title: Downbeat down south.
abstract: A 59-year-old woman with late-onset diabetes mellitus presented with a 4-week history of oscillopsia and vertigo. Physical examination revealed downbeating nystagmus in the primary position that worsened on right gaze and left gaze. Magnetic resonance imaging of the brain and orbits showed enhancement and signal abnormality in the right temporal lobe without evidence of a cervicomedullary junction lesion. Serum anti-glutamic acid decarboxylase 65 (GAD65) antibody titer was markedly elevated. Given these findings, her vertigo and downbeat nystagmus were likely secondary to elevated anti-GAD antibodies.
authors.affiliation: Baylor College of Medicine, Houston, TX, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Ophthalmology, Houston Methodist Hospital, Houston, TX, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Morgan
authors.affiliation: Department of Ophthalmology, Houston Methodist Hospital, Houston, TX, USA.
authors.forename: Angelina Espino Barros
authors.initials: AE
authors.lastname: Palau
authors.affiliation: West Houston Medical Center, Department of Family Practice, Houston, TX, USA.
authors.forename: Janice A
authors.initials: JA
authors.lastname: Mudd
authors.affiliation: Baylor College of Medicine, Houston, TX, USA; Department of Ophthalmology, Houston Methodist Hospital, Houston, TX, USA; Department of Ophthalmology, Weill Cornell Medical College, Houston, TX, USA; Department of Neurology, Weill Cornell Medical College, Houston, TX, USA; Department of Neurosurgery, Weill Cornell Medical College, Houston, TX, USA. Electronic address: AGLee@HoustonMethodist.org.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Lee
authors.affiliation: Department of Medicine (Neurology), University of British Columbia, Vancouver, BC, Canada; Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC, Canada; Department of Psychology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Jason J S
authors.initials: JJ
authors.lastname: Barton
mesh_terms: D001323:Autoantibodies / Q000097:blood*; D001327:Autoimmune Diseases / Q000150:complications*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000209:etiology*; D014717:Vertigo / Q000209:etiology
chemical_list: D001323:Autoantibodies
keywords: anti-GAD antibodies; autoimmune disease; downbeat nystagmus; magnetic resonance imaging