Numb toes on run - question

So I finally got to run last night for a bit and had forgotten that once in a while my toes want to go numb after about 2 miles. There is no pattern than I can tell of. This doesn't happen all the time but is not consistent with anything I can tell of. It's happened on the treadmill, concrete, cold, heat, etc. Once, I ran about 4 miles on the treadmill, when I stopped, I realized I could not feel my toes until almost 1/2 hour later.
I'd like to blame my running shoes but I would get this all the time then?

I'de hate to blame my runnig shoes, get new ones, then realize I still have the same problem. Has anyone ever had to resolve this kind of issue before?

Thanks for any help,
Eddie