Intermittent rhythmic delta activity

Intermittent rhythmic delta activity (IRDA) is a type of brain wave abnormality found in electroencephalograms (EEG).^[1]

Types

It can be classified based on the area of brain it originates from:

• frontal (FIRDA)
• occipital (OIRDA)
• temporal (TIRDA)^[2]

It can also be

• Unilateral
• Bilateral

Cause

It can be caused by a number of different reasons, some benign, unknown reasons, but also are commonly associated with lesions, tumors, and encephalopathies.^[3] Association with periventricular white matter disease and cortical atrophy has been documented and they are more likely to show up during acute metabolic derangements such as uremia and hyperglycemia.^[4]

Diagnosis