The purpose of this study is to create a patient registry to collect and analyze information on subjects treated with Sabril and the prescribers of Sabril.

This prospective registry is part of the overall Risk Evaluation and Mitigation Strategy (REMS) required for Sabril by the United States Food and Drug Administration (FDA). All physicians who prescribe Sabril and all patients who take Sabril will be enrolled in a H. Lundbeck A/S-sponsored program called "SHARE" (Support, Help and Resources for Epilepsy), and the data that are collected and entered into the SHARE database will form the basis of this patient registry.

Prior to any prescription being filled by one of the specialty pharmacies, the prescribing physician and the patient must be enrolled in SHARE. A call center (SHARE Call Center) will act as the hub for a network of select specialty pharmacies. Participation in both SHARE and the patient registry is mandatory.

Information regarding prescriber specialty and location, patient demographic and disease characteristics will be collected through SHARE and entered into the database. Patients will be assigned a unique patient identifier upon entry into the registry, and all data related to that patient will be associated with this identifier.

Early in therapy (within 2-4 weeks for Infantile Spasms patients and 3 months for adult refractory Complex Partial Seizures patients), a mandatory benefit/risk assessment will occur. If the benefit of Sabril therapy exceeds the risk of vision loss, the prescribing physician will complete and submit the appropriate SHARE form and the patient will continue into the maintenance therapy phase of treatment. The outcome of this benefit/risk assessment will be entered into the database.

Regular assessments of vision are required during Sabril therapy to contribute information related to the ongoing benefit/risk assessments. The required assessments will occur at baseline, every 3 months during therapy, and about 3-6 months after stopping Sabril. The visual assessment results will be recorded and submitted using the appropriate SHARE forms, and the data will be entered into the database. A copy of the visual field will be included.

Patients will participate in the registry for as long as they receive Sabril therapy. Patients who discontinue treatment with Sabril, but are treated with it again at a later time will be treated as a single patient in the registry.

Inclusion Criteria:

• All patients in the U.S. who are prescribed Sabril must participate in this patient registry in order to receive Sabril.

All patients in the U.S. who are prescribed Sabril must participate in this patient registry in order to receive Sabril. There are no other eligibility criteria for this study.