Scientific Symposium EVER New Evidence for Pharmacological Treatment in Post-Stroke Recovery

Background and purpose – Most functional upper extremity motor recovery occurs in the first 4 weeks after ischemic stroke both in humans and in rodent models. The majority of recovery in humans is spotaneous (i.e. occurs as a result of endogenous repair processes rather than rehabilitative interventions). However, in rodents models, spontaneous recovery is rare. In a mouse model of stroke, we tested the hypothesis that Cerebrolysin, a polypeptide preparation shown to enhance neuronal plasticity, can act early after stroke to enhance motor recovery, either spontaneous recovery or recovery associated with motor training. Methods – Adult C57Bl/6 mice were trained to perform a skilled prehension task to an asymptotic level of performance after which they underwent photocoagulation-induced stroke in the caudal forelimb area (rodent primary motor cortex). The mice were then retrained after a 7-day delay in the presence or absence of Cerebrolysin injected IV daily. Results – We have previously shown that training-associated recovery of prehension is complete if training is initiated after a 1-day delay but incomplete if training is initiated after a 7-day delay, even with additional training days. However, daily Cerebrolysin administration after stroke was associated with complete recovery of prehension by day 8 even in the absence of training. Stroke volumes were similar across all groups. Conclusions – We conclude that Cerebrolysion administration beginning during an early time window can lead to spontaneous recovery of motor function (i.e. independent of rehabilitative interventions) and that this recovery is independent of a protective effect on stroke volume. This is one of the first demonstrations of spontaneous motor recovery in a rodent. Our mouse model, with all of the attendant genetic benefits, may allow us to determine at the cellular and molecular level how behavioral training and endogenous plasticity interact to mediate recovery. Steven R. Zeiler Johns Hopkins, Baltimore, MD, USA Timing, training, and spontaneous recovery after stroke: in animals, in humans