Evaluation of focal cerebral lesions. Role of electroencephalography in the era of computed tomography.

We have reviewed the principal electroencephalographic findings in focal cerebral lesions and indicated practical applications for EEG in the era of CT. CT has restricted the use of EEG for detecting and localizing brain lesions, but it has also allowed EEG to focus appropriately on physiologic rather than anatomic issues. Clinically important focal electroencephalographic abnormalities may occur in the absence of CT lesions, and clinicians must understand the implications of such dissociations.