Delayed rehabilitation lessens brain injury and improves recovery after intracerebral hemorrhage in rats.

Rehabilitation improves recovery after intracerebral hemorrhage (ICH) in rats. In some cases, brain damage is attenuated. In this study, we tested whether environmental enrichment (EE) combined with skilled reach training improves recovery and lessens brain injury after ICH in rats. Collagenase was injected stereotaxically to produce a moderate-sized striatal ICH. One week after ICH rats were either placed into a rehabilitation (REHAB) or control (CONT) condition. The REHAB rats received 15 h of EE and four 15-minute reach-training sessions daily over 5 days a week for 2 weeks. The CONT rats stayed in standard group cages. Skilled reaching (staircase test), walking (horizontal ladder) and forelimb use bias (cylinder test) were assessed at 4 and 6 weeks after ICH. Lesion volume, corpus callosum volume and cortical thickness were calculated 46 days after ICH. The REHAB treatment reduced lesion volume by 28% (p=0.019) without affecting the corpus callosum volume (p=0.405) or cortical thickness (p=0.300), thus indicating that protection was due to lessening striatal injury. As well, REHAB significantly improved skilled reaching ability in the staircase apparatus at 4 (p=0.002) and 6 weeks (p<0.001) post-ICH. Transient benefit was obtained in the ladder test at 4 weeks (p=0.021). Unexpectedly, REHAB treatment lessened spontaneous use of the contralateral-to-ICH limb at 4 (p=0.045) and 6 weeks (p=0.041). In summary, the combination of EE and reach training significantly attenuates lesion volume (striatal injury) while improving skilled reaching and walking ability. These findings encourage the use of early rehabilitation therapies in patients suffering from basal ganglia hemorrhaging.