Figure 1. Localization of the Piriform Cortex and Voxel-Based Morphometry (VBM) Results.

The position of the piriform cortex relative to other mesiotemporal structures is illustrated using 3-dimensional (3D) reconstructions (A) and magnetic resonance imaging (MRI) sections (B). Numbers are Montreal Neurological Institute (MNI) section coordinates. The remnant of the piriform cortex is outlined on postsurgical MRI scans of 2 cases (C). The left image is from a right-handed woman in her 30s with incomplete resection of the piriform cortex who continued having seizures after epilepsy surgery. The right image is from a right-handed man in his 40s with more extensive resection of the piriform cortex who became seizure free. Both cases had right-sided temporal lobe epilepsy (TLE) with neuropathologically confirmed hippocampal sclerosis. The statistical parametric maps for the interaction between seizure-free (SF) vs non–seizure-free (NSF) groups and preoperative vs postoperative scans are displayed in the lower half of the Figure (D). This comparison allows determination of gray matter decreases due to epilepsy surgery (ie, comparing postoperative with preoperative images) that were present in SF but not in NSF participants. The statistical mask of significant gray matter volume decreases (red; threshold, uncorrected P < .001) for left- (n = 68) and right-sided (n = 39) TLE is superimposed on coronal (top), axial (middle), and sagittal (bottom) views of a standard MRI template (numbers below are MNI section coordinates). The probability of a voxel being surgically resected is overlaid in blue (range, 10%-100%). Also displayed are zoomed sections in rectangles and 3D reconstructions of neocortical resection margins.