My mother in law had a pace maker fitted about 9 months ago and since coming out of the general anasthetic her left started shaking. The Drs first thought it was maybe nearve damage from the operation but it was then investigated that it may be Parkinsons which it turned out to be.
She exhibited no signs of Parkinsons Desease prior to the General Anasthetic I have read a French study into connection of Demensia being brought on by general anasthetic in the elderly and I thought there may be a possible connection between P.D and General Anasthetics
Andy
You then might want to have her see a neurologist to discuss PD medicine, such as carb/levodopa, which might help the shaking.
Sorry to read about this sad situation. I hope you find the answers to your questions.