Deep brain stimulation of the Vim nucleus of the thalamus for the treatment of tremor

The surgical treatment of tremor has evolved considerably in the past few y ears. Of the several conditions associated with severe tremor, the most com mon are Parkinson's disease (PD) and essential tremor (ET). Levodopa therap y reduced drastically the number of patients with PD who require surgery be cause of inadequate control. However, there remains a small number of "trem or dominant" PD patients for whom surgical treatment is often the best opti on. The ventralis intermediate nucleus (Vim) of the thalamus has been the p referred surgical target for the treatment of parkinsonian tremor for many years, but this is now challenged by the subthalamic nucleus (STN). Deep br ain stimulation (DBS) of either target possesses high therapeutic efficacy against tremor in PD. ET may be difficult to treat pharmacologically. Thala motomy is an effective surgical procedure for ameliorating ET but may be as sociated with persistent neurologic deficits. DBS of the thalamus is also a highly effective means of reducing ET. DBS appears to be safer than thalam otomy and is now the recommended surgical procedure.