Nothing more was said. Only that she had a fall in the bathroom a few days ago and hit her head. Speculation on the NG show is that possibly she could have had a blood clot in her brain from hitting her head and that it burst on her.
Nancy's forte is speculation...I still can't imagine how she (NG) performed in a real court of law. Her theory sounds plausible...I would probably guess that the fall was helped by being in a groggy, druggy state (ANS seemed very out of it in her most recent interviews).