Hi Bulldog!
Welcome to the PLS club! This forum is filled with funny, knowledgable, wise and caring people and even though I rarely contribute (my bad!), I truly appreciate all they offer and I'm sure you will too.
I know that many here are surprised at the speed with which your neurologist suspected PLS, and that's reasonable since the vast majority of neuro's are so reticent to make the diagnosis. (And yes, the patient is supposed to be observed for a number of years before earning the PLS acronym.) But I believe your neuro was just being very forthcoming and sharing his hunch with you. It's odd that you didn't have an EMG/NCV (not bragging, but I've had four!), but I'd bet that they'll be included in your next round of appointments.
I really wanted to chime in today because we share so many of the same odd symptoms. We even started to notice something was wrong while sporting it up with the kids. In my case, my upper body moved right to hit a tennis forehand but my right leg didn't play along...down I went. I didn't fare much better while skiing with my family; I got slower and it became immeasurably harder.
You mentioned that your limp comes and goes in severity; I don't find that to be at all odd. Spasticity is one of PLS's hallmarks. In my case it increases and decreases in direct relation to a variety of stimuli...or lack thereof. If it's cold, my legs freeze up; if it's warm out, I can walk semi-normally. Emotion is another exacerbating factor, whether it be a high stress, no fun situation, or, as you mentioned, watching your son pitch the closing inning. I haven't left a ball field or an auditorium after watching my boys, all on my own steam, in years. I'm a zombie. So if spasticity is what's causing your gait issues, then it totally makes sense that it comes and goes. I'd include your question about your trembling legs in this category, too. I get that, as well.
I wouldn't worry about the 20 year prognosis. I'm not sure there's much to back that up.
I haven't had night-time cramps for a while now. They came and then mercifully left! One thing you might try is using an exercise band with a loop on the end to put your foot in, and then holding the other end, so as to hold your foot/leg in a cramp-breaking position as you go back to sleep. It worked for me. And there's always a nice bedtime banana...chock-full of potassium.
Pain isn't usually listed as a PLS symptom, but many of us have it from time to time. Likewise, sensory issues definitely aren't normally in the picture, as PLS affects motor, not sensory, neurons. I'm a medical enigma (my third neuro told me so!), however, because i do have some slight sensory deficits...so who knows?!?
I drink very rarely, but when I do indulge in a glass of wine (or two...sshhh!), I, too, resemble a drunk toddler. It really doesn't take much. What a show we'd put on if we all got together for happy hour. Oh my!
I don't think I hit all of your questions, but I gave it a shot! Good luck with your second opinion appointment and keep your spirits up...PLS is slow in progression and we humans are remarkably adaptable!
Cheers, Namaste, Peace-out, etc.
Traveler (This code name thing is kind of fun!)