Corpus callosum area and sectioning: a radioanatomical study correlated with MRI and cadaver morphometry.

PURPOSE: The corpus callosum (CC) is the primary interhemispheric connection between the two cerebral hemispheres. Besides their similar morphological characters, there are differences in their measurements. This study aimed to divide the CC into groups using planes based on the anterior commissure (AC) and posterior commissure (PC) and to detect differences in CC magnetic resonance imaging (MRI) and cadaver samples between these groups. METHODS: The study included 80 patients (40 male and 40 female patients) who underwent normal MRI in the midsagittal plane, and 38 cerebral hemispheres from 40 adult cadaver brains, with each hemisected in the midsagittal plane. The medial surface of the CC was divided vertically into three parts (the anterior, middle, and posterior zones) according to the AC and PC. Areas and parameters were measured in both the cadaveric hemispheres and patient MRI images. RESULTS: The total CC area and CC areas between, anterior, and posterior to the AC-PC vertical lines were the same in both the MRI and cadaver samples. In addition, morphometric measurements like the CC length, AC-PC length, and CC height at the AC and PC vertical lines, and their correlations were also found to be similar between the MRI and cadaver samples. CONCLUSION: This study proposes three areas according to AC and PC classification (anterior, middle, and posterior). This new proposed classification is suitable for stereotactic interventions and is useful for obtaining data from MRI images. However, it should be kept in mind that there may be changes and variations.

Impact of Post-Master PhD Degree on Publication Productivity in Neurosurgery.

AIM: To evaluate the impact of the post-master PhD degree on publication productivity in neurosurgery. MATERIAL AND METHODS: An online national electronic survey was designed based on the recent literature and factors related to publication productivity. The survey was conducted to simply evaluate main bibliometrics of the participants consisting of neurosurgeons in different stages of their career. The survey was distributed via email to all Turkish Neurosurgical Society members. RESULTS: A total of 220 neurosurgeons participated and answered the survey. Neurosurgeons that had published their Master's dissertation were found to have significantly higher number of published articles, citations and Hirsch (h)-index during their career (p < 0.001). Neurosurgeons with a PhD degree who have been involved in such program were found to have significantly higher number of published articles and h-index (p < 0.01). A majority of neurosurgeons who were involved in a PhD program were found to work in university hospitals (41.5%) and research and training hospitals (26.8%). Clinical anatomy, neuroscience, and molecular/ genetic biology were the most common PhD programs. CONCLUSION: Standardization in measurability of scientific productivity is mandatory to maintain stability and move further in academic activity. PhD programs have a significant contribution to academic performance and scientific productivity. Surgical residents and young neurosurgeons should be encouraged to be involved in such PhD training programs to promote success in both neurosurgery and scientific arenas.

Microsurgical anatomy of the anterior cerebral artery and the arterial supply of the cingulate gyrus.

PURPOSE: The cingulate gyrus is a potential surgical area to treat tumours, psychiatric diseases, intractable pain and vascular malformations. The aim of the study was to define the topographic anatomy and arterial supply of the cingulate gyrus located on the medial surface of the cerebral hemisphere. METHODS: We studied thirty-six hemispheres, each hemisected in the midsagittal plane. The vertical thickness of the cingulate gyrus was measured at the anterior commissure (AC), posterior commissure (PC), and genu levels of the corpus callosum. The branches of the anterior and posterior cerebral arteries supplying each zone were noted separately. The arterial pathways were transformed to digital data in AutoCAD to identify the condensation and reduction areas. RESULTS: The mean AC-PC distance was 27.17 ± 1.63 mm. The thinnest region was the genu level of the corpus callosum (10.29 mm). The superior internal parietal artery (SIPA), inferior internal parietal artery (IIPA) and pericallosal artery (PrCA) supplied all zones of the cingulate gyrus. The anterior zone received the greatest supply. The arterial condensation and reduction areas on both sides of cingulate gyrus and its x, y, and z coordinates specified. CONCLUSIONS: The target cingulotomy (TC) area was determined for anterior cingulotomy. The properties of the TC area are that the thinnest region of the cingulate gyrus is supplied relatively less than other areas and is close to the anterior cingulotomy areas in the literature. The arterial reduction area (ARA) was found to be suitable for corpus callosotomy in terms of avoiding haemorrhage.

Topographical Anatomy of the Superficial Temporal Artery.

AIM: To describe in detail the gross anatomy of the superficial temporal artery (STA), its course and branches, its relationships with the branches of the facial nerve, and certain anatomical and surgical landmarks to preserve these structures in daily neurosurgical practice, and to use the STA during revascularization surgery. MATERIAL AND METHODS: This cadaveric study was conducted on 16 cadaver heads bilaterally, in which 32 silicon/latex-injected STAs were dissected using a microdissection technique in a neuroanatomy laboratory. The distances between the facial nerve, tragus, STA, superficial temporal vein (STV), and imaginary lines created between important anatomical landmarks were measured. The curvilinear lengths of STA and STV were also measured. RESULTS: The average distances of the most posteriorly located branch of the facial nerve to the frontal region and the tragus at the midpoint of zygoma in the horizontal plane, at the superior border of the zygoma and at the level of the superior border of the parotid gland, were measured as 25.39, 29.84, and 15.56 mm, respectively. The average distance directly measured between the tragus and STA was 39.29 mm, and that between the tragus and STV was 20.26 mm. The average curvilinear lengths of the frontal and parietal branches of STA were 97.63 and 96.45 mm, respectively. CONCLUSION: Understanding the clinical anatomy of the STA and its branches and its relationships with other structures is of critical importance for a successful and noncomplicated surgery. Our findings will be useful not only for surgical approaches such as pterional craniotomy and orbitozygomatic approaches but also for cerebral revascularization.

