The purpose of the study is to investigate the effect of lesion characteristics in ExAblate Transcranial Magnetic Resonance guided Focused Ultrasound Surgery (MRgFUS) of the Vim thalamic nucleus. Clinical measures will be used to study patients suffering from medication-refractory tremor, Essential Tremor or idiopathic Parkinson's Disease.~This study is designed as a prospective, observational, and clinical study. Assessments will be made before and after MRgFUS for; clinical tremor relief, quality of life (QoL) improvements, assessment of adverse events, and correlations of these measures with the size and shape of the lesion and the surrounding edema .
The study will investigate Essential Tremor and Parkinson's Disease patients who underwent Magnetic Resonance guided Focused Ultrasound Surgery (MRgFUS). We will evaluate the effect of lesion characteristics on tremor and on quality of life after the procedure as compared with the baseline prior to the procedure.