What Causes Involuntary Tremors In A Person With History Of Cardiac Arrest?

Hello My Dad is a chronic failure patient and has to go under hemodialysis every alternate day since 2009. In this journey he suffered three cardic arrests One on 18th sept 2012 and other two on 19th sept 2012 due to hyperkalemia.. luckily Doctors managed to revive his heart all three times. Though the condition was very critical due to drop on Blood pressure and unability to dialyse him, He managed to survive and come out of it with jus 3 days of memory loss prior to this episode.. Now the problem is: After two months of his dicharge in Oct 2012 an unusual involuntary tremoring was discovered which stopped after taking Rivotril 0.5mg which was prescribed by the Nephrologist. These tremous were then seen very occassionally like approximately once in six months later the frequency increased to quaterly, monthly, weekly and thn daily increasing the severity of the tremors..(he eventually faced lot of drugs to settle this problem which include lonazep, rivotril, larpoz etc.) His Brain MRI, CT and Angiograpy was tested normal also all other tests we done which were referd by the nephrologist and other doctors. Psychologist concluded by saying it is not a psychologycal case as the tremors are involuntary but informed that he has solution only over the withdrawal of drugs not the problem. Now the problem is so intense that these drugs has eventually stopped recting on his tremors.. Currently only lopez 2ml injection in vein seems to be working for him. Though we try not to giv him the full dose but there is no other option in case the tremors does nt stop. these days the tremors are so intense that some times they occur 3 times a day. kindly note the tremors are so severe and get more worst if not stoped that his bones start paining, he involuntary hurts himself by banging himself to nearby objects which results in physical damage to him, within few minutes he vomits specially if on full stomach. In is really traumatic for me and my family. I need to find solution to this but i feel helpless as per the things that are goin on. I hope ill be able to get something positive from you. His Age is 57. Resident of Goa, India. Hereditary Diabetes since last 20yrs. Takes insulin since last 7 yrs. Blood Pressure problem since last 10 to 12 yrs. I am sure ill get some kind of solution from you.. Thankyou Thanks a lot for this platform.