S-103 | A dissection through the pathways of BA-25 (Subgenual Cyngulate Gyrus) in deep brain stimulation

Neural Circuits and Systems Neuroscience
Author: Valeria Luciana Trofa Ojeda | Email: val.trofa@gmail.com

Facundo Villamil^1°2°, Melanie Catena-Baudo^1°, Valeria Trofa^1°,  Julieta Rodriguez Valdivia^1°, Juan Navarro^1°, Catalina Dolccimelli^1°, Paloma Suárez^1°,  Micaela Piñero^1°, Gonzalo Bonilla^1°, Mariana Bendersky^3°

^1° Neuroanatomy Laboratory, III Department of Anatomy, School of Medicine, University of Buenos Aires, Paraguay 2155, C1121, Buenos Aires, Argentina.
^2° Surgical Neuroanatomy Laboratory, Neurosurgery Department, FLENI, Montañeses 2325, C1428 Buenos Aires, Argentina.
^3° “Anatomía Viviente” Laboratory, III Department of Anatomy, School of Medicine, University of Buenos Aires, Paraguay 2155, C1121, Buenos Aires, Argentina

Introduction
Deep brain stimulation on the subgenual cingulate gyrus (SCG) is currently an aim for major depressive disorder. The connections between white matter underneath the SCG are still under investigation and we believe that its knowledge may help us became clear about the network that participates on the mechanism of DBS, and improve electrode placement.
Objective
Carrying out a deep investigation around the anatomical connections of the SCG by tractography, and the second and most extended study of cadaveric dissections of this region.
Methods
Tractographies were made using software DSI Studio with a template of 1065 healthy human brains, and a perspective of 1 ROI on the ventromedial frontal cortex. The tracts were observed in a three dimensional plane. Results were compared with cadaveric dissections made in 12 human hemispheres with Klinger Technique.
Result
In this study, seven main connections were found: Cingulum fibers; Fibers from the uncinated fasciculus; Forceps minor; Frontostriatal fibers; Accumbofrontal fasciculus; Fibers communicating both amygdala through forceps minor; Fibers from IFOF’s deep portion.
Conclusion
The SCG exhibited a network of white matter connections with the limbic system, prefrontal cortex and mesial-temporal areas. Three bundles of white mater were described that were not considered in previous studies; this may be useful to improve the electrode placement. These findings can help explaining the SCG’s part in disorders.