The goal of our study was to apply the APE2 and RITE2 scores in a cohort of autoimmune encephalitis (AE) patients at Stanford with immune-mediated seizures.

Early identification and immunotherapy in those with immune-mediated seizures are associated with better neurologic outcomes and reduction of seizures. There have been previously published scoring systems to identify antibodies (Ab) and responsiveness to immunotherapy that were applied to our cohort.

This was a retrospective study at Stanford University Hospital with chart review of the electronic medical record between 2008-2021. Patients were included if they had acute symptomatic seizures secondary to autoimmune encephalitis or autoimmune-associated epilepsy as defined by the International League Against Epilepsy (ILAE) and possible, auto-Ab negative but probable, or definite AE using diagnostic criteria from Graus. Patients were excluded if no Ab panel was drawn or the patient was lost to follow-up. Chart review was used to calculate scores.

Fifty-six patients were identified, and 3 were excluded. The APE2 score ≥ 4 to predict positive serum Ab had a sensitivity of 92.7% and specificity of 6.7%. The RITE2 score ≥ 7 to predict seizure responsiveness to immunotherapy had a sensitivity of 92.9% and specificity of 60%.

The APE2 and RITE2 scores were sensitive in our patients, which implies that these scores can likely be used to identify patients within the Stanford cohort who may have seropositive AE and may benefit from early immunotherapy. Our APE2 score and RITE2 scores were less specific than Dubey’s, likely due to patient selection. We only included those with suspected AE with seizures, whereas Dubey included a broader, more heterogenous patient population including those with Parkinsonism, stroke, memory disorders, and other neurologic disorders.