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Purpose In middle fossa approach, middle meningeal artery is sacrified during the surgery but, sacrification of this artery sometimes disrupts the supply of the ganglion geniculate, causing facial nerve palsy. The aim of this study is to show the petrosal artery that originates from the middle meningeal artery and feeds the ganglion geniculate, which can be seen very rarely in surgical and cadaver dissections.Method In Cerrahpaşa Faculty of Medicine, Micro-Endoneurosurgery and Neuroanatomy Laboratory, the middle fossa approach was applied with the help of a microscope on 2 silicone-injected cadavers with classical methods. Each stage of the dissections was 3D photographed.Result After temporal craniotomy, the foremen spinosum and the middle meningeal artery (OMA) were reached by retraction of the temporal lobe. Mandibular and maxillary branches of trigeminal nerve were exposed after going on dissecting anterior to foramen spinosum. Sometimes these structures may be covered with bone tissue and light drilling may be required for dissection. After greater petrosal nerve and ganglion geniculate are exposed, arcuate eminence is pierced approximately 60 degrees medially, and internal acoustic canal is opened superiorly and 7–8. nerve bundle is reached.Conclusion OMA gives rise to the petrosal artery, a branch that supplies the ganglion geniculate. If the OMA is to be sacrificed during surgery, this should be done above the petrosal artery level so that the arterial supply of the ganglion geniculate is not impaired. Preservation of the petrosal artery is important in neurosurgery practice.

Surgical access to the ventral pontomedullary junction (PMJ) can be achieved through various corridors depending on the location and extension of the lesion. The jugular tubercle (JT), a surgically challenging obstacle to access the PMJ, typically needs to be addressed in transcranial exposures. We describe the endoscopic endonasal transclival approach (EETCA) and its inferolateral transtubercular extension to assess the intradural surgical field gained through JT removal. We also complement the dissections with an illustrative case. EETCA was surgically simulated, and the anatomical landmarks were assessed in eight cadaveric heads. Microsurgical dissections were additionally performed along the endoscopic surgical path. Lastly, we present an intraoperative video of the trans-JT approach in a patient with lower clival chordoma. The EETCA allowed adequate extracranial visualization and removal of the JT. The surgical bony window—obtained along the clivus and centered at the JT via the EETCA—measured 11 × 9 × 7 mm. Removal of the JT provided an improved intradural field within the lower third of the cerebellopontine cistern to expose an area bordered by the cranial nerves VII/VIII and flocculus superior and anterior margin of the lateral recess of the fourth ventricle and cranial nerves IX–XI inferiorly, centered on the foramen of Luschka. Removal of the JT via EETCA improves exposure along the lower third of the cerebellopontine and upper cerebellomedullary cisterns. The inferolateral transtubercular extension of the EETCA provides access to the lateral recess of the fourth ventricle, in combination with the ventral midline pontomedullary region.

Objective Surgical access to the third ventricle can be achieved through various corridors depending on the location and extent of the lesion; however, traditional transcranial approaches risk damage to multiple critical neural structures. Methods Endonasal approach similar to corridor of the reverse third ventriculostomy (ERTV) was surgically simulated in eight cadaveric heads. Fiber dissections were additionally performed within the third ventricle along the endoscopic route. Additionally, we present a case of ERTV in a patient with craniopharyngioma extending into the third ventricle. Results The ERTV allowed adequate intraventricular visualization along the third ventricle. The extracranial step of the surgical corridor included a bony window in the sellar floor, tuberculum sella, and the lower part of the planum sphenoidale. ERTV provided an intraventricular surgical field along the foramen of Monro to expose an area bordered by the fornix anteriorly, thalamus laterally, anterior commissure anterior superiorly, posterior commissure, habenula and pineal gland posteriorly, and aqueduct of Sylvius centered posterior inferiorly. Conclusion The third ventricle can safely be accessed through ERTV either above or below the pituitary gland. ERTV provides a wide exposure of the third ventricle through the tuber cinereum and offers access to the anterior part as far as the anterior commissure and precommissural part of fornix and the whole length of the posterior part. Endoscopic ERTV may be a suitable alternative to transcranial approaches to access the third ventricle in selected patients.

Background The corpus callosotomy (CCT) has been reported as an effective procedure to alleviate drop attacks. However, the extent of CCT remains debatable. Classical studies suggest that motor fibers traverse mainly through the anterior half of the corpus callosum (CC), although recent diffusion tensor imaging studies described that motor fibers crossed the CC in a more posterior location, emphasizing the posterior midbody and the isthmus. Methods Cortical and subcortical structures were examined in 30 hemispheres prepared for white matter fiber dissection. Dissections were carried out under surgical magnification to trace fibers originating from the primary motor cortex and their course through the CC. The distance of the most anterior and posterior motor fibers to the tip of the genu were measured, and the extent of CCT enabling disconnection of all motor fibers was calculated. Results Motor fibers coursed through the posterior half of the CC in the majority of hemispheres, mainly locating in posterior midbody and the isthmus. Callosal fibers should be interrupted to an average of 61% ± 0.07% point of the CC to reach the anterior limit of motor fibers and to an average of 69% ± 0.07% point to include posterior limit of motor fibers. Motor fibers were extending until the posterior one third of the CC in 22 specimens. Conclusions Anterior-half CCT did not include all motor fibers in any specimen. Anterior two thirds CCT disrupted all motor fibers in one fourth of the cases. Our findings suggest that an ideal CCT should extend to the posterior midbody and isthmus of the CC.

The most common approaches in the treatment of epilepsy, the trans-sylvian selective amygdalohippocampectomy (SAH) and the anterior temporal lobe resection (ATLR) reach the medial temporal lobe through different surgical routes. Our aim was to delineate the white matter (WM) fiber tracts at risk in relation to trans-sylvian SAH and ATLR by defining each fascicle en route to medial temporal lobe during each approach. ATLR and trans-sylvian SAH were performedand related WM tracts en route to medial temporal region were presented in relation to the relevant approaches and surrounding neurovascular structures. The WM tracts most likely to be disrupted during trans-sylvian SAH along the roof of the temporal horn were the UF - and less commonly IFOF - at the layer of the external capsule, anterior commissure, anterior bend of optic radiations, and sublenticular internal capsule. Amygdaloid projections to the claustrum, putamen and globus pallidus, the tail of caudate and the peduncle of the lentiform nucleus were also in close proximity to the resection cavity. Fiber tracts most likely to be impaired during ATLR included the UF, ILF, IFOF, anterior commissure, optic radiations, and, less likely, the vertical ventral segment of the arcuate fascicle. Both ATLR and trans-sylvian SAH carry the risk of injury to WM pathways, which may result in unpredictable functional loss. A detailed 3-D knowledge of the related connectional anatomy will help subside neurocognitive, neuroophtalmologic, neurolinguistic complications of epilepsy surgery, providing an opportunity to tailor the surgery according to patient's unique connectional and functional anatomy.

Purpose To evaluate the expression of G-protein coupled estrogen receptor (GPER1), aromatase, estrogen receptor α (ERα), estrogen receptor β (ERβ), pituitary tumor transforming gene (PTTG), and fibroblast growth factor 2 (FGF2) in GH-secreting and non-functioning adenomas (NFA). Methods Thirty patients with acromegaly and 27 patients with NFA were included. Gene expression was determined via quantitative reverse transcription polymerase chain reaction (QRT-PCR). Protein expression was determined via immunohistochemistry. Results There was no difference, in terms of gene expression of aromatase, ERα, PTTG, and FGF2 between the two groups (p>0.05 for all). ERβ gene expression was higher and GPER1 gene expression was lower in GH-secreting adenomas than NFAs (p0.05 for all). GPER1 gene expression was positively correlated to ERα, ERβ, PTTG, and FGF2 gene expression (p Conclusions GPER1 is expressed at both gene and protein level in a substantial portion of GH-secreting adenomas and NFAs. The finding of a positive correlation between GPER1 and ERα, ERβ, PTTG, and FGF2 gene expression and aromatase and GPER1 protein expression suggests GPER1 along with aromatase and classical ERs might mediate the effects of estrogen through upregulation of PTTG and FGF2.

