Hire counsel. If any of this is true, you are up against a determined foe. You can use AVVO search to find an attorney in your locale.
We do not have a client/attorney relationship until you make an appointment, we discuss your case face to face, I accept a retainer, and we explictly agree to enter into representation.
This is a little confusing, and I can't help but believe there is more to the story. Why would a court permit your brother's attorney testify against him, did your brother do something? How did this attorney get such control over your brother? Is there any chance the attorney was assigned by the court?
In any event, if you want to have more access to your brother and more control over his treatment, you should hire and attorney to explore your options.
I am licensed in New Mexico and Pennsylvania, and therefore any discussion of issues related to other states must considered within that context. In addition, my comments are not intended to create a legal representation but merely to respond to the limited facts presented by the question. Any opinion herein is not meant as a precise statement of legal rights or as a recommendation of any particular course of action. A more complete legal review can be obtained through local counsel.