P541: Impact of specialty clinic evaluation on antiepileptic prescribing patterns in patients with Angelman syndrome

Introduction: Intractable epilepsy in a common feature of Angelman syndrome and is often resistant to pharmacologic treatment, frequently requiring combination therapy with multiple antiepileptic agents.While there are no universally accepted guidelines for the pharmacologic management of epilepsy in Angelman syndrome, the literature increasingly recommends newer antiepileptic agents such as levetiracetam, lamotrigine, and clobazam as first-line agents in Angelman syndrome given their similar efficacy and more favorable side effect profile when compared to older antiepileptic medications such as valproate.Evaluation at a specialty clinic may influence adherence to these evolving treatment preferences.This study aimed to determine whether patients with Angelman syndrome who have been evaluated by the University of North Carolina Angelman Syndrome Clinic were more likely to be prescribed antiepileptic agents in accordance with current recommendations.Methods: A retrospective chart review was performed to determine the antiepileptic medication history of patients in the University of North Carolina medical system with an established diagnosis of Angelman syndrome.Inclusion criteria consisted of all patients in the University of North Carolina medical system identified to have an ICD10 diagnosis of Angelman syndrome (Q93.51).Out of 163 patients who met inclusion criteria, 5 patients who did not have a confirmed genetic diagnosis of Angelman syndrome and 4 patients who ultimately received an alternative genetic diagnosis were excluded from analysis.The remaining 154 patients were assessed for demographic information, current and previous antiepileptic medication history, and whether they had been evaluated by the University of North Carolina Angelman Syndrome Clinic.Results: Of the 154 patients assessed, 123 (79.9%) had been evaluated by the University of North Carolina Angelman Syndrome Clinic and 31 (20.1%) had not.The proportion of patients currently prescribed preferred antiepileptic agents who had been evaluated by the specialty clinic compared to those who had not was 40.6% vs 32.3% for levetiracetam, 10.6% vs 6.5% for lamotrigine, and 27.3% vs 16.1% for clobazam.The proportion of patients currently prescribed the non-preferred agent valproate who had been evaluated by the specialty clinic compared to those who had not was 6.5% vs 16.3%.Using Bayesian inference with a beta(1,1) uninformative prior, we estimated that specialty clinic patients had a 91.6% probability (95% CrI: 85.7%-96.0%) of receiving preferred antiepileptic agents vs 75.0%(95% CrI: 56.3%-89.8%)for non-specialty clinic patients, with a 98.2% probability that specialty clinic evaluation is associated with higher rates of preferred antiepileptic prescribing.Conclusion: This study demonstrates that engagement with the University of North Carolina Angelman Syndrome Clinic is associated with improved adherence to current recommendations for the pharmacologic management of epilepsy in Angelman syndrome.These findings highlight the value of multidisciplinary specialty clinic involvement in optimizing pharmacologic treatment plans and potentially improving overall clinical outcomes in patients with Angelman syndrome.