Spatial memory and hippocampal volume in humans with unilateral vestibular deafferentation.
Patients with acquired chronic bilateral vestibular loss were recently found to have a significant impairment in spatial memory and navigation when tested with a virtual Morris water task. These deficits were associated with selective and bilateral atrophy of the hippocampus, which suggests that spatial memory and navigation also rely on vestibular input. In the present study 16 patients with unilateral vestibular deafferentation due to acoustic neurinoma were examined 5- to 13-yrs post-surgery. Volumetry of the hippocampus was performed in patients and age- and sex-matched healthy controls by manually tracing the structure and by an evaluator-independent voxel-based morphometry. Spatial memory and navigation were assessed with a virtual Morris water task. No significant deficits in spatial memory and navigation could be demonstrated in the patients with left vestibular failure, whereas patients with right vestibular loss showed a tendency to perform worse on the respective tests. Impairment was significant only for one computed measure (heading error). The subtle deficiencies with right vestibular loss are compatible with the recently described dominance of the right labyrinth and the vestibular cortex in the right hemisphere. Volumetry did not reveal any atrophy of the hippocampus in either patient group.
Hüfner
Katharina
K
Department of Neurology, Ludwig-Maximilians University, Munich, Germany. katharina.huefner@med.uni-muenchen.de
Hamilton
Derek A
DA
Kalla
Roger
R
Stephan
Thomas
T
Glasauer
Stefan
S
Ma
Jun
J
Brüning
Roland
R
Markowitsch
Hans J
HJ
Labudda
Kirsten
K
Schichor
Christian
C
Strupp
Michael
M
Brandt
Thomas
T
D000704:Analysis of Variance; D016009:Chi-Square Distribution; D005260:Female; D007839:Functional Laterality; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008568:Memory / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011930:Reaction Time; D013028:Space Perception / Q000502:physiology*; D015837:Vestibular Diseases / Q000473:pathology* / Q000503:physiopathology*