Anatomical considerations in selective amygdalohippocampectomy techniques for refractory temporal lobe epilepsy: a cadaveric study with emphasis on white matter tract anatomy.

PURPOSE

Mesial temporal lobe epilepsy is a common form of focal drug resistant epilepsy in adults. Various mesial temporal lobe structures are integral in the genesis of temporal seizures and the hippocampal sclerosis is the primary neuropathological finding in these cases. Surgical treatment is considered the preferred management. This study aims to analyze the anatomical and surgical aspects of various resection techniques of selective amygdalohippocampectomy (SAHE)and clarify the critical anatomical landmarks and technical nuances associated which each method.

METHODS

Through dissection of five human head and brain specimens we evaluated three primary surgical approaches for SAHE-transsylvian, transcortical, and subtemporal - and additionally discussed laser interstitial thermal therapy (LITT). We examined the anatomical considerations of the temporal lobe and its white matter tracts, as well as the technical aspects of each approach.

RESULTS

The transcortical approach provides direct access to mesial structures but requires precise placement of the corticotomy based on hemisphere dominance to avoid arcuate fascicle and optic radiation. The subtemporal approach preserves all above white matter tracts but may risk interruption of the inferior longitudinal fasciculus. The transsylvian approach allows for comprehensive exposure but poses risks to tracts within limen insulae, namely uncinate and inferior fronto - occipital fascicles. Additionally, there is a risk to middle cerebral artery and its branches. LITT offers a minimally invasive alternative with comparable outcomes and reduced risk of cognitive side effects.

CONCLUSION

Selective amygdalohippocampectomy and its variants, including LITT, are surgical strategies for managing mesial temporal lobe epilepsy. Each approach has distinct anatomical and technical considerations that influence the choice of a technique. Due to complex anatomy of temporal lobe and white matter tracts variability more research is essential for achieving favourable outcomes.