Altered cortical synchronization in photosensitive idiopathic generalized epilepsy
Alessandro Benedetto1, Cecilia Steinwurzel2, Francesco Turco2
1Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy.
Epilepsia
|August 13, 2026
Summary
Patients with photosensitive epilepsy exhibit heightened but unstable brain activity, showing increased cortical excitability and disrupted neural synchronization. This suggests a network state prone to seizures triggered by light.
Area of Science:
- Neuroscience
- Epileptology
- Clinical Electrophysiology
Background:
- Idiopathic generalized epilepsy (IGE) with photosensitivity presents unique challenges in understanding neural dynamics.
- Assessing cortical excitability and synchronization is crucial for characterizing epilepsy pathophysiology.
Purpose of the Study:
- To investigate cortical excitability and synchronization in photosensitive IGE using steady-state visual evoked potentials (SSVEPs).
- To identify potential biomarkers for network instability in photosensitive epilepsy.
Main Methods:
- Recorded SSVEPs from the occipital cortex in IGE patients and healthy subjects (HSs) during photic stimulation (8 and 16 Hz).
- Analyzed evoked/induced responses, inter-trial phase clustering (ITPC), EEG energy, and resting-state alpha-peak dynamics.
Main Results:
- Patients displayed greater EEG energy and broadband power, especially in induced SSVEP responses.
- Reduced phase coherence (lower ITPC) was observed in patients despite increased amplitude.
- Resting-state analysis showed heightened broadband power and unstable alpha oscillations with greater peak frequency variability.
Conclusions:
- Photosensitive IGE involves exaggerated cortical excitability and disrupted synchronization, leading to temporally unstable neural activity.
- SSVEP measures and alpha-variability may serve as functional biomarkers for network instability in photosensitive epilepsy.
