Treatment of Paroxysmal Kinesigenic Dyskinesia With Use of Low Dose Oxcarbazepine: Experience at a Pediatric Tertiary Care Center. (2038)

Objective: Paroxysmal kinesigenic dyskinesia (PKD) has classically been treated with carbamazepine and phenytoin in children and adults. Side effect profiles of these drugs limit their use, especially in those that require prolonged treatment. Scant literature exists regarding dosing regimens and efficacy of other antiepileptics for this disorder. We describe a series of nine patients with PKD treated effectively with low doses of oxcarbazepine. Background: Paroxysmal dyskinesias are a rare group of conditions that manifest as abnormal involuntary movements occurring episodically and last seconds to minutes. In PKD, attacks are induced by sudden movements and last seconds to minutes, often occurring 20 or more times daily. Treatment has been carbamazepine or phenytoin with doses in children comparable to those used for epilepsy. Design/Methods: A retrospective chart review included patients under 18 years of age with a diagnosis of PKD (based on ICD9/10 codes and/or clinical documentation) evaluated at Texas Children’s Neurology clinics from 2012–2019 and trialed on oxcarbazepine. Results: Twenty charts were queried; 10 patients met inclusion criteria. Mean age of onset was 9.45 years. Movements described included dystonia (90%), chorea (50%), or a combination of both (40%). PRRT2 pathogenic variants were identified in 60% of patients. Medical history included benign familial infantile epilepsy (BFIE) (20%) and migraine (20%). Pertinent family history included PKD (40%), BFIE (10%), migraine (10%), essential tremor (30%), and cervical dystonia (10%). Oxcarbazepine was effective in obtaining complete remission in 9 patients and was the only medication utilized in 8. Average lowest effective dose was 617 mg daily (10.8 mg/kg/day) with no adverse effects. Conclusions: Carbamazepine and phenytoin have been known to be effective in management of PKD. In our cohort, oxcarbazepine was found to be effective and in doses much lower than those used in epilepsy without adverse effects. We propose a trial of oxcarbazepine for first line treatment of PKD. Disclosure: Dr. Hull has nothing to disclose. Dr. Abid has nothing to disclose. Dr. Parnes has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Kadmon Corporation, Teva Neuroscience, and Medlink.