Carisbamate Retention Study (CaReS): Comparative Study on the Long Term Effectiveness, Safety and Tolerability of Carisbamate Compared to Two Other Frequently Prescribed Anti-epileptic Drugs (AEDs) in Patients With Epilepsy.

Inclusion Criteria:

• Patients must weigh >= 45 kg (~100lbs)

• established diagnosis, for at least 3 months prior to screening, of partial onsetseizures, including simple partial motor, complex partial, or secondarily generalizedseizures

• At least 1 but no more than 120 partial onset seizures during the 3-monthretrospective baseline period prior to screening

• History of monotherapy AED treatment failure at at least 1 but not more than 4 AEDs inthe past

• Females must be postmenopausal for at least 2 years, surgically sterile, abstinent,or, if sexually active, practicing an acceptable method of birth control (eg,intrauterine device, double barrier method, male partner sterilization) before entryand throughout the study

• Females must have a negative serum beta chorionic gonadotropin pregnancy test resultat screening/randomization

• Current AED treatment with at least 1 and no more than 2 AEDs given at a stable dose 30 days prior to screening

• For adolescents (as defined by local regulations), a responsible person must beavailable to accompany the patient to the study center at each visit, to providereliable information for the safety and effectiveness evaluations, and to accuratelyand reliably dispense the study drug as directed, if required in the opinion of theinvestigator.

Exclusion Criteria:

• Must not have a generalized epileptic syndrome, primary generalized seizures, atonicseizures, typical or atypical absence seizures nor only simple partial type seizureswith manifestations other than motor symptoms (i.e, simple partial sensory)

• No history of unprovoked status epilepticus in the last 6 months prior to screeningnor history of Lennox-Gastaut or West Syndrome

• More than 3 days of sedative or benzodiazepine use for seizures in the 3 months monthsprior to screening

• No clinical evidence of significant cardiac disease

• ALT > 1.5 times the upper limit of normal or total bilirubin above the upper limit ofnormal at screen

• No history of drug-induced liver injury, diagnosis of any form of chronic liverdisease, cirrhosis, or liver cancer nor positive hepatitis serology as determined bymultiantigen enzyme immunoassay (EIA)

• No past or current with topiramate or levetiracetam for any reason

• No current use of vagal nerve stimulator

• No diagnosis of psychotic disorder, bipolar disease, or major depression or otherneurologic conditions, serious or medically unstable systemic disease, suicidalideation or attempts, or homicide attempts at any time in the past 2 years

• Unable to swallow solid oral dosage forms whole with the aid of water (patients maynot chew, divide, dissolve, or crush the study drug)

• Anyone who falls under the precautions, warnings or contraindications outlined in thelocal topiramate and/or local levetiracetam package insert.