Kinsbourne is a pediatric neurologist who has been into anti-vaccinationism since the very beginning, apparently. Currently he is a mainstay of vaccine-related court cases, and a favorite authority for anti-vaccinationist everywhere. He participated in the Autism Omnibus trials as one of the expert witnesses to back up the rather paranoid ravings of main witness Dr. Vasken Aposhian (Aposhian had to admit during cross-examination that he had made up his hypothesis three or four weeks prior to the trial).
Kinsbourne’s status in the anti-vax movement seems to be relatively similar to that of Wakefield-acolyte Arthur Krigsman (here and here). They do have respectable credentials, but their claims and theories are unhinged to the point where one suspects, well, let's call it a tenuous hold on reason. Kinsbourne is well covered on whale.to, and that website has managed to dig out some remarkable, insanely paranoid screeds from him.
That is not to say that Kinsbourne has not had some success – and his claims in other cases may indeed contain some accuracy. The lunacy part comes in when you use you credentials to actually specialize in testifying against vaccines, regardless of the case, the evidence for the claims made, or the plausibility of the purported mechanisms.
Diagnosis: Hard to tell, really – but there is no doubt that paranoia has managed to suppress a genuinely scientific approach to evidence. He comes across as something like the Michael Behe of anti-vaccinationism.