Endonasal endoscopic approach for sellar metastatic pathologies: a national observation.

PURPOSE: Sellar metastases are rare lesions. Recent improvements in diagnosis and treatment strategies have prolonged survival but increased the probability of metastatic tumors. Evaluation with clinical symptomatology and meticulous laboratory examination is crucial. We present our multicenter national study on sellar metastases to evaluate and underline the main clinical, endocrine, and radiological considerations regarding the diagnosis and endonasal endoscopic management of such rare lesions. METHODS: A medical literature-based retrospective study was planned across 13 neurosurgical centers in Turkey, where a data survey was conducted to collect information regarding sellar metastases surgically treated using the endoscopic endonasal approach, including clinical presentation, radiographic features, primary tumor origin, histopathological confirmation, time to metastasis, treatment, and patient outcomes. RESULTS: Between 2010 and 2020, 54 patients (22 women [40.7%] and 32 men [59.3%]) who underwent surgery with the endonasal endoscopic approach and had pathologically proven sellar metastases (overall incidence, 0.54%) were included. Of the patients, 59.3% had no known malignancy and presented with new-onset symptoms, 79.6% reported headache, 51.9% complained of some degree of visual deficits, and 50% had cranial nerve symptoms. Tissue biopsy was performed in 7.4% of the patients, whereas gross or subtotal resection was achieved in the remaining patients. CONCLUSION: To our knowledge, this is the largest series of patients surgically treated with the endonasal endoscopic approach for sellar metastases. For these patients, the treatment focus should be on management modalities for increasing quality of life instead radical treatment options with survival benefit.

The microanatomy of the Sylvian fissure.

PURPOSE: Microsurgical anatomy of the Sylvian fissure is still a popular research topic for neurosurgeons. It is important for surgeons who perform skull base and Sylvian fissure surgical procedures to master the anatomy of the region. In our study, we aimed to review the current literature on the subject. METHODS: We reviewed the literature concerning the Sylvian fissure. In addition, we made a microdissection of four human cadaveric brains in order to take images of relevant anatomic structures. RESULTS: The Sylvian fissure includes both superficial and deep compartments. From the beginning of the surface structures and variable thickened subarachnoid membrane to the vascular structures located at the operculo-insular compartment, the surgical technique requires meticulous dissection in all stages of the surgery. CONCLUSIONS: From the view of neurosurgery, novel anatomical knowledge should enhance the success of the surgery. From the view of neuroscience, the Sylvian fissure and the Sylvian cistern have unique anatomical, vascular, and genotypical properties to the other areas of the cerebrum, making them complex and special.

Morphology of the trigeminal ganglion: anatomical structures related to trigeminal radiofrequency rhizotomy.

BACKGROUND: Trigeminal neuralgia is the most common example of craniofacial neuralgia. Its etiology is unknown and is characterized by severe episodes of paroxysmal pain. The trigeminal ganglion and its adjacent anatomical structures have a complex anatomy. The foramen ovale is of great importance during surgical procedures such as percutaneous trigeminal rhizotomy for trigeminal neuralgia. OBJECTIVE: We aimed to identify the anatomical structures associated with the trigeminal ganglion and radiofrequency rhizotomy on cadavers and investigate their relationship with the electrodes used during rhizotomy to determine the contribution of the electrode diameter and length to the effectiveness of the lesion formation on the ganglion. METHODS: Five fresh-frozen cadaver heads injected with red silicone/latex were used. A percutaneous puncture was made by inserting of a cannula through the foramen ovale to create a pathway for electrodes. The relationships between the electrodes, Meckel's cave, trigeminal ganglion, and neurovascular structures were observed and morphometric measurements were obtained using a digital caliper. RESULTS: Trigeminal ganglion, therefore the electrode in its final position, shows proximity with important anatomical structures. The electrode was inserted posteriorly into the foramen ovale in all of the specimens and was located on the retrogasserian fibers. This study revealed that the electrodes targeting the ganglion and passing through the foramen ovale may cause a radiofrequency lesion due to the contact effect of the dura itself pressing on the electrode. Pushing the cannula beyond the petroclival angle may result in puncturing of the dura propria and moving further away from the target area. CONCLUSION: The success of radiofrequency rhizotomy is directly related to the area affected by the lesion. Understanding the mechanism of action underlying this procedure will ensure the effectiveness, success, and sustainability of the treatment.

Temporal Artery and Temporal Region Supplied by the Middle Cerebral Artery: An Anatomical Study.

ABSTRACT: This study was conducted to describe in detail the branching patterns of cortical branches from the middle cerebral artery supplying the feeding of the temporal region, to define the arterial structure of temporal artery (TA) and to determine the effect of this arterial supply to the temporal region. The arteries of brains (n = 22; 44 hemispheres) were prepared for dissection after filling them with colored latex. TA was defined, and its classification was described, specifying its relationship with other cortical branches. A new classification was defined related to TA terminology. TA was found in 95% of cadavers, and it originated as an early branch in 75% and from the inferior trunk in 24% of cadavers. TA was classified as Type 0: No TA, Type I: single branch providing two cortical branches, Type II: single branch providing three or more cortical branches and Type III: double TA. Type I-TA (45%) was the most common, and Type II-TA arterial diameter was significantly larger than that of other types. All cadavers showed the cortical branches of temporal region from middle cerebral artery, anterior TA , middle TA, posterior TA and temporooccipital artery, except temporopolar artery (81%). Temporopolar artery, anterior TA, and middle TA primarily originated from TA, an early branch, but posterior TA and temporooccipital artery primarily originated from the inferior trunk. Detailed knowledge about cortical branches together with TA and also this region's blood supply would enable increased prediction of complications, especially in cases with these region-related pathologies, and would make interventions safer.