Case Report: Right frontal periventricular heterotopia underlying secondary network epilepsy with a Lennox–Gastaut phenotype: multimodal SEEG, CCEP, and rs-fMRI evidence
- 1Department of Functional Neurosurgery, Comprehensive Epilepsy Unit, Ruijin Hospital Luwan Branch, Shanghai Jiao Tong University, School of Medicine , ,
- 2Department of Radiology, Ruijin Hospital Luwan Branch, Shanghai Jiao Tong University, School of Medicine , ,
Abstract
Objective: Lennox–Gastaut syndrome (LGS) is generally regarded as a developmental and epileptic encephalopathy involving distributed brain networks, although a focal structural abnormality may occasionally recruit bilateral cortical and thalamic circuits and produce an LGS phenotype. We characterized the spatiotemporal organization of such a network and its changes after focal SEEG-guided radiofrequency thermocoagulation (RF-TC).
Methods: A 50-year-old woman with drug-resistant epilepsy, multiple seizure types, diffuse slow spike-and-wave discharges, generalized paroxysmal fast activity, intellectual impairment, and right frontal periventricular heterotopia (PVH) underwent stereo-electroencephalography (SEEG). Cortico-cortical evoked potentials (CCEPs) were acquired before and after SEEG-guided radiofrequency thermocoagulation (RF-TC). Resting-state functional MRI (rs-fMRI), obtained before and 3 months after RF-TC, was analyzed using three seeds: the entire right frontal PVH and the right and left centromedian thalamic nuclei (CM).
Results: SEEG identified the earliest sustained ictal activity within the sampled right frontal PVH-related medial contacts, accompanied by high-frequency activity. This was followed by ipsilateral lateral frontal recruitment, contralateral frontal synchronization, and subsequent bilateral CM involvement. Two-stage RF-TC of the onset and early-recruited networks was followed by seizure freedom through 9 months. After RF-TC, right-sided stimulation produced markedly attenuated lesion-related CCEP responses, whereas left-sided responses and responses between thalamic contacts showed little appreciable change. Descriptive rs-fMRI difference maps demonstrated decreased local frontal connectivity around the treated territory and increased long-range connectivity for the PVH seed; both CM seeds showed predominantly increased connectivity with distributed cortical and cerebellar regions.
Conclusion: In this patient, a focal PVH-related epileptogenic network was associated with secondary bilateral cortical and thalamic recruitment underlying an LGS phenotype. CCEP and rs-fMRI captured complementary aspects of postoperative network change: attenuation of stimulation-evoked propagation and postoperative changes in intrinsic functional connectivity, respectively.
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BibTeX
@article{wang2026case,
title = {{Case Report: Right frontal periventricular heterotopia underlying secondary network epilepsy with a Lennox–Gastaut phenotype: multimodal SEEG, CCEP, and rs-fMRI evidence}},
author = {Changquan Wang and Jing Hong and Jialin Ji and Caicai Zhang and Wenzhen Chen and Jiwen Xu},
journal = {Frontiers in neuroscience},
year = {2026},
month = sep,
doi = {10.3389/fnins.2026.1961911},
url = {https://europepmc.org/article/PMC/PMC13661969},
note = {CC BY},
}
RIS
TY - JOUR
TI - Case Report: Right frontal periventricular heterotopia underlying secondary network epilepsy with a Lennox–Gastaut phenotype: multimodal SEEG, CCEP, and rs-fMRI evidence
AU - Changquan Wang
AU - Jing Hong
AU - Jialin Ji
AU - Caicai Zhang
AU - Wenzhen Chen
AU - Jiwen Xu
PY - 2026
DA - 2026/09/30
JO - Frontiers in neuroscience
DO - 10.3389/fnins.2026.1961911
UR - https://europepmc.org/article/PMC/PMC13661969
AB - Objective: Lennox–Gastaut syndrome (LGS) is generally regarded as a developmental and epileptic encephalopathy involving distributed brain networks, although a focal structural abnormality may occasionally recruit bilateral cortical and thalamic circuits and produce an LGS phenotype. We characterized the spatiotemporal organization of such a network and its changes after focal SEEG-guided radiofrequency thermocoagulation (RF-TC). Methods: A 50-year-old woman with drug-resistant epilepsy, multiple seizure types, diffuse slow spike-and-wave discharges, generalized paroxysmal fast activity, intellectual impairment, and right frontal periventricular heterotopia (PVH) underwent stereo-electroencephalography (SEEG). Cortico-cortical evoked potentials (CCEPs) were acquired before and after SEEG-guided radiofrequency thermocoagulation (RF-TC). Resting-state functional MRI (rs-fMRI), obtained before and 3 months after RF-TC, was analyzed using three seeds: the entire right frontal PVH and the right and left centromedian thalamic nuclei (CM). Results: SEEG identified the earliest sustained ictal activity within the sampled right frontal PVH-related medial contacts, accompanied by high-frequency activity. This was followed by ipsilateral lateral frontal recruitment, contralateral frontal synchronization, and subsequent bilateral CM involvement. Two-stage RF-TC of the onset and early-recruited networks was followed by seizure freedom through 9 months. After RF-TC, right-sided stimulation produced markedly attenuated lesion-related CCEP responses, whereas left-sided responses and responses between thalamic contacts showed little appreciable change. Descriptive rs-fMRI difference maps demonstrated decreased local frontal connectivity around the treated territory and increased long-range connectivity for the PVH seed; both CM seeds showed predominantly increased connectivity with distributed cortical and cerebellar regions. Conclusion: In this patient, a focal PVH-related epileptogenic network was associated with secondary bilateral cortical and thalamic recruitment underlying an LGS phenotype. CCEP and rs-fMRI captured complementary aspects of postoperative network change: attenuation of stimulation-evoked propagation and postoperative changes in intrinsic functional connectivity, respectively.
SN - 1662-4548
SN - 1662-453X
ER -