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Epidermoid tumors of the cerebellopontine angle and posterior fossa account for approximately 1% of all intracranial tumors. Classifications that may guide surgical planning in the current neurosurgical practice are lacking. This study aimed to focus on the surgical outcome and suggest a classification system that may aid neurosurgeons in determining the goal of resection to minimize morbidity and mortality rates.The study population comprised patients who underwent surgery and follow-up for tissue-proven epidermoid tumors between 2015 and 2020. Patients' data, including demographic features, clinical symptomatology, the extent of surgical resection, and postoperative outcomes, were retrospectively evaluated. A new classification system was designed based on the anatomical-radiological findings and was evaluated in terms of clinical symptomatology, radiological features, surgical approach, and postoperative outcomes.The patient population comprised 22 women (57.9%) and 16 men (42.1%), with a mean age of 34.9 years. A practical classification system based on the radiological-anatomical vertical (1, 2, and 3) and horizontal (a, b, and c) tumor extensions was designed. No significant differences were found in the patients in terms of sex/age. The most commonly observed symptom was gait disturbance (34.2%). The preoperative tumor diameter was significantly larger in the subtotal resection (STR) group than in the gross total resection (GTR) and near-total resection (NTR) groups. Significantly more cistern involvement was observed in the STR group than in the GTR group. The GTR, NTR, and STR rates were higher in grade 1, 3, and 2 cases, respectively. The subgroup 'a' was correlated with higher resection rates (GTR and NTR), whereas the subgroup 'b' was correlated with STR.Our suggested classification system represents a simple and practical model that may guide neurosurgeons in predicting the goal of resection during surgical planning and in minimizing potential morbidity.

Background Postoperative cerebrospinal fluid (CSF) fistula following cranial or spinal surgery is associated with increased morbidity and mortality. To prevent CSF fistulas, various techniques have been described. Here, we describe the arachnoid membrane continuous-running suture technique in cisterna magna reconstruction for preventing postoperative CSF leakage. Methods After craniotomy and dural opening, the incision of the arachnoid of the cisterna magna was performed using a diamond blade. To prevent the arachnoid from drying out and shrinking during surgery, it was periodically irrigated with warm saline solution. Posterior fossa surgery was performed. When closing the membranes, the arachnoid membrane was closed with the running-suture technique. After the first surgical knot was made in the cranial end of the arachnoid opening, continuous suturing with a 2-mm distance between the stitches was performed without stretching them. After every 3 stitches, the free end of the thread was pulled gently along the suturing axis, and the edges of the arachnoid were closed. After the arachnoid edges were approximated, the surgical knot was tied. Watertight closure was checked by performing the Valsalva maneuver at the end of the surgery. Results No CSF leakages were observed after surgery. Conclusions Arachnoid membrane suturing seems to be safe and effective in preventing postoperative CSF leakage and CSF-related complications. Using continuous running suturing alone, without any sealant, might be effective in cases with untraumatized arachnoid membrane.

Background Ulnar nerve entrapment neuropathy at the elbow is the most common upper-extremity entrapment neuropathy after carpal tunnel syndrome. Surgical treatment can be complicated by perineural scarring and fibrosis, which may lead to recurrent symptoms. Expanded polytetrafluoroethylene (ePTFE) is a synthetic polymer with antiadhesive properties. Objective To introduce the operative technique and outcomes of anterior subcutaneous transposition with ePTFE (ASTEP) in primary and recurrent cubital tunnel neuropathy. Methods We studied 14 adult patients (11 men, 3 women; mean age, 45 yr) with cubital tunnel neuropathy (10 primary, 4 revision) who underwent surgery with the ASTEP technique between January 2008 and May 2018. Pain, numbness in the fourth/fifth fingers, and weakness of the intrinsic hand muscles were the most common presenting symptoms. Surgical outcomes were assessed using the modified McGowan and Wilson-Krout criteria. Results The average (± standard deviation) preoperative symptom duration was 12.1 ± 5.2 mo (McGowan Grade 1, n = 5; Grade 2, n = 6; Grade 3, n = 3). No intraoperative or postoperative complications were observed with the ASTEP technique. Postoperative follow-up ranged from 9 mo to 7 yr (mean, 4.3 yr). All 14 patients experienced improvement in or complete resolution of their symptoms after this unique intervention. Conclusion Our novel technique of anterior transposition of the ulnar nerve with ePTFE was safe and highly effective in treating primary and recurrent ulnar nerve entrapment neuropathy at the elbow and represents an alternative to the current techniques.

