Rationale:
In 2017, a new classification of epilepsy by the International League Against Epilepsy acknowledged the concept of “epilepsy of immune etiology.” However, there is a scarcity of epidemiological data and information regarding the impact of these disorders on healthcare planning and resource allocation. This study aims to estimate the prevalence and incidence of autoimmune seizures and epilepsy, as well as evaluate the disease burden associated with these conditions.
Methods:
We performed a population-based epidemiology study in Olmsted County, Minnesota, with patients identified between January 1, 1996 to June 30, 2019, using the medical records linkage system of the Rochester Epidemiology Project (REP). Age and sex specific population count were obtained from REP census data. Prevalence and incidence were calculated for all autoimmune seizure/epilepsy as all as acute symptomatic seizures secondary to autoimmune encephalitis (ASS) and autoimmune associated epilepsy (AAE). Morbidity was estimated using disability-adjusted life
Results:
On December 31, 2019, age and sex-adjusted overall prevalence of autoimmune seizures and epilepsy was estimated at 6.87 per 100,000 population, with adjusted prevalence of 5.51 per 100,000 for AAE and 5.12 per 100,000 for active epilepsy. The majority of the patients tested positive for neural autoantibody, with high titer serum GAD65 IgG being the most common autoantibody. The incidence rate of autoimmune seizure/epilepsy from 1996-2019 was 0.33 per 100,000 person-years. The incidence rate of seropositive and seronegative autoimmune seizure/epilepsy were 0.14 and 0.18 per 100,000 respectively. The age and sex standardized DALYs of autoimmune seizures and epilepsy was 41.13 per 100,000 population in 2019.
Conclusions:
Although autoimmune seizure/epilepsy is a rare condition, it is associated with considerable clinical morbidity.
Funding: None