Bring back the zombies

In Philadelphia, US, a company called Bioquark may start later this year injecting stem cells into the spinal cords of brain-dead people, along with other measures (but not including getting a lightning bolt to strike them), in order to stimulate the growth of fresh neurons, and bring them back to life.

Interesting questions arise. If they do manage to bring a legally dead person back to life, can we say that it is the same person? Or a different one?

Picture source: André Ribeiro