Objective Cervical meningiomas are uncommon intradural-extramedullary tumors that have a tendency to be situated anterior to the spinal cord. The optimal surgical corridor to reach purely ventral cervical meningiomas has not been established. This article presents a series of patients with ventral cervical meningiomas treated via 1 of 2 microneurosurgical approaches: the anterior approach with corpectomy and fusion or the posterolateral approach. Methods Eight patients who underwent surgical resection of solitary, histopathologically confirmed, intradural-extramedullary cervical meningiomas of purely ventral location were retrospectively examined. Preoperative and postoperative Nurick scores quantified the degree of ambulatory function. Patients were followed for an average of 2.1 years after surgery. Postoperative imaging was performed to determine the extent of resection and to assess for tumor recurrence. Results Two patients with lower cervical meningiomas underwent resection via an anterior approach with single-level corpectomy and fusion. Six patients were treated via a posterolateral approach including ipsilateral hemilaminectomy and partial facetectomy without fusion. No intraoperative or postoperative complications were observed. Gross total resection was achieved in 8 of 8 patients, although 1 patient exhibited tumor recurrence. Improvement in ambulatory function was observed in all patients. Conclusions Purely ventral cervical meningiomas are uncommon and pose unique technical challenges for neurosurgeons. We document favorable outcomes from 2 cases of lower cervical meningioma treated via an anterior approach and 6 cases of upper cervical tumors treated via a posterolateral approach. This series demonstrates operative considerations for effectively managing ventral cervical meningiomas.

Glioblastoma multiforme (GBM), characterized by a high rate of proliferation and migration capacity, is an incurable brain tumor in adults. Interleukin-33 (IL-33), a member of the IL-1 cytokine superfamily and a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5), a family of zinc dependent metalloproteinases are known to have an essential roles in GBM migration and invasion. Previous studies have separately revealed elevated expressions of IL-33 and ADAMTS5 in GBM; however, the interaction between IL-33 and ADAMTS5 in GBM pathogenesis has remained unclear. Here, using publically available GlioVis and GEPIA programs, we showed that mRNA expression of IL-33 and ADAMTS5 is significantly high in GBM cells, and a positive correlation between IL-33 and ADAMTS5 was also determined in these cells. In parallel with the mRNA data of IL-33 and ADAMTS5, by Western blot analysis, protein levels were found to be elevated in GBM tissues and increased gradually with the disease progression. Primary GBM cells and low-grade glioma cells were then treated with IL-33 to examine its stimulating effect on ADAMTS5 expression. Exposure to IL-33 raised ADAMTS5 protein levels in a dose-dependent manner. Finally, the wound healing method was performed to confirm the impact of IL-33 on migration in primary GBM cells. IL-33 promoted migration of primary GBM cells three-times higher than untreated GBM cells. Thus, the current study suggests for the first time that IL-33 might have a role in play a part in GBM progression through induction of ADAMTS5 expression and promotion of migration in GBM cells.

Objective The supraorbital keyhole approach through an eyebrow incision has been a potentially less invasive approach as an alternative to the standard pterional craniotomy. We aimed to review procedures for anterior and middle cranial fossa lesions and identify lessons learned from addressing various pathologies through this approach. Methods We retrospectively reviewed 106 consecutive patients who underwent this approach. We documented patients' age, sex, pathology, clinical results, extent of tumor resection, complications, use of endoscope, and cosmetic results. Results Our series addressed a variety of pathologies. Male patients accounted for 55% of the cohort and mean age was 51.7 (2–79) years. Notably, 52% of patients underwent resection of extra-axial masses. Gross total resection was achieved in 74.4% of intra-axial lesions according to postoperative imaging. Two (1.9%) patients developed transient ptosis. One (0.9%) patient developed an allergic reaction to titanium. No cerebrospinal fluid fistula or rhinorrhea occurred. Three patients developed temporary diabetes insipidus after resection of parasellar lesions (2 craniopharyngiomas and 1 pituitary adenoma). In 14 patients with olfactory groove meningiomas, 6 (42.8%) suffered from absence or diminished olfaction postoperatively, and 2 (14.2%) developed postoperative anosmia. Five (38.5%) patients underwent a subsequent resection of recurrent glial tumors. Four weeks postoperatively, 95% of patients demonstrated acceptable cosmetic results. Cosmetic results for 6 (5%) patients were unavailable. Conclusions The supraorbital keyhole approach may be safely used for various lesions within the anterior and middle cranial fossa. The effectiveness and limitations of this approach and possible complications are discussed. This is a valuable approach for selected patients.

