Many if not most brain injury cases are settled out of court either through a mediation or negotiation. In some states arbitration, which is similar to a hearing with a judge, will also decide the outcome of the case. Ask your attorney about their success rate in settlement both in and out of the courtroom.
A brain injury attorney may work with the family to establish guardianship or a Power of Attorney for the appropriate family member. This person then would be responsible for making decisions for the injured person through the legal process.