Background: Stem cell therapy for stroke is in its initial stages as an option to restore lost neurological functions after stroke.
Objective: To provide a comprehensive review of studies involving stem cells in stroke treatment and the new evidence from the ongoing clinical trials.
Methodology: We performed a systematic study of various published journals in online medical libraries using Pubmed, Sciencedirect and Ahajournal. Evidence synthesis is done with specific search words of – stem cell therapy, stroke, trophic factor, neural progenitor cell, pathophysiology, mechanism of action, clinical trial and mesenchymal stem cell in various combinations. Emphasis was given to articles published 2000 onwards.
Results: Current research on stem cell therapy for stroke focuses on transplantation and endogenous neurogenesis of stem cells in brain. The sub-ventricular zone in the adult brain is identified as an endogenous resource of neuronal precursors that can be recruited to adjacent lesioned areas. Several factors can increase adult neurogenesis by stimulating formation or improving survival of new neurons, such as FGF-2, EGF, stem cell factor, erythropoietin, BDNF, caspase inhibitors, and anti-inflammatory drugs. Much of the beneficial effects of stem cell in stroke models are related to secretion of trophic factors.
Conclusion: The complex pathophysiology involving various trophic factors, growth factor and gene modification in animal studies have showed promising result. Future research involving these trophic factors should open up new additional or clinically significant alternative for the treatment of stroke.