It's really hard to say, but it sounds neurological. Vitamin/mineral deficiency could be to blame, but and infection like tetanus or e coli could be to blame as well. I'd isolate in a carrier or a box so it can rest give multivitamin in water via syringe, and perhaps some honey/egg mixed with water. Without knowing what the animal was exposed to or bloodworm, anything but supportive treatment is a shit in the dark! I hope it does well and recovers, if you are able to find a local avian vet. You're lucky.