Stem cell therapy for stroke: lessons learned from recent successful randomized trials of interventional therapy for stroke

Cell-based therapy is a promising approach for treating acute stroke patients as well as those with fixed neurological deficits, and therefore, the number of stem cell trials conducted on stroke patients is increasing. However, more studies are needed to conclude the efficacy of stem cell therapy because while several studies showed a beneficial effect, there was significant bias in subsequent studies. Meanwhile, there have been recent advances in stroke treatment such as endovascular therapy for acute ischemic stroke and catheter-based closing of a patent foramen ovale in cryptogenic stroke. Clinical trials of the latter two interventional therapies have very similar histories of consistent success after repeated failures. In this review, the factors related to the success of these interventional therapies are discussed and applied to stem cell therapy for stroke patients. Through continued efforts, there is hope for success in stem cell therapy for stroke patients.