Low ambient temperature as the only meteorological risk factor of seizure occurrence: A multivariate study

Background: The onset of epileptic seizures is influenced by weather, which is multifactorial. It is unknown which specific weather factors affect the occurrence of seizures. Objectives: We studied the correlation between the onset of epileptic seizures and multiple weather parameters based on a population-based registry profile. Methods: We determined the number of patients who visited emergency services in Taiwan diagnosed as having epilepsy. Then we used a linear regression model to analyze the monthly average number of patients who received emergency treatment for epilepsy in relation to temperature, barometric pressure, accumulated precipitation, relative humidity, and hours of sunshine. The Poisson regression model was used to analyze multiple meteorological factors in relation to the number of daily emergency visits because of epilepsy. A receiver operating characteristic curve was used to determine the cutoff temperature for the occurrence of seizures. Results: Temperature appeared to be the robust factor for the onset of epilepsy. For every 1 °C decrease in temperature, there was a relative risk increase of 1.016 in the number of emergency visits as a result of epilepsy. Temperature lower than 18 °C had the best predictive value for seizure. Barometric pressure, accumulated precipitation, relative humidity, and the number of hours of sunshine were not related to the occurrence of seizures. Significance: Our results suggest that temperature is the only influential meteorological factor that affects seizure occurrence.