My husband needs help.

My husband had an accident when he was five - fell face first off a bicycle onto the pavement.  After this he wet the bed until he was 12.  He hid under his desk in Kindergarten and the teacher told his parents that he was "retarded" and would probably never learn to read or write.  He has had severe chronic facial pain, headaches, muscle tightness in his arms and legs, numbness in his penis and several other symptoms.  None of the 20 doctors we have seen has been able to diagnose him.  He recently had an MRI of his head and the found a developmental venous anomaly.  So far, all the articles I've read say that a DVA is nothing to worry about.  My question is, can a DVA cause any or all of my husband's symptoms?  He is ready to commit suicide because of the pain and I don't know how to help him and the doctors we have seen haven't been able to help him either.  They also are now refusing to prescribe pain medication for him....something about "liability."