Principal Investigator left the study site on December 28, 2012.

The purpose of this study is to determine if Zonisamide is effective in reducing tremors in patients with Essential Tremor.

The subjects will remain on their usual medication and a baseline assessment using the Fahn Tolosa Marin tremor rating scale will be performed and will be video taped.

Inclusion Criteria:

1. Diagnosis of Essential Tremor based on the Tremor Investigational Group criteria for definite or probable Essential Tremor.
2. Age: 18 years or over.
3. Willingness and ability to comply with the study requirements and give informed consent.

Exclusion Criteria:

1. Known history of psychiatric disorder, major depression, dementia, aplastic anemia, or Stevens-Johnson syndrome.
2. Known alcohol or substance abuse in previous 12 months.
3. Positive pregnancy test.
4. Unwillingness to use adequate contraceptive methods if of childbearing potential.
5. Known allergy to sulfonamides.
6. Laboratory abnormalities prior to onset of trial.

•<=18 years Male/Female Hx essential tremor

PI has left the institution and we are unable to accurately assess the data from the remaining records.