FIRDA
Pronunciation: FUR-dah
Also written as: FIRDA — Frontal Intermittent Rhythmic Delta Activity
Frontal intermittent rhythmic delta activity indicating metabolic encephalopathy or increased intracranial pressure.
Full Definition
FIRDA (Frontal Intermittent Rhythmic Delta Activity) is an EEG pattern characterized by rhythmic delta waves (1-3 Hz) occurring intermittently in the frontal regions, often with maximum amplitude at the frontal midline. This pattern typically indicates metabolic encephalopathy, increased intracranial pressure, or deep midline structural lesions affecting the diencephalon. FIRDA may also be seen in toxic-metabolic states, hepatic encephalopathy, or medication effects. The rhythmic nature and frontal predominance help distinguish it from other forms of focal or generalized slowing.
Usage
Usage note: Often confused with TIRDA (temporal) or simple focal slowing.
In Context
- "FIRDA was present throughout the recording, suggesting metabolic encephalopathy." — ICU EEG monitoring report
- "The intermittent frontal rhythmic delta activity raised concern for increased intracranial pressure." — Emergency EEG consultation