The deep knowledge of hippocampal microsurgical anatomy is paramount in epilepsy surgery. One of the most used techniques is those proposed by Niemeyer.
Purpose: To describe the hippocampal anatomy in detail and to present a technique in which preoperative anatomical points in MRI are identified to guide the corticotomy.
Method: Microsurgical dissections were performed in twenty brain hemispheres and eight cadaveric heads to identify temporal lobe and hippocampus structures. Thirty two patients with drug-resistant temporal lobe epilepsy underwent a selective amygdalohippocampectomy with Niemeyer's technique being measured three preoperative MRI preoperative distances to guide the corticotomy.
Results: The hippocampus was divided in head, body and tail and its microsurgical anatomy described in detail. The MRI measurements are presented and discussed.
Conclusion: The knowledge of the complex anatomy of the hippocampus can be achieved in a three-dimensional way during microsurgical dissections. The preoperative MRI measurement is a reasonable guide to perform temporal corticotomy in Niemeyer's technique.