Transient ischemic attacks: electrophysiological (conventional and topographic EEG) and radiological (CCT) evaluation

The value of electrophysiological tests: conventional electroencephalography (EEG), topographic EEG analysis as well as computerized tomography (CT) in the diagnosis and evaluation of 25 patients with manifestations of transient ischemic attacks (TIA) in the domain of the carotid system was assessed. Normal CT was the rule in TIA patients except in 8% of the cases, where nonspecific changes of brain atrophy were described. Conventional EEG, topographic EEG and spectral analysis could detect abnormalities in 48%, 80% and 64% of TIA cases respectively. None of the abnormal EEG records could be missed by topographic EEG analysis. 32% of the records were diagnosed as abnormal by topographic EEG, while conventional EEG failed to detect abnormalities. Spectral analysis of the EEG results revealed a significant decrease regarding mean high limit alpha percent power, and a significant increase regarding mean low and high limit theta percent power, as well as a significant increase of the mean high limit of the slow activities (delta + theta)/fast activities (alpha + beta) percent power ratio in the TIA group as compared to the normal control group.