Phase I clinical trials to start soon for proving neural stem cells:

Battens disease is a fairly rare neurodegenerative disease that targets infants and young children. This is a autosomal recessive disorder (that is, they occur when a child inherits two copies of the defective gene, one from each parent) Occurs in an estimated 4 of every 100,000 births in the United States
The disease manifests because of genetic mutations that prevents nerve cells from properly disposing off spent lipids and proteins resulting in the excess buildup of these materials in the brain causing slow eventual neuronal death.
In a documented case, the patient goes from having vision problems, to being blind, to having motor issues, to being bedridden and ultimately to death by the time the patient was in her teens.

StemCells Inc is scheduling phase I clinical trials to see if neuronal stem cells transplanted to willing patients (infants and young children) can actually help secrete enough of an enzyme that will help breakdown the harmful aggregates of protien/lipid buildup. The company has a very good story at http://www.stemcellsinc.com/clinicaltrials/clinicaltrials.html.