Aim: The third ventricle is a funnel-shaped cavity located deep in the brain and difficult to access with surgical approach. The anterior commissure is an anatomical structure located on the anterior wall of the third ventricle. This study aimed to demonstrate the use of the anterior interhemispheric transcallosal approaches to access the third ventricle, evaluate the microsurgical anatomy of the anterior commissure and investigate the morphological features of this region. Methods: Eleven cadaveric brain specimens were dissected using microsurgical tools. Different anterior interhemispheric routes to the third ventricle were demonstrated, and stepwise dissections were performed to expose the limbs of the anterior commissure. Morphological measurements of the anterior commissure and the third ventricle were carried out. Results: The anterior limb of the anterior commissure extends towards the anterior perforating substance, olfactory bulb, anterior olfactory nucleus and the orbitofrontal cortex. The posterior limb extends from the basal part of the caudate nucleus, passes below the substantia innominata and courses through the basal part of the putamen. It constitutes the major component of the anterior commissure and is composed of temporal and occipital fibers. The mean length of the anterior commissure body was 16.2 ± 4.2 (range 9.7–24.2) mm, while the mean width was 4.3 ± 0.7 (range 2.8–5.1) mm. Conclusion: A better understanding of the microsurgical anatomy and morphometric features of the third ventricle and anterior commissure increases the success of surgical interventions and prevents possible complications in this region.

Introduction Acromegaly is a chronic disease of increased growth hormone (GH) secretion and elevated insulin-like growth factor-I (IGF-I) levels induced by a pituitary adenoma. HMGA2 (high mobility group A2) and AIP (aryl hydrocarbon receptor-interacting protein) expression levels are related to GH-secreting adenomas, and also a response to Somatostatin Analogs (SSAs). We studied SNPs in miR-107 and miR-23b that related with AIP and HMGA2 genes respectively and control their expression, and also SNP in the 3'UTR of HMGA2 gene. Our aim was to investigate genotype distributions of the studied SNPs, as well as the possible relationship between disease and/or response to SSAs treatment in patients with acromegaly. Material and Methods Genotypes were determined by qRT-PCR method from DNA materials obtained blood samples of acromegaly patients (141) and healthy individuals (99). The genotype distributions of patients and healthy groups, as well as the relationship between the clinical data of the disease and genotypes were statistically compared. Results In acromegaly patients with T-allele, p53 expression (p=0.049) was significantly higher. In patients with CT+TT genotype and T-allele who were responder to SSA-treatment Ki-67 index (respectively p=0.019, p=0.020 respectively) was higher. We did not observe the genotypes for miR-23b and miR-107 polymorphisms in the patients and control group of Turkish population. Conclusion The genetic variations of the miRNAs genes related with HMGA2 and AIP genes were not seen in our study. Although there is no relationship between HMGA2-rs1351394 polymorphism and acromegaly disease, T allele was associated with some clinical features related to adenoma in patients with acromegaly.

Objective: The aim of this study is to evaluate the microsurgical anatomy of human brain frontal lobe association white matter pathways (course, start and target zones), relationships with each other and its potential functional role with reference to clinical trials in the literature. Material and Methods: This study was performed between June 2013-August 2014 at Istanbul University Cerrahpaşa Faculty of Medicine, Microsurgery-Neuroanatomy Laboratory of Department of Neurosurgery. Ten postmortem human brain specimens were prepared in accordance with Klingler’s method. Brain hemispheres were dissected step by step from lateral to medial and medial to lateral under operating microscope and images were captured at every stage. Results: As a results of the white matter fiber dissection step by step, white matter association pathways associated with frontal lobe or short white matter tracts in frontal lobe were shown to correlate clinical studies known in the literature. Conclusion: Knowledge of the anatomofunctional role of fiber tracts helps to understand pre-, intra-and postoperative clinical “disconnection syndromes” and white matter tumoral invasion patterns, and may improve presurgical planning and surgical strategy, thereby potentially decreasing surgical morbidity. © 2020 by TürkiyeKlinikleri.

Purpose This study aims to evaluate the applicability of the endoscopy-assisted presigmoid retrolabyrinthine approach, advantages, disadvantages, and the applicability of surgery with pre-op radiological parameters; identify important landmarks; and to reveal their relationships with important structures in the surgical field with objective data. Also, we aim to improve the surgical technique for increasing reachable anatomic structure. Methods Mastoid drilling and endoscopy-assisted presigmoid retrolabyrinthine approach were performed and endoscopic instruments were used to obtain the three-dimensional pictures. Computed tomography images were evaluated to correlate to the anatomic data. Results In terms of pre-operative radiological evaluation of the applicability of the presigmoid approach were investigated with selected radiological parameters. The endoscopy-assisted presigmoid retrolabyrinthine approach applied to cadavers the relationship, distances between important anatomical landmarks, and anatomical structures in the surgical field recorded. The anatomical structures that could reach with the application of the procedure were recorded. The relationship between pre-operative measured radiological parameters and surgical results was evaluated with objective data. Additional combinations to improve this surgical method discussed and the results of our combination were recorded with photographs. Conclusion Although the presigmoid retrolabyrinthine approach has facilitated with the assistance of endoscope, it has observed that there are still some difficulties, and it has been concluded that the radiological parameters are useful in evaluating the applicability of this surgery. It observed that this surgery can be performed more effectively with combinations.

Background: Acromegaly is a disease that occurs as a result of excessive growth hormone caused by pituitary adenomas. Some acromegaly patients show resistance to somatostatin analog (SSA) treatment. Filamin-A (FLNA) and β-arrestins are thought to play a role in the response to SSAs. We aimed to investigate the relationship between FLNA-rs782079491 and β-arrestin-2-rs34230287 single-nucleotide polymorphisms and disease risk, as well as treatment response in patients with acromegaly in the Turkish population. Methods: The genotypes of 110 acromegaly patients and 99 controls were determined by realtime PCR. The genotype distributions were compared with clinical data on the disease. Results: There was no association between the β-arrestin-2 gene polymorphism and the response to SSA treatment in acromegaly patients. For responder patients to SSAs, the β-arrestin-2-rs34230287 CT+TT genotype was associated with higher microadenoma as compared with the CC genotype (p = 0.017). The FLNA polymorphism was not observed in the study group. Conclusions: We showed that there was no association between the polymorphic genotypes of FLNA and β-arrestin-2 genes with acromegaly disease and SSAs response in the Turkish population. However, there was a relationship between β-arrestin-2 and some of the clinical characteristics. Furthermore, the CC genotype and the C allele are risk factors associated with tumor growth rate in acromegaly patients. 34669321

A better understanding of the surgical anatomy of the cerebellar peduncles in different surgical approaches and their relationship with other neural structures are delineated through cadaveric dissections. We aimed to revisit the surgical anatomy of the cerebellar peduncles to describe their courses along the brain stem and the cerebellum and revise their segmental classification in surgical areas exposed through different approaches. Stepwise fiber microdissection was performed along the cerebellar tentorial and suboccipital surfaces. Multiple surgical approaches in each of the cerebellar peduncles were compared in eight silicone-injected cadaveric whole heads to evaluate the peduncular exposure areas. From a neurosurgical point of view, the middle cerebellar peduncle (MCP) was divided into a proximal cisternal and a distal intracerebellar segments; the inferior cerebellar peduncle (ICP) into a ventricular segment followed by a posterior curve and a subsequent intracerebellar segment; the superior cerebellar peduncle (SCP) into an initial congregated, an intermediate intraventricular, and a distal intramesencephalic segment. Retrosigmoid and anterior petrosectomy approaches exposed the junction of the MCP segments; telovelar, supratonsillar, and lateral ICP approaches each reached different segments of ICP; paramedian supracerebellar infratentorial, suboccipital transtentorial, and combined posterior transpetrosal approaches displayed the predecussation SCP within the cerbellomesencephalic fissure, whereas the telovelar approach revealed the intraventricular SCP within the superolateral recess of the fourth ventricle. Better understanding of the microsurgical anatomy of the cerebellar peduncles in various surgical approaches and their exposure limits constitute the most critical aspect for the prevention of surgical morbidity during surgery in and around the pons and the upper medulla. Our findings help in evaluating radiological data and planning an operative procedure for cerebellar peduncles.

