My 88 y/o father in law has a history of diabetes. In the past three years there has been a decline in his health. His balance is off, looking at him - the right side of his body has dropped an inch, he has major balance problems, his right hand shakes continuously, he has fallen twice a month in the last 6 months for no reason. He is having some signs of behavioral changes. His sugar levels are 80 - 100. He eats healthy meals and regularly. My wife an I are thinking Parkinsons or something of this nature, may I ask for other medical possibilities to question his PCP about?