Contents lists available at ScienceDirect Clinical Neurology and Neurosurgery journal homepage: www.elsevier.com/locate/clineuro Neurosurgical issues of bariatric surgery: A systematic review of the literature and principles of diagnosis and treatment Daniele Bongetta a,b, ⁎ , Cesare Zoia a , Sabino Luzzi a,c , Mattia Del Maestro a,d , Andrea Peri e , Germana Bichisao f , Debora Sportiello f , Isabella Canavero g , Andrea Pietrabissa b,e , Renato J. Galzio a,b a Neurosurgery Unit, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy b Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Italy c Department of Emergency and Organ Transplantation, University of Bari “Aldo Moro”, Italy d Department of Life, Health and Environmental Sciences (MESVA), University of L'Aquila, Italy e General Surgery Unit II, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy f Anesthesia and Intensive Care Unit I, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy g Emergency Neurology Unit, IRCCS Mondino Foundation, Pavia, Italy ARTICLE INFO Keywords: Bariatric Obesity Neurosurgery Intracranial hypertension Neuropathy Pituitary Cushing ABSTRACT Bariatric surgery is gaining popularity as the treatment of choice of morbid obesity since this condition is constantly increasing over the last decades. Several complications have emerged as the number of surgeries and follow-up data increase. No systematic review of the neurosurgery-related potential complications has been performed to date. Objective of this work is to fill this gap. We reviewed the literature for bariatric surgery- related complications involving the neurosurgical practice. Moreover, we present explicative cases dealing with peri- and post-operative therapeutic precautions. Three pathological mechanisms emerged. The first is related to intracranial pressure alterations and may imply either intracranial hypertension or hypotension syndromes in the operative or post-operative periods. The second is the deficiency of macro- and micro-nutrients which are potential risk factors for neuro- or myelo-encephalopathies, fetal malformations and spine disorders. The third is a dysregulation of both autonomic and endocrine / pituitary control. Neurosurgeons must be aware of the several, multifactorial neurosurgery-related complications of bariatric surgery as their prevalence is likely to be higher in the next few years. 1. Introduction The WHO reports that obesity is the fifth leading risk for mortality and its prevalence has nearly tripled since 1975. [1] In patients who have not responded to medical treatments, bariatric surgery (BS) is advised if BMI > 35–40 kg/m 2 [2]. The surgical aim is basically to re- strict food intake with procedures such as the positioning of a gastric band around the upper stomach or the removal of the greater curvature of the stomach to create a sleeve-like pouch. More complex procedures also imply the division of the GI tract in order to alter the absorption of food. The mean weight loss is of 20-35% in a 2-3-year span. [3] Besides BS-specific complications, several reports have been published about systemic complications, some of which also involved the central and peripheral nervous systems. The analysis of the relationship between obesity and the neurosurgical practice reported controversial results [4–6]. Still, no study has systematically evaluated the relationship be- tween BS and the neurosurgical practice. The aim of this study is to review the potential neurosurgery-related complications of BS focusing on etiopathological mechanisms. Preventive precautions and treatment caveats will be discussed also by means of explicative cases. 2. Materials and methods In January 2018 we electronically searched PubMed/MEDLINE, EMBASE and The Cochrane Library to find articles dealing with the topic of neurosurgical complication of BS, with no time nor language restrictions. The original query yielded 489 articles. We used this search strategy in PubMed: ((((((((((csf hypotension) OR csf hypertension) OR https://doi.org/10.1016/j.clineuro.2018.11.009 Received 11 October 2018; Received in revised form 9 November 2018; Accepted 11 November 2018 ⁎ Corresponding author at: UOC Neurochirurgia, Fondazione IRCCS Policlinico San Matteo, Viale Golgi 16, 27100 Pavia. Tel.: +393289672299; Fax: +390382502342. E-mail address: danielebongetta@hotmail.com (D. Bongetta). Clinical Neurology and Neurosurgery 176 (2019) 34–40 Available online 13 November 2018 0303-8467/ © 2018 Elsevier B.V. All rights reserved. T