Ronald R. Tasker, often called “Ron,” born in Toronto on December 18, 1927, died peacefully near his home on April 19, 2023, at the age of 95 years, after a long and productive life. He was predeceased by his beloved and ever-present wife, Mary M. Tasker (shown in Fig. 1), née Craig, in 2003. He is survived by his children (Moira, James, Ronald, and Alison (shown in Fig. 2)), grandchildren (Gavin, Liam, Kiley, and Quinn), sister (Elizabeth), sister-in-law (Sheila), and a long list of admiring neurosurgeons, who had the privilege to train and learn with him. A celebration of Ron’s life was held in Toronto on June 17, 2023, at the University of Toronto (UofT) Faculty Club.

Fig. 1.

Mary and Ron at a younger age.

Fig. 1.

Mary and Ron at a younger age.

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Fig. 2.

Ron and Alison, his youngest child.

Fig. 2.

Ron and Alison, his youngest child.

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Ron had a deep love of natural history, first nourished as a small boy by exploring the Don River Valley behind his home in East York (Toronto) with his father. Having a precocious mind, Ron entered UofT at age 16 on a classic’s scholarship, graduating in Honours Science (Physiology) at Victoria College (UofT) in 1948 (BA), where he was awarded the Lieutenant Governor’s Medal [1]. Ron’s first and lifelong passion was natural history and the pursuit of field biology, with interests in birds, butterflies, orchids, wildflowers, sedges, and frogs. He pursued these interests with zeal during his travels at home and abroad, frequently accompanied by his wife Mary [1]. Ron reveled in identifying birds worldwide by their markings and songs. He meticulously collected butterflies and plants from around the world. Ron housed his collections at his home office and in his greenhouse. If you were lucky, he would give you a guided tour of the world through his plants and butterflies, which I had the privilege to appreciate (O.V.-F.).

Ron was a renowned and active “layman” bird watcher in Canada. Accordingly, he was a member of the Board of Directors (1975–1980, 1982–1990, and 1991–1995) and Chairman (1978–1980, 1983–1987, and 1988–1996) of the Long Point Bird Observatory – Birds Canada; a member of the Executive Board of Directors of the Federation of Ontario Naturalists (1982–1984); and Trustee of The Nature Conservancy of Canada (1987 and 1994) [2]. In 1991, he authored, with Holmes, Hess, and Hanks, The Ontario Butterfly Atlas [3].

During his undergraduate studies, Ron worked in the laboratory of Dr. Charles Best, the co-discoverer of insulin, who, together with Ron’s mother, advised him to study medicine. Ron listened, graduating in medicine (MD) from UofT in 1952. He was the recipient of the Saddington Medal in Pathology (1950) and the Cody Silver Medal (1952). Under the tutelage of Dr. Harry Botterell, Ron trained in neurosurgery at UofT from 1953 to 1959 (FRCSC, 1959), during which time he also completed a master’s degree (MA) in physiology (1954). Upon completing his neurosurgical training, Ron made a pilgrimage to Madison, Wisconsin, as a postdoctoral McLaughlin Traveling Fellow to work with the preeminent neurophysiologist Clinton Woolsey, who, to use Ron’s words, taught him to think about the nervous system in an organized fashion. Following his time in Wisconsin, Ron traveled to major functional neurosurgery centers in Paris, Stockholm, and Freiburg, to train with Tailarach, Guiot, Leksell, and Hassler (1959–1961) [1, 2, 4].

In 1961, Ron returned to Toronto and joined the staff of the Division of Neurosurgery, Department of Surgery, Toronto General Hospital (TGH), UofT, where he was distinguished as a Markle Scholar (1961–1966), and in 1978 was promoted to Full Professor. Ron taught in the Faculty of Medicine at UofT for over 40 years. He was a very active member of the Graduate Faculty of Medical Science, School of Graduate Studies, and the Playfair Neuroscience Institute from 1978 to 1999, when he became an Emeritus Member [1, 2, 4].

Ron headed the Division of Neurosurgery at TGH from 1979 to 1989. The Division of Neurosurgery at TGH was amalgamated in 1989 with the Division of Neurosurgery at Toronto Western Hospital (TWH), under the leadership of Charles Tator. Ron continued his superb work in functional neurosurgery as a senior neurosurgeon at TWH until his retirement in 1998, when he was appointed as honorary staff (shown in Fig. 3) [2, 4]. In the same year, Ron’s wife Mary organized a stereotactic conference in Pond Inlet, Baffin Island, in the Canadian Arctic, to celebrate Ron’s retirement [5]. Ron continued to go to his office following his retirement, once a week on Wednesdays, to see some of his patients who simply refused to see any other doctor [2]. In August 2023, a group of functional neurosurgeons convened in Ilulissat, Greenland, for the most recent Arctic meeting, where Ron’s legacy was once again celebrated [5].

Fig. 3.

Ron in his office at the Toronto Western Hospital. He gifted me the Leksell stereotactic apparatus in the photo before my return to Goiânia, Brazil (O.V.-F.).

