Seizures, climate and pollution: is there evidence of an association?

Epilepsy, a chronic neurological disorder affecting more than 65 million people worldwide, is characterized by recurrent seizures caused by abnormal neuronal discharges. Beyond its diverse etiologies, growing evidence suggests that environmental and meteorological factors, including air pollution, may influence seizure occurrence.

To evaluate the association between meteorological variables, air pollutants, and hospital admissions for seizures in the province of Lleida (Spain) over a 10-year period (2010-2019).

Daily hospital admissions for seizures (ICD-10 code G40) were analyzed together with meteorological variables (temperature, atmospheric pressure, humidity, precipitation, and solar irradiation) and air pollutants (NO₂, PM₁₀, CO, O₃, and SO₂). Distributed lag non-linear models (DLNM) with quasi-Poisson regression were applied to estimate exposure-response relationships and delayed effects, adjusting for long-term trends, seasonality, and day of the week.

A total of 4,755 seizure-related admissions were recorded, representing 0.52% of all emergency visits. The frequency of seizures increased during colder months and periods of poor air quality. Low daily mean temperatures (<2.5th percentile) and high NO₂ concentrations (>99th percentile) were both significantly associated with higher seizure risk (up to +40% and +42% relative risk, respectively; p < 0.05). The association with NO₂ remained significant after adjusting for temperature.

Cold temperatures and elevated NO₂ levels are independently associated with an increased number of seizure-related emergency admissions. These findings highlight the potential neurological impact of air pollution and extreme weather, emphasizing the need for preventive public health measures and further research to clarify the underlying mechanisms.