Yes, at least 4 and 2 spinal taps, among other things. One of the neurologist said that he has "white brain matter disease" but another neurologist said that is not unusual for someone his age and for someone who has had diabetes for over 40 years. So we are still in limbo.

Yes, at least 3 MRIs of the brain. It so happens that he is in the hospital right now as his legs could not hold him up and he fell several times and hurt his elbow yesterday. So now they are doing another MRI of the brain.