Recently, the World Federation of Neurosurgical Societies Spine committee recommended that additional research on cost-benefit analysis of various surgical approaches for cervical spondylotic myelopathy be carried out and their efficacy with long-term outcomes be compared. Unfortunately, it is highly probable that the oblique corpectomy (OC) will not be included in cost-benefit investigations due to its infrequent application by neurosurgeons dealing with the spine. In this cadaveric study, head and necks of 5 adult human cadavers stained with colored latex and preserved in 70% alcohol solution were dissected under a table-mounted surgical microscope using 3× to 40× magnifications. The OC approach was performed to simulate real surgery, and the neurovascular structures encountered during the procedure and their relations with each other were examined. Oblique corpectomy was performed unilaterally, although neck dissections were performed bilaterally on 10 sides in all 5 cadavers. At each stage of the dissection, multiple three-dimensional photographs were obtained from different angles and distances. For an optimal OC, both the anterior spinal cord must be sufficiently decompressed and sufficient bone must be left in place to prevent instability in the cervical spine. Oblique corpectomy is a valid and potentially low cost alternative to other anterior and posterior approaches in the surgical treatment of cervical spondylotic myelopathy. However, meticulous cadaver studies are essential before starting real surgical practice on patients in order to perform it effectively and to avoid the risks of the technique.

Purpose To investigate the relationship of Fibroblast Growth Factor Receptor-4 (FGFR-4) expression with radiologic, pathologic, and clinical parameters in pituitary adenomas. Methods Among 307 patients who underwent pituitary surgery for a pituitary adenoma between 2000 and 2015, we included 161 patients (53 gonadotroph, 26 corticotroph, 25 null cell, 22 lactotroph, 13 somatotroph, 8 adenomas with unusual combination, 7 Pit-1 positive adenomas, and 7 lactosomatotroph) based on availability of pathology specimens. Patients’ radiologic, pathologic, and clinical parameters were determined. FGFR-4 immunostaining was evaluated using a semi-quantitative histologic score (H-score). Results The mean follow-up period was 61 (IQR=32–84) months. The median H-scores for FGFR-4 were higher in patients without remission, those with residual lesion, and T2-hyperintense adenoma (p0.05). There was no significant difference (p>0.05) when the H-score and Ki-67 levels were assessed in terms of sex, sellar-dural invasion, Knosp and a grading system for superior, inferior, parasellar, anterior and posterior tumor extension Classification, tumor function or presence of poor subtype. Adenomas with Ki-67 expression ≥3% had higher FGFR4 expression levels than those with Conclusions Higher levels of FGFR-4 in pituitary adenomas could be use a marker for more aggressive tumor behavior.

Objective Plurihormonal pituitary adenomas (PPAs) have recently been divided into 2 subtypes: pituitary specific transcription factor 1–positive plurihormonal pituitary adenomas (PIT-1+ PPAs) and plurihormonal adenomas with unusual immunohistochemical combinations (PAwUIC). The purpose of this study was to review patients with PPAs, elucidate their clinicopathologic characteristics, and present the surgical results. Methods Records were analyzed for 665 patients who underwent endoscopic endonasal transsphenoidal surgery for pituitary adenomas between 2007 and 2018. Data were reviewed for 27 patients who met the definition of PPAs and delineated regarding clinical, radiologic, pathologic features, and surgical outcomes. Results Of the 27 patients, 18 had PAwUIC, and 9 patients were diagnosed with PIT-1+ PPAs. Twenty-four patients (88.8%) had macroadenomas, including 6 giant adenomas (≥4 cm) (22.2%). Cavernous sinus invasion was found in 12 patients (44.4%). Pathologic examinations showed high aggressivity in nearly half of the patients. Most patients with PAwUIC (77.8%) had features of nonfunctioning pituitary adenomas, and only 4 had features of hormone-secreting pituitary adenomas. Gross total resection rates were 57.1% for PAwUIC and 77.8% for PIT-1+ PPAs. The remission rate for hormone-secreting pituitary adenomas was 100% in this case series. Mean follow-up was 74.4 ± 33 months (range, 6–121 months) for overall groups. Conclusions To our knowledge, this is the first study to describe the clinicopathologic features of newly classified PPAs, which are characterized by aggressive behavior with higher values of percentage of cavernous sinus invasion. Relevant pathologic diagnosis of PPAs is crucial for appropriate management and follow-up.

To investigate the effects of preoperative somatostatin analogue (SSA) treatment on the annual cost of all acromegaly treatment modalities and on remission rates. The medical records of 135 patients with acromegaly who were followed at endocrinology clinic of Cerrahpasa Medical Faculty for at least 2 years after surgery between 2009 and 2016 were reviewed. The mean follow-up time was 50.9 ± 25.7 months. Early remission was defined according to 3rd month values in patients who didn’t achieve remission, and 6th month values in patients who achieved remission at the 3rd month after surgery. The early and late remission rates of the entire study population were 40% and 80.7%, respectively. The early remission of the preoperative SSA-treated group (61.5%) was significantly higher than SSA-untreated group (31.2%) (p = 0.002). The early remission of the preoperative SSA-treated patients with macroadenomas (52.2%) was also significantly higher than the SSA-untreated group (23.5%) (p = 0.02). In the subgroup analysis; this difference was much more pronounced in invasive macroadenomas (p = 0.002). There were no differences between the groups in terms of late remission.The median annual cost of all acromegaly treatment modalities in study population was €3788.4; the cost for macroadenomas was significantly higher than for microadenomas (€4125.0 vs. €3226.5, respectively; p = 0.03). Preoperative SSA use in both microadenomas and macroadenomas didn’t alter the cost of treatment. The increase in the duration of preoperative medical treatment had no effect on early or late remissions (p = 0.09; p = 0.8). Preoperative medical treatment had no effect on the costs of acromegaly treatment. There was a benefical effect of pre-operative SSA use on early remission in patients with macroadenomas; however, this effect didn’t persist long term.

The cervical oblique corpectomy (OC) approach has the advantages of no grafting or instrumentation necessities and theoretically maintains natural neck motions. However, the risk of cervical sympathetic trunk (CST) injury and Horner’s syndrome is one of the main difficulties of this demanding surgical approach. The upper necks of 3 adult human cadavers (6 sides) were dissected under a Zeiss surgical microscope. OC was performed in a stepwise manner to simulate the surgical procedure. We specifically studied the technique of the protection of the CST during the cervical OC approach. The superior ganglion of the cervical sympathetic chain is located under the prevertebral fascia over the longus capitis muscle at the level of C3 transverse process, while the CST is situated under the prevertebral fascia over the longus colli muscle. The CST courses obliquely from superolateral to inferomedial. The ganglia and CST are carefully dissected; the fascia of the longus colli muscle is cut medially, preferably in the midline over the vertebrae, and the fascia lifted up. Then, the aponeurotic flap is gently retracted laterally to cover the sympathetic chain safely and secured with a 3/0 suture laterally. Preservation of the CST while performing cervical OC is essential to avoid postoperative Horner’s syndrome. The placement of self-retaining retractors, particularly inferiorly, where the sympathetic chain is located more medially, is probably the main cause of its injury. Further studies are needed documenting the incidence of Horner’s syndrome in the application of this technique to live patients.

