Surgical Application of Magnetic Resonance Imaging Anatomy for Temporal Lobe Epilepsy Surgery

ABSTRACT

Anterior temporal lobectomy is the most popular surgical method for mesiobasal temporal lobe epilepsy. The key point in anterior temporal lobectomy is to resect lateral neocortex as little as possible, and mesiobasal structures as much as possible without surgical complication. We analyzed surgical anatomy on MRI scans of 20 persons to evaluate the relationships of anatomical structures related with surgical steps in anterior temporal lobectomy. On the oblique axial scan, the distance from temporal pole to anterior margin of hippocampus was 29.8+/-1.5mm. The length of hippocampus to the level of posterior margin of cerebral peduncle was 25.6+/-2.4mm. On the oblique coronal image through hippocampal head, the distance between the surface of superior temporal sulcus and lateral margin of temporal horn roof was 32.5+/-2.2mm. The angle between middle fossa base line and the line connecting superior temporal sulcus and lateral margin of temporal horn roof was 33.6+/-5.2 degree. The distance between lateral temporal surface and brain stem, and that between lateral temporal surface and collateral sulcus was 49.9+/-1.9mm and 40.6+/-3.3mm, respectively. The distance between collateral sulcus and lateral margin of temporal horn roof was 14.2+/-1.8mm, and the angle between middle fossa base line and the line connecting lateral margin of temporal horn roof and collateral sulcus was 60.4+/-7.4 degree. On the sagittal image, the angle between superior temporal sulcus and hippocampal axis was 18.8+/-1.1 degree. In conclusion, surgical complication of anterior temporal lobectomy can be reduced by careful consideration of anatomical relationships between anatomical structures encountered in each surgical steps in anterior temporal lobectomy.