| Language dominance and mapping based on neuromagnetic oscillatory changes: comparison with invasive procedures. | |
| | |
MedLine Citation:
|
PMID: 19681682 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
OBJECT: Event-related cerebral oscillatory changes reflect regional brain activation. In a previous study, the authors proposed a new method to determine language dominance: examine frontal oscillatory changes during silent reading by using synthetic aperture magnetometry (SAM). The authors' aims in the present study were to establish a normal template for this method, to confirm the results of their previous study with a larger patient population, and to evaluate their method with respect to language localization. METHODS: A statistical group analysis of 14 healthy volunteers was conducted to establish a normal control. Language dominance and localization were then evaluated in a larger population of 123 consecutive patients. Study participants were instructed to silently read 100 visually presented words. Using SAM, the spatial distribution of the oscillatory changes was obtained as the Student t statistic by comparing the current density for each voxel between 1 second before and 1 second after each word presentation. Group analyses of the healthy volunteers were performed using statistical nonparametric mapping. Language dominance in the patients was determined according to the laterality index (LI) calculated using peak t values of the left and right frontal desynchronizations. Language dominance was prospectively assessed, and the results were compared with those of the Wada test (63 patients). Language localization results were quantitatively compared with those of stimulation mapping (17 patients). RESULTS: Group analysis of the healthy volunteers indicated beta to low gamma band desynchronization in the left frontal area and alpha to beta desynchronization in the left parietotemporal areas. In patients, the frontal language areas were detected in 118 persons (95.9%). Lateralization of beta or low gamma desynchronization in the inferior or middle frontal gyri corresponded well with language dominance. The introduction of the LI resulted in a quantitative evaluation of language dominance, whose results were concordant with those of the Wada test in 51 (85.0%) of 60 cases. The distance between the estimated frontal language areas and stimulation-positive sites was 6.0 +/- 7.1 mm (mean +/- SD). CONCLUSIONS: This study is the first in which magnetoencephalography (MEG) was used to determine language dominance in a large population, and the results were compared with those of the Wada test. Moreover, language localization results obtained using MEG were compared with those obtained by invasive mapping. The authors' method, which is based on neuromagnetic oscillatory changes, is a new approach for noninvasively evaluating the frontal language areas, a procedure that has been problematic using MEG dipole methods. Synthetic aperture magnetometry is a noninvasive alternative to Wada testing for language dominance and helps to determine stimulation sites for invasive mapping. |
| | |
Authors:
|
Masayuki Hirata; Tetsu Goto; Gareth Barnes; Yuka Umekawa; Takufumi Yanagisawa; Amami Kato; Satoru Oshino; Haruhiko Kishima; Naoya Hashimoto; Youichi Saitoh; Naoki Tani; Shiro Yorifuji; Toshiki Yoshimine |
Publication Detail:
|
Type: Comparative Study; Evaluation Studies; Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: Journal of neurosurgery Volume: 112 ISSN: 1933-0693 ISO Abbreviation: J. Neurosurg. Publication Date: 2010 Mar |
Date Detail:
|
Created Date: 2010-03-02 Completed Date: 2010-04-08 Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 0253357 Medline TA: J Neurosurg Country: United States |
Other Details:
|
Languages: eng Pagination: 528-38 Citation Subset: AIM; IM |
Affiliation:
|
Department of Neurosurgery, Osaka University Medical School, Suita, Osaka, Japan. mhirata@nsurg.med.osaka-u.ac.jp |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adolescent Adult Brain / physiology*, physiopathology Brain Mapping / methods* Brain Neoplasms / physiopathology Electric Stimulation Epilepsy / physiopathology Evoked Potentials Female Functional Laterality Humans Language* Magnetoencephalography / methods* Male Middle Aged Periodicity* Reading Signal Processing, Computer-Assisted Young Adult |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Potential financial impact of restriction in "never event" and periprocedural hospital-acquired cond...
Next Document: Subthalamic nucleus deep brain stimulator placement using high-field interventional magnetic resonan...