A Study for Diagnostic Usefulness of Computer Assisted EEG Topography

J Korean Neurol Assoc > Volume 4(1); 1986 > Article

Journal of the Korean Neurological Association 1986;4(1): 43-54.

뇌파 등전위 분포도 (Computer assisted EEG Topography)의 임상적 유용성에 대한 연구

김두응, 권오상 , 민병근

중앙대학교 신경과.

A Study for Diagnostic Usefulness of Computer Assisted EEG Topography

Do-Eung Kim, M.D., Oh-Sang Kwon, M.D. and Byung Kun Min, M.D.

Department of Neurology, College of Medicine, Chung Ang University

Abstract

The authers studied the diagnostic usefulness of the Topographic analysis of EEG, using Topography ststem 700 (San-ei), in evaluation of supratentorial focal cerebral lesions of 27 patients with various etiology, comparing with visual anslysis of EEG. Focal cerebral lesions, which were proven with brain C-T, were 11 cases of cerebral infarction, 6 of intracranial hematoma, 6 of cerebral gliolysis and 4 of others. The topography system displays the spatial distribution of activity in the classic delta, theta, alpha and beta frequency and computed mapping of EEG displays equipotential maps of square of roots of power spectra over each frequency band. For visual analysis of slow waves and background activity changes, Mayo classification system of EEG abnormality was used and for visual evaluation of topographic display, above system was also applied with some modification in order to compare with the data of visual analysis of conventional EEG. The results of the study were as follows; 1. While visual analysis of conventional anlysis of EEGs showed abnormality only in 13 cases (48.1%) of 27, topographic analysis showed abnormality in 22 cases (81.5%). Topographic analysis was more sensitive than than visual analysis of the EEG and topographic analysis was thought to be more sensitive in assessment of local slow waves as well as minor changes, especially slight asymmetry, of background EEG activity. 2. Topographic analysis showed higher concor dance rate (55.6%) to the brain C-T finding in lateralization of supratentorial focal cerbral lesion than that (44.4%) of visual analysis of the conventional EEG.