Objective Projections from the dentate nucleus (DN) follow a certain organized course to upper levels. Crossing and noncrossing fibers of the dentatorubrothalamic (DRT) tract terminate in the red nucleus and thalamus and have various connections throughout the cerebral cortex. We aimed to establish the microsurgical anatomy of the DN in relation to its efferent connections to complement the increased recognition of its surgical importance and also to provide an insight into the network-associated symptoms related to lesions and microsurgery in and around the region. Methods The cerebellum, DN, and superior cerebellar peduncle (SCP) en route to red nucleus were examined through fiber dissections from the anterior, posterior, and lateral sides to define the connections of the DN and its relationships with adjacent neural structures. Results The DN was anatomically divided into 4 areas based on its relation to the SCP; the lateral major, lateral anterosuperior, posteromedial, and anteromedial compartments. Most of the fibers originating from the lateral compartments were involved in the decussation of the SCP. The ventral fibers originating from the lateral anterosuperior compartment were exclusively involved in the decussation. The fibers from the posteromedial compartment ascended ipsilaterally and decussated, whereas most anteromedial fibers ascended ipsilaterally and did not participate in the decussation. Conclusions Clarifying the anatomofunctional organization of the DN in relation to the SCP could improve microneurosurgical results by reducing the complication rates during infratentorial surgery in and around the nucleus. The proposed compartmentalization would be a major step forward in this effort.

Background Any preoperative diagnostic assessment that can predict the success of the operation in acromegaly will provide a positive impact on overall remission rates. The aim of this study is to present whether signal intensity on T2-weighted Magnetic Resonance Imaging could predict postoperative results in acromegaly patients. Methods We analyzed our surgical results in regard to T2-weighted images in newly diagnosed consecutive 124 patients with acromegaly, operated between 2014 and 2019. The T2-intensity of the pure somatotroph adenomas was correlated with the clinical, radiological, surgical and histopathological characteristics of the acromegaly patients. Results We found a predominance of T2-hyperintensity in our series (45%) and the T2-hypointense pure somatotroph adenomas were detected in only 34% of our patients. Total resection was performed in 72% of newly diagnosed acromegaly patients in this series. Accordingly, total resection was achieved in 69% of the T2-hyperintense group, 77% of the T2-hypointense group and 69% of the T2-isointense group. The surgical remission rates for the T2-hyper-, hypo- and isointense groups were 55%, 80%, and 69%, respectively. The surgical remission rate in the T2-hyperintense group was significantly lower than those of hypo- and isointense groups in newly diagnosed acromegaly patients. Conclusions This study demonstrates a close relationship between the T2 signal intensity and the surgical remission rates in acromegaly. T2 signal intensity seems to be an indicator of the degree of surgical resection completeness in pure somatotroph adenomas. The implications suggest that preoperative T2-intensity may directly predict the probability of post-surgical remission as an important independent factor in patients with newly diagnosed acromegaly.

Surgical access to the ventral pontomedullary junction (PMJ) can be achieved through various corridors depending on the location and extension of the lesion. The jugular tubercle (JT), a surgically challenging obstacle to access the PMJ, typically needs to be addressed in transcranial exposures. We describe the endoscopic endonasal transclival approach (EETCA) and its inferolateral transtubercular extension to assess the intradural surgical field gained through JT removal. We also complement the dissections with an illustrative case.EETCA was surgically simulated, and the anatomical landmarks were assessed in eight cadaveric heads. Microsurgical dissections were additionally performed along the endoscopic surgical path. Lastly, we present an intraoperative video of the trans-JT approach in a patient with lower clival chordoma.The EETCA allowed adequate extracranial visualization and removal of the JT. The surgical bony window-obtained along the clivus and centered at the JT via the EETCA-measured 11 × 9 × 7 mm. Removal of the JT provided an improved intradural field within the lower third of the cerebellopontine cistern to expose an area bordered by the cranial nerves VII/VIII and flocculus superior and anterior margin of the lateral recess of the fourth ventricle and cranial nerves IX-XI inferiorly, centered on the foramen of Luschka.Removal of the JT via EETCA improves exposure along the lower third of the cerebellopontine and upper cerebellomedullary cisterns. The inferolateral transtubercular extension of the EETCA provides access to the lateral recess of the fourth ventricle, in combination with the ventral midline pontomedullary region.

Chondrosarcoma, a malignant bone tumor, is rarely encountered in the cervical spine. This article describes a patient whose neck pain and dysphagia were caused by an expansive, destructive lesion with calcification that was located in the body of the axis (C2 vertebra), the first time a chondrosarcoma has been reported in this location.

Objective A thorough follow-up study in which the same clinic presents the change in the surgical outcomes of acromegaly over the years, is still lacking in the endoscopic era. In this study, we intended to evaluate the clinical characteristics, radiological features, surgical and late remission rates of newly diagnosed acromegaly patients treated in our clinic between 2014 and 2019 in order to delineate the surgical remission status according to radiological, microscopic, and hormonal features. As a follow-up to our initial report, we also aimed to display the change of surgical remission rates over time in a tertiary center. Methods A total of newly diagnosed 106 patients with acromegaly, who underwent endoscopic endonasal trans-sphenoidal approach (EETSA) in the last five years were retrospectively analyzed and presented in this study. Medical records were reviewed in clinical, biochemical, pathological, and radiological aspects to assess the relationship of preoperative patient characteristics with surgical remissions. Results The percentages of the giant pituitary adenomas (≥4 cm), adenomas with suprasellar extension and adenomas with surgically proven invasion of the cavernous sinus in the present series were 13%, 34%, and 20%, respectively. Gross total resection was achieved in 80% of the patients. Surgical remission and late remission rates were 66% and 86%, respectively. Nine (9.4%) patients in our current report had postoperative transient diabetes insipidus. The mean follow-up period in this series was 36.1 ± 18.1 (range 12–59) months. Conclusion The presented surgical results are considerably better than our published initial series of acromegaly patients operated in the same clinic between 2007 and 2014. The improvement in surgical remission rate support a positive surgical volume - remission rate relationship for acromegaly in the era of endoscopic endonasal skull base approaches. One possible factor for better results may be the increasing surgical experience in EETSA, which follows a trend toward gradual improvement of long-term late remissions via a multidisciplinary approach.

Objectives: The purpose of this study is to find out the accuracy of bilateral cavernous sinus sampling (CSS) for preoperative tumor lateralization within the pituitary in Cushing’s disease (CD). Methods: Sixty-five patients who had undergone transsphenoidal surgery (TSS) following CSS for CD between 2000-2016 at our institution were analyzed retrospectively. All patients underwent bilaterally CSS with corticotropin-releasing hormone (CRH) stimulation. Radiological, preoperative, and pathological findings with remission status were correlated with CSS data. The accuracy of CSS is decided according to compliance with the magnetic resonance imaging (MRI), pathology or remission after surgery of the normal MRI cases. Results: CSS indicated the correct lateralization in 52 (80%) patients. There was the same level elevation of both sides in 3 patients who had central adenoma. Remission rate in the final follow-up was 83.87% for 65 patients. We found out the contralateral pathological side in 13 (20%) of the patients showing false lateralization. Twenty-four patients with normal MRI had a positive accuracy rate of 83%. Of those patients, with a positive accuracy of CSS sampling, 18 (90%) had a positive remission. As a result of the Kappa analysis, statistically significance and relation was found between the final diagnosis and lateralization test (κ=0,63 p < 0.001). Conclusions: Our results showed that CSS is a safe and reliable method for microadenomas which has high diagnostic accuracy (80%) in indicating the correct lateralization in CD, providing us higher remission rates in a challenging pathology.

Biomarkers predicting tumor aggressiveness in pituitary adenomas have been largely investigated, albeit, with inconsistent results. We investigated the relationship of Fibroblast Growth Factor Receptor-4 (FGFR-4) expression and determined its relationship with radiological, pathological, and clinical parameters. In our study, 650 patients who were followed up for pituitary disease were reviewed from medical charts retrospectively. Of the 307 patients who underwent pituitary surgery for a pituitary adenoma between 2000 and 2015, we selected 161 cases on the basis of availability of pathology specimen of hypophysis tissue in our center. Patients’ radiological, pathological, and clinical parameters were obtained from medical charts. FGFR-4 immunostaining was evaluated using a semiquantitative Histologic score (H score). The mean age of the patients was 56.02 ± 14.80 years. Ninety-two (57.1%) were male and 69 (42.9%) were female. The mean follow-up period was 68.94 ± 44.15 months. Pathological examination revealed the following subtypes; 53 nonfunctioning pituitary adenomas, 26 corticotroph adenomas, 25 hormone receptor negative adenomas, 22 mammotroph adenomas, 13 somatotroph adenomas, 8 combined hormone secreting adenomas, 7 somatomammotroph, and 7 PIT-1 positive adenomas. The mean tumor size was 26.83 ± 14.92 mm. In patients with cavernous sinus invasion, the mean adenoma size was significantly higher than those without (p 0.05 for all). The mean H-score, Ki-67, and adenoma size were significantly higher in patients without remission than those with remission (p 67 levels (p>0.05). When the H-score and Ki-67 levels were assessed in terms of gender, sellar-dural invasion, tumor function or presence of poor subtype, no significant difference was detected (p>0.05 for all). The mean H score and adenoma size were significantly higher in patients with Ki-67≥ 3 than those with 0.05 for all). In our study, we demonstrated that patients with residual lesion and those without remission had high expression of FGFR-4. Also FGFR-4 levels were positively correlated with Ki-67 which itself correlated with lack of remission. Taken together, our results indicate that higher levels of FGFR-4 and Ki-67 in pituitary adenomas might indicate a more aggressive tumor phenotype.

