A chronic brain condition characterized by attention difficulty, hyperactivity (not necessarily in terms of energy levels, but the inability to stop the brain/thoughts from jumping from subject to subject), and impulsiveness. While most doctors require the presentation of symptoms presented in childhood, traumatic brain injury patients (like those of us with Chiari) can develop a Secondary Attention Deficit Hyperactivity Disorder (SADHD) or Acquired Attention Deficit Hyperactivity Disorder (AADHD) that can be temporary (from certain medications or anesthesia) or permanent (from the damage itself).