Background Spinal arachnoid cysts (SACs) are uncommon lesions in the spinal canal. They are usually asymptomatic, but can occasionally cause mass effect leading to neurologic symptoms. They can be congenital or secondary to a variety of causes. They can produce a variety of neurologic symptoms including pain, weakness, sensory changes, incontinence, and more. Surgical intervention may be necessary when SACs cause symptomatic mass effect. Methods Thirteen consecutive patients who underwent surgical intervention for an SAC were retrospectively reviewed. The data included presenting symptoms, imaging findings, neurologic status, and follow-up. Results Of the 13 patients, the majority of cases were located in the thoracic spine (54%) and all but one case were located dorsally or dorsolaterally. Furthermore, 38% were located extradurally and 54% were located intradurally. Pain (80%) was the most common presenting symptom. Most patients had improvement or complete resolution of their symptoms after intervention. Extradural SACs and their capsules were completely resected, whereas intradural SACs underwent fenestration. No complications occurred in this series. Conclusions SACs are usually asymptomatic, but rarely cause mass effect and neurologic deficits requiring surgical intervention. Surgical intervention is tailored to the position of the cysts' dorsal or ventral locations. Pain and weakness are the most likely symptoms to improve, whereas sensory symptoms are least likely to improve.

Objective In this study, we investigated if and when dural tenting sutures are necessary during craniotomy. Methods Results from 437 patients 18–91 years of age (average, 43.5 years) who underwent supratentorial craniotomy between 2014 and 2019 were evaluated. The patients were categorized into 1 of 3 groups: patients who had at least 3 prophylactic dural tenting sutures placed before opening of the dura (group 1); patients who had at least 3 dural tenting sutures placed after surgery was completed, during closure (group 2); or patients who had no dural tenting sutures (group 3 [control]). All such sutures in groups 1 and 2 were placed in the circumference of the craniotomy and dural junction. No central dural tenting sutures were placed in any of the patients. Results Among the 437 patients, 344 underwent surgery for the first time and 93 were undergoing a second surgery. Cranial computed tomography imaging was performed for each patient 1 hour, 3 days, and 1 month after surgery. In group 1, 3 patients had a cerebral cortex contusion and 2 patients had acute subdural hematoma after the sutures were placed. In groups 2 and 3, none of the patients had a cerebral cortex contusion or acute subdural hematoma. Fewer complications were observed when dural tenting sutures were placed during postsurgical closure. Conclusions Placing dural tenting sutures is an important technique for ensuring hemostasis. However, when not needed, they seem to cause inadvertent complications. As our results suggest, knowing when and where to use them is equally important.

BACKGROUND: Approaching ambient cistern lesions is still a challenge because of deep location and related white matter tracts (WMTs) and neural structures. OBJECTIVE: To investigate the white matter anatomy in the course of 3 types of transtemporal-transchoroidal fissure approaches (TTcFA) to ambient cistern by using fiber dissection technique with translumination and magnetic resonance imaging fiber tractography. METHODS: Eight formalin-fixed cerebral hemispheres were dissected on surgical corridor from the temporal cortex to the ambient cistern by using Klingler's method. The trans-middle temporal gyrus, trans-inferior temporal sulcus (TITS), and trans-inferior temporal gyrus (TITG) approaches were evaluated. WMTs that were identified during dissection were then reconstructed on the Human Connectome Project 1021 individual template for validation. RESULTS: The trans-middle gyrus approach interrupted the U fibers, arcuate fasciculus (AF), the ventral segment of inferior frontoocipital fasciculus (IFOF), the temporal extensions of the anterior commissure (AC) posterior crura, the tapetum (Tp) fibers, and the anterior loop of the optic radiation (OR). The TITS approach interrupted U fibers, inferior longitudinal fasciculus (ILF), IFOF, and OR. The TITG approach interrupted the U fibers, ILF, and OR. The middle longitudinal fasciculus, ILF, and uncinate fasciculus (UF) were not interrupted in the trans-middle gyrus approach and the AF, UF, AC, and Tp fibers were not interrupted in the TITS/gyrus approaches. CONCLUSION: Surgical planning of the ambient cistern lesions requires detailed knowledge about WMTs. Fiber dissection and tractography techniques improve the orientation during surgery and may help decrease surgical complications. Copyright © 2020 by the Congress of Neurological Surgeons.

