• The primary efficacy outcome is the overall normalized, restricted Tremor Rating Scale (TRS) score after carisbamate treatment compared to placebo treatment.
  

• Overall normalized TRS score; overall normalized unrestricted TRS score, raw TRS total score, raw TRS subscale scores, normalized TRS subscale scores; Physician and Subject Global Impression of Change; and CES-D, POMS and QUEST scores.
  

The hypothesis of the study is that carisbamate will be effective in the treatment of Essential Tremor compared to placebo as measured by the Fahn-Tolosa-Marin Tremor Rating Scale (TRS). This randomized (study medication assigned by chance) study has 3 Phases: Screening/Washout, Double Blind Treatment (the physician and patient do not know the name of the study medication), and Exit. The Double Blind Treatment Phase has 2 Treatment Periods. Since this is a cross-over study, all subjects who complete the full Double Blind Treatment Phase will have the opportunity to take carisbamate. Carisbamate is administered as 100 mg oral tablets. During Treatment Period 1, patients will take 2 tablets of their assigned study medication (either carisbamate or placebo) two times a day for 21 days. Patients will return for clinical evaluations approximately 1 week after starting the study medication and at the end of Treatment Period 1. Patients will then reduce their dose of study medication to 1 tablet twice a day for 3 days prior to stopping all study medication for at least 11 days. Before entering Treatment Period 2, patients will return for a clinical evaluation. During Treatment Period 2, patients will take 2 tablets of their assigned study medication two times a day for 21 days. Patients will return for clinical evaluations approximately 1 week after starting the second study medication and at the end of Treatment Period 2. Patients will then reduce their study medication to 1 tablet twice a day for 3 days before stopping all study medication. Patients will return for a clinical evaluation approximately 1 week after stopping all study medication and will be contacted by telephone approximately 30 days after the last dose of study medication. Safety will be assessed during each study visit by monitoring adverse events, clinical laboratory testing, physical and neurological examinations and electrocardiograms.

Patients will take 2 carisbamate 100mg tablets 2 times a day (400 mg/day) for 21 days during one Treatment Period and 2 matching placebo tablets 2 times a day for 21 days during the other Treatment Period. Patients will reduce the dose of study medication for 3 days at the end of each Treatment Period. There will be times during the study when no study medication is taken.