title: Magneto-encephalographic measurement of neural activity during period of vertigo induced by cold caloric stimulation.
abstract: The aim of this study was to investigate neural activity during period of vertiginous sensation, induced by caloric stimulation. After caloric vestibular stimulation (CVS) by cold water of five volunteers (n=5, age: 30+/-10), auditory evoked magnetic fields (AEFs) during the subsequent period of vertiginous sensations were measured by magnetoencephalography (MEG). Current-arrow maps (CAMs) were produced to estimate the spatial current distribution of the AEF responses, and a rotation value (dI(rot)) was calculated from the CAM. The worth of the dI(rot) values as indicators of vertigo was evaluated by comparing them with earlier reported values for elderly control (n=11, age: 67+/-5) and chronic dizziness (CD) (n=27, age: 68+/-8) groups (obtained from AEF responses with no the CVS). Although all volunteers felt vertigo during the AEF measurements, the AEF waveforms and CAM pattern only showed slight changes. While the dI(rot) values (1.43+/-0.73) just after CVS were not significantly different from those (1.59+/-0.46) for the elderly controls, they were significantly different from those (3.54+/-1.34) for the CD patients. These findings suggest that (i) the new parameter (dI(rot)) is more sensitively indicates dizziness (non-rotatory sensation) than vertigo (ii) the auditory cortical region may play an important role in body-balance perception of floating sensations.
authors.affiliation: Medical System Research Department, Central Research Laboratory, Hitachi, Ltd., 1-280 Higashi-Koigakubo, Kokubunji-shi, 185-8601, Tokyo, Japan. kandori@crl.hitachi.co.jp
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kandori
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Oe
authors.forename: Kotaro
authors.initials: K
authors.lastname: Miyashita
authors.forename: Shinji
authors.initials: S
authors.lastname: Ohira
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Naritomi
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Chiba
authors.forename: Kuniomi
authors.initials: K
authors.lastname: Ogata
authors.forename: Masahiro
authors.initials: M
authors.lastname: Murakami
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Miyashita
authors.forename: Keiji
authors.initials: K
authors.lastname: Tsukada
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D000375:Aging; D000465:Algorithms; D001931:Brain Mapping; D002150:Caloric Tests; D002908:Chronic Disease; D003080:Cold Temperature / Q000009:adverse effects*; D004244:Dizziness / Q000503:physiopathology; D004584:Electronystagmography / Q000379:methods; D005072:Evoked Potentials, Auditory / Q000502:physiology; D005260:Female; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012399:Rotation; D013702:Temporal Lobe / Q000503:physiopathology; D013997:Time Factors; D014717:Vertigo / Q000503:physiopathology*