Children with drug-resistant focal epilepsy and focal cortical dysplasia who undergo complete resection of Morphometric Analysis Program (MAP)-positive regions are more likely to experience seizure-free outcomes compared with children who receive no or partial resection, according to a study published in the European Journal of Neurology.
Using a 2002 to 2015 surgical database, researchers included a consecutive cohort of pediatric patients with drug-resistant focal epilepsy and focal cortical dysplasia who underwent epilepsy surgery before ≤21 years of age, had a preoperative 1.5T or 3T MRI, had a negative presurgical MRI, and had ≥12 months of postsurgical follow-up data (n=78).
MAP on T1-weighted volumetric MRI was used to perform MRI postprocessing, and the researchers compared these data with an age-specific normal pediatric population (n=370). Surgical outcome and pathology data were also used to confirm the pertinence of MAP-positive areas.
Approximately 56% of patients (n=44) demonstrated positive MAP regions. In the 3- to 5-year, 5- to 10-year, 10- to 15-year, and 15- to 21-year-old age groups, the MAP-positive rates were 100% (2 of 2), 77% (13 of 17), 63% (15 of 24), and 40% (14 of 35), respectively. Approximately 45% of patients with temporal resection and 63% of patients with extratemporal resection had MAP-positive rates. Compared with patients with no or partial resection of the MAP-positive regions, patients who received complete resection of MAP-positive regions were more likely to experience a seizure-free outcome (P <.001).
In addition, patients who had no or partial resection of MAP-positive regions experienced worse seizure outcomes compared with MAP-negative patients (P =.002). The extratemporal group was more likely to experience a seizure-free outcome if they had complete resection of the MAP-positive regions (P =.001), whereas the temporal group did not achieve a seizure-free status after complete resection (P =.070).
A limitation of the study includes its retrospective nature, which may have given way to selection bias.
The researchers suggested that the higher MAP-positive rate in the younger age groups emphasizes the importance of voxel-based morphometric MRI postprocessing “for presurgical evaluation for pediatric patients without visually apparent lesions on the MRI.”
Wang W, Lin Y, Wang S, et al; Pediatric Imaging, Neurocognition and Genetics Study. Voxel-based morphometric MRI postprocessing in nonlesional pediatric epilepsy patients using pediatric normal databases [published online January 27, 2019]. Eur J Neurol. doi: 10.1111/ene.13916