Intermittent rhythmic delta activity patterns

► Intermittent rhythmic delta activity is a typical EEG pattern originally described by Cobb in 1945. ► It is classified into three distinct forms according to the main cortical region involved on the EEG: frontal (FIRDA), temporal (TIRDA), and occipital (OIRDA) intermittent delta activity. ► In contrast to FIRDA and OIRDA, TIRDA is highly indicative of ipsilateral pathology. ► OIRDA and TIRDA are highly correlated with epilepsy, whereas FIRDA is a rather nonspecific EEG pattern.