Grant: Project Grant - PA: Neurosciences, Mental Health and Addiction

Aneurysmal subarachnoid hemorrhage (SAH) is a life-threatening neurological illness: it is bleeding in the brain after a bulging blood vessel (a brain aneurysm) ruptures. Although SAH accounts for 5% of all strokes, it puts a significant burden on many patients during their most productive years given the relatively young age of onset. Complications following SAH are common and contribute significantly to disability. Several medications were tested to target those complications, but only one - nimodipine - has been proven to benefit the health and wellbeing of patients. All SAH patients should receive nimodipine for 21 days at a fixed dose. However, our preliminary work suggested that patients are not getting equal amounts of nimodipine into their blood. In addition, the two different forms (structural mirror images) of nimodipine might have different effects. It is not clear, however, if reduced amounts of nimodipine lessen its benefit and contribute to worsening health and wellbeing of patients. We need to address this knowledge gap immediately. Some patients are likely not getting the full benefit of nimodipine, and most of their doctors are completely unaware of the problem. The overall goal of this research is to characterize the clinical consequences and predictors of different nimodipine doses and confirm whether the two forms of nimodipine exhibit different effects. We will conduct a multi-centre prospective study in adult patients admitted for SAH to the participating hospitals. Participants will have blood samples collected to determine the amount of each type of nimodipine in the body and to check for effects on patient disability at 90 days following SAH. We will also check the factors affecting nimodipine levels to suggest dose recommendations tailored to each patient. The findings of this research will highlight the potential uses of the different nimodipine mirror images and help to develop personalized nimodipine dosage regimens in SAH patients.