Rehabilitation promotes recovery after whole blood-induced intracerebral hemorrhage in rats.

BACKGROUND Rehabilitation improves recovery after intracerebral hemorrhage (ICH) caused by collagenase infusion into the striatum of rats by promoting dendritic growth and reducing brain injury in this model. OBJECTIVE Effective preclinical testing requires multiple models because none, including the collagenase model, perfectly mimics human ICH. Thus, the authors assessed enhanced rehabilitation (ER), a combination of environmental enrichment and task-specific motor training, on skilled reaching, lesion size, and dendritic plasticity after whole blood-induced, striatal ICH. METHODS Three groups of rats were trained to retrieve food in a reaching task prior to ICH. One group was euthanized at 7 days, whereas 2 groups survived 7 weeks post-ICH. Of the latter, 1 group received 2 weeks of ER starting at 7 days, whereas controls did not. Reaching success was assessed 6 weeks after ICH. Lesion volume and dendritic length and complexity (contralateral striatum) were assessed. RESULTS The ICH caused reaching deficits that were markedly attenuated by ER as observed previously in the collagenase model. In contrast to that model, there was a time-dependent decline in dendritic length after untreated, whole blood-induced ICH. Furthermore, behavioral recovery was not accompanied by changes in lesion volume or contralateral dendritic morphology. CONCLUSIONS Converging data from animal models support the use of rehabilitation for ICH patients. However, although rehabilitation effectively promotes behavioral recovery, the mechanisms of action vary by model making it difficult to predict clinical effects.