Isak Prohovnik, PhD, one of the creative forces in the development of modern methods of quantitating cerebral perfusion, died suddenly in October 2012. Isak was born in Israel in 1950 of Holocaust survivors. He has an extended family in Israel and was raised by his mother and by his many relatives in Kibbutz Neve Eitan. His formative years took place against the backdrop of Israel’s tumultuous formation. A precocious child and avid reader, he came to know 7 languages. After his compulsory military service, he graduated with a BA from Tel Aviv University. He worked as a sky marshal on Israeli commercial flights. On one such flight he met scientists from Sweden’s Lund University, a fateful encounter which fired his imagination and led to his seeking further education in Sweden. He received his PhD degree in 1980 from Lund University under the mentorship of Prof. Jarl Risberg.1 At this time, Lund had become a preeminent center for clinical and translational neuroscience, and pioneering advances in cerebral physiology were coming from Scandinavia. He worked briefly in the industry (Novo Diagnostic Systems, Copenhagen), which brought him to the United States and interaction with Columbia University. In 1982, Herbert Pardes, then director of the NYS Psychiatric Institute and Chairman of Psychiatry at Columbia P&S, recruited Isak to the faculty. He became the Director for Brain Imaging at the Department of Biological Psychiatry at the New York State Psychiatric Institute, Columbia University. His early work that brought him wide recognition was following in the footsteps of the great Scandinavian cerebral physiologists in the development of 133Xe washout cerebral blood flow methodology. His most important contributions were in helping to shape the definitive approach to cerebral blood flow quantitation when the tracer was given intravenously or by inhalation, as pioneered by Walter Obrist. The deconvolution techniques and 133Xe methods undergirded approaches now in wide use for CT-based and MR-based estimates of cerebral perfusion. Isak coedited an important monograph on this topic,2 and developed an improved initial slope method for Xenon clearance.3 His interests were protean; he developed experimental approaches to study a wide range of other neurological disorders, including adult ischemic stroke, Alzheimer disease, systemic lupus erythematosus, and Moyamoya syndromes. His breakthrough work in sickle cell disease described the paradox that sickle cell disease, although a hyperemic state, resulted in relative perfusion insufficiency and both clinical and silent stroke.4 This early work led to transcranial Doppler studies and further MRI studies. Ultimately, sickle cell disease researchers developed biomarkers for the primary prevention of cerebrovascular accidents based on this early work. He also collaborated on seminal studies that characterized the cerebral perfusion and intravascular pressure alterations caused by high-flow shunting from brain arteriovenous malformations, and how they are affected by neurosurgical treatment.5 He influenced many neuroanesthesiologists, including William L. Young (UCSF), Shailendra Joshi (Columbia), Arthur Schwartz (Mt. Sinai), Lauren Fleischer (Stonybrook), Patricia Fogarty-Mack (Cornell), Tomoki Hashimoto (UCSF), and Dhanesh Gupta (Northwestern); he indirectly influenced trainees associated with those faculties. Prohovnik left Columbia in 1995 and moved back to Israel for 2 years working in Brain Imaging at Sheba Medical Center, Tel Hashomer, Israel. In order to pursue MRI studies, he next moved to Yale University where he did a postdoctoral fellowship in Diagnostic Radiology, later moving to Mt. Sinai where he became a Professor of Psychiatry and Radiology. At Sinai, he continued his brain imaging studies making contributions in renal disease, pediatric hypertension, psychiatric disorders, and Creutzfeldt-Jacob Disease,6 where he performed research concurrently in both the United States and Israel. Recently he became a public figure in his hometown of Port Jefferson, NY, where he ran for and was elected to a seat on the school board. He was passionately interested in education and the teaching of science. He also was intrigued with the politics of change and budget compromises. He became an active mentor for high school students competing in the Intel Science Competitions. He seemed energized by this chance to impact science education. Despite never being a politician, as he grew older he became a politician to advance education. He is survived by his wife and 2 daughters. Isak served as a mentor to the authors of this memorial obituary and many others. He helped shape our understanding of cerebrovascular flow physiology and the broader field of clinical neuroscience, and he contributed generously to the Journal of Neurosurgical Anesthesiology. He has left a durable legacy of innovative thinking and scientific rigor on the authors, his colleagues, his children, and future generations. He was an accomplished and consummate scientist on whose shoulders we are honored to stand.
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Mar 21, 2014
Blake D Niederhauser + 3
Open Access