Epilepsia | 2019
Epilepsy in Asia
Abstract
Epilepsies are a global public health problem affecting approximately 50 million people, 80% of whom live in low‐ and middle‐income countries. Epilepsies are associated with a high social, psychological, and economic burden for patients, particularly in Asian countries, where the stigma of epilepsy remains high and discrimination against people with epilepsy is common. The risk of premature death among patients with epilepsy is approximately 2–3 times higher than that in the general population, but is up to 5 times greater in Asian cohorts.3–5 Premature death may be related to the underlying cause of the disease, comorbidities, accidents occurring during a seizure, status epilepticus, sudden unexplained death in epilepsy, or suicide. Asia is a diverse region, with heterogeneous economies and differing healthcare systems; thus access to treatment varies throughout the region. Limited resources, lack of access to treatment, stigmatization, cultural beliefs, and lack of knowledge exclude up to 90% of people with epilepsy in low‐income countries from being adequately treated. In fact, the magnitude of the treatment gap is highest in Asia, which is also the most highly populated region in the globe. Conversely, poor seizure control contributes to low educational achievement, poor employment opportunities and productivity, increased morbidity and mortality, and reduced quality of life. Antiepileptic drugs (AEDs) are more widely available in urban than in rural areas of Asia, and their supply is notoriously unreliable in rural areas, where lack of financial resources can result in treatment interruption. Newer AEDs, with more favorable safety profiles, may not be available in all countries. Epilepsy specialists also tend to be accessible only in urban areas. There is limited epilepsy research coming from Asian countries, and standardized epidemiologic and surveillance studies are needed to provide comparative data across the region. Furthermore, results of clinical trials performed in European or North American countries do not necessarily translate to Asian populations who may experience variability in drug response due to a different genetic background. For example, there are significant racial differences in the degree of hepatic CYP isoenzyme expression, and AED‐induced cutaneous adverse reactions may occur more frequently in Han Chinese and Thai populations. Perampanel is a new noncompetitive α‐amino‐3‐hydroxyl‐ 5‐methyl‐4‐isoxazole‐propionate (AMPA) receptor antagonist that has been approved as adjunctive therapy for focal seizures with or without secondary generalization and primary generalized tonic–clonic seizures, and as monotherapy for focal seizures. Perampanel is now available in more than 55 countries, including in Asia. The pivotal, randomized, double‐blind, placebo‐controlled phase 3 clinical trials were performed among global populations,10–14 and the data for Asian patients have been analyzed separately and are reported in this supplement. The first article of this supplement describes the burden of epilepsy in Asia and reviews the current management and treatment challenges. In the second article, Potschka and Trinka assess the profile of perampanel and its potential for broad‐spectrum use. In the following 3 articles, the data for perampanel use in Asian patients enrolled in phase 3 clinical trials are reported. Tsai et al assess the efficacy, safety, and tolerability of perampanel as adjunctive therapy in Asian patients with focal epilepsy with or without secondary generalization; Nishida et al examine its efficacy and safety in Asian patients with primary or secondarily generalized tonic– clonic seizures; and Inoue et al investigate the long‐term use of perampanel in Asian patients with refractory focal seizures or complex partial seizures with or without secondary generalization. The 3 studies each found that the efficacy, safety, and tolerability of perampanel in Asian patients were similar to the results for the non‐Asian patients in phase 3 trials, suggesting a benefit also for this patient population. The challenge for the future is to reduce the treatment gap in Asia through standardized research, implementation of evidence‐based epilepsy guidance for low‐ and middle‐ income countries, and better availability of effective AEDs. Given the results for Asian patients, the addition of perampanel to the treatment armamentarium increases the choice of AEDs in this part of the world.