Abstracts

Rationale: To describe the continuous electroencephalographic (cEEG) findings in antibody proven autoimmune encephalitides (AE). Methods: Retrospective review of cEEG findings of patients hospitalized at Emory University Hospital with antibody proven AE from 01/01/12 to 12/31/16. Results: 60 patients (male 40%, Caucasian 62%, median age 46)  with antibody proven AE [N-methyl-D-aspartate receptor (NMDA) 17%, glutamic acid decarboxylase (GAD) 13%, acetylocholine receptor (ACh) 10%, thyroid peroxidase/thyroglobulin antibody (TPO/TG) 10%, voltage-gated calcium channel (VGCC) 8%, voltage-gated potassium channel (VGKC) 13%, anti Ro/SSA and anti La/SSB 7%, Dopamine 2%, Mixed 20%] were studied. 72% had abnormal magnetic resonance imaging (MRI) findings and 70% had abnormal lumbar puncture (LP) findings. 63% of patients had substantial abnormalities in their cEEG. Seizures were seen in 48% of them (41% of which with NMDA or GAD antibodies). New Onset Refractory Status Epilepticus (NORSE) was seen in 18% of patients (45% of which had GAD antibodies). Lateralized (LPDs), generalized (GPDs) and bilateral independent (BIPDs) discharges were seen in 22%, 18% and 8% of patients respectively (without specific antibody association). Lateralized (LRDA) was seen in 8% and generalized (GRDA) in 27% of patients (44% of which had NMDA antibodies). 53% of patients had poor outcome on discharge. Conclusions: More than half of patients with antibody proven AE have substantial cEEG abnormalities. Electrographic seizures are seen in approximately 48% of AE in the acute phase, most commonly those with antibodies against NMDA and GAD. NORSE was seen in 18% of patients, most commonly in those with GAD antibodies. GRDA is seen more commonly with NMDA encephalitis. Funding: none