Objectives:The shape and localization of the scalp incision are the factors that affect surgical outcome. With the help of developing technology, it is aimed to decrease the size of incisions and decrease the morbidity. The ideal shape and length of the incision should not disrupt the scalp feeding and provide the best possible wound healing, but also have to provide adequate control of the surgical field. In our study, we aimed to observe the effects of linear scalp incision on patients’ surgical comfort and wound healing.Materials and Methods:In our retrospective study, we evaluated linear scalp incision in 26 patients with supratentorial cortical-subcortical tumors between 2017 and 2018. Tumor location was determined by neuronavigation and linear incision lines were planned pre-operatively in all patients.Results:The size of superficially located tumors was equal or less than 5 cm. The average length of incision was 9.2 cm and was parallel to the coronal suture. No difficulties were seen in reaching the lesion in terms of incision length or location. There was no significant morbidity and mortality in the postoperative period, except of patients which were temporary paresis. No complications were seen in wound healing. Silk sutures were taken on average for 7.4 days. Thirty four of the thirty two patients were discharged on the 3rd postoperative day.Conclusion:A linear incision can be applied as an alternative to other incisions in superficially localized and to adequate size (≤5 cm) supratentorial region tumors which were determined with neuronavigation.

Objective Intracerebral hemorrhage continues to be a major global problem. No standard treatment or surgical procedure has been identified for intracerebral hemorrhages. High morbidity and mortality rates caused by conventional approaches and the disease itself have necessitated more-invasive treatment methods. The endoscopic approach is a more minimally invasive method than craniotomy, which is another alternative surgical treatment. Methods We compared intracerebral hematoma drainage in 2 groups of 17 patients each, treated with minimally invasive endoscopic method versus craniotomy. All the patients were treated for supratentorial spontaneous hemorrhage between December 2013 and February 2017 at the Neurosurgery Clinic of Ankara University Faculty of Medicine. Results We retrospectively evaluated 34 patients surgically treated between December 2013 and February 2017. All patients underwent surgery within the first 24 hours. Patients in the early surgery group had better surgical outcomes. In the neuroendoscopic group, Glasgow Coma Scale increased from 6 to 11 at 1 week postoperatively compared with 5 to 9 in the craniotomy group. Conclusions Minimally invasive endoscopic hematoma evacuation may be a good alternative surgical method for treating supratentorial spontaneous cerebral hematomas.

The location of burr holes in posterolateral cranial base approaches should be appropriate to provide an adequate operative field, and surgical freedom is crucial for bone window opening. The aim of this study was to search for more convenient and easily detectable landmarks in comparison with current landmarks in posterolateral cranial base surgery. Twenty 3-dimensional reconstructed head and neck computed tomography angiography images (group 1) and 20 cadaver heads (group 2) were evaluated. An imaginary line connecting the angle of the mandible and the mastoid tip was extended upward. A second line passing through the lateral edge of the zygomatic arch was also extended posteriorly. The authors examined if the first line met with the sigmoid sinus throughout its course and determined the location of the intersection point of these 2 lines relative to the sigmoid-transverse sinus junction. The intersection point did not correspond to the sinus region in 3 images from group 1 and 4 specimens from group 2. The matching of the mandibula-mastoid line trajectory with the sigmoid sinus course was unacceptable in 4 images and 5 cadavers. For venous anatomy preservation and anatomic skull base fossa orientation during posterolateral cranial base approaches, upward extension of the mandibula-mastoid line can be a proper landmark for surgical planning in this region. The authors' proposed superficial anatomical line and intersection point over the skull could be used as a reliable indicator for the external projection of the sigmoid sinus and an appropriate initial burr-hole location.

