symptoms of a mass lesion in the region of cerebellar vermis

my son is 8 years old 61 lbs and was involved in a sudden stop on his school bus he tumbled out of his seat rolling head first down the bus isle. he recieved whiplash along with lower back strain and left leg pain (pins & needles) but the leg pain began about 3 days later.  He was taken to the emergency room on 3-19-08 and a CAT Scan of neck and back showed negative to fracture.  3 days later he began having headaches and severe leg pain in the left leg, his peditritian wanted him to be re-evaluated in the ER due to the severe left leg (Pins and needle) symptoms.  A leg cat scan and a brain cat scan was performed all negative. The orthopedic surgeon susspected early stages of RSD but to be on the safe side 1 month later after the accident a MRI non contrast was ordered and the findings were 1. unremarkable cervical spine 2. T2 hyperintense and T1 isointense mass legion in the region of cerebellar vermis.  Of course further testing of the brain has been ordered but "WHAT ARE SYMPTOMS THAT I SHOULD BE LOOKING FOR ? and could this injury have manafested itself as a direct result of the bus accident, because during the three days after the accident it was negative on the neck CAT Scan and Brain Cat Scan but now 1 month later apparent on the MRI. Any help on this puzzle would be greatly appreaciated

[pam21]

could you write me at ***@**** I would like to know what they found out about your son, I have a mass also that was found three weeks ago but they don't know what it is, I also had left leg pain and then it stop after one day.