title: Using Low Levels of Stochastic Vestibular Stimulation to Improve Balance Function.
abstract: Low-level stochastic vestibular stimulation (SVS) has been associated with improved postural responses in the medio-lateral (ML) direction, but its effect in improving balance function in both the ML and anterior-posterior (AP) directions has not been studied. In this series of studies, the efficacy of applying low amplitude SVS in 0-30 Hz range between the mastoids in the ML direction on improving cross-planar balance function was investigated. Forty-five (45) subjects stood on a compliant surface with their eyes closed and were instructed to maintain a stable upright stance. Measures of stability of the head, trunk, and whole body were quantified in ML, AP and combined APML directions. Results show that binaural bipolar SVS given in the ML direction significantly improved balance performance with the peak of optimal stimulus amplitude predominantly in the range of 100-500 μA for all the three directions, exhibiting stochastic resonance (SR) phenomenon. Objective perceptual and body motion thresholds as estimates of internal noise while subjects sat on a chair with their eyes closed and were given 1 Hz bipolar binaural sinusoidal electrical stimuli were also measured. In general, there was no significant difference between estimates of perceptual and body motion thresholds. The average optimal SVS amplitude that improved balance performance (peak SVS amplitude normalized to perceptual threshold) was estimated to be 46% in ML, 53% in AP, and 50% in APML directions. A miniature patch-type SVS device may be useful to improve balance function in people with disabilities due to aging, Parkinson's disease or in astronauts returning from long-duration space flight.
authors: Department of Health and Human Performance, University of Houston, Houston, Texas, United States of America.
authors: Rahul
authors: R
authors: Goel
authors: Wyle Science, Technology and Engineering Group, Houston, Texas, United States of America.
authors: Igor
authors: I
authors: Kofman
authors: Neuroscience Laboratory, NASA Johnson Space Center, Houston, Texas, United States of America.
authors: Jerome
authors: J
authors: Jeevarajan
authors: Wyle Science, Technology and Engineering Group, Houston, Texas, United States of America.
authors: Yiri
authors: Y
authors: De Dios
authors: Department of Otolaryngology-Head and Neck Surgery, Baylor College of Medicine, Houston, Texas, United States of America.
authors: Helen S
authors: HS
authors: Cohen
authors: Neuroscience Laboratory, NASA Johnson Space Center, Houston, Texas, United States of America.
authors: Jacob J
authors: JJ
authors: Bloomberg
authors: Universities Space Research Association, Houston, Texas, United States of America.
authors: Ajitkumar P
authors: AP
authors: Mulavara
mesh_terms: D000328:Adult; D004558:Electric Stimulation; D019054:Evoked Potentials, Motor / Q000502:physiology*; D006801:Humans; D008297:Male; D008416:Mastoid; D009038:Motion; D009039:Motion Perception / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D012018:Reflex; D013269:Stochastic Processes; D014722:Vestibule, Labyrinth / Q000502:physiology