Fig. 3.

Ron in his office at the Toronto Western Hospital. He gifted me the Leksell stereotactic apparatus in the photo before my return to Goiânia, Brazil (O.V.-F.).

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Ron was a classically trained scientist in the analog methods of early modern medicine. He pioneered clinical neurophysiology by adopting digital technology and instrumentation in the operating room and by melding his training in neurophysiology and stereotactic neurosurgery. His groundbreaking and meticulous study of the deepest centers of the human brain was enabled by his use of objective, quantifiable metrics and in-house, purpose-built instrumentation and by his assembly of multidisciplinary collaborators [1, 2, 5]. To cite a few of these collaborators, one cannot forget the formidable neuroscientists Leslie Organ, Jonathan Dostrovsky, Bill Hutchison, and Karen Davis. Assisted by these neurophysiologists, Ron mapped the human thalamus and midbrain during stereotactic procedures for pain and movement disorders, relying on macrostimulation. Ron became the world’s pre-eminent brain cartographer, a modern-day Magellan, for his neurophysiological exploration of previously unexplored deep brain targets in humans [1, 2, 4].

Derived from these intraoperative studies was one of his most important contributions, The Thalamus and Midbrain of Man, which Ron published in 1982 [1, 2, 4, 5]. Ron was an early adopter of microelectrode recording (MER) of neuron activity in conjunction with deep brain stimulation (DBS). He adapted equipment from his laboratory for use in the operating room (MER machines for human use were not available at that time), incorporating MER into his surgical armamentarium. This was a tremendous technological advance in the field [2]. In spite of the importance of his procedures, however, they were performed in an operating room that was half the size of a “regular” OR because they took considerable time. In those modest facilities, Ron performed his groundbreaking neuroscience surgeries [1, 5].

Although a very complete functional neurosurgeon, Ron’s principal areas of expertise were pain and movement disorders. In fact, pain was the apple of his eye. This supposition is supported by his main contributions to the field: he was the first to firmly establish the difference between nociceptive and neuropathic pain; to categorize the three elements of neuropathic pain (steady, intermittent, and evoked pain); to develop a new understanding of neuropathic pain mechanisms; to determine the strategy for treating the different elements of neuropathic pain; and to perform the physiological mapping of the sensory (also motor) thalamus and midbrain [2].

In addition to his seminal contributions to the field, Ron’s other great achievement perhaps was to establish a school of functional neurosurgery in Toronto, having visitors from all over the world come to learn from his wisdom [4]. He was very proud of the many residents and fellows he trained (shown in Fig. 4). He loved to teach and learn from others.

Fig. 4.

Ron and his fellows during the commemoration of his 90th birthday. Seated, Zelma Kiss (Calgary, Canada) and Ron Tasker. Standing, from left to right, Osvaldo Vilela-Filho (Goiânia, Brazil), Andy Parrent (London, Canada), Bob Coffey (NY, USA), and Fred Lenz (Baltimore, USA).

Fig. 4.

Ron and his fellows during the commemoration of his 90th birthday. Seated, Zelma Kiss (Calgary, Canada) and Ron Tasker. Standing, from left to right, Osvaldo Vilela-Filho (Goiânia, Brazil), Andy Parrent (London, Canada), Bob Coffey (NY, USA), and Fred Lenz (Baltimore, USA).

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Ron’s academic career was extremely fruitful. He authored five books. The most well-known are The Thalamus and Midbrain of Man (1982) and the bible of our field, Textbook of Stereotactic and Functional Neurosurgery, co-edited by Philip Gildenberg, first edition (1998), and also by Andres Lozano, second edition (2009). Excluding abstracts and posters, Ron authored 326 publications (articles and book chapters). He was also invited to lecture at many renowned institutions around the world on over 300 occasions. Ron also had a busy administrative career. Highlights include his service as President of the American Society for Stereotactic and Functional Neurosurgery (1980–1981), World Society for Stereotactic and Functional Neurosurgery (1985–1989), Canadian Pain Society (1991–1994), and Aesculapian Society (2003) [2].

Ron was the recipient of seventeen awards during his distinguished career. The best known in our field is the Spiegel & Wycis Medal of the World Society for Stereotactic and Functional Neurosurgery – WSSFN (1993) [1, 2, 4, 5]. In 1997, the Joint Section on Pain of the American Association of Neurological Surgeons (AANS) and Congress of Neurological Surgeons (CNS) established the Ronald R. Tasker Young Investigators Award in Pain Research [2, 4]. In 1999, the R.R. Tasker Chair in Functional Neurosurgery was endowed in the Department of Surgery at UofT to mark his many contributions to this field of medicine [1, 2]. This chair was first held by Andres Lozano (shown in Fig. 5) and, since 2021, by Suneil Kalia. In 2005, Ron was honored with the title of Professor Emeritus – Neurosurgery at UofT and was appointed as an Officer of the Order of Canada – the latter being the most important title a civilian can receive in that country [1, 2]. In 2013, upon my proposal (O.V.-F.), the WSSFN established the Ronald Tasker Award, to be given to the most accomplished, actively practising functional neurosurgeon (ages 36–65) in the years that preceded the WSSFN meeting [6]. To date, four colleagues have received this award: Andres Lozano (2013), David Roberts (2017), Jocelyn Bloch (2019), and Joachim Krauss (2022).