The endoscopic endonasal transclival approach (EETA) is less invasive than traditional open approaches; however, there is currently limited data on the pre-operative features that may predict success of the EETA. Surgical landmarks and exposure of the EETA and expanded EETA are assessed. We retrospectively measured multiple anatomic features in 154 adult dry skulls, 22 C1 and C2 dry bone vertebrae, and 500 paranasal sinus computed tomography (CT) scans. We also dissected 13 formalin-fixed, silicone-injected adult cadaveric heads. Relevant qualitative and quantitative data were obtained with CT (n = 10) and cadaveric dissection (n = 13). They are expressed as mean (SD), as appropriate and compared with unpaired t tests. Categorical variables were compared with chi(2) tests. We determined the prevalence of clival and sphenoid sinus anatomic variations and assessed potential exposure of the craniovertebral region, based on the relative position of the nasal bone tip, posterior point of the hard palate, and their relation to the position of C1 and C2. Depending on anatomic features, EETA should allow visualization of the ventral brainstem. The mean (SD) dimensions of the surgical window for EETA were 43.2 (5.1) x 18.3 (1.1) mm, in the craniocaudad and horizontal dimensions, respectively. The craniocaudad dimension enlarged to 60.2 (4.7) mm with expanded EETA. The EETA allowed satisfactory exposure for odontoid and C1 anterior arch resection (expanded EETA) in all specimens, regardless of the orientation of the palate. The combination of preoperative radiographic assessment and intraoperative considerations allows safe and effective application and facilitate selection of the most appropriate approach. (C) 2020 Elsevier Ltd. All rights reserved.

gungor, abuzer/0000-0002-2792-7610 WOS: 000517784600066 PubMed: 31863894 BACKGROUND: The need for a better understanding of the subthalamic nucleus (STN)'s vascular anatomy is still evident because revealing its vascular supply may increase insight in the pathogenesis of related disorders, such as STN ischemia. The mechanisms under motor, behavioral, and cognitive changes following deep brain stimulation treatment may also be explained by its pattern of vascularization. The primary goal of this study was to delineate the vascularization of the STN and highlight the predominant perforating arteries supplying its territory. METHODS: Fiber dissections were performed with the modified Klingler technique under 6-40x magnification by preserving all vascular structures. RESULTS: The thalamic and subthalamic regions were dissected from medial to lateral in silicone-injected cadavers. The STN was revealed as a biconvex-shaped structure surrounded by dense inferolateral bundles of myelinated fibers, the zona incerta, bordering the superolateral portion of the red nucleus. The ventral limit of the STN was the substantia nigra, and the internal capsule traversed from its inferior to anterolateral side. The premamillary artery, a large perforator arising from the posterior communicating artery, constantly supplied the STN and was followed proximally along the anterior third ventricular floor toward its origin. The premamillary artery was found to be one of the posterior perforators of the posterior communicating artery in all hemispheres. CONCLUSIONS: The 3-dimensional microsurgical anatomy of the deep-seated STN region is complex, and the additional knowledge on its vascularization should improve our understanding of its surgical anatomy.

Background Recently, neuromodulation through deep brain stimulation (DBS) has appeared as a new surgical procedure in the treatment of some types of dementia and epilepsy. The mammillothalamic and mammillotegmental tracts are involved among the new targets. To our knowledge, a review article focused specifically on these mammillary body efferents is lacking in the medical literature. Their contribution to memory is, regrettably, often overlooked. Methods A review of the relevant literature was conducted. Results There is evidence that mammillary bodies can contribute to memory independently from hippocampal formation, but the mechanism is not yet known. Recent studies in animals have provided evidence for the specific roles of these mammillary body efferents in regulating memory independently. In animal studies, it has been shown that the disruption of the mammillothalamic tract inhibits seizures and that electrical stimulation of the mammillary body or mammillothalamic tract raises the seizure threshold. In humans, DBS targeting the mammillary body through the mammillothalamic tract or the stimulation of the anterior thalamic nucleus, especially in the areas closely related to the mammillothalamic tract, has been found effective in patients with medically refractory epilepsy. Nonetheless, little knowledge exists on the functional anatomy of the mammillary body efferents, and their role in the exact mechanism of epileptogenic activity and in the memory function of the human brain. Conclusions A comprehensive knowledge of the white matter anatomy of the mammillothalamic and mammillotegmental tracts is crucial since they have emerged as new DBS targets in the treatment of various disorders including dementia and epilepsy.

Purpose Evaluation of the lacrimal gland volume (LGV) and its correlation with tear film functions, serum growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels in acromegaly patients compared to a control group was aimed. Methods This prospective case-control study included the eyes of 38 patients with uncontrolled (UA) and 48 patients with controlled acromegaly (CA) and 44 patients with nonfunctioning pituitary adenoma. LGV of the patients was evaluated at the baseline, 3rd, and 6th-month visits with magnetic resonance imaging. Schirmer's test, tear breakup time (TBUT), and ocular surface disease index (OSDI) scores were evaluated at the same visits. Their correlation with serum IGF-1 and GH was investigated. Main outcome measure was the difference in mean LGV. Results The mean LGV of the acromegaly patients at the baseline visit (116.0 ± 33.2 mm3) and the 3rd-month visit (119.5 ± 36.4 mm3) was higher than the control group (65.2 ± 22.3 mm3 and 63.2 ± 22.3 mm3, respectively; p 0.05). Among all patients, IGF-1 and GH levels showed a positive correlation with the LGV (p 0.05). Conclusion Acromegaly patients may have larger lacrimal glands compared to the controls and this increase correlated with the increased IGF-1 and GH levels. Lacrimal gland volume may have no effect on its tear film related functions.

OBJECTIVE The relationship of the white matter tracts to the lateral ventricles is important when planning surgical approaches to the ventricles and in understanding the symptoms of hydrocephalus. The authors' aim was to explore the relationship of the white matter tracts of the cerebrum to the lateral ventricles using fiber dissection technique and MR tractography and to discuss these findings in relation to approaches to ventricular lesions. METHODS Forty adult human formalin-fixed cadaveric hemispheres (20 brains) and 3 whole heads were examined using fiber dissection technique. The dissections were performed from lateral to medial, medial to lateral, superior to inferior, and inferior to superior. MR tractography showing the lateral ventricles aided in the understanding of the 3D relationships of the white matter tracts with the lateral ventricles. RESULTS The relationship between the lateral ventricles and the superior longitudinal I, II, and III, arcuate, vertical occipital, middle longitudinal, inferior longitudinal, inferior frontooccipital, uncinate, sledge runner, and lingular amygdaloidal fasciculi; and the anterior commissure fibers, optic radiations, internal capsule, corona radiata, thalamic radiations, cingulum, corpus callosum, fornix, caudate nucleus, thalamus, stria terminalis, and stria medullaris thalami were defined anatomically and radiologically. These fibers and structures have a consistent relationship to the lateral ventricles. CONCLUSIONS Knowledge of the relationship of the white matter tracts of the cerebrum to the lateral ventricles should aid in planning more accurate surgery for lesions within the lateral ventricles.

