Evaluation of stroke using EEG frequency analysis and topographic mapping

Frequency analysis and topographic mapping of EEG were studied in 20 consecutive patients with mild stroke and in 20 age-matched normal subjects. Abnormally large increases in delta and decreases in alpha activity were seen over the scalp in 17 of 20 patients and in no normal subjects. Theta was unreliable by itself. The scalp area so localized appeared correct in each case compared with signs, symptoms, and neuroimaging studies. These computerized EEG analysis techniques were abnormal significantly more often than routine EEGs. The results obtained here with simple techniques agree with past studies done with more complex types of EEG analysis.