Fig. 5.

Ron Tasker and Andres Lozano.

Fig. 5.

Ron Tasker and Andres Lozano.

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Throughout his brilliant career, Ron established himself as a world-renowned functional neurosurgeon, teacher, mentor, and role model, who was highly regarded for his clarity of thinking and his indisputable professional honesty and integrity [1, 2]. But that is enough about Ron Tasker the functional neurosurgeon/neuroscientist and naturalist. Now, I would like to write a bit about the person he was (O.V.-F.).

What a marvelous human being and family man! And an incomparable mentor and friend! Soon after I arrived in Toronto in 1991, prior to the start of my fellowship, Ron invited my wife (Maria Ivone Vilela) and I to his home on a Friday evening for wine and cheese. That evening, sensing how difficult our adjustment was to a new city and country, he offered us the third floor of his house as living quarters during our time in Toronto. As we had already rented an apartment, Ron decided to lend me his car for the weekend so we could purchase some furniture. The next day, his sweet wife Mary personally introduced us to some of the best and most economical furniture vendors across the city. She also lent us some of their own furniture and gifted us a stunning set of crystal wine glasses. And that was only the beginning! Ron and Mary invited us back to their home on numerous occasions and treated us as family at very special Christmas and New Year’s gatherings that Maria and I were honored to join (O.V.-F.) [2].

During my time in Toronto (1991–1992) (shown in Fig. 6), as part of my main research, I had the opportunity to review the files of all patients who had undergone DBS for the treatment of refractory chronic pain. After collecting all the data and making the innumerable tables to analyze the results, we remained uncertain of how to best publish the findings. In 1993, Ron was invited to write a chapter on DBS for the Control of Intractable Pain for the fourth edition of the neurosurgical bible, Neurological Surgery, edited by Julius R. Youmans. Ron had all the data and could easily have authored this chapter alone but instead invited me to serve as a co-author. It is difficult to imagine a greater honor for a young neurosurgeon, especially one from a developing country (O.V.-F.) [2]!

Fig. 6.

Ron Tasker and Osvaldo Vilela-Filho.

Fig. 6.

Ron Tasker and Osvaldo Vilela-Filho.

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During the final week of my fellowship, in every free moment of his busy days, either in his office or in the OR, Ron sat with me and reviewed, step-by-step, writing with his own hands, the most important practical aspects in the surgical treatment mainly of pain and movement disorders, but also of spasticity and psychiatric disorders (shown in Fig. 7). I suppose he wanted to be certain I was fully prepared to start my practice as a functional neurosurgeon. Have you ever encountered someone who went to these lengths in your training? I have kept his writings and explanations as some of my most treasured belongings (O.V.-F.).

Fig. 7.

Ron Tasker’s handwritten notes (1992) for Osvaldo Vilela-Filho summarizing some practical aspects of ventral intermediate nucleus DBS or thalamotomy.

Fig. 7.

Ron Tasker’s handwritten notes (1992) for Osvaldo Vilela-Filho summarizing some practical aspects of ventral intermediate nucleus DBS or thalamotomy.

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When I left Toronto, the amount of money required to acquire the equipment necessary to start my practice in Goiânia, Brazil, was approximately USD 150,000. This cost was well beyond the realm of affordability for a young neurosurgeon at the start of his career. Ron proposed that I take some of his older equipment (one Leksell frame and two OWL radiofrequency generators) that were in perfect condition but had been replaced by newer models in his laboratory (shown in Fig. 3). He also offered me some additional equipment, electrodes, and cables. Ron’s tremendous generosity was likely the most important factor enabling me to launch my neurosurgical career in Goiânia at full speed (O.V.-F.) [2].

Perhaps what is more challenging than the career of a full professor is that of a “real” professor. This latter characteristic is shared by very few, and Ron firmly cemented his place in this very special group. I learned much from him, but above all, Ron instilled in me his philosophical way to approach patients harboring chronic intractable pain in a standard fashion – knowledge that simply cannot be acquired from books or papers. I continue to follow his approach in my own practice, my small contribution to honoring Ron’s neurosurgical legacy (O.V.-F.) [2].

Ron was my mentor, friend, and second father. He was an outstanding functional neurosurgeon and professor, who loved and knew how to teach, making difficult matters simple. A man of great honesty and wisdom, Ron was the owner of an immense heart and immeasurable kindness. He was a wonderful husband, father, and friend, and above all, a very humble, modest human being. Ron’s life serves as a true example for those in our discipline (O.V.-F.) [2]!

The authors have no conflicts of interest to declare.

This study was not supported by any sponsor or funder.

O.V.-F., A.M.T., and A.M.L. conceptualized, wrote, and reviewed the manuscript.

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