@cstross
Heard a neurologist today, saying it looked more like a seizure than a stroke.
A stroke would be some kind of vascular event, usually with a brain bleed or at least cutoff of blood flow to part of the brain. McConnell didn't show the usual signs (e.g., no left-right asymmetry/paralysis).
But a seizure, something vaguely like petit mal where you just zone out for a while (among many, many other things), does seem to fit.
Also, head trauma can induce this sort of epileptiform problem:
https://www.epilepsy.com/causes/structural/traumatic-brain-injury-and-epilepsy
That's relevant because he's fallen several times this year, at least once inducing a concussion and cracking some ribs. Whacking your skull on concrete is a bad idea in general, but brain trauma leading to seizures is a particularly excellent reason not to do so.
I noticed today that he didn't lack speech entirely during the episode. When somebody asked him, "Did you hear the question, Senator?", he was able to say "Yes" to that. But he was otherwise locked up. A real neurologist might be able to make something of that.
And no doubt his personal doctors are doing so. The best the rest of us can do is guesswork.
The overall conclusion, though, is independent of guesswork details and quite clear: he's too old to be a senator.
Even if the Latin root of "senator" is "old man" (senex, senatoris). Roman senators would perhaps have preferrred "elders", but still "old guys in charge" fits the data pretty well.