Sure.
Neuro issues can be caused by all kinds of things... brain tumors, head trauma, O2 deprivation, high fever, toxins, even birth defects. Some I swear are just not wired right and listen to the voices in their head.
What you describe sounds pretty dang generic though and could be any number of things, from bad eye sight to ear issues to pain, allergic reactions... and of course, neuro issues.
Just curious, but is it seasonal in any way? I've had a few horses do what you describe (if I'm reading correctly) but it's due to nasty flies burrowing up into the tender skin between their back legs and chewing away, or from hives from the same. But if you bend down and look, you can see the bites. If it's a stallion or gelding, have you ruled out his sheath as being an issue? Warm, dark, moist can make for some nasty, painful issues.
Down here in Texas we get some monster dinosaur bugs that could carry away small toddlers, and when they bite, they HURT worse then any bee or wasp and can cause a histamine reaction in the skin.