From the Research
FIRDA in EEG refers to Frontal Intermittent Rhythmic Delta Activity, which is an abnormal pattern seen on electroencephalogram recordings, and its presence should prompt further investigation to identify the underlying cause, as treating the primary condition often leads to resolution of this EEG pattern. This pattern is commonly associated with metabolic encephalopathies, increased intracranial pressure, hydrocephalus, and certain drug effects, as reported in a study published in 2021 1. It may also be seen in patients with deep midline lesions affecting the thalamus or diencephalon.
Some of the key conditions associated with FIRDA include:
- Metabolic encephalopathies
- Increased intracranial pressure
- Hydrocephalus
- Certain drug effects
- Deep midline lesions affecting the thalamus or diencephalon
- Neurodegenerative disease
- Hypoxic encephalopathy
- Systemic infection
- Encephalitis
A recent study published in 2023 2 demonstrated that FIRDA can also serve as an epileptic biomarker of deep-seated midline seizure-onset zones, and its abolishment following stereoelectroencephalography (SEEG)-guided radiofrequency ablation correlates with clinical improvement.
While FIRDA itself doesn't require specific treatment, it serves as an important diagnostic clue that can guide clinical management of the patient's neurological condition. The presence of FIRDA should prompt further investigation, including imaging studies and laboratory tests, to identify the underlying cause. Treatment of the underlying condition often leads to resolution of the FIRDA pattern on EEG.
In terms of antiepileptic drug effects on EEG, a study published in 2006 3 investigated the quantitative EEG effects of carbamazepine, oxcarbazepine, valproate, and lamotrigine monotherapy in patients with beginning epilepsy. The results showed that each drug had distinct effects on EEG parameters, such as absolute band-power and alpha mean frequency.
However, the most recent and highest quality study on this topic is not directly related to the question of FIRDA meaning in EEG. Therefore, the answer is based on the study published in 2021 1, which provides the most relevant and up-to-date information on the clinical significance of FIRDA. The presence of FIRDA on EEG should prompt further investigation to identify the underlying cause, and treatment of the primary condition often leads to resolution of this EEG pattern.