Association between enlarged perivascular space (ePVS) density and stereo-electroencephalography (SEEG) biomarkers of epileptogenicity

Q: What is the main objective of the study?

To determine whether enlarged perivascular space (ePVS) density is associated with SEEG biomarkers of epileptogenicity.

Q: How were ePVS density and SEEG biomarker data obtained?

ePVSs were automatically segmented from 3T pre-SEEG T1-weighted MRI, and ePVS density was computed at hemispheric, sub-lobar, and contact levels; SEEG epileptogenicity was evaluated using interictal biomarkers such as spikes, fast ripples, and cross-rates of high-frequency oscillations.

Q: What were the key findings about the relationship between ePVS and the epileptogenic zone?

In the whole cohort, ePVS density was not associated with the epileptogenic zone at hemispheric, sub-lobar, or contact levels, and there was no association with interictal epileptogenic biomarkers at all levels in the overall analysis.

Sep 30, 2026

Uploaded by dabgoudw

Objective: explore whether enlarged perivascular space (ePVS) density relates to stereo-electroencephalography (SEEG) biomarkers of epileptogenicity. Methods: retrospective analysis of consecutive SEEG patients from an Australian site; automatic ePVS segmentation on 3T pre-SEEG T1-weighted MRI, with ePVS density assessed at hemispheric, sub-lobar, and contact levels. Epileptogenic zone (EZ) contacts were primary-EZ contacts selected for RF thermocoagulation, and biomarker thresholds used the top 10% interictal spikes, fast ripples, and cross-rates of HFO-spikes. Results: no EZ or interictal biomarker association in the overall cohort; inverse associations appeared in MRI-negative-only and selected subgroups, with mesial temporal ePVS inversely linked to fast ripples and HFO-spikes. Conclusion: ePVS density may not be a consistent SEEG-defined biomarker; altered relationships in MRI-negative cases need further study.

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CategoryHealthcare

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Abstract

Objective

Methods

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DOI: 10.1111/epi.18614 RESEAR CH ARTICLE Association between enlarged perivascular space (ePVS) density and stereo-electroencephalography (SEEG) biomarkers of epileptogenicity Jacob Bunyamin1 | Benjamin Sinclair1,2 | Thanomporn Wittayacharoenpong1,2 | Parveen Sagar1,2 | William Pham1 | Zhibin Chen1,2 | Noam Bosak1,2 | Joshua Laing1,2 | Matthew Gutman1,3 | Martin Hunn1,3 | Patrick Kwan1,2 | Terence J. O'Brien1,2 | Meng Law1,4,5 | Andrew Neal1,2 1Department of Neuroscience, School of Translational Medicine, Monash University, Melbourne, Victoria, Australia 2Department of Neurology, Alfred Health, Melbourne, Victoria, Australia 3Department of Neurosurgery, Alfred Health, Melbourne, Victoria, Australia 4Department of Radiology, Alfred Health, Melbourne, Victoria, Australia 5Department of Electrical and Computer Systems Engineering, Monash University, Melbourne, Victoria, Australia Correspondence Andrew Neal, Department of Neuroscience, School of Translational Medicine, Monash University, 99 Commercial Road, Melbourne, VIC 3004, Australia. [Email:](Email: andrew.neal@monash.edu)[ andrew.neal@monash.edu](Email: andrew.neal@monash.edu) Funding information Monash University Abstract Objective: We aim to explore the association between enlarged perivascular space (ePVS) density and stereo-electroencephalography (SEEG) biomarkers of epileptogenicity. Methods: We retrospectively analyzed consecutive SEEG patients from an Australian site. We automatically segmented ePVSs from 3T pre-SEEG T1-weighted magnetic resonance imaging (MRI) scans and calculated ePVS (1) hemispheric,(2) sub-lobar, and (3) contact-level density. We defined the epileptogenic zone (EZ) SEEG contacts as those identified as the primary EZ and then selected for radiofrequency thermocoagulation (RF-TC) . We classified contacts generating the top 10% of interictal epileptogenicity biomarkers (spikes, fast ripples, and cross-rates of high-frequency oscillations [HFO]*spikes) . We assessed the relationship at each level for the whole cohort and its subgroups: MRInegative-only, different voxel sizes ( .9 mm3/1 .0 mm3), contact locations (mesial temporal/neocortical), and seizure-free patients. Results: From 53 RF-TC patients, ePVS density was not associated with the EZ at the hemispheric (p = .995), sub-lobar (p = .090), or contact (p = .999) level in the whole cohort. In the MRI-negative-only subgroup and 1.0 mm3 isotropic subgroup, ePVS density was inversely associated with EZ (odds ratio [OR] .76, 95% confidence interval [CI]: .61–.93, p = .009 and OR .83, 95% CI: .69–.99, p = .036, respectively) . There was no association between ePVSs and the interictal epileptogenic biomarkers at all levels in the whole cohort. At the subgroup level, mesial temporal ePVS density was inversely associated with the top 10% of fast ripples (OR .09, 95% CI: .04–.24, p < .001) and cross-rates of HFO*spikes (OR .22, 95%CI: .11–.44, p < .001), whereas in the neocortex, ePVSs were positively This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. © 2025 The Author(s). Epilepsia published by Wiley Periodicals LLC on behalf of International League Against Epilepsy. associated with fast ripples (OR 1.10, 95% CI: 1.01–1.18, p = .018), which maybe driven by the interictal biomarker organization rather than epileptogenicity. Significance: ePVS density may not be a consistent biomarker of SEEG-defined epileptogenicity. The relationship between reduced ePVS and epileptogenicity in MRI-negative cases warrants further study, as this may shed light on underlying pathobiology and EZ biomarkers. Different imaging techniques may be able to capture the relationship between the glymphatic system disruption and epileptogenicity. KEYWORDS ep

FAQs

What is the main objective of the study?

To determine whether enlarged perivascular space (ePVS) density is associated with SEEG biomarkers of epileptogenicity.

How were ePVS density and SEEG biomarker data obtained?

ePVSs were automatically segmented from 3T pre-SEEG T1-weighted MRI, and ePVS density was computed at hemispheric, sub-lobar, and contact levels; SEEG epileptogenicity was evaluated using interictal biomarkers such as spikes, fast ripples, and cross-rates of high-frequency oscillations.

What were the key findings about the relationship between ePVS and the epileptogenic zone?

In the whole cohort, ePVS density was not associated with the epileptogenic zone at hemispheric, sub-lobar, or contact levels, and there was no association with interictal epileptogenic biomarkers at all levels in the overall analysis.

Sep 30, 2026

Uploaded by dabgoudw