Intralesional administration of allogeneic bone marrow stromal cells reduces functional deficits after intracerebral hemorrhage.

When a severe neurological lesion occurs as a consequence of intracerebral bleeding, no effective treatment for improving the outcome is currently available. In the present study, intracerebral hemorrhage (ICH) was induced by stereotactic injection of 0.5 U of collagenase type IV in the striatum of adult Wistar rats, and three days later, intralesional administration of 2 x 10(6) allogeneic bone marrow stromal cells (BMSC) in saline (n:10), or saline only (n:10), was performed. In the following 30 days, functional outcome was evaluated in each animal by rotarod and the modified neurological severity score (mNSS) test. Progressive and functional improvement was observed in BMSC-transplanted rats compared with controls, together with morphological images suggesting that intracerebral administration of BMSC increases endogenous neurogenesis at the level of subventricular zone (SVZ). These findings suggest that local administration of allogeneic BMSC could be useful to reduce the neurological deficits caused by intracerebral hemorrhage.