The fibrotic tissue that appears following nerve damage can prevent axonal regeneration. Expanded polytetrafluor ethylene (ePTFE) is a synthetic polymer with antiadhesive properties and a safe history of use in neurosurgery. The aim of this study was to use ePTFE to prevent postsurgical adhesions in patients undergoing anastomosis surgery and report the results. Between January 2014 and May 2018, six patients with primary and secondary peripheral nerve cuts underwent anastomosis (one with allograft and five with autografts). The anastomotic region was wrapped with ePTFE to form a barrier. The mean follow-up period was 28 months (minimum 3 months, maximum 4 years). In three of six patients whose nerve integrity was lost due to various reasons, there was an improvement in electrophysiological recordings. The allograft was used in a patient with peroneal nerve injury; the sural nerve was used as a graft in other patients. In three patients, the defect was more than 4 cm. Early surgery and defect size are important factors to consider when treating peripheral nerve anastomosis. Development of intraneural and perineural adhesions postsurgery can be problematic. ePTFE is an inert polymer that prevents adhesions from forming after anastomosis surgery. © 2020, Association of Surgeons of India.

In this study the three-dimensional anatomy of the corona radiata and tapetum via the fiber dissection and diffusion tensor imaging of the brain for ventricular surgery was demonstrated. Ten formalin-fixed cerebral hemispheres were dissected for corona radiata and tapetum via Klingler's fiber dissection method under an operating microscope. The corona radiata and tapetum were dissected through lateral and medial surfaces of the cerebral hemisphere, respectively. All surgical routes for ventricular lesions were evaluated for white matter fibers during and after dissections. Corona radiata and tapetum fibers were demonstrated by dissecting hemispheres through lateral and medial aspects of the brain. The internal capsule contains all fibers that extend from thalamus to cortex and cortex to thalamus, brainstem, and spinal cord. These fan-shaped fibers extending from cortex to internal capsule were named the corona radiata. The corona radiata is not a specific pathway, and it is composed of several different fiber pathways. The tapetum contains splenium and body fibers of the corpus callosum. Tapetum is located immediately medial to the ependymal line of the ventricular wall and forms a fiber layer in the medial optical radiation on the coronal and axial sections. Surgical planning for ventricular lesions requires detailed information regarding white matter fibers that can be obtained by the fiber dissection and diffusion tensor imaging of the brain to decrease surgical complications.

PubMed ID: 29906582, Objective: To examine the surgical results of unilateral lumbar discectomy in patients with bilateral leg pain and discuss short- and long-term outcomes within the limits of lumbar decompression. Methods: We analyzed 60 patients with unilateral disc herniation who underwent unilateral lumbar discectomy and hemipartial laminectomy between 2014 and 2017. Group 1 (30 patients) had bilateral leg pain and unilateral lumbar disc herniation. Pain lateralization was determined radiologically. Group 2 (30 patients) had unilateral leg pain and unilateral lumbar disc herniation. Pain scores were preoperatively evaluated with visual analog scale (VAS) for both legs and Oswestry Disability Index (ODI) for overall life quality. In both groups, surgery was performed on the ipsilateral side of the herniated disc. Scores were repeated on postoperative day 1 and 1, 3, 6, 12, and 24 months later. VAS score differences for pain lateralization and disc levels were compared in group 1. ODI score differences were compared between both groups. Results were statistically analyzed. Results: VAS score differences were statistically significant at all follow-up time points in patients with ipsilateral and contralateral pain. VAS score differences between L4–L5 and L5–S1 level discopathies were statistically insignificant for all time points in both groups. All postoperative ODI score decreases for all time points were statistically significant (P < 0.001) for both groups, whereas the differences between groups 1 and 2 were statistically insignificant. Conclusions: Conventional lumbar disc surgery alone is sufficient for the ipsilateral side of radiologically demonstrated disc herniation in patients with bilateral leg pain. © 2018 Elsevier Inc., Preparation for the publication of this article was partly supported by Turkish Neurosurgical Society.

