This study was undertaken to evaluate the influence that subject‐specific factors have on intracranial interictal epileptiform discharge (IED) rates in persons with refractory epilepsy.
One hundred fifty subjects with intracranial electrodes performed multiple sessions of a free recall memory task; this standardized task controlled for subject attention levels. We utilized a dominance analysis to rank the importance of subject‐specific factors based on their relative influence on IED rates. Linear mixed‐effects models were employed to comprehensively examine factors with highly ranked importance.
Antiseizure medication (ASM) status, time of testing, and seizure onset zone (SOZ) location were the highest‐ranking factors in terms of their impact on IED rates. The average IED rate of electrodes in SOZs was 34% higher than the average IED rate of electrodes outside of SOZs (non‐SOZ;
The current study ranks the relative influence that subject‐specific factors have on IED rates and highlights the importance of considering certain factors, such as SOZ location and ASM status, when analyzing IEDs for clinical or research purposes.