Intermittent rhythmic delta activity (IRDA) is a type of brain wave abnormality found in electroencephalograms (EEG). It is found in the frontal (FIRDA) or occipital (OIRDA) areas of the brain and can be caused by a number of different reasons, some benign, unknown reasons, but also are commonly associated with lesions, tumors, and encephalopathies.
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Intermittent rhythmic delta activity Wikipedia(Text) CC BY-SA