Recurrent febrile seizures in children are associated – according to recent study results – with an increased risk of psychiatric disorders and epilepsy in adulthood. Possibly an effect on the temporal lobe could be decisive.
Febrile seizures are relatively common in childhood, affecting an estimated 3% to 4% of children. Generally, such seizures are considered benign. However, Danish researchers now found that the 30-year risk of epilepsy and psychiatric disorders in children with three or more febrile seizures was 15% and 30%, respectively. In comparison, the risk of mental illness and epilepsy in unaffected individuals is 2% and 17%, respectively. The study also showed that mortality is increased in patients with recurrent febrile seizures who then develop epilepsy.
The researchers defined three subpopulations of children with febrile seizures and no prior diagnosis of epilepsy, cerebral palsy, intracranial tumors, severe head trauma, or intracranial infections. These subpopulations included children who had experienced at least one febrile seizure, those who had experienced at least two, and those who had experienced at least three. The risk of recurrence before 5 years of age in children who had a febrile seizure was 22.7%. With each additional bout of fever, this risk increased.
From other national registries, investigators collected data on epilepsy and psychiatric disorders. They used competing risk regressions to estimate cumulative incidences and Cox regression to arrive at hazard ratios (HRs) for the risk of occurrence of these disorders in different age groups as a function of the number of febrile seizures.
Children with a febrile seizure were found to have a sevenfold increased risk of epilepsy diagnosis at age 5 years (HR: 7.11). However, if the child had three or more febrile seizures, the risk was increased 42-fold (HR: 42.06). When psychiatric disorders were included, the researchers found that the 30-year risk at birth was about 17%. Again, there was a gradual increase with each subsequent bout of fever. In the subgroup with three or more febrile seizures, the risk was nearly 30%.
Direct or indirect effect?
The reason for the increased risk could not be proven. It has been speculated that it may be an effect of febrile seizures on the temporal lobe. But it could also be possible that it is a genetic confusion that increases the risk of febrile seizures, as well as the risk of psychiatric disorders. Further research may shed more light on the matter.
Source: 5th Congress of the European Academy of Neurology (EAN).
InFo NEUROLOGY & PSYCHIATRY 2019; 17(6): 39 (published 11/24/19, ahead of print).