Background Transoral robotic surgery has been used successfully to assist many surgical procedures. Here, we report its first use as pure robotic surgery, applied to excise an odontoid metastatic mass. Case Description A 48-year-old woman was hospitalized due to a lesion consistent with metastasis that extended to the pharyngeal constrictor muscles and that had completely destroyed the odontoid bone. Occipitocervical fixation was performed initially, and transoral surgery took place 5 days later. The da Vinci Surgical System Robot was used to resect the tumor. The patient was discharged with a very good general condition. Conclusions This article presents the first pure robotic surgery for odontoid. The increasing number of robot-assisted cases will demonstrate the necessity of this evolution in neurosurgery and should accelerate the process.

Cauda equina syndrome manifests as bilateral leg pain and sensory disturbances in the perianal region. In this article, authors describe patient with posterior epidural disc migration of a lumber disc fragment causing cauda equina syndrome and provide review of the literature.

Pure extradural spinal arteriovenous malformations (AVMs) are formed with an epidural artery, a nidus and an arterialized intradural vein in the absence of vertebral cavernous hemangioma and uncommon lesions. The most common extradural tumors are metastasis, lymphomas, benign tumors and malignant bony tumors. Herein, we present a-29-year-old Turkish woman with pure extradural mass that histopathologically diagnosed as AVM. When an extradural spinal compressive mass is detected, neurosurgeons should consider on AVM in differential diagnosis and requirement of selective spinal angiography.

Literature defines the landmarks to identify the courses and locations of the transverse and sigmoid sinuses on the outer surface of the skull and inner surface of the scalp. These natural landmarks may only be helpful after skin incision and are inadequate to determine the length and size of the skin incision. Still, there is a need to identify palpable landmarks easily to determine the ideal location to open the initial burr hole before an operation. Twenty-eight dried adult human skulls and 2 cadavers were evaluated. The zygomatic root, the inion, and the mastoid process were identified on the external, and the grooves for sigmoid and transverse sinuses, on the internal surfaces. The distances between the 3 landmarks and the midpoints, and the shortest distances of the midpoints to the border of the groove for sigmoid sinus and groove for transverse sinus were measured. Statistically significant differences were evaluated for both sides. Based on the measurements, the defined "artificial landmarks" can be considered safe points that involve no vascular structures and may be used to perform the initial burr hole during posterolateral approaches. Identification of the midpoints and palpation of the defined landmarks easily before the operation render the study feasible and practical unlike with natural landmarks. To avoid venous injury, the midpoints of mastoid-inion line and zygomatic root-inion line can be used safely in skin incision during posterior fossa approaches and craniotomy. Copyright © 2013 by Mutaz B. Habal, MD.

Amaç: Bu çalışmanın amacı beyin arterlerinin üç boyutlu yapısını koruyarak korozyon tekniği kullanarak ortaya çıkarmak. Korozyon yöntemi daha önce koroner ve testiküler arterleri göstermede kullanılmış olmasına rağmen beyin arterlerini göstermede ilk defa kullanılmıştır. Metod: Taze insan beyni her iki internal karotid ve baziller arterlerinden kanülize edilerek irrige edildi. Ardından renklendirilmiş polyester ile dolduruldu. Korozyon işlemi için dilüe sülfirik asit ile dolu kabın içinde bekledikten sonra su ile geride kalan küçük atıklar dikkatlice temizlendi. Bu şekilde beynin üç boyutlu yapısı ortaya çıkarıldı. Sonuçlar: Enjeksiyon-korozyon yöntemi en derin yerleşimdeki vasküler yapıları dahi üç boyutlu yapısı ile ortaya çıkarabilen yeni bir ekspozisyon yöntemidir. Tartışma: Vasküler yapılar normalde kadaverik diseksiyon yöntemi ile ortaya çıkarılmaktadır. Bu şekilde yapılan diseksiyonlarda vasküler yapıların orjinleri hakkında bilgi edinilebilirken anatomic pozisyonları ve projeksiyonları hakkında bilgi edinebilmek mümkün olmamaktadır. Enjeksiyon-korozyon yöntemi vasküler yapıları kraniumdaki normal duruş pozisyonlarında, en ufak bir dal dahi zarar görmeden, en ince ayrıntısına kadar üç boyutlu olarak ortaya çıkarabilmemizi sağlamıştır. Serebral arteryel yapıların projeksiyonları da korunarak bu şekilde ortaya çıkarılabilmesinin nöroşirürji eğitimine ve bundan sonraki vasküler çalışmalara çok önemli katkıları olacağına inanmaktayız.

