The electroencephalogram and acute ischemic stroke. Distinguishing cortical from lacunar infarction
R. A. Macdonell, G. A. Donnan, P. F. Bladin, S. F. Berkovic and C. H. Wriedt
Department of Neurology, Austin Hospital, Victoria, Australia.
One hundred consecutive cases of clinically diagnosed, acute forebrain
infarction were studied using computerized tomography (CT) and
electroencephalography (EEG). Computed tomography confirmed brain
infarction in 91 patients and was normal in the remaining nine. Each EEG
was read independently by two experienced electroencephalographers without
knowledge of CT or clinical details and their findings were compared with
those of CT. Lateralized theta and/or delta activity predicted ipsilateral
cortical infarction with a sensitivity of 76% and specificity of 82%. In
contrast, cerebral hemisphere lacunae produced similar EEG abnormalities in
only a few cases (9%). Electroencephalography is particularly useful
following stroke if the initial CT excludes hemorrhage but does not detect
infarction. In conjunction with clinical details, the EEG can then be used
to indicate the likelihood of cortical involvement and thus suggest the
likely pathophysiologic mechanism of infarction.
