For Batten disease treatment, what type of stem cells are used?

For Batten disease treatment, I want to know the type of stem cells being used? How many cells? Is there a reason the number of cells can't be increased? It is my understanding that in the Stem Cells Inc., trial for Batten disease the last 5 patients received 1 Billion purified neural stem cells. Little improvement was observed. The patients were stabilized for a time but improvement was minimal. 20 Million is 2% of the cells used in the US trial, why are these numbers so different?

For the treatment of Batten disease, our doctors prefer to use neural stem cells, and in the treatment procedure, there are 4 separate stem cell injections (once per week) with 5 million stem cells in each injection. According to our clinical research and laboratory tests an individual can only handle a limited number of stem cells from external sources effectively. For children suffering from Batten disease, 5 million stem cells in each injection is the most effective number. If we implanted more stem cells into the patient's body there would be no improvement but it would add to the cost and more importantly, it would add a risk of developing encephalitis and other side effects.