I do not have ET myself; however, my hubby does. He tried every medication available that he could take, with no improvement. In Nov. 2012 he had Deep Brain Stimulation surgery to improve his right hand.
It worked. The neurologist, R. Pahwa, MD, was amazed that it also improved his head bobbing and voice since it does not always improve those areas. Now he is beginning the process of working to improve his left hand issues. The same surgery is used for some Parkinson's patients.
http://www.neurology.org/content/53/7/1447.abstract R. Pahwa, MD is mentioned in the link. Do research, talk to your Dr. You don't have to settle without checking all avenues. I wish you the best.