Henry Joseph Macaulay Barnett (10 February 1922 – 20 October 2016), known by his colleagues and friends as "Barney", was a Canadian physician and neurologist. He was also a leading clinical stroke researcher as a result of being the principal investigator in several major clinical trials. As a clinical scientist, he did pioneering research in stroke prevention, beginning with the use of aspirin.
Professional career
After graduating from the University of Toronto Schools he received his medical degree from the University of Toronto in 1944, while working summers in pathology. He was interested in pursuing pathology and this summer work first exposed him to the structure of the diseased human brain.
After medical school, he did postgraduate training in Neurology in Toronto, London and Oxford, working under Charles Symonds, Hugh Cairns and Richard Doll. On faculty in Toronto as a neurologist from 1952 to 1969, he gained enormous experience early in his career. His neurology service at Sunnybrook Hospital occupied 70 beds and he first recognized carotid stump syndrome, stroke from mitral prolapse, external carotid artery steal, post-traumatic syringomyelia and tumor-related syringomyelia. He founded the Department of Neurosciences at Sunnybrook Hospital in 1967.
He started to work at the University Hospital in London, Ontario and the University of Western Ontario in 1974, persuaded to leave Toronto by his friend and neurosurgeon Charles Drake. Together, they founded the Department of Clinical Neurological Sciences, which was multidisciplinary and the world's first to include neurology, neurosurgery, neuroradiology and neuropathology faculty appointments.
thumb|Henry Barnett and [[Charles George Drake|Charles Drake in front of the University Hospital, London, in 1973]]
Dr. Barnett was the founding president of the Canadian Stroke Society, which later merged with the Heart and Stroke Foundation of Canada, which had been formed in 1952.
He was a reviewer for many medical and scientific journals including Stroke. He served as its chief editor from 1982 to 1987 and ultimately, his own biography appeared in that journal, written by his disciple-neurologists J David Spence and Vladimir Hachinski. On Barnett's arrival in London, there were 2 neurologists already, and the question he was asked was why any more would be needed. By providing a valuable service, the Neurology team grew quickly from 2 Neurologists and no residents to 14 Neurologists and 6 residents.
Neuroradiology was clinically promoted: every patient with a stroke had a carotid angiogram – unheard of in those days – so what had happened to the patient could be analysed. Barnett was truly one of the fathers of Stroke Neurology.
Neuropathology was deemed core by Barnett, who had spent summer time in pathology as a medical student. Running an academic enterprise, he insisted that an autopsy was done on every patient who died, so learning could occur and families could have closure. Results were presented in weekly clinico-pathologic conferences
Aspirin in stroke
Aspirin had been used to prevent stroke since the 1960s but had not been scientifically proven to be effective in a randomized clinical trial. By inhibiting the enzyme cyclooxygenase, aspirin blocks the production of thromboxane in platelets, potentially reducing clot formation and preventing ischemic stroke. After obtaining funding from the Medical Research Council of Canada, in 1978, Barnett published the results from 585 patients in his randomized clinical trial demonstrating the effectiveness of aspirin in preventing stroke. giant aneurysms or skull base surgery requiring sacrifice of major vessels for tumor removal.
North American Symptomatic Carotid Endarterectomy Trial (NASCET)
Another common surgical procedure alleged to prevent stroke was studied by Barnett, carotid endarterectomy. This surgical procedure on the neck removes the source of thrombi that form and then detach and embolize to occlude brain vessels from atherosclerotic plaque from the bifurcation of the carotid artery in the neck. The procedure had been done since 1954 but without proof of effectiveness in preventing stroke, and was declining. After applying for and receiving NIH grant funding to test the hypothesis that the procedure worked in patients with over 70% carotid stenosis, Barnett recruited 659 patients into his randomized clinical trial, finding this surgery effective in preventing stroke. and thus Dr. Barnett spearheaded the establishment of carotid artery surgery for preventing stroke.
The question remained if carotid endarterectomy was beneficial in patients with lower degrees of carotid stenosis, i.e. less than 70%. To answer that question, Barnett and colleagues randomly enrolled 2226 patients, 1108 receiving carotid endarterectomy and 1118 receiving medical care alone. In 1998, this clinical trial found that patients with 50%-70% stenosis had a moderate reduction in stroke and death rates, but that patients with less than 50% stenosis did not benefit from surgery.