pawpaw's head

What is the matter with Pawpaw's head? He is having some kind of weird spells. two times now in about two weeks. He gets a weird dizzy or full feeling and becomes clumsy. Similar to before he had his Chiari surgery. Thought that was going to take care of the problem. Why does it come and go? The Internist doesn't know and is going to send him to a Neurologist. The MRI doesn't show a stroke or a brain tumor, so thank God for that, The carotid sono and the echo were ok too. So now we look for Zebras. We don't have time for this kind of foolishness so they better come up with something fixable. We have stuff to do that does not include being any sicker than we already are for goodness sake.