Assessing functional outcomes following intracerebral hemorrhage in rats

Translational neuroprotective and drug development studies need to be gauged against well-characterized functional outcomes, including motor, sensory and cognitive domains. Since intracerebral hemorrhage (ICH) causes dramatic neurological and cognitive deficits in humans, we hypothesized that ICH would result in prolonged motor–sensory and learning/memory deficits in rats. Neurological tests of sensorimotor functions were performed before ICH, 1–3 days and 10 weeks after ICH. Water maze, open field, and rotarod performance was tested 2 and 8 weeks after ICH. Early neurological evaluations revealed significant deficits, with almost full recovery by 10 weeks. The water maze revealed significant learning (but not motor) deficits at 2 weeks, but by 8 weeks, the learning deficits had diminished and significant motor deficits had emerged, coinciding with a drop in activity. The injured hemisphere showed significant atrophy at sacrifice. Therefore, ICH produced detectable cognitive and motor deficits in rats that evolved over a 10-week period, and thereby provides a suitable baseline for analysis of future therapeutic interventions following hemorrhagic stroke.