Yağmurlu, Kaan

Purpose: Microsurgical anatomy of the corticospinal tract, its functional role and crucial points in differential diagnosis were evaluated. There is no consensus about its differences and cerebral origin of the corticospinal tract. Tractography and cadaver dissection can help to investigate the characteristics of the corticospinal tract. Also, amyotrophic lateral sclerosis is hard to diagnose as it has common symptoms and signs with other disorders. Methods: Three formalin-fixed human brains (six sides) were dissected by the Klingler technique in a stepwise manner from the lateral to medial and superior to inferior under 6x–40x magnification using a surgical microscope. All stages of the dissection were photographed using three-dimensional method. Lastly, we present a patient with the sign of drop foot who underwent electromyographical and radiological examination, diagnosed as atypic amyotrophic lateral sclerosis. Results: The connections of the corticospinal tract, in particular the travel in the in trajectories of stepwise in manner cerebral origin. We demonstrated a case report with anatomic correlation to define the damage of corticospinal tract in variable levels. Crucial landmarks, connections, eloquent brain areas that related to the corticospinal tract were emphasized. Conclusion: So that pointing the importance of such disorders to keep in mind as not to move forward with incorrect operation decision. Trajectory of one of the largest desending pathway, corticospinal tract and the relationship with different diagnosis should be considered.

OBJECTIVE The purpose of this study was to describe in detail the cortical and subcortical anatomy of the central core of the brain, defining its limits, with particular attention to the topography and relationships of the thalamus, basal ganglia, and related white matter pathways and vessels. METHODS The authors studied 19 cerebral hemispheres. The vascular systems of all of the specimens were injected with colored silicone, and the specimens were then frozen for at least 1 month to facilitate identification of individual fiber tracts. The dissections were performed in a stepwise manner, locating each gray matter nucleus and white matter pathway at different depths inside the central core. The course of fiber pathways was also noted in relation to the insular limiting sulci. RESULTS The insular surface is the most superficial aspect of the central core and is divided by a central sulcus into an anterior portion, usually containing 3 short gyri, and a posterior portion, with 2 long gyri. It is bounded by the anterior limiting sulcus, the superior limiting sulcus, and the inferior limiting sulcus. The extreme capsule is directly underneath the insular surface and is composed of short association fibers that extend toward all the opercula. The claustrum lies deep to the extreme capsule, and the external capsule is found medial to it. Three fiber pathways contribute to form both the extreme and external capsules, and they lie in a sequential anteroposterior disposition: the uncinate fascicle, the inferior fronto-occipital fascicle, and claustrocortical fibers. The putamen and the globus pallidus are between the external capsule, laterally, and the internal capsule, medially. The internal capsule is present medial to almost all insular limiting sulci and most of the insular surface, but not to their most anteroinferior portions. This anteroinferior portion of the central core has a more complex anatomy and is distinguished in this paper as the “anterior perforated substance region.” The caudate nucleus and thalamus lie medial to the internal capsule, as the most medial structures of the central core. While the anterior half of the central core is related to the head of the caudate nucleus, the posterior half is related to the thalamus, and hence to each associated portion of the internal capsule between these structures and the insular surface. The central core stands on top of the brainstem. The brainstem and central core are connected by several white matter pathways and are not separated from each other by any natural division. The authors propose a subdivision of the central core into quadrants and describe each in detail. The functional importance of each structure is highlighted, and surgical approaches are suggested for each quadrant of the central core. CONCLUSIONS As a general rule, the internal capsule and its vascularization should be seen as a parasagittal barrier with great functional importance. This is of particular importance in choosing surgical approaches within this region.