Long-term seizure outcomes after pediatric temporal lobectomy: does brain MRI lesion matter?

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>There is emerging data that adults with temporal lobe epilepsy (TLE) without a discrete lesion on brain MRI have surgical outcomes comparable to those with hippocampal sclerosis (HS). However, pediatric TLE is different from its adult counterpart. In this study, the authors investigated if the presence of a potentially epileptogenic lesion on presurgical brain MRI influences the long-term seizure outcomes after pediatric temporal lobectomy.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>Children who underwent temporal lobectomy between 2007 and 2015 and had at least 1 year of seizure outcomes data were identified. These were classified into lesional and MRI-negative groups based on whether an epilepsy-protocol brain MRI showed a lesion sufficiently specific to guide surgical decisions. These patients were also categorized into pure TLE and temporal plus epilepsies based on the neurophysiological localization of the seizure-onset zone. Seizure outcomes at each follow-up visit were incorporated into a repeated-measures generalized linear mixed model (GLMM) with MRI status as a grouping variable. Clinical variables were incorporated into GLMM as covariates.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>One hundred nine patients (44 females) were included, aged 5 to 21 years, and were classified as lesional (73%), MRI negative (27%), pure TLE (56%), and temporal plus (44%). After a mean follow-up of 3.2 years (range 1.2–8.8 years), 66% of the patients were seizure free for ≥ 1 year at last follow-up. GLMM analysis revealed that lesional patients were more likely to be seizure free over the long term compared to MRI-negative patients for the overall cohort (OR 2.58, p &lt; 0.0001) and for temporal plus epilepsies (OR 1.85, p = 0.0052). The effect of MRI lesion was not significant for pure TLE (OR 2.64, p = 0.0635). Concordance of ictal electroencephalography (OR 3.46, p &lt; 0.0001), magnetoencephalography (OR 4.26, p &lt; 0.0001), and later age of seizure onset (OR 1.05, p = 0.0091) were associated with a higher likelihood of seizure freedom. The most common histological findings included cortical dysplasia types 1B and 2A, HS (40% with dual pathology), and tuberous sclerosis.</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>A lesion on presurgical brain MRI is an important determinant of long-term seizure freedom after pediatric temporal lobectomy. Pediatric TLE is heterogeneous regarding etiologies and organization of seizure-onset zones with many patients qualifying for temporal plus nosology. The presence of an MRI lesion determined seizure outcomes in patients with temporal plus epilepsies. However, pure TLE had comparable surgical seizure outcomes for lesional and MRI-negative groups.</jats:p></jats:sec>

PET/MRI Applications in Pediatric Epilepsy

“…43,45 Reports demonstrate MCD as a common underlying histopathology in pediatric patients with pure temporal lobe epilepsy, with a predominance of type 1B and 2A focal cortical dysplasia. 46 It is important to keep in mind that many patients with pediatric TLE actually have temporal plus nosology. While detection of a lesion on MRI remains an important preoperative determinant of long-term seizure freedom following pediatric temporal lobectomy, 18 F-FDG-PET has proven invaluable in the workup of pediatric patients with refractory epilepsy.…”

Fast Automated Stereo-EEG Electrode Contact Identification and Labeling Ensemble

“…Imaging and SEEG Hardware MRI Preoperative 3.0T MRIs were performed using Philips Ingenia (Best, The Netherlands) or GE Signa Architect (GE Healthcare, Waukesha, WI, USA) scanners. The protocol included sagittal isotropic 1-mm 3D T1-weighted gradient-recalled echo (1-mm axial and coronal multiplanar reformations), axial FSE T2-weighted (3to 4-mm slice thickness at 3-to 4.5-mm intervals), axial T2-FLAIR (4-mm slice thickness at 4.5-mm intervals), coronal oblique T2-FLAIR (perpendicular to the plane of the hippocampus, 3-to 4-mm slice thickness at 3-to 4-mm intervals), and sagittal isotropic 1-mm 3D T2-FLAIR (1-mm axial and coronal multiplanar reformations) sequences [7].…”

Challenging Cortical Explorations in Difficult-to-Localize Seizures: The Rationale and Usefulness of Perisylvian Paralimbic Explorations With Orthogonal Stereoelectroencephalography Depth Electrodes

“…4,5 The perisylvian cortex is associated with the clinical semiology of temporal lobe epilepsies and ventromedial and periopercular frontal epilepsies, [6][7][8] such as prominent autonomic and psychomotor behavioral manifestations. 6,7,[9][10][11][12][13] Thus, in suspected temporal lobe epilepsies, and particularly those with hypothesized anterior perisylvian involvement, sampling of paralimbic (PL) areas in the anterior perisylvian regions (ie, the most caudal aspects of the orbitofrontal surface, subgenual of the anterior cingulate, the rostral ventral limen insulae and the dorsal-mesial aspects of the temporal pole) is highly relevant for the accurate anatomic demarcation of the EZ. The failure to explore these PL areas may result in the inadequate interpretation of the EZ's location and extent, inadequate treatment, and failure to achieve seizure freedom.…”