Umbilical cord blood cells and brain stroke injury: bringing in fresh blood to address an old problem.

Degeneration of brain tissue following stroke leads to functional impairment with limited brain self-repair. New evidence suggests that delivery of circulating CD34(+) human umbilical cord blood cells can produce functional recovery in an animal stroke model with concurrent angiogenesis and neurogenesis leading to some restoration of cortical tissue. While some alternative interpretations of this data are offered herein, the study provides encouraging evidence of functional recovery from stroke in an animal model using stem cell therapy.