Thanks so much for your patience. Weirdest thing! I hope it can be fixed quickly.
With regards to your question about PLS/ALS and a study of patients to figure out why people develop PLS instead of ALS- I haven't seen anything out there with that specific goal quite yet. However, there is definitely research interest- and I have spoken to two different neuros about it. Dr David Taylor is the the VP of Research at ALS Canada, and he brought it up as a potential focus of study in the future. It's been discussed as a way to figure out what people with PLS have that prevents them from developing LMN issues and harness that to try to slow down the disease process in those with ALS. My own neuro also brought it up, so I think the idea is percolating in the neuro world.
It sounds like currently the biggest push is to find biomarkers for PLS first. I participated in an imaging study (MRI) that indicates there are some things that show up in people with PLS that do not show in ALS- so could be used to differentiate. From what I understand, there is evidence that there is some sort of neural repair/regrowth/new connections in a particular part of the brain in the researcher's study subjects with PLS. She hasn't published a paper yet, but has presented the initial findings at a couple of conferences- likely to drum up more funding and interest.
~Fiona