Objective Fiber dissection studies of the cerebrum have focused on the lateral surface. No comparable detailed studies have been done on the medial and inferior surfaces. The object of this study was to examine the fiber tracts, cortical, and subcortical structures of the medial and inferior aspects of the brain important in planning operative approaches along the interhemispheric fissure, parafalcine area, and basal surfaces of the cerebrum. Methods Twenty formalin-fixed human hemispheres (10 brains) were examined by fiber dissection technique under ×6–×40 magnifications. Results The superior longitudinal fasciculus I, cingulum, inferior longitudinal fasciculus, uncinate fasciculus, optic radiations, tapetum, and callosal fibers were dissected step by step from medial to lateral, exposing the nucleus accumbens, subthalamic nucleus, red nucleus, and central midline structures (fornix, stria medullaris, and stria terminalis). Finally, the central core structures were dissected from medial to lateral. Conclusions Understanding the fiber network underlying the medial and inferior aspects of the brain is important in surgical planning for approaches along the interhemispheric fissure, parafalcine area, and basal surfaces of the cerebrum.

The molecular mechanisms underlying the formation of nonfunctioning pituitary adenomas (NFAs) are largely unknown. In this study, we aimed to understand the relationship between NFAs and functional pituitary adenomas and the possible role of proteins involved in cell cycle, senescence, and DNA damage control mechanisms in the etiology of NFA. We analyzed pATM-S1981, pRb-S608, Rb, pE2F1-S364, p16, E2F1, p73, cyclin D1, and CHEK2 protein expression (in a group of 20 patients with acromegaly, 18 patients with Cushing's disease (CD), and 29 NFA patients) by immunohistochemistry and their relevant mRNA expression by qRT-PCR (in a group of 7 patients with acromegaly, 7 patients with CD, and 7 NFA patients). The clinical and histopathological results on the patients were statistically evaluated. pE2F1-S364 protein expression in the CD group was significantly lower than that in the NFA and acromegaly groups (p = 0.025, p = 0.034, respectively). However, the expression of the p16 protein was lower than in the NFA group than in the CD and acromegaly groups (p = 0.030, p = 0.033, respectively), and E2F1 protein expression was significantly higher in the NFA group than in the CD group (p = 0.025). p73 protein expression in patients with acromegaly was significantly higher (p = 0.031) than that in the CD group. CHEK2 mRNA expression in the CD group was significantly higher than that in the acromegaly group (p = 0.012). The selective and tumor-specific associations between E2F1, pE2F1-S364, CHEK2, and p73 mRNA and protein levels indicate their involvement in pituitary adenoma formation in NFA, CD, and acromegaly patients.

Tanriover, Necmettin/0000-0001-7628-9443; Middlebrooks, Erik/0000-0002-4418-9605; gungor, abuzer/0000-0002-2792-7610; Balak, Naci/0000-0002-2395-0004 WOS: 000475895100123 PubMed: 31103757 BACKGROUND: Approaching the thalamus from any angle remains a challenge because of its deep-seated location and intimate relations with adjacent important neurovascular structures and functions such as relaying sensory and motor signals and cognition. Our aim was to explore the relationship of the white matter tracts of the cerebrum to the thalamus using a fiber dissection technique, to delineate anatomic principles of approaches to the thalamus, and to discuss the tracts at risk in relation to each approach. METHODS: The thalamus was subdivided into 6 different regions and 13 approaches were examined in an attempt to describe a surgical road map. RESULTS: To reach the anteroinferior, medial, and lateral parts of the thalamus, the anterior and middle group approaches were used, and to reach the posterosuperior and posteroinferior thalamus, posterior and middle group approaches were used. The anteroinferior zone was the most difficult site to be accessed and the posterosuperior thalamus had the maximum number of alternative approaches. The distal transsylvian approach to the posterosuperior thalamus and the supracarotid infrafrontal approach to the anteroinferior thalamus had the highest number of neural structures severed within the surgical corridor. The infratentorial approaches and the suboccipital transtentorial approach preserve most of the white matter tracts en route to the posterosuperior and medial posteroinferior parts of the thalamus. CONCLUSIONS: When the surgical approaches for thalamic lesions are defined, white matter tracts along the surgical route should be taken into consideration.

To evaluate the potential value of machine learning (ML)-based histogram analysis (or first-order texture analysis) on T2-weighted magnetic resonance imaging (MRI) for predicting consistency of pituitary macroadenomas (PMA) and to compare it with that of signal intensity ratio (SIR) evaluation. Fifty-five patients with 13 hard and 42 soft PMAs were included in this retrospective study. Histogram features were extracted from coronal T2-weighted original, filtered and transformed MRI images by manual segmentation. To achieve balanced classes (38 hard vs 42 soft), multiple samples were obtained from different slices of the PMAs with hard consistency. Dimension reduction was done with reproducibility analysis, collinearity analysis and feature selection. ML classifier was artificial neural network (ANN). Reference standard for the classifications was based on surgical and histopathological findings. Predictive performance of histogram analysis was compared with that of SIR evaluation. The main metric for comparisons was the area under the receiver operating characteristic curve (AUC). Only 137 of 162 features had excellent reproducibility. Collinearity analysis yielded 20 features. Feature selection algorithm provided six texture features. For histogram analysis, the ANN correctly classified 72.5% of the PMAs regarding consistency with an AUC value of 0.710. For SIR evaluation, accuracy and AUC values were 74.5% and 0.551, respectively. Considering AUC values, ML-based histogram analysis performed better than SIR evaluation (z = 2.312, p = 0.021). ML-based T2-weighted MRI histogram analysis might be a useful technique in predicting the consistency of PMAs, with a better predictive performance than that of SIR evaluation.

Objective Rathke's cleft cysts (RCCs) may have various anatomic, clinical, and radiologic characteristics, which may be related to their differences in texture or consistency. The purpose of the study was to investigate RCCs based on consistency. Methods We retrospectively reviewed 25 cases of patients with RCCs who underwent endoscopic endonasal transsphenoidal surgery between 2008 and 2018. Cases were divided into 3 types based on cyst consistency: fluid (serous) or type A (n = 4); semi-fluid (mucoid) or type B (n = 17); and non-fluid (caseous) or type C (n = 4). Demographic, clinical, radiologic, and surgical characteristics for each group were analyzed. Results All type A RCCs (100%) had visual impairment. The mean age (42.8 ± 13 years) and cyst volume (2442.5 ± 533.6 mm3) were higher in these patients. T1-weighted images were hypointense and T2-weighted images were hyperintense on magnetic resonance imaging. Type B RCCs were more frequently encountered (68%). Although headache was the most common (82.3%) symptom, endocrine disorders were also prevalent (52.9%). T1-weighted images were typically isointense or hyperintense on magnetic resonance imaging. Type C RCCs had the youngest patient population (30.3 ± 10.2 years) and T2-weighted images were predominantly hypointense in this group. Conclusions The proposed novel consistency classification of RCCs will provide a practical tool for more accurately estimating the nature of the pathology, because each type has its own specific characteristics. Furthermore, the new classification of RCCs may aid in planning a consistency-specific surgery.

Pediatric pituitary adenomas are rare lesions. Incidence is reported between 1 and 10% of all childhood brain tumors and between 3 and 6% of all surgically treated adenomas. Although pituitary adenomas present with symptoms of hormone hypersecretion or neurological disruptions secondary to mass effect, they are almost constantly benign. Characteristics of patients may vary in different studies according to age, gender, size of adenoma, hormonal activity, and recurrence rates. Data on consecutive pediatric patients who were operated for pituitary adenoma with endoscopic endonasal transsphenoidal surgery (EETS) and transsphenoidal microsurgery (TMS) in the Department of Neurosurgery, Istanbul University Cerrahpasa Medical Faculty, Istanbul, Turkey, in the Neurosurgical Unit of the San Matteo Hospital, Pavia, Italy, and in the Division of Neurological Surgery Department of Biotechnology and Life Sciences, University of Insubria-Varese, ASST Sette Laghi, Ospedale di Circolo e Fondazione Macchi, Varese, Italy, between July 1997 and May 2018, were analyzed. Twenty-seven patients (11 males and 16 females), who were 18 years old or younger at the time of surgery, were included in the study. Medical records, images, and operative notes of patients were retrospectively reviewed. There were 16 females (59.3%) and 11 males (40.7%). Mean age was 15.3 ± 3.3 (4–18). Thirty-two surgical procedures were performed for 27 patients (6 children required second operation). Thirteen patients (48.14%) had Cushing’s disease (CD), 5 patients (18.5%) had growth hormone (GH)-secreting adenoma, 5 patients (18.5%) had prolactinoma, and 4 patients (14.8%) had non-functional adenoma. Twenty-two patients (81.4%) met remission criteria, and 5 patients (18.5%) did not meet remission criteria. Four patients met remission criteria after the second operation. Transsphenoidal approach affords effective release of mass effect and not only restoration but also perpetuation of normal endocrine functions in the majority of pediatric pituitary adenoma patients. Satisfactory results are reported with both EETS and TMS in the literature. Despite the technical difficulties in pediatric age, transsphenoidal resection of adenoma is still the mainstay treatment that provides cure in pediatric patients.

