Related Experiment Videos
Factors prognostic of unprovoked seizures after febrile convulsions
Insights
Children with febrile convulsions face a fivefold increased risk of unprovoked seizures. Complex febrile convulsions significantly elevate this risk, especially with multiple features.
Area of Science:
- Neurology
- Pediatrics
- Epilepsy Research
Background:
- Febrile convulsions are common in childhood.
- The long-term risk of unprovoked seizures following febrile convulsions requires further elucidation.
- Identifying prognostic factors for subsequent unprovoked seizures is crucial for risk stratification.
Purpose of the Study:
- To evaluate the risk of unprovoked seizures after initial febrile convulsions.
- To identify factors that predict the occurrence of subsequent unprovoked seizures in children.
Main Methods:
- A cohort study of 687 children with an initial febrile seizure in Rochester, Minnesota.
- Long-term follow-up to assess the incidence of unprovoked seizures until age 25.
- Analysis of simple versus complex febrile convulsion features (focal, prolonged, or recurrent) and their association with seizure risk.
Main Results:
- Children with febrile convulsions had a fivefold excess risk of unprovoked seizures (7% by age 25).
- Risk increased with complexity: 2.4% for simple, 6-8% for one complex feature, 17-22% for two, and 49% for three complex features.
- Complex features strongly predicted partial unprovoked seizures; seizure history and family history predicted generalized-onset seizures.
Conclusions:
- Complex febrile convulsions are associated with a substantially higher risk of subsequent unprovoked seizures, particularly partial-onset seizures.
- Findings suggest a potential predisposition to generalized-onset seizures, while complex febrile seizures may indicate underlying brain conditions.
- Risk stratification based on febrile convulsion characteristics is essential for predicting long-term epilepsy risk.
Abstract:
We evaluated the risk of unprovoked seizures after febrile convulsions and the factors prognostic of them in a cohort of 687 children who had an initial febrile seizure while residing in Rochester, Minnesota. Overall, children with febrile convulsions had a fivefold excess of unprovoked seizures, and the risk until the age of 25 was 7 percent. The risk ranged from 2.4 percent among children with simple febrile convulsions to 6 to 8 percent among children with a single complex feature--i.e., focal or prolonged seizures or repeated episodes of febrile convulsions with the same illness. For children with any two of the complex features, the risk was 17 to 22 percent, and for those with all three features, 49 percent. The occurrence of subsequent partial unprovoked seizures was strongly associated with all three of the complex features, whereas the occurrence of subsequent unprovoked seizures of generalized onset was associated with the number of febrile convulsions and a family history of unprovoked seizures. These results are consistent with the view that the increased risk of generalized-onset unprovoked seizures reflects a predisposition to both simple febrile convulsions and generalized-onset unprovoked seizures. The association between complex febrile convulsions and partial seizures, on the other hand, may reflect either a causal association or the presence of preexisting brain disease that is responsible for both the complex febrile seizures and later partial seizures.