I think it can be managed, but not cured. It can be managed well. I think the changes to the brain are too much to fix, although I know that the brain is plastic, and can change a lot. New neural pathways can be forged so one doesn't react to triggers in the way they have in the past. Avoiding triggers doesn't help, dealing with triggers helps the brain heal. I have heard several people online say they healed from PTSD, but they had never been diagnosed by a professional.