Abstracts

Rationale: Perampanel (PER) is approved as adjunctive therapy for partial-onset seizures with or without secondary generalization and for primary generalized seizures in patients above age 12 years. Adverse effects include anger, hostility, homicidal ideation, dizziness, gait disturbance, somnolence and falls. Since institutionalized adults with severe intellectual disability and intractable epilepsy often have additional significant medical and behavioral disorders requiring multiple medications, we were concerned that adverse effects of PER would outweigh potential benefis of seizure reduction. We review the outcome in 12 patients initiated on PER over a 2&1/2 year period. Methods: An observational study was conducted between August, 2014 and November, 2016. Twelve adults with intractable epilepsy living in a State Development Center were started on PER according to pharmacy records. Dosage of PER ranged from 4mg to 12mg daily. All had severe intellectual disability as well as various other medical and behavioral diagnoses. There were 6 men and 6 women, ages 41 to 63 years. All were taking at least 2 other AED's besides PER, and 8 had VNS. Data regarding syndrome, seizure types, concomitant and previous AED's, adverse effects, and efficacy were extracted from medical records, discussions with primary care physicians as well as staff caregivers, and regular Neurology Clinic visits through March, 2017.  Results: There was >50% decrease in seizure frequency in 10 of the 12 (83%), decreased severity in one whose seizure frequency was unchanged, and no clear improvement in one. Only one of the 12 was independently ambulatory prior to starting PER, and he developed no problems with gait ataxia or falls. One person had increased irritability shortly after starting PER and it was discontinued, but restarted several months later without difficulty. Another had increased irritabilty when dosage was raised from 4mg to 6mg QD; dosage resumed at 4mg without adverse effects. There were no other concerns about irritability, agitation, self-injurious behavior, or behavioral outbursts associated with PER. We saw no idiosyncratic reactions. Conclusions: Perampanel was associated with good efficacy and minimal ongoing side effects in this population with chronic severe encephalopathy and intractable epilepsy. Future research in these patients may be warranted.  Funding: No funding was received in support of this abstract.