There are few therapies available for regrowing or regenerating brain cells in stroke victims after their condition has stabilized.  Flooding the affected brain areas with stem cells might help.

I find some encouragement in this:

It is not cell replacement, but works through an indirect mechanism -- something that helps improve the tissue that remains.

Cell-based treatment for strokes is based on this concept: Brains try to heal themselves, but need help.

"Around the stroke, cells are still alive, but they're in a hostile environment," said Case. They retract from the threat. And their connections to adjacent cells, called synapses, are damaged. This makes rehabilitation more difficult because damage interrupts the internal communication needed to think, talk walk.

Cell-based therapies like SB623 seem to create a healing environment, reducing inflammation and exuding supportive growth chemicals. Brain cells adjacent to the damage extend themselves, Case explained, "and new synapses form."

The new cells don't replace the injured cells; in fact, they seem to disappear from the brain within a month. But their introduction seems to help, even after they're gone.

"Cell-based therapies are in their infancy. Every day is a learning experience," said Stephanie Kolakowsky-Hayner, director of rehabilitation research at Santa Clara Valley Medical Center and the chairwoman of the conference.

"The potential to regrow brain cells is very exciting," she said.

Also, I didn't realize stroke was so common:

Stroke is the third largest cause of death and the single largest cause of adult disability in America, causing paralysis, impaired thinking, speech and motor control, according to the U.S. Centers for Disease Control and Prevention.

A stroke, sometimes called a brain attack, occurs when a clot blocks the blood supply to the brain or when a blood vessel in the brain bursts. This kills brain cells responsible for an array of physical and mental functions.