title: Quantitative EEG and low resolution electromagnetic tomography (LORETA) imaging of patients with persistent auditory hallucinations.
abstract: Electrophysiological studies have demonstrated gamma and beta frequency oscillations in response to auditory stimuli. The purpose of this study was to test whether auditory hallucinations (AH) in schizophrenia patients reflect abnormalities in gamma and beta frequency oscillations and to investigate source generators of these abnormalities. This theory was tested using quantitative electroencephalography (qEEG) and low-resolution electromagnetic tomography (LORETA) source imaging. Twenty-five schizophrenia patients with treatment refractory AH, lasting for at least 2 years, and 23 schizophrenia patients with non-AH (N-AH) in the past 2 years were recruited for the study. Spectral analysis of the qEEG and source imaging of frequency bands of artifact-free 30 s epochs were examined during rest. AH patients showed significantly increased beta 1 and beta 2 frequency amplitude compared with N-AH patients. Gamma and beta (2 and 3) frequencies were significantly correlated in AH but not in N-AH patients. Source imaging revealed significantly increased beta (1 and 2) activity in the left inferior parietal lobule and the left medial frontal gyrus in AH versus N-AH patients. These results imply that AH is reflecting increased beta frequency oscillations with neural generators localized in speech-related areas.
authors.affiliation: Department of Psychiatry, Ilsanpaik Hospital, Inje University College of Medicine, 2240 Daehwa-dong, Ilsan-gu, Goyang city, Gyeonggi-do 411-706, Korea. lshpss@hanmail.net
authors.forename: Seung-Hwan
authors.initials: SH
authors.lastname: Lee
authors.forename: Jonathan K
authors.initials: JK
authors.lastname: Wynn
authors.forename: Michael F
authors.initials: MF
authors.lastname: Green
authors.forename: Hyun
authors.initials: H
authors.lastname: Kim
authors.forename: Kang-Joon
authors.initials: KJ
authors.lastname: Lee
authors.forename: Min
authors.initials: M
authors.lastname: Nam
authors.forename: Joong-Kyu
authors.initials: JK
authors.lastname: Park
authors.forename: Young-Cho
authors.initials: YC
authors.lastname: Chung
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004569:Electroencephalography; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality / Q000502:physiology; D006212:Hallucinations / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000503:physiopathology*; D014057:Tomography, X-Ray Computed