Abstracts

Rationale: Pediatric autoimmune neuropsychiatric disorder associated with Streptococcal infections (PANDAS) is a rare disorder characterized by unusually rapid onset of obsessive-compulsive disorder (OCD) and/or tic disorders; onset and exacerbations occur as sequelae of group A streptococcal infections. Associated neurological abnormalities include motoric hyperactivity and adventitious movements, including choreiform movements or tics. Seizures are not typical of this disorder. There are no reports of electroencephalographic (EEG) findings in this patient population described in the literature. This study aims to report EEG findings in children with pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS). Methods: Screening EEGs were obtained prospectively as part of a larger study in a consecutive series of 42 children (ages 3-12 years old) diagnosed clinically with PANDAS. Routine EEGs (n=42) and prolonged overnight EEGs (n=14) were performed between 2011 and 2014 at the NIH Clinical Center. Results: No children in this series had a reported history of seizures or epilepsy. However, there were 7 cases with abnormal EEG findings (16.6%). Among them, there were 4 children with EEG findings of focal or multifocal spike/sharp and wave epileptiform abnormalities (9.5%). There were 2 cases with non-specific diffuse and 1 case with right temporal focal slowing (7.1%). Conclusions: In this retrospective review of EEG findings in children with PANDAS, 16.6% had abnormal EEG findings. There were epileptiform abnormalities in 9.5%, although none of the patients had a history of seizures. Interictal epileptiform discharges have been reported in 1.9-3.5% of healthy children without epilepsy. Therefore, these findings indicate some degree of increased cortical irritability, and possibly an increased risk of seizures in this population. Background slowing on EEG, found in 7.1% of these patients, suggests cerebral dysfunction, although this finding is non-specific as to etiology. To our knowledge, this is the first report of abnormal EEG findings in this population.