Pioneered the use of aspirin for stroke prevention

After research training at the University of Oxford, Dr. Barnett became a neurologist at the Toronto General Hospital, moving to London, Ontario, in 1969 where he was Chief of the Division of Neurology at Victoria Hospital and University Hospital. He carried out many of the most important large multi-centred trials on methods of preventing stroke, including the first randomized trial demonstrating the effectiveness of aspirin.

In 1974, he founded, together with neurosurgeon Dr. Charles Drake, the Department of Clinical Neurological Sciences, which has played an important international role in the study and treatment of cerebral-vascular diseases. Among Dr. Barnett's many awards, he was made an Officer of the Order of Canada in 1984.

Dr. Barnett's extensive investigations of stroke and stroke prevention stimulated national and provincial "Heart" foundations to change their names to include "Stroke": hence, for example, the "Heart and Stroke Foundation."

Dr. Barnett was quick to attribute his success to the work of his team. In this excerpt from his acceptance speech for the 1983 Royal Bank Award, he publicly credits his team: "The work of one individual or group in any community, large or small, is pyramided upon the work of many, and this mix is of great consequence to the strength, the very fabric, and ultimately the height of the structure."