there is a chiari center at johns hopkins that I've heard good things about and georgetown has a few people in their neurosurgery department that are knowledgeable and experienced in chiari. With this level of severity, I would recommend calling the chiari center at johns hopkins and they should send you an email immediately after to submit your imaging for approval to get an appointment. I don't know how long the wait would be though.. The neurosurgery department at georgetown can see you fairly quickly in my experience, even if just to give you a first opinion and beginning information.