Microsurgical Anatomy of Medial Temporal Lobe in North-West Indian Population: Cadaveric Brain Dissection

The medial temporal lobe (MTL) is a highly complex neuroanatomical structure of tremendous neurosurgical importance. It is a common site for epilepsy, vascular lesions, and tumors. Owing to the critical location behind the sphenoid wing, it is more prone for traumatic contusion often with surgical implications. Hence, its microneurosurgical anatomy needs to be evaluated in detail.

Twelve formalin-fixed human cadaveric brains from North-west Indian population were dissected under neurosurgical microscope and various dimensions of the MTL and their distance from important neurovascular structures were measured.

The MTL consists of important neural structures such as parahippocampal gyrus, uncus, hippocampus, temporal horn, and choroidal fissure. The average distance of tentorium from the uncus was 1.96 mm. The temporal horn and the inferior choroidal point were located from the anterior temporal pole at 22.9 mm and 30.9 mm, respectively. Important vessels that are intimately related to the MTL were anterior choroidal artery (AchA), posterior communicating artery, the P1 segment of posterior cerebral artery, and the M1 segment of middle cerebral artery.

Complex anatomic and cytostructural organization makes the MTL unique. In this study, along with the descriptive anatomy, morphometric measurements of various structures were performed. The uncus and its relation to other neurovascular structures is well described in literature, but its exact distance from them as determined in this study is particularly helpful in guiding the surgeons while approaching in this area. Knowledge of the distance of the temporal horn from various surfaces is important while opening the temporal horn to avoid unnecessary damage to nearby structures.