I am so sorry for what you are going through and you and Frank are in my prayers. I read your comment about supra nuclear palsy and your son's very understandable fear. Has your husband been tested for genetic defects in the last year or so? My family genetic defect c9 orf 72 was only identified in late 2011. It can also cause psp I have an aunt who has it. You might want to consider testing for it. It would give your son the option of testing when he is an adult. If he knows the gene and it is negative it would enable him not to worry. Gene testing is a very personal choice but if the family gene is unknown there is no way to find out. I am sorry to bring this up but it sounds like this will be an ongoing issue for your son
Again you are in my prayers
Nikki
Again you are in my prayers
Nikki