Authors :
Presenting Author: Ravindranadh M Chowdary, DM – NIMHANS
Allen James, DM – NIMHANS
arun sasidharan, PhD – NIMHANS
Rashmi Arasappa, MD – NIMHANS
Harish Thippeswamy, MD – NIMHANS
Ajay Asranna, MD, DM – NIMHANS
K Raghavendra, MD, DM – NIMHANS
Viswanathan LG, DM – NIMHANS
Sanjib Sinha, MD, DM – NIMHANS
Rationale:
This study investigates the neurophysiological effects of Levetiracetam (LEV) and Valproate (VPA) on brain activity using high-density electroencephalography (HD-EEG), with a specific focus on spatial power and functional connectivity metrics derived from graph theory. It further explores the relationship between these EEG-derived measures and irritability, a common neuropsychiatric side effect of antiseizure medications.
Methods:
In this prospective, case-control, hospital-based study, patients with epilepsy and normal MRI findings, either drug-naïve or on monotherapy with LEV or VPA, were enrolled. HD-EEG (64-channel) recordings were obtained from 20 patients in the LEV group (7 naïve, 13 non-naïve) and 15 patients in the VPA group (6 naïve, 9 non-naïve). Spectral power distribution and functional connectivity were assessed across standard frequency bands (delta: 0.5–4 Hz, theta: 4–8 Hz, alpha: 8–13 Hz, beta: 13–30 Hz, gamma: 30–80 Hz). Irritability was quantified using the Irritability Rating Scale.
Results:
Qualitative analysis of EEG spectral power and connectivity did not reveal consistent within-group patterns at one-month post-treatment. Functional connectivity metrics showed no significant correlation with irritability scores across 31 EEG sessions. However, spectral power analysis identified a significant negative correlation between irritability scores and theta power at left frontal and bilateral occipital regions (r = –0.393, p = 0.031), indicating that greater irritability was associated with reduced theta power. A reduction in theta power post-treatment was observed in the LEV group but not in the VPA group, potentially explaining the higher irritability scores observed in the LEV group.
Conclusions:
This study presents preliminary evidence of an inverse relationship between theta band power—particularly in left frontal and occipital regions—and irritability in patients treated with LEV. These findings suggest that HD-EEG, especially theta power metrics, may serve as a potential biomarker to monitor and predict irritability in epilepsy treatment. Larger, longitudinal studies are warranted to validate these findings and assess their clinical utility in guiding medication choice and dosage adjustments.
Funding: Non funded