This study is a retrospective study of participants who received perampanel as primary or secondary monotherapy at approximately 40 centers in Europe, Asia, and Australia. Primary monotherapy is defined as the administration of perampanel in the absence of any concomitant antiepileptic drugs (AEDs). Secondary (conversion) monotherapy is defined as the conversion of perampanel from adjunctive therapy to monotherapy by withdrawing concomitant AEDs.