he also endured great physical abuse by care givers

He emphatically denied it in respect of his second wife. He is said the reports were hurtful and then something to the effect extreme bad taste. He did not refer to any other abuse, but he was remarkably complimentary of people in general. Given the way he had to speak I guess he rationed his comments to the most important (to him).

He was asked by Dara O'Brian (a comedian who gave up astro-physics at Uni) if he felt pain, and replied that Motor Neuron disease meant it wasn't pain he felt. But there was obviously discomfort in other ways.