Medical Doctor (MD)
Neurology, Medical Research
EEGs are used to detect interictal discharges (IEDs) in patients with a known history of epilepsy, but there is unclear evidence in regards to the utility of this information. There is contradicting information in regards to whether the presence of and frequency of these IEDs can predict measures of epilepsy severity, possibly due to subject selection and recording modalities. In an effort to increase generalizability, we studied a population with very little exclusion criteria using routine EEGs, a technique used most commonly in clinical practice. We predicted that there would be an association between seizure frequency and the detection and/or frequency of IEDs. We also predicted that there would be an association between anti-epileptic drug (AED) usage and the detection and/or frequency of IEDs.
We analyzed the EEGs and clinical records of 920 patients from the Cooper University Health Care Neurology outpatient clinic. Patients, ages 18 and over, who presented for outpatient routine EEG recording between January 2015 and June 2017 were included in this study. A total of 144 patients with a history of at least two unprovoked seizures were included in our analyses.
We did not find an association between seizure frequency and the presence of and/or frequency of IEDs. Anti-epileptic drug use was not associated with the presence of and/or frequency of IEDs. Other characteristics, such as epilepsy duration, age at the time of EEG, and time from most recent seizure, had no association with the presence of and/or frequency of IEDs.
In our study population, interictal EEG did not serve any utility in determining epilepsy severity. These results are similar to one other study that focused on a general patient population like ours. However, our study differs from others which focused on more specific subject populations. As a result, clinicians should take into account the patient’s age, particular epilepsy syndrome, and EEG recording modality when determining the utility of IEDs.
Miller, Ryan, "Utility of interictal EEG in determining epilepsy severity" (2018). Cooper Medical School of Rowan University Capstone Projects. 11.