“Stanford researchers ‘stunned’ by stem cell experiment that helped stroke patient walk”
(Washington Post — June 2, 2016)
The one-time therapy involved surgeons drilling a hole into the study participants’ skulls and injecting stem cells in several locations around the area damaged by the stroke.  These stem cells were harvested from the bone marrow of adult donors.  While the procedure sounds dramatic, it is considered relatively simple as far as brain surgery goes. The patients were conscious the whole time and went home the same day.