Türk Nöroşirürji Dergisi 2023 , Vol 33 , Num 3
Microsurgical Neuroanatomy of Anterior and Posterior Commissures
Buruç ERKAN1
1Başakşehir Çam ve Sakura Şehir Hastanesi, Beyin ve Sinir Cerrahisi Kliniği, İstanbul, Türkiye The anterior commissure is positioned anterior to the fornix column, situated above the optic chiasm and the lamina terminalis. It is proposed to have a role in transmitting interhemispheric stimuli, including visual, auditory, and olfactory cues. In instances where the corpus callosum is disrupted, the anterior commissure takes on the corpus callosum"s function. Furthermore, it conveys seizure activity from the limbic system to the opposite hemisphere. The anterior commissure is comprised of two components: the anterior limb and the posterior limb. The anterior limb projects toward the orbitofrontal region and the olfactory nucleus. Conversely, the posterior limb extends through Gratiolet"s canal into the temporal occipital and amygdala regions. Another commissural fiber, the posterior commissure, is situated on the dorsal surface of the upper cerebral aqueduct within the inferior pineal lamina. This structure connects the pretectal nuclei, playing a significant role in the pupillary light reflex. Understanding the microsurgical anatomy of the posterior commissure is crucial for pineal region surgery. While the anterior commissure holds importance in lateral and 3rd ventricle surgery, epilepsy surgery (hemispherectomy etc.), as well as temporal lobe surgery, a comprehension of the microsurgical anatomy of the posterior commissure is essential for pineal region surgery. Anahtar Kelimeler : Anterior commissure, Diffusion tensor imaging, Fiber dissection, Posterior commissure, White matter