Adult epilepsy in a North Norwegian County - incidence, prevalence, clinical features, and mortality (2012-2022)

Epilepsy affects 0.5-1 % of the population and remains a significant neurological disorder. This study examines the epidemiology and clinical characteristics of epilepsy among adults in Troms County, Northern Norway, from 2012 to 2022. We focus on incidence, prevalence, diagnostic approaches, treatment outcomes, use of advanced therapies, mortality rates, and epilepsy-related deaths, including Sudden Unexpected Death in Epilepsy (SUDEP). Methods We conducted a retrospective cohort study using electronic health records to identify adults with active epilepsy (ICD-10 code G40) from 2012 to 2022. Patients were included if they had experienced at least one seizure in the past five years or were actively receiving treatment. Data on demographics, diagnostic evaluations, antiseizure medication use, advanced therapies (vagus nerve stimulation, ketogenic diet), and mortality were analyzed. Factors associated with seizure control and mortality were assessed using multivariate logistic regression and Cox regression, respectively. Results Out of 1606 patient records, 1211 met the inclusion criteria, yielding a prevalence of 687 per 100,000 and an incidence of 43 per 100,000. Sixty percent of patients achieved seizure freedom. Age at diagnosis (OR 0.94, 95 % CI 0.91-0.97, p < 0.001) and number of antiseizure medications (OR 0.60, 95 % CI 0.54-0.66, p < 0.001) were negatively associated with seizure freedom. Only 2 % of patients received vagus nerve stimulation, and 0.4 % followed a ketogenic diet. Over 8407 person-years, 307 deaths occurred, corresponding to standardized mortality ratios of 2.76 for women and 2.70 for men. Sixteen deaths were epilepsy-related, including SUDEP. Key mortality risk factors included poor seizure control, male sex, advanced age, and abnormal EEG/MRI findings. Conclusions The epilepsy prevalence of 0.69 % aligns with Nordic data. The high proportion (39.5 %) of patients with uncontrolled seizures underscores the need for improved treatment strategies and expanded access to advanced therapies. We observed a nearly threefold increase in standardized mortality rates. Advanced age, male sex, poor seizure control, and abnormal EEG or MRI findings were significantly associated with increased mortality. These findings emphasize the need for individualized management strategies to improve long-term outcomes in epilepsy care.