Dear WendyB:
I am sorry to hear about your daughter, but it does sound like your doing all the correct things for her. Does she have other delays, inaddition to gross motor? I would suggest an MRI of the brain. Now that she is older, it will give the pediatric neurologist a better look into the possibilities of diffuse cortical atrophy, if it indeed real, and if there might be other things going on. One can see diffuse cortical atrophy by noting the size of the ventricles. If they are large or age, then this might be an indication of atrophy. The subarchnoid or subdural space is outside the brain and the ventricles lie inside the brain so one would not be mistaken for the other. One can see this on the CT, but an MRI will give a better view of the miyelination pattern and the amount of myelination. I feel that one need to know what might be the cause and then if possible do what we can to correct the problem.
Sincerely,
CCF Neuro MD