Predictive value of the electroencephalogram in acute hemispheric lesions.

We studied the electroencephalogram and computed tomography in twenty cases with ischemic strokes with unilateral electroencephalographic slowing associated with abnormality of background activity on the contralateral side, compared with twenty other cases who had primarily unilateral electroencephalographic abnormality and no contralateral slowing. Electrographic parameters evaluated included field, amplitude, frequency, persistence and reactivity of focal or lateralized slowing. Computed tomographic findings studied included lesion size, density, mass effect and location. Clinical findings studied included level of consciousness and outcome. Contralateral abnormality of background rhythm correlated with impairment of consciousness and poor outcome.