Look up Harlequin Syndrome; it is often benign, but a neurological workup can put your fears to rest.
http://en.wikipedia.org/wiki/Harlequin_syndrome
http://www.medhelp.org/posts/Neurology/Harlequin-syndrom/show/893809
http://rarediseases.info.nih.gov/GARD/Disease.aspx?diseaseID=8610
http://content.nejm.org/cgi/content/full/357/20/e22
http://www.nature.com/nrneurol/journal/v1/n1/full/ncpneuro0040.html
http://jnnp.bmj.com/cgi/content/abstract/51/5/635
You may want to ask about it on the Neurology Expert Forum (link in the right column of this page, third box from the bottom under "related expert forums) to get more information from an expert from the Cleveland Clinic.
You're also welcome to hop over to the dysautonomia community; I think there is autonomic involvement in this condition. We've had a few people with it stop by our forum in the past; I'm not sure if any are around now or not but either way we can try to find you more information.
Best wishes,
heiferly.