Abstracts

Rationale: Since its description in 2007, Anti-NMDA receptor (NMDAR) encephalitis has been diagnosed with increasing frequency amongst the pediatric population. Many patients present with seizures as part of their clinical spectrum. EEG results were reviewed in children with confirmed NMDAR encephalitis to identify specific characteristic EEG findings in this population.Methods: A retrospective chart review was performed of EEG findings in patients with laboratory confirmed NMDAR encephalitis (serum/CSF) seen at Children s Medical Center Dallas from 2010-2013. All EEGs were interpreted by pediatric epileptologists at UT Southwestern Medical Center. Results: Ten patients with NMDAR encephalitis who had EEGs done as part of their workup at our institution were included (6 males, 4 females). In one case both EEGs reviewed were normal. The remainder had at least one abnormal EEG during their clinical course. A total of 44 EEGs were reviewed and 37 of these were considered abnormal. Amongst these, 65% showed generalized continuous or intermittent slowing, and 14% showed focal slowing. Epileptiform abnormalities were seen in 38% of EEGs that included generalized spike-wave complexes in 7 EEGs, focal spike-wave complexes in 6 EEGs, paroxysmal fast activity in 2 EEGs and clinical seizures in 2 EEGs (one focal and one generalized). Only one of our patients had an EEG pattern considered an extreme delta brush on one of the EEGs.Conclusions: Nine out of ten patients identified with NMDAR encephalitis had abnormal EEGs during the course of their illness. Focal and generalized slowing in theta and delta frequencies were the most common abnormal findings in these patients. Only one of our patients presented with an extreme delta brush that in adults has been associated with NMDAR encephalitis.