Testing for PANDAS might be a good idea. Some doctors aren't on to this yet, so you might want to google it first, so you can have some info in case your doctor looks at you like you have two heads.
Also, yeast overgrowth, other pathogens, or chemicals can cause things like this. Our son used to have what we used to call "The scaries." What you describe sounds very familiar. For absolutely no reason he would come running to me screaming and clinging onto me like he saw a ghost. When we cleaned up his diet those went away. We still don't know what it was all about, but eliminating processed foods and household toxins is what we did. We actually have him on the GAPS diet, but you could look at www.westonaprice.org for info on foods or go to GAPS diet.com. If your daughter does not have any develpmental delays, then you probably wouldn't have to go on the diet, but just "cleaning-up" the diet would probably be helpful.
Blessings,
T. E.