title: Electrical tongue stimulation normalizes activity within the motion-sensitive brain network in balance-impaired subjects as revealed by group independent component analysis.
abstract: Multivariate analysis of functional magnetic resonance imaging (fMRI) data allows investigations into network behavior beyond simple activations of individual regions. We apply group independent component analysis to fMRI data collected in a previous study looking at the sustained neuromodulatory effects of electrical tongue stimulation in balance-impaired individuals. Twelve subjects with balance disorders viewed optic flow in an fMRI scanner before and after 5 days of electrical tongue stimulation. Nine healthy controls also viewed the visual stimuli but did not receive any stimulation. Multiple regression of the 47 estimated components found two that were modulated by the visual stimuli. Component 7, comprised primarily of the primary visual cortex (V1), responded to all visual stimuli and showed no difference in task-related activity between the healthy controls and the balance-impaired subjects before or after stimulation. Component 11 responded only to motion in the visual field and contained multiple cortical and subcortical regions involved in processing information pertinent to balance. Two-sample t-tests of the calculated signal change revealed that the task-related activity of this network is greater in balance-impaired subjects compared with controls before stimulation (p=0.02), but that this network hypersensitivity decreases after electrical tongue stimulation (p=0.001).
authors.affiliation: Neuroscience Training Program, University of Wisconsin, Madison, Wisconsin 53705, USA. jcwildenberg@wisc.edu
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Wildenberg
authors.forename: Mitchell E
authors.initials: ME
authors.lastname: Tyler
authors.forename: Yuri P
authors.initials: YP
authors.lastname: Danilov
authors.forename: Kurt A
authors.initials: KA
authors.lastname: Kaczmarek
authors.forename: Mary E
authors.initials: ME
authors.lastname: Meyerand
mesh_terms: D000328:Adult; D001921:Brain; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D005684:Gait / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009039:Motion Perception / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods*; D004856:Postural Balance / Q000502:physiology*; D025341:Principal Component Analysis / Q000379:methods*; D011597:Psychomotor Performance / Q000502:physiology; D014059:Tongue / Q000502:physiology*