Great videos Mark!
Just musing here now on what I watched happening with Chris as you have me thinking about it all in that context.
One of Chris's very early symptoms was jaw clonus. It would happen (before he started slurring his speech even) when any breeze would touch him, even a warm breeze.
Around 12 months later when he was diagnosed, the neurologist called 5 other doctors into the room to watch and have a go with the little hammer at producing the clonus response in his jaw. They seemed to find it fascinating, but didn't bother to really explain to either of us what it was all about. I had to research it myself later :?
Now I'm wondering about the leg clonus he developed in the last few months. His entire leg would jerk rhythmically like that ankle in the video, but it seemed to be mostly the larger thigh muscles, so I wonder, with what you said about the joints if it was coming from his hips. It wasn't in the lower legs even though he had a babinski response for some years before we knew anything was happening to him. I didn't know then about babinski, we just used to laugh at his incredible foot reaction to suddenly being touched at all. It was classic babinski in every aspect. Ironic how you can think something is just 'how that person is' until you find there is a name for it and that it is an indication of something very wrong.
The clonus in his leg would trigger when we would get him ready for a standing transfer, and I would have to just slightly reposition his leg to help it stop. That's what makes me wonder about the hips as it would be as I would get him to sit forward. When doing this from the hospital bed his knees would be far straighter than when in a chair and his feet were not even on the floor, so I don't think it was the knees.
In the last weeks it could start once we got him on his feet and was really scary as his legs were so weak, so keeping him upright and helping reposition the leg a little was a trial. By that point he was no longer walking at all, just some standing transfers but mostly hoist transfers.
As a CALS it was often a weird mix of watching something like this with real interest, fascination even, and also incredible dismay at what was happening to his body.