hopefully your son has seen someone by now, but just in case I happened to go for a second opionion of my MRI and lucked out that my doc is a Vascular-Neurosurgeon. I'm going for a CTangiogram soon, to rule out the vertebral arteries hopefully. hope you are all doing well.
A neurosurgeon or a vascular surgeon....not exactly sure which would be better. Your personal physician would probably make that call. What area of the country do you live in? Jo