title: Hippocampal gray matter volume in bilateral vestibular failure.
abstract: Bilateral vestibular failure (BVF) is a severe chronic disorder of the labyrinth or the eighth cranial nerve characterized by unsteadiness of gait and disabling oscillopsia during head movements. According to animal data, vestibular input to the hippocampus is proposed to contribute to spatial memory and spatial navigation. Except for one seminal study showing the association of impaired spatial navigation and hippocampal atrophy, patient data in BVF are lacking. Therefore, we performed a voxel-wise comparison of the hippocampal gray matter volume (GMV) in a clinically representative sample of 27 patients with incomplete BVF and 29 age- and gender-matched healthy controls to test the hypothesis of hippocampal atrophy in BVF. Although the two groups did not generally differ in their hippocampal GMV, a reduction of GMV in the bilateral hippocampal CA3 region was significantly correlated with increased vestibulopathy-related clinical impairment. We propose that GMV reduction in the hippocampus of BVF patients is related to the severity of vestibular-induced disability which is in line with combined hippocampal atrophy and disorders of spatial navigation in complete vestibular deafferentation due to bilateral nerve section. Clinically, however, the most frequent etiologies of BVF cause incomplete lesions. Accordingly, hippocampus atrophy and deficits in spatial navigation occur possibly less frequently than previously suspected. Hum Brain Mapp 37:1998-2006, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Neurology, University of Lübeck and University Hospital Schleswig-Holstein, Lübeck, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Göttlich
authors.affiliation: Department of Neurology, University of Lübeck and University Hospital Schleswig-Holstein, Lübeck, Germany.
authors.forename: Nico M
authors.initials: NM
authors.lastname: Jandl
authors.affiliation: Department of Neurology, University of Lübeck and University Hospital Schleswig-Holstein, Lübeck, Germany.|Institute of Psychology II, University of Lübeck, Lübeck, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Sprenger
authors.affiliation: Department of Neurology, University of Lübeck and University Hospital Schleswig-Holstein, Lübeck, Germany.
authors.forename: Jann F
authors.initials: JF
authors.lastname: Wojak
authors.affiliation: Department of Neurology, University of Lübeck and University Hospital Schleswig-Holstein, Lübeck, Germany.|Institute of Psychology II, University of Lübeck, Lübeck, Germany.
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Münte
authors.affiliation: Department of Neurology, University of Lübeck and University Hospital Schleswig-Holstein, Lübeck, Germany.|Institute of Psychology II, University of Lübeck, Lübeck, Germany.
authors.forename: Ulrike M
authors.initials: UM
authors.lastname: Krämer
authors.affiliation: Department of Neurology, University of Lübeck and University Hospital Schleswig-Holstein, Lübeck, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Helmchen
mesh_terms: D000368:Aged; D001284:Atrophy / Q000473:pathology; D000071699:Bilateral Vestibulopathy / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D016022:Case-Control Studies; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D066128:Gray Matter / Q000000981:diagnostic imaging / Q000473:pathology*; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology; D012044:Regression Analysis; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
keywords: bilateral vestibular failure; hippocampus; magnetic resonance imaging; voxel-based morphometry