One recent discovery I've made is that I've apparently been deficient in the mineral magnesium for some time (possibly most of my life).
It's kind of complicated how I came to suspect this, but a couple of weeks ago I read some stuff that suggested it would be a possibility, so I went out and got a supplement & tried it. Within a couple of hours I felt more alert, and it seemed to help my urinary problems (the main reason I was looking) quite a bit. Then I discovered that I was walking faster on the track at the gym, and my wife thinks I'm standing a bit straighter. And I've noticed some improvement in a few other neurological symptoms.
The symptoms of magnesium deficiency are kind of wishy-washy, but all pretty much fit with PPS. The supplement is relatively cheap and, from everything I've read, pretty safe -- it's what's used in milk of magnesia and several other laxatives, so if you took way too much you'd get loose stools before you could overdose to any extent.
It comes as magnesium oxide, magnesium citrate, magnesium oxalate, magnesium aspartate, and a couple of others. The oxide/oxalate formations are not recommended because of low "bioavilability" (and you might also want to avoid the oxalate form if you suffer from kidney stones). Probably the magnesium citrate form is best (though I haven't tried it yet).
A check of the local vitamin racks found numerous choices, both in chemistry and in potency. I've been taking a 100% "daily value" supplement (and took two a day for the first several days). At two a day I had soft stools, but no noticeable problems at one a day. (I weigh about 210 pounds.) My guess is that a version claiming 50% "daily value" would be fine for most here.
I'm taking magnesium oxide, 600mg if I recall correctly. I plan to switch to magnesium citrate soon -- I picked out the oxide before I thoroughly researched it.
It is kind of weird that docs rarely do tests for this condition (though I understand that testing is a little tricky). When you look at the symptoms it should be a no-brainer for a neuro workup.