Diagnostic Yield of Routine EEG in Adults with Active Epilepsy

Area of Science:

• Neurology
• Neurophysiology

Background:

• Routine electroencephalogram (rEEG) is a key diagnostic tool for suspected seizures.
• However, rEEG can be normal in individuals with epilepsy, and its diagnostic yield varies by patient group.
• The utility of rEEG in adults with active epilepsy has not been well-reported.

Purpose of the Study:

• To determine the diagnostic yield of routine electroencephalogram (rEEG) in a real-world cohort of adults with active epilepsy.
• To evaluate the effectiveness of serial rEEGs in capturing epileptiform abnormalities.

Main Methods:

• A single-center study involving adults with video electroencephalogram (vEEG)-confirmed active epilepsy and prior rEEG.
• Analysis of neurophysiology findings from 171 rEEGs across 68 patients.
• Assessment of the yield of interictal epileptiform abnormalities (IIEAs) from serial rEEG recordings.

Main Results:

• Out of 171 rEEGs, 54.4% were normal, 24.6% showed non-specific abnormalities, and 21.1% captured IIEAs.
• The first rEEG yielded IIEAs in 22.1% of cases.
• Cumulative yield of IIEAs increased with serial testing, peaking at 33.8% by the fourth rEEG.

Conclusions:

• Serial routine electroencephalogram (rEEG) has a limited diagnostic yield for interictal epileptiform abnormalities in adults with active epilepsy.
• Findings suggest that rEEG may not be a highly effective standalone investigation for diagnosing active epilepsy in this population.
• The study highlights the need for further research into optimal diagnostic strategies for epilepsy in adults.