My granddaughter was diagnosed with an arachnoid cyst on her brain when she was 3 mos old.?

The neurosurgeon said nothing to worry about but do another CT in a year, which we did. Again, he said nothing to worry about. She just turned 2 yrs old but for the past year or so she would scream, arch her back & neck & fling herself backward. I have read that these are symptoms of subarachnoid hemorrhage, however, my daughter and myself would attribute it to a temper tantrum sinc she would always do it when having her diaper changed. She has had these type tantrums/spells ever sinc she was born. Now that she is a little older she has started to hold the back of her head with both hands, often crying, often not. She has also been awakended during a deeps sleep with uncontrollable screaming and arching back. Could she be having hemorrhages? We have an appointment with a diferent neurologist this week but should we not waste time and rather get her straight to a Mayo clinic? if so, which one of the 3 Mayos would be best for pediatric neurology? Also, since the past 6 mos. the top of her skull has a protruding ridge along the center whci we were told is an overlapping of the skull bones where they form to meet at the center. Could this be related to the arachnoid cyst or 2 different issues? Does anyone know of a good neurologist/neurosurgeon for us to take her to?