Pediatric Pertussis Infection May Increase Epilepsy Risk
The incidence rate of children with pertussis developing epilepsy was 1.56 compared with 0.88 in the general population.
Although the absolute risk of developing epilepsy is low, children with hospital-diagnosed pertussis were associated with a slightly higher risk of developing epilepsy compared with the general population, according to research published in JAMA.
“Pertussis, during the acute phase, is associated with seizures in infants, but the likelihood of developing epilepsy is unknown,” wrote Morten Olsen, MD, PhD, from the Department of Clinical Epidemiology at Aarhus Universty Hospital in Denmark. “We therefore conducted a population-based cohort study of the association between pertussis and risk of childhood epilepsy … To our knowledge, this is the first study to examine the risk of epilepsy following pertussis.”
To identify the pertussis cohort, the researchers examined data from the population-based medical registries that cover all Danish hospitals and found 4,700 patients with pertussis born between 1978 and 2011. They then identified 10 individuals from the general population for every 1 patient with pertussis (n= 47,000) matched by sex and year of birth.
The researchers found that out of the 4,700 patients with pertussis, 90 children developed epilepsy (incidence rate, 1.56 [95% CI, 1.55-1.57] per 1,000 person years) compared with 511 children in the comparison cohort (incidence rate, 0.88 [95% CI, 0.88-0.88] per 1,000 person-years). The cumulative incidence of epilepsy at age 10 years was 1.7% (95% CI, 1.4%-2.1%) for the pertussis cohort and 0.9% in the comparison cohort.
Hazard ratios varied from 1.7 to 2.3 in patients diagnosed with pertussis younger than age 3. Patients who were diagnosed with pertussis over the age of 3 did not have an increased risk of epilepsy compared with the general population (HR, 1.0 [95% CI, 0.5-1.8]).
Potential mechanisms for the observed association include “hypoxic brain damage from coughing, perhaps via increased intrathoracic and intra-abdominal pressure and central nervous system hemorrhages.”