Tanriover, Necmettin/0000-0001-7628-9443; gungor, abuzer/0000-0002-2792-7610 WOS: 000496966300110 PubMed: 31351206 BACKGROUND: Magnetic resonance imaging-guided laser interstitial thermal therapy (LITT) is an emerging minimally invasive procedure for the treatment of deep intracranial lesions. Insular lesions are challenging to treat because of the risk of damaging important surrounding structures. The precise knowledge of the neural structures that are at risk along the trajectory and during the ablation is essential to reduce associated complications. This study aims to describe the relevant anatomy of the anterior frontal LITT trajectory to the insular region by using sectional anatomy and fiber dissection technique. - METHODS: Three silicone-injected cadaveric heads were used to implant laser catheters bilaterally to the insular region by using a frameless stereotactic technique from a frontal approach. Sections were cut in both the oblique axial plane parallel to the trajectory and in the coronal plane. White matter fiber dissections were used to establish the tracts related to the laser trajectory from lateral to medial and medial to lateral. RESULTS: Supraorbital regions were selected as entry points. After crossing the frontal bone, the track intersected the inferior frontal lobe. The catheter was illustrated reaching the insular region medial to the inferior fronto-occipital fasciculus and insular cortex, and superior to the uncinate fasciculus. The uncinate fasciculus, extreme capsule, claustrum, external capsule, and putamen were traversed, preserving the major vascular structures. CONCLUSIONS: Independent of the insular area treated, an understanding of the neuroanatomy related to the anterior frontal laser trajectory is essential to improve the ability to perform LITT of this challenging region.

OBJECTIVEDespite the extensive use of the subthalamic nucleus (STN) as a deep brain stimulation (DBS) target, unveiling the extensive functional connectivity of the nucleus, relating its structural connectivity to the stimulation-induced adverse effects, and thus optimizing the STN targeting still remain challenging. Mastering the 3D anatomy of the STN region should be the fundamental goal to achieve ideal surgical results, due to the deep-seated and obscure position of the nucleus, variable shape and relatively small size, oblique orientation, and extensive structural connectivity. In the present study, the authors aimed to delineate the 3D anatomy of the STN and unveil the complex relationship between the anatomical structures within the STN region using fiber dissection technique, 3D reconstructions of high-resolution MRI, and fiber tracking using diffusion tractography utilizing a generalized q-sampling imaging (GQI) model.METHODSFiber dissection was performed in 20 hemispheres and 3 cadaveric heads using the Klingler method. Fiber dissections of the brain were performed from all orientations in a stepwise manner to reveal the 3D anatomy of the STN. In addition, 3 brains were cut into 5-mm coronal, axial, and sagittal slices to show the sectional anatomy. GQI data were also used to elucidate the connections among hubs within the STN region.RESULTSThe study correlated the results of STN fiber dissection with those of 3D MRI reconstruction and tractography using neuronavigation. A 3D terrain model of the subthalamic area encircling the STN was built to clarify its anatomical relations with the putamen, globus pallidus internus, globus pallidus externus, internal capsule, caudate nucleus laterally, substantia nigra inferiorly, zona incerta superiorly, and red nucleus medially. The authors also describe the relationship of the medial lemniscus, oculomotor nerve fibers, and the medial forebrain bundle with the STN using tractography with a 3D STN model.CONCLUSIONSThis study examines the complex 3D anatomy of the STN and peri-subthalamic area. In comparison with previous clinical data on STN targeting, the results of this study promise further understanding of the structural connections of the STN, the exact location of the fiber compositions within the region, and clinical applications such as stimulation-induced adverse effects during DBS targeting.

The anterior temporal lobectomy (ATL) and selective amygdalohippocampectomy (SelAH) have been used for surgical treatment of mesial temporal lobe epilepsy. We examined the comprehensive white matter tract anatomy of the temporal lobe to gain an insight into the trans-middle temporal gyrus, a lateral approach which has been commonly used. The transmiddle temporal gyrus approach was performed in a stepwise manner on cadaveric human heads to examine the traversing white matter pathways through it and the structures located in the temporal horn. We reviewed the literature to compare the trans-middle temporal gyrus approach with other SelAH techniques based on surgical outcomes. There does not appear to be a significant difference in seizure outcome between SelAH and ATL. However, the SelAH provides a better neuropsychological outcomes than the ATL in selected patients. Each SelAH approach has individual advantages and disadvantages. Based on our anatomical study, in the transcortical amygdalohippocampectomy technique through the middle temporal gyrus the white matter pathways to be encountered. In the temporal horn, the collateral eminence, hippocampus, lateral ventricular sulcus, choroidal fissure, inferior choroidal point, choroid plexus, fimbria of the fornix, and amygdala are exposed. The subpial dissection is performed along the lateral ventricular sulcus from the collateral eminence on lateral side and from the choroidal fissure on medial side by microdissector for en bloc resection of the hippocampus proper. The trans-middle temporal gyrus approach is commonly used in treatment of mesial temporal lobe epilepsy patients. A better anatomical and functional understanding of the structures of the temporal lobe is crucial for safer and more accurate surgery.

Objective To evaluate the microsurgical anatomy of the fiber tract connections of the supplementary motor area (SMA) and pre-SMA, and examine its potential functional role with reference to clinical trials in the literature. Methods Ten postmortem formalin-fixed human brains (20 sides) and 1 cadaveric head were prepared following Klingler's method. The fiber dissection was performed in a stepwise fashion, from lateral to medial and also from medial to lateral, under an operating microscope, with 3D images captured at each stage. Our findings were supported by in vivo magnetic resonance imaging tractography in 2 healthy subjects. Results The connections of the SMA complex, composed of the pre-SMA and the SMA proper, are composed of short “U” association fibers and the superior longitudinal fasciculus I, cingulum, claustrocortical fibers, callosal fibers, corticospinal tract, frontal aslant tract, and frontostriatal tract. The claustrocortical fibers may play an important role in the integration of motor, language, and limbic functions of the SMA complex. The frontostriatal tract connects the pre-SMA to the putamen and caudate nucleus, and also forms parts of both the internal capsule and the dorsal external capsule. Conclusions The SMA complex has numerous connections throughout the cerebrum. An understanding of these connections is important for presurgical planning for lesions in the frontal lobe and helps explain symptoms related to SMA injury.

Background The nucleus accumbens (NAc) has been a target for deep brain stimulation (DBS) in the treatment of depression and obsessive-compulsive disorder (OCD). Objective To examine the anatomy and connections of the NAc using a fiber dissection technique. Methods Ten human brains and 2 whole cadaveric heads were examined by fiber dissection technique and ×6 to ×40 surgical magnification. The NAc was examined from the lateral, medial, superior, and inferior sides to define its fiber connections and relationships with adjacent cortical and subcortical structures. Magnetic resonance imaging (MRI) with 1-mm slices was used to define its neuronavigation coordinates. Results Eight tracts, the uncinate fasciculus, cingulum, stria medullaris thalami, fornix, diagonal band of Broca, stria terminalis, medial olfactory stria, and forceps minor, form a capsule around the anterior, inferior, and medial sides of the NAc. The uncinate fasciculus connects along the inferior and adjacent part of the medial side of the NAc, the cingulum and diagonal band along the medial surface, the medial olfactory stria along the posteromedial and adjacent part of the inferior surface, the forceps minor along the anteromedial surface, and the stria terminalis, fornix, and stria medullaris along the posterosuperior surface. The subcortical gray matter related to the NAc includes the septal nuclei, indusium griseum, substantia innominata, caudate nucleus, and hypothalamus. The cortical areas communicating with and overlying the NAc are reviewed. Conclusion An increased understanding of the fiber connections and neural relationships of the NAc should allow more accurate DBS targeting for the treatment of psychiatric disorders.

