I am a novice here so I don't have much to share but your last bit about head knocks puts me in mind of the neuro-psychiatrist Dr. Daniel Amen and his work doing SPECT brain scans in his practice. I find his work fascinating and we sought out one of his clinics in investigating our son's issues with good results. I like how he SHOWS the diagnosis in the SPECT pics and doesn't simply rely on subjective checklists. His website is www.amenclinics.org.