How Can Chiari Malformation Causing Chronic Pain Be Treated?

My 10 year old son was diagnosed with Chiari in 2007. In 2008 he underwent decompression surgery. The severity of his headaches dramatically decreased, however for the past few years we have been struggling with day to day pain. He has severe body aches and headaches which are just less severe. We are currently being treated at Lucille Packard Children's Hospital in Palo Alto,Ca. I feel as if this condition is so misunderstood by physicians. I love the neuro dept. at LPCH however I had to fight to get them to listen. Jaden can rarely attend school and is in pain for most of his days.. I need any advice as to what types of treatments are out there for the chronic pain associated with this condition. Sincerely, Brooke Foard