Analyze the clinical characteristics and seizure outcomes in a previously described cohort of patients with autoimmune epilepsy with at least 18 months of follow-up after confirmation of autoantibody positivity. 

Identification of autoimmune epilepsy is important as these patients may be refractory to conventional anticonvulsant medications and may benefit from immunotherapy. Additionally in some of these patients there may be an underlying malignancy. In this study we examine long term seizure outcomes in epilepsy patients seropositive for neural-specific antibodies targeting variety of cell surface and intracellular protein

This is an observational retrospective case series with clinical data collected between 2013 and 2019 utilizing the electronic medical records at two tertiary care hospitals. 

Of 34 patients originally described, 16 had follow-up of at least 18 months following antibody testing. Mean follow up was 39.62 months (range: 23-79 months). The mean age was 53.5 (range: 31-81 yrs), 5 were women (31.2%), 6 were African Americans and 6 were Hispanic. Eleven patients (68.75%) had received immunomodulatory therapy, of which 9 had received IV steroids (7 also received either IVIG or plasmapheresis) while 6 received other immunomodulatory therapies (rituximab, etc). Eight patients had abnormal MRIs while 12 had abnormal EEGs. A temporal seizure onset was described in 10 patients. 8 patients were seizure free at last clinic visit with anticonvulsant medication reduction occurring in 3 patients; 2 patients saw medication increases. On univariate analysis no dependent variable (immunomodulatory therapy, gender, MRI abnormality, EEG abnormality, mesial temporal sclerosis) was significantly associated with the independent variable (seizure freedom).

Variablity of immunotherapy and anti-convulsant regimens utilized in retrospective studies limits assessment of therapies associated long-term seizure freedom. This suggests the need for a prospective interventional trial to provide more evidence to determine factors affecting seizure freedom in patients with autoimmune epilepsy.