OBJECT The aim of this study was to examine the arcuate (AF) and superior longitudinal fasciculi (SLF), which together form the dorsal language stream, using fiber dissection and diffusion imaging techniques in the human brain. METHODS Twenty-five formalin-fixed brains (50 hemispheres) and 3 adult cadaveric heads, prepared according to the Klingler method, were examined by the fiber dissection technique. The authors’ findings were supported with MR tractography provided by the Human Connectome Project, WU-Minn Consortium. The frequencies of gyral distributions were calculated in segments of the AF and SLF in the cadaveric specimens. RESULTS The AF has ventral and dorsal segments, and the SLF has 3 segments: SLF I (dorsal pathway), II (middle pathway), and III (ventral pathway). The AF ventral segment connects the middle (88%; all percentages represent the area of the named structure that is connected to the tract) and posterior (100%) parts of the superior temporal gyri and the middle part (92%) of the middle temporal gyrus to the posterior part of the inferior frontal gyrus (96% in pars opercularis, 40% in pars triangularis) and the ventral premotor cortex (84%) by passing deep to the lower part of the supramarginal gyrus (100%). The AF dorsal segment connects the posterior part of the middle (100%) and inferior temporal gyri (76%) to the posterior part of the inferior frontal gyrus (96% in pars opercularis), ventral premotor cortex (72%), and posterior part of the middle frontal gyrus (56%) by passing deep to the lower part of the angular gyrus (100%). CONCLUSIONS This study depicts the distinct subdivision of the AF and SLF, based on cadaveric fiber dissection and diffusion imaging techniques, to clarify the complicated language processing pathways.

Pituitary adenomas are rare in childhood in contrast with adults. Adrenocorticotropic hormone (ACTH)-secreting adenomas account for Cushing’s disease (CD) which is the most common form of ACTH-dependent Cushing’s syndrome (CS). Treatment strategies are generally based on data of adult CD patients, although some difficulties and differences exist in pediatric patients. The aim of this study is to share our experience of 10 children and adolescents with CD. Medical records, images, and operative notes of 10 consecutive children and adolescents who underwent transsphenoidal surgery for CD between 1999 and 2014 in Cerrahpasa Faculty of Medicine were retrospectively reviewed. Mean age at operation was 14.8 ± 4.2 years (range 5–18). The mean length of symptoms was 24.2 months. The mean follow-up period was 11 years (range 4 to 19 years). Mean preoperative cortisol level was 23.435 μg/dl (range 8.81–59.8 μg/dl). Mean preoperative ACTH level was 57.358 μg/dl (range 28.9–139.9 μg/dl). MR images localized microadenoma in three patients (30%), macroadenoma in four patients (40%) in our series. Transsphenoidal microsurgery and endoscopic transsphenoidal surgery were performed in 8 and 2 patients respectively. Remission was provided in 8 patients (80%). Five patients (50%) met remission criteria after initial operations. Three patients (30%) underwent additional operations to meet remission criteria. Transsphenoidal surgery remains the mainstay therapy for CD in pediatric patients as well as adults. It is an effective treatment option with low rate of complications. Both endoscopic and microscopic approaches provide safe access to sella and satisfactory surgical results.

Carotid endarterectomy (CEA) is a surgical intervention that may prevent stroke in asymptomatic and symptomatic patients. Our aim was to examine the microsurgical anatomy of carotid artery and other related neurovascular structures to summarize the CEA that is currently applied in ideal conditions. The upper necks of 2 adult cadavers (4 sides) were dissected using ×3 to ×40 magnification. The common carotid artery, external carotid artery (ECA), and internal carotid artery were exposed and examined. The surgical steps of CEA were described using 3-D cadaveric photos and computed tomography angiographic pictures obtained with help of OsiriX imaging software program. Segregating certain neurovascular and muscular structures in the course of CEA significantly increased the exposure. The division of facial vein allowed for internal jugular vein to be mobilized more laterally and dividing the posterior belly of digastric muscle resulted in an additional dorsal exposure of almost 2 cm. Isolating the ansa cervicalis that pulls hypoglossal nerve inferiorly allowed hypoglossal nerve to be released safely medially. The locations of the ECA branches alter depending on their anatomical variations. The hypoglossal nerve, glossopharyngeal nerve, and accessory nerve pierce the fascia of the upper part of the carotid sheath and they are vulnerable to injury because of their distinct courses along the surgical route. Surgical exposure in CEA requires meticulous dissection and detailed knowledge of microsurgical anatomy of the neck region to avoid neurovascular injuries and to determine the necessary surgical maneuvers in cases with neurovascular variations.

To investigate the value of machine learning (ML)-based high-dimensional quantitative texture analysis (qTA) on T2-weighted magnetic resonance imaging (MRI) in predicting response to somatostatin analogues (SA) in acromegaly patients with growth hormone (GH)-secreting pituitary macroadenoma, and to compare the qTA with quantitative and qualitative T2-weighted relative signal intensity (rSI) and immunohistochemical evaluation. Forty-seven patients (24 responsive; 23 resistant patients to SA) were eligible for this retrospective study. Coronal T2-weighted images were used for qTA and rSI evaluation. The immunohistochemical evaluation was based on the granulation pattern of the adenomas. Dimension reduction was carried out by reproducibility analysis and wrapper-based algorithm. ML classifiers were k-nearest neighbours (k-NN) and C4.5 algorithm. The reference standard was the biochemical response status. Predictive performance of qTA was compared with those of the quantitative and qualitative rSI and immunohistochemical evaluation. Five hundred thirty-five out of 828 texture features had excellent reproducibility. For the qTA, k-NN correctly classified 85.1% of the macroadenomas regarding response to SAs with an area under the receiver operating characteristic curve (AUC-ROC) of 0.847. The accuracy and AUC-ROC ranges of the other methods were 57.4–70.2% and 0.575–0.704, respectively. Differences in predictive performance between qTA-based classification and the other methods were significant (p

Objective To review the results of sphenoid sinus lateral recess (SSLR) cerebrospinal fluid (CSF) leaks treated with the endoscopic endonasal minimal transpterygoid approach (EEMTPA) and to discuss the surgical technique and outcomes. Methods We performed a retrospective analysis of 13 cases who underwent SSLR CSF leak repair through the EEMTPA in our clinic between September 2008 and December 2017. Demographic and etiological features with reconstruction and surgical outcomes were examined. Mean follow-up time was 6.1 years. Results In regard to etiology, the SSLR CSF leaks included 9 patients with spontaneous, 2 patients with traumatic, and 2 with iatrogenic causes. CSF leak was at the left lateral recess in 8 cases and at right lateral recess in 5 cases. Nine patients had empty sella syndrome, and 11 patients had meningoencephaloceles in addition to SSLR CSF leaks. All patients underwent surgery through the EEMTPA, and a multilayer closure with tissue overlay grafts were used for reconstruction. A pedicled nasoseptal flap and/or pedicled middle turbinate flap were applied to the area of the leak in all cases. One patient had a persistent CSF leak and another had recurrence, both of which required revision surgery. Our overall success rate was 100%. Conclusions EEMTPA is a safe and effective method that can be used to treat challenging pathologies at the SSLR, including CSF leaks accompanying meningoencephaloceles. Furthermore, the success rate of EEMTPA for SSLR CSF leaks can be increased by applying endoscopic skull base reconstruction techniques such as the pedicled nasoseptal flap and pedicled middle turbinate flap.