We evaluated MELD’s clinical utility using an independent sample.

Focal cortical dysplasia (FCD) is the commonest etiology of pediatric pharmacoresistant epilepsy (PRE). Surgery can be curative, but lesions can be poorly demarcated on MRI. The Multi-centre Epilepsy Lesion Detection (MELD) project designed an automated, machine-learning algorithm to segment FCD on preoperative MRIs.

Images from PRE, healthy control (HC), and “MRI-negative” subjects were segmented by MELD. PRE patients with lesional preoperative MRIs were also segmented manually; overlap between manual/MELD masks was measured by Dice Similarity Coefficient. Outcomes measured: Sensitivity: % patients with MELD/manual mask overlap; Specificity: % HC yielding no MELD clusters. In MRI-negative patients, resulting MELD clusters were compared to estimated seizure onset zones (SOZ) from presurgical data.

90 PRE, 19 HC and 17 MRI-negative patients were included. Twenty-two patients were excluded due to inadequate preprocessing. Sensitivity was 38.2%. Specificity was 36.8%. MELD accuracy by lobe (%): frontal, 46.2%; temporal, 26.9%; parietal, 11.5%; multilobar, 15.38%. MELD accuracy by FCD pathology: Type I, 23.1%; IIa, 23.1%; IIb, 42.3%; III, 7.7%; NA, 3.9%. Frontal and Type IIb FCDs were the most accurately masked. Temporal and Type I FCDs were the most inaccurately masked. Engel I outcomes were similar between accurate (65.4%) and inaccurate masks (72.4%). MELD localized lesions in eight MRI-negative patients (42%); four had resections with Engel I outcome.

Our sensitivity, specificity, and MRI-negative detection were lower than the original MELD study (65%, 52%, 62.9%, respectively). Pathology influenced accuracy: well-defined Type IIb were detected more often than the more nebulous Type I FCDs. Compared to the original MELD study, our population included more temporal lesions and Type I FCD, which are harder to mask. Importantly, FCD detection in “MRI-negative” cases demonstrates potential for real-world SOZ prediction in nonlesional patients, improving diagnostic confidence, surgical decision making and rates of seizure free outcomes.