When medications are not effective, one additional option is surgery to destroy the abnormal brain cells that are responsible for the tremors. These cells are located deep in the brain in the thalamus in a bilateral structure called the basal ganglia. There are several nuclei (collections of brain cells) in the thalamus, but the one that is related to tremors is called the ventral intermediate nucleus (VIN). The operation, thalamotomy, can be done by conventional stereotatic surgery or by the use of a Gamma knife (which uses radiation). Since there is one thalamus in each side of the brain, the thalamotomy could be unilateral or bilateral. An additional option is by deep brain stimulation (DBS) with implanted electrodes.