Hawking got lucky that his degeneration stabilized before it became fatal, but we shouldn't discount the incredible amount of mental discipline it takes him to

Hawking got lucky that his degeneration stabilized before it became fatal, but we shouldn't discount the incredible amount of mental discipline it takes him to live his life. I suspect this discipline is at least partially responsible for his survival. Though ALS doesn't affect cognition directly, most patients quickly become more-or-less unresponsive once they've lost the motor skills required for communication. It seems like they go mad from understimulation. I wouldn't be surprised if this leads to a faster death, as they are more likely to just "give up" if breathing or swallowing becomes hard. Hawking clearly has a vibrant inner mental life, which keeps him engaged with reality. The will to communicate his ideas and the means he has to do so through his custom technology may explain some of why he is surviving so long.