Mechanisms, Equipment, HazardsAnesthetic Management of Parturients With Arnold Chiari Malformation-I: A Multicenter Retrospective StudyGruffi, T.R.; Peralta, F.M.; Thakkar, M.S.; Arif, A.; Anderson, R.F.; Orlando, B.; Coffman, J.C.; Nathan, N.; McCarthy, R.J.; Toledo, P.; Habib, A.S. Author Information Department of Anesthesiology, Northwestern University Feinberg School of Medicine, Chicago, IL Obstetric Anesthesia Digest 39(4):p 197, December 2019. | DOI: 10.1097/01.aoa.0000603712.91574.56 Buy Metrics Abstract (Int J Obstet Anesth. 2019;37:52–56) In patients with Arnold Chiari malformations (ACM) the cerebellum herniates through the foramen magnum and displaces the lower pons and medulla. In addition, the flow of cerebrospinal fluid from the fourth ventricle is impaired, and dynamic or static herniation of brain tissue can occur. In ∼25% of patients with ACM, the pressure gradient generated by this condition can lead to the development of a syringomyelia, which is an abnormal cavitation within the spinal cord. Type 1 Arnold Chiari malformations (ACM-1) is the most common of 4 categories of ACM, and women with ACM-I are usually not diagnosed until adulthood. Some of these patients are asymptomatic while others may manifest symptoms such as headache, ataxia, and sensorimotor impairments of the extremities. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.