Vestibular loss and balance training cause similar changes in human cerebral white matter fractional anisotropy.
Patients with bilateral vestibular loss suffer from severe balance deficits during normal everyday movements. Ballet dancers, figure skaters, or slackliners, in contrast, are extraordinarily well trained in maintaining balance for the extreme balance situations that they are exposed to. Both training and disease can lead to changes in the diffusion properties of white matter that are related to skill level or disease progression respectively. In this study, we used diffusion tensor imaging (DTI) to compare white matter diffusivity between these two study groups and their age- and sex-matched controls. We found that vestibular patients and balance-trained subjects show a reduction of fractional anisotropy in similar white matter tracts, due to a relative increase in radial diffusivity (perpendicular to the main diffusion direction). Reduced fractional anisotropy was not only found in sensory and motor areas, but in a widespread network including long-range connections, limbic and association pathways. The reduced fractional anisotropy did not correlate with any cognitive, disease-related or skill-related factors. The similarity in FA between the two study groups, together with the absence of a relationship between skill or disease factors and white matter changes, suggests a common mechanism for these white matter differences. We propose that both study groups must exert increased effort to meet their respective usual balance requirements. Since balance training has been shown to effectively reduce the symptoms of vestibular failure, the changes in white matter shown here may represent a neuronal mechanism for rehabilitation.
German Center for Vertigo and Balance Disorders, University Hospital Munich, Campus Grosshadern, Munich, Germany; Graduate School of Systemic Neurosciences, Ludwig-Maximilians University, Planegg-Martinsried, Germany.
Nadine
N
Hummel
German Center for Vertigo and Balance Disorders, University Hospital Munich, Campus Grosshadern, Munich, Germany; Department of Neurology, University Hospital Munich, Campus Grosshadern, Munich, Germany.
Katharina
K
Hüfner
German Center for Vertigo and Balance Disorders, University Hospital Munich, Campus Grosshadern, Munich, Germany; Graduate School of Systemic Neurosciences, Ludwig-Maximilians University, Planegg-Martinsried, Germany; Department of Neurology, University Hospital Munich, Campus Grosshadern, Munich, Germany; Institute for Clinical Neurosciences, University Hospital Munich, Campus Grosshadern, Munich, Germany.
Thomas
T
Stephan
Department of Neuroradiology, University Hospital Munich, Campus Grosshadern, Munich, Germany.
Jennifer
J
Linn
German Center for Vertigo and Balance Disorders, University Hospital Munich, Campus Grosshadern, Munich, Germany; Department of Neurology, University Hospital Munich, Campus Grosshadern, Munich, Germany.
Olympia
O
Kremmyda
German Center for Vertigo and Balance Disorders, University Hospital Munich, Campus Grosshadern, Munich, Germany; Institute for Clinical Neurosciences, University Hospital Munich, Campus Grosshadern, Munich, Germany.
Thomas
T
Brandt
German Center for Vertigo and Balance Disorders, University Hospital Munich, Campus Grosshadern, Munich, Germany; Graduate School of Systemic Neurosciences, Ludwig-Maximilians University, Planegg-Martinsried, Germany.
Virginia L
VL
Flanagin
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology / Q000502:physiology; D016880:Anisotropy; D001519:Behavior / Q000502:physiology; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D004856:Postural Balance; D014722:Vestibule, Labyrinth / Q000473:pathology* / Q000503:physiopathology*; D066127:White Matter / Q000473:pathology* / Q000503:physiopathology; D055815:Young Adult