Abstracts

Rationale: While seizures are well described in Angelman Syndrome (AS), they are less commonly seen among the Prader Willi Syndrome (PWS) population. The purpose of this study is to characterize the prevalence and clinical characteristics of epilepsy in PWS. Methods: Retrospective review of medical records was conducted on all patients with PWS at Children’s Hospital Boston from 2005-2009. Records were reviewed for presence of seizures, seizure types, EEG features, neuroimaging findings and outcome. Review of genotype analysis for each case was also conducted. Results: Of the 73 patients identified, 21 (28.7%) had a history of seizures. Seizure types included absence (47.6%), atonic/tonic (19%), tonic-clonic (9.5%), and complex partial seizures (23.8%). Review of EEG features showed focal findings in 47.6% cases, generalized abnormalities in 19%, and normal findings in 33.3% cases. Approximately 83% of PWS patients with epilepsy were started on anti-epileptic treatment, and 60% of these patients had good seizure control. Neuroimaging studies were normal in 11 cases; while non-focal abnormalities were observed in 3 cases. Genotypic analysis and correlation with phenotype will also be presented. Conclusions: Epilepsy is common among patients with PWS. In our study, the most common seizure type was staring spells and complex partial seizures. Non- epileptic behavioral staring is also common. Unlike AS, seizures are less common and well controlled with medications. We also hypothesize that large gene deletions may be associated with epilepsy in PWS.