Temporal encephalocele and epileptogenesis—Reflections of MRI metrics of brain parenchymal tethering

We read with great interest the article by Kondylis et al., titled “Novel magnetic resonance imaging insights from surgically confirmed temporal lobe encephaloceles support tethering as a potential mechanism of epileptogenesis” (Epilepsia, 2025).1 The authors deserve commendation for their meticulous work and for introducing Talairach-based MRI metrics—the frontotemporal aperture (FTA) and opercular angle (OA)—to quantify tethering-related alterations. These findings advance preoperative assessment of temporal encephaloceles and offer valuable mechanistic insights into their epileptogenic potential. Although ipsilateral FTA and OA values were significantly larger, case-wise data were absent; individual measurements would highlight variability and aid threshold definition for clinical use. Multivariate analyses could confirm independence from lesion volume or location, with normative ranges boosting applicability. In 11 patients with stereo-electroencephalography (SEEG), correlating maximal FTA/OA widening regions with electrophysiological-onset zones would validate tethering via structural–functional evidence. Surgical details note hippocampal preservation in most cases despite >3 cm resections; clarifying “sparing resection” and extent of parahippocampal/entorhinal cortex removal would refine anatomic clarity. Correlations between encephalocele site/degree and Sylvian fissure widening merit discussion, particularly for outliers (e.g., Grid F in sagittal view, Grid A – in axial view). Contralateral larger encephalocele volumes showed narrower Sylvian fissures per new metrics, challenging the tethering effect; hemi-ellipsoid volume assumptions overlook usual ovoid/multiple possible shapes, and tabulated individual volumes would address outliers. Seizure and neuropsychological outcomes post-sparing resections would justify decisions; future work should assess inter-observer reproducibility across MRI platforms. We would be willing to know if your cases had any MRI T2 sequence intensity changes noted at the neck of encephalocele, which we have appreciated in few of our operated cases, reflecting excessive stretch and implicating chronic tethering effects of encephalocoele. Finally, the comparison focused on encephaloceles vs mesial temporal sclerosis (MTS) cases; a subgroup analysis of encephaloceles with vs without tethering features would more directly support the hypothesis. Etiologic details (e.g., spontaneous, traumatic, or linked to intracranial hypertension) would also enhance interpretation, given the varying structural and pathophysiologic mechanisms. This elegant study introduces promising quantitative biomarkers for temporal lobe tethering in epileptogenesis. Expanded analyses, including statistical validation and SEEG correlations, would strengthen its impact. None. The authors declare no conflicts of interest. We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this report is consistent with those guidelines. Data sharing not applicable to this article as no datasets were generated or analysed during the current study.