I am not aware of valproic acid causing dystonia, and I can find no reports in the literature. However, there are some reports of it helping with the dystonia. What you are describing may be dystonia, but without evaluating your son, I can not be sure. A second opinion with another pediatric neurologist at an academic center is reasonable. They can review the imaging and confirm the absense of abnormalities and recommend other tests to have checked. Has a MRI of the cervical spine been performed, this may also be helpful to exclude structural lesions in this area. Lastly, blood work to exclude causes for dystonia should be evaluated. You should discuss this with either your pediatrician or neurologist, and proceed from there. Good luck.
I'm trying to understand for what reason my queston was ignored by the neurologist?????