Purpose: The arterial vascularization of the pineal gland (PG) remains a debatable subject. This study aims to provide detailed information about the arterial vascularization of the PG. Methods: Thirty adult human brains were obtained from routine autopsies. Cerebral arteries were separately cannulated and injected with colored latex. The dissections were carried out using a surgical microscope. The diameters of the branches supplying the PG at their origin and vascularization areas of the branches of the arteries were investigated. Results: The main artery of the PG was the lateral pineal artery, and it originated from the posterior circulation. The other arteries included the medial pineal artery from the posterior circulation and the rostral pineal artery mainly from the anterior circulation. Posteromedial choroidal artery was an important artery that branched to the PG. The arterial supply to the PG was studied comprehensively considering the debate and inadequacy of previously published studies on this issue available in the literature. Conclusions: This anatomical knowledge may be helpful for surgical treatment of pathologies of the PG, especially in children who develop more pathology in this region than adults. © 2013 Springer-Verlag Berlin Heidelberg.

Object The branching structure of the middle cerebral artery (MCA) remains a debated issue. In this study the authors aimed to describe this branching structure in detail. Methods Twenty-seven fresh, human brains (54 hemispheres) obtained from routine autopsies were used. The cerebral arteries were first filled with colored latex and contrast agent, followed by fixation with formaldehyde. All dissections were done under a microscope. During examination, the trunk structures of the MCA and their relations with cortical branches were demonstrated. Lateral radiographs of the same hemispheres were then obtained and comparisons were made. Angles between the MCA trunks were measured on 3D CT cerebral angiography images in 25 patients (50 hemispheres), and their correlations with the angles obtained in the cadaver brains were evaluated. Results A new classification was made in relation to the terminology of the intermediate trunk, which is still a subject of debate. The intermediate trunk was present in 61% of cadavers and originated from a superior trunk in 55% and from an inferior trunk in 45%. Cortical branches supplying the motor cortex (precentral, central, and postcentral arteries) significantly originated from the intermediate trunk, and the diameter of the intermediate trunk significantly increased when it originated from the superior trunk. In measurements of the angles between the superior and intermediate trunks, it was found that the intermediate trunk had significant dominance in supplying the motor cortex as the angle increased. The intermediate trunk was classified into 3 types based on the angle values and the distance to the bifurcation point as Group A (pseudotrifurcation type), Group B (proximal type), and Group C (distal type). Group A trunks were seemingly closer to the trifurcation structure that has been reported on in the literature and was seen in 15%. Group B trunks were the most common type (55%), and Group C trunks were characterized as the farthest from the bifurcation point. Group C trunks also had the smallest diameter and fewest cortical branches. Similarities were found between the angles in cadaver specimens and on 3D CT cerebral angiography images. Beyond the separation point of the MCA, trunk structures always included the superior trunk and inferior trunk, and sometimes the intermediate trunk. Conclusions Interrelations of these vascular structures and their influences on the cortical branches originating from them are clinically important. The information presented in this study will ensure reliable diagnostic approaches and safer surgical interventions, particularly with MCA selective angiography.

The objective of this study was to analyze relationship of the intervertebral disc to the nerve root in the intervertebral foramen. Fourteen formalin-fixed cadavers were studied and measurements were performed. At the medial line of the neural foramen, the disc-root distance gradually increased from L1-L2 to L5-S1. The shortest distance between the disc to nerve root was L1-L2 (mean, 8.2 mm) and the greatest distance was found at L3-L4 (mean, 10.5 mm). In the mid-foramen, the disc-root distance decreased from L1-2 to L5-S1. The shortest distance from the disc to nerve root was found at L5-S1 (mean, 0.4 mm); and the greatest distance, at L1-L2 (mean, 3.8 mm). For the lateral line, the distance between an intersection point between the medial edge of the nerve root and the superior edge of the disc and lateral line of the foramen consistently increased from L1-L2 to L5-S1. The shortest distance from nerve root to the lateral border of the foramen, at the point where the nerve root crosses disc was at level L1-L2 (mean, 2.6 mm), the greatest distance, L5-S1 (mean, 8.8 mm). The width of the foramina progressively increased in a craniocaudal direction (mean, 8.3-17.8 mm from L1-2 to L5-S1, respectively). The mean height of the foramina was more or less the same for disc levels (range, 19.3-21.5). The results showed that nerve roots at lower levels traveled closer to the midline of the foramen. This morphometric information may be helpful in minimizing the incidence of injury to the lumbar nerve root during foraminal and extraforaminal approaches.

