsy showed that the risk of epilepsy with focal‐onset seizures was higher (HR, 1.97; 1.87–2.07) than that of epilepsy with generalized‐onset seizures (HR, 1.66; 1.56–1.76). The HR for other or unspecified epilepsy was 1.87 (1.81–1.93).
Peripheral infection may affect the brain through initiation of immunologic cascades and brain‐reactive antibodies, thereby increasing the risk of epilepsy, researchers noted.
The current findings indicate that the inflammatory processes occurring in response to peripheral infections may also harm the brain, possibly shedding light on the association with epilepsy and psychiatric morbidity alike, they added.