In my experience horses that are down because of neurological problems tend to flail more than that are down and not neurologic. The neurologic horses paddle their legs, toss their heads and are really dangerous to be around. They get up and stumble or fall and lurch around. The horses that are non-neurolgic are quieter and more coordinated, they still fail but its more predictable and less spastic looking. Once up or halfway up they either get all the way up and are steady or they can't get up and sort of settle and lay down. There is less panic I guess.