Object Although infrequent, injury to adjacent neurovascular structures during posterior approaches to lumbar intervertebral discs can occur. A detailed anatomical knowledge of relationships may decrease surgical complications. Methods Ten formalin-fixed male cadavers were used for this study. Posterior exposure of the lumbar thecal sac, nerve roots, pedicles, and intervertebral discs was performed. To identify retroperitoneal structures at risk during posterior lumbar discectomy, a transabdominal retroperitoneal approach was performed, and observations were made. The distances between the posterior and anterior edges of the lumbar intervertebral discs were measured, and the relationships between the disc space, pedicle, and nerve root were evaluated. Results For right and left sides, the mean distance from the inferior pedicle to the disc gradually increased from L1–2 to L4–5 (range 2.7–3.8 mm and 2.9–4.5 mm for right and left side, respectively) and slightly decreased at L5–S1. For right and left sides, the mean distance from the superior pedicle to the disc was more or less the same for all disc spaces (range 9.3–11.6 mm and 8.2–10.5 mm for right and left, respectively). The right and left mean disc-to-root distance for the L3–4 to L5–S1 levels ranged from 8.3 to 22.1 mm and 7.2 to 20.6 mm, respectively. The root origin gradually increased from L-1 to L-5. The right and left nerve root–to-disc angle gradually decreased from L-3 to S-1 (range 105°–110.6° and 99°–108°). Disc heights gradually increased from L1–2 to L5–S1 (range 11.3–17.4 mm). The mean distance between the anterior and posterior borders of the intervertebral discs ranged from 39 to 46 mm for all levels. Conclusions To avoid neighboring neurovascular structures, instrumentation should not be inserted into the lumbar disc spaces more than 3 cm from their posterior edge. Accurate anatomical knowledge of the relationships of intervertebral discs to nerve roots is needed for spine surgeons.

BACKGROUND: Although injury to the lumbar arteries during anterior spinal approaches is often encountered, there are few published articles regarding the relationship between the lumbar arteries and spinal cord ischemia. OBJECTIVE: To examine the morphology of the lumbar arteries and to emphasize their clinical importance. METHODS: With the aid of a surgical microscope, 80 lumbar arteries in 10 formalin-fixed male cadavers were studied. Measurements of these structures were made and relationships observed. RESULTS: The spinal artery was usually the first branch of the lumbar artery. The greatest lumbar artery diameter was at L4 and had a mean diameter of 3.25 mm; the smallest diameter was identified at L2 and had a mean diameter of 2.05 mm. The largest spinal artery diameter was at L3 (mean, 0.56 mm) and the smallest at L1 (mean, 0.42 mm). The largest anastomotic artery diameter was at L4 (mean, 0.42 mm) and the smallest at L1 (mean, 0.32 mm). For the right and left sides, the mean greatest distance between the origin of the lumbar artery and the tendinous arch was at L4 (mean, 40.9 and 31.8 mm, respectively) and the least at L1 (mean, 31.8 and 22.5 mm, respectively). The mean of the greatest distance between the anastomotic branch and the base of the transverse process of the lumbar vertebrae was at L4 (mean, 4.41 and 4.35 mm, respectively) and the smallest at L1 (mean, 4.04 and 4.08 mm, respectively). CONCLUSION: These anatomic findings of the lumbar segmental arteries would be useful for emphasizing their surgical importance.

Object Knowledge of the cranium projections of the gyral structures is essential to reduce the surgical complications and to perform minimally invasive interventions in daily neurosurgical practice. Thus, in this study the authors aimed to provide detailed information on cranial projections of the eloquent cortical areas. Methods Ten formalin-fixed adult human skulls were obtained. Using sutures and craniometrical points, the crania were divided into 8 windows: superior frontal, inferior frontal, superior parietal, inferior parietal, sphenoidal, temporal, superior occipital, and inferior occipital. The projections of the precentral gyrus, postcentral gyrus, inferior frontal gyrus, superior