Faculty Collaboration Database

Neuromagnetic source imaging of abnormal spontaneous activity in tinnitus patient modulated by electrical cortical stimulation. Annu Int Conf IEEE Eng Med Biol Soc 2009;2009:1940-4

Date

12/08/2009

Pubmed ID

19964017

DOI

10.1109/IEMBS.2009.5333457

Scopus ID

2-s2.0-77951011480 (requires institutional sign-in at Scopus site)   24 Citations

Abstract

Electrical cortical stimulation (CS) of the auditory cortices has been shown to reduce the severity of debilitating tinnitus in some patients. In this study, we performed MEG source imaging of spontaneous brain activity during concurrent CS of the left secondary auditory cortex of a volunteer suffering from right unilateral tinnitus. CS produced MEG artifacts which were successfully sorted and removed using a combination of sensor and source level signal separation and classification techniques. This contribution provides the first proof of concept reporting on analysis of MEG data with concurrent CS. Effects of CS on ongoing brain activity were revealed at the MEG sensor and source levels and indicate CS significantly reduced ongoing brain activity in the lower frequency range (<40Hz), and emphasized its higher (>40Hz), gamma range components. Further, our results show that CS increased the spectral correlation across multiple frequency bands in the low and high gamma ranges, and between the alpha and beta bands of the MEG. Finally, MEG sources localized in the auditory cortices and nearby regions exhibited abnormal spectral activity that was suppressed by CS. These results provide promising evidence in favor of the Thalamocortical Dysrhytmia (TCD) hypothesis of tinnitus, and suggest that CS may prove to be an effective treatment of tinnitus when targeted to brain regions exhibiting abnormal spontaneous activity.

Author List

Ramirez RR, Kopell BH, Butson CR, Gaggl W, Friedland DR, Baillet S

MESH terms used to index this publication - Major topics in bold

Auditory Perception
Brain Mapping
Cerebral Cortex
Electric Stimulation
Functional Laterality
Hearing
Humans
Magnetic Resonance Imaging
Magnetics
Magnetoencephalography
Motor Cortex
Radiation
Sensitivity and Specificity
Speech
Theta Rhythm
Tinnitus