Clinical utility of topographic EEG brain mapping

Topographic EEG brain mapping was performed on 100 patients referred for both EEG and neuroimaging procedures. Topographic maps were abnormal in 78% of patients with stroke, 50% with head trauma and 100% of those with space occupying lesions (tumor, abscess or intracerebral hematoma). Of the patients with abnormal EEG maps 30% had either sole or better localization with mapping than routine EEG or neuroimaging procedures. In no cases were there false localizing abnormalities by EEG mapping. Topographic mapping appears to provide better detection of low amplitude slow activity not easily discernible by routine EEG. It also provides faithful correspondence with localization of many lesions on neuroimaging procedures, and at times distinguishes abnormalities not immediately definable by CT/MRI. Topographic EEG mapping is a valuable adjunct to routine EEG.