Voxel‐based morphometric magnetic resonance imaging (MRI) postprocessing in MRI‐negative epilepsies

ObjectiveIn the presurgical workup of magnetic resonance imaging (MRI)‐negative (MRI− or “nonlesional”) pharmacoresistant focal epilepsy (PFE) patients, discovering a previously undetected lesion can drastically change the evaluation and likely improve surgical outcome. Our study utilizes a voxel‐based MRI postprocessing technique, implemented in a morphometric analysis program (MAP), to facilitate detection of subtle abnormalities in a consecutive cohort of MRI− surgical candidates. MethodsIncluded in this retrospective study was a consecutive cohort of 150 MRI− surgical patients. MAP was performed on T1‐weighted MRI, with comparison to a scanner‐specific normal database. Review and analysis of MAP were performed blinded to patients' clinical information. The pertinence of MAP+ areas was confirmed by surgical outcome and pathology. ResultsMAP showed a 43% positive rate, sensitivity of 0.9, and specificity of 0.67. Overall, patients with the MAP+ region completely resected had the best seizure outcomes, followed by the MAP− patients, and patients who had no/partial resection of the MAP+ region had the worst outcome (p < 0.001). Subgroup analysis revealed that visually identified subtle findings are more likely correct if also MAP+. False‐positive rate in 52 normal controls was 2%. Surgical pathology of the resected MAP+ areas contained mainly non–balloon‐cell focal cortical dysplasia (FCD). Multiple MAP+ regions were present in 7% of patients....
Source: Annals of Neurology - Category: Neurology Authors: Tags: Research Article Source Type: research