6 May 2014
It was with great interest that we encountered the recent article by Kapila et al. . The preclinical studies from this group have contributed significantly to our understanding of the relationship between the perioperative period and cognitive loss. However, with respect to translation, we believe that a much more cautionary note is due here than presented by the article. First, the evidence in humans that the perioperative period is linked to incident dementia is weak at best. Many contradictory clinical studies exist and there is simply no consensus at this point. Second, the mechanism of post-operative cognitive decline (POCD) in people is unknown, and any relationship between POCD and dementia, although suspected, is unproven, so statements like ‘Neuroinflammatory processes as a result of surgical trauma and anesthetic insult are, as aforementioned, major factors in the pathogenesis of POCD and resulting AD’ are premature. Finally, and most concerning in our view, are the comments regarding mitigation. It is entirely premature, and perhaps perilous, to promote one anesthetic, or perioperative management strategy, as being of lower risk for the development of POCD or incident dementia. This is simply not known at this point, and the even the preclinical evidence is only suggestive at best. What we need are well-designed, adequately powered, prospective studies, so that the presence and nature of any association between anesthesia, surgery and Alzheimer’s disease can be clarified. The conversion of, what are essentially hypotheses, in the Kaplia et al. paper, to conclusions and recommendations requires a far more substantive body of such research.Lis Evered, Associate Professor, Melbourne Medical School, University of Melbourne; Centre for Anaesthesia and Cognitive Function, St. Vincent’s Hospital, Melbourne; firstname.lastname@example.orgRod Eckenhoff, Vice Chair for Research, Austin Lamont Professor of Anesthesiology & Critical Care, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USAJeff Silverstein, Professor of Anesthesiology, Surgery, and Geriatrics & Palliative Care, Icahn School of Medicine at Mount Sinai, New York, NY, USAGreg Crosby, Associate Professor, Harvard Medical School, Department of Anesthesiology, Perioperative, and Pain Medicine, Brigham & Women's Hospital, Boston, MA, USADavid Scott, Associate Professor, Department of Surgery, University of Melbourne; Director, Department of Anaesthesia, St. Vincent’s Hospital, Melbourne, AustraliaEsther Oh, Assistant Professor, Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, USAStacie Deiner, Associate Professor of Anesthesiology, Neurosurgery, Geriatrics and Palliative Care, The Icahn School of Medicine, Mt. Sinai, NY, USAReference:  Kapila AK, Watts HR, Wang T, Ma D (2014) The impact of surgery and anesthesia on post-operative cognitive decline and Alzheimer’s disease development: biomarkers and preventive strategies. J Alzheimers Dis, doi: 10.3233/JAD-132258.