The Ottawa Hospital Research Institute has one of the strongest neuroscience and stroke research programs in the country, thanks to outstanding basic and clinical scientists, and a number of partner organizations including the University of Ottawa, The Ottawa Hospital, the Canadian Stroke Network, and the Heart and Stroke Foundation Centre for Stroke Recovery.
A stroke occurs when the blood supply to part of the brain is interrupted, either by a blood clot or burst artery. Without oxygen, the brain rapidly loses the ability to function, and irreversible damage can occur in just minutes. Standard clot-busing drugs can lessen the damage in many types of stroke, but they are only safe to use within a few hours of an attack. Clinician-scientists at the OHRI are conducting research to improve acute stroke treatment. For example, they are testing an alternative clot-busting drug that can be administered up to nine hours after a stroke. If it proves to be as effective as the standard therapy, thousands of stroke patients could benefit.
While clot-busting drugs can lessen stroke damage by restoring blood flow to the brain, many scientists believe that the next generation of therapies will be able to prevent the death of brain cells at the molecular level. The OHRI is leading an intense effort to determine which proteins and genes control brain cell death, because understanding this process is the first step in developing these next-generation treatments. While some researchers are studying death of neuron cell bodies (grey matter), others are investigating damage to nerve fibres that connect different parts of the brain (white matter). Another molecular research project focuses on a phenomenon known as “preconditioning,” in which a short period of blood deprivation makes the brain more able to resist a later stroke. The aim of this research is to identify genes in the brain that are turned on or off by the preconditioning process. Several candidates have been identified, and further research may eventually lead to neuroprotective drugs that mimic the effects of these pre-conditioning genes.
Another exciting area of stroke research involves finding ways to stimulate the regeneration of brain tissue. Very recently, it was considered dogma that once a brain cell died, it could never be replaced, but in the last few years, mounting evidence has shown that stem cells do exist in the adult brain, and they can be coaxed into generating new brain cells. Clinical investigators at the OHRI are conducting a pilot study to determine if a natural protein called Granulocyte-Colony Stimulating Factor may be able to stimulate recovery of function in stroke patients. Other researchers are dissecting in more detail the molecular pathways that control stem cells in the brain.
While it will likely take many years to fully develop and test these regenerative treatments, stroke patients today can regain many of their abilities through rehabilitation programs. OHRI investigators based at The Ottawa Hospital Rehabilitation Centre are developing and testing new types of physical conditioning for stroke patients. They are also investigating nutritional management and driving programs to improve health and quality of life of patients recovering from stroke.
Finally, a big part of stroke research will always be prevention. It is estimated that control of the known stroke risk factors would avoid 50% of the strokes suffered. These include high blood pressure, high cholesterol, smoking, diabetes and heart disease. The Ottawa Hospital now has an active stroke prevention clinic to ensure that the risk factors are controlled, because once a patient has suffered a stroke, the chance of having another substantially increases. Clinical investigators at the OHRI are involved in a number of clinical trials, and their research is contributing to better stroke prevention in Ottawa and around the world.
• Dr. Antoine Hakim
• Dr. Paul Albert
• Dr. Hsaio-Huei Chen
• Dr. Matthew Hogan
• Dr. Leo Renaud
Note: Stroke research at the OHRI is supported by The Ottawa Hospital Foundation, the Heart and Stroke Foundation of Canada, the Heart and Stroke Foundation of Ontario, the Canadian Stroke Network, the Canadian Institutes of Health Research, the Ontario Ministry of Research and Innovation, and many other agencies.