Electroencephalogram and sodium pertechnetate /sup 99m/Tc brain scan

Both electroencephalography and brain scanning are very sensitive diagnostic procedures. The EEG has an overall higher rate of false-positivity (15%) and a lower rate of false-negativity (18%). In contrast, brain scanning has an overall lower incidence of false-positivity (< 2%), but a higher incidence of false-negativity (33%). Combined electroencephalographic and scanning procedures increase overall diagnostic accuracy for detection of intracranial lesions (85%). Brain scanning is more specific than EEG: the cause of the lesion can be predicted correctly in 64% of abnormal scanning, but in only 27% of abnormal EEGs. A lesion not detected by either scan or EEG is most likely to be vascular, small, and deep-seated. Brain scanning and electroencephalography are recommended as screening procedures of choice in routine investigation of patients in whom an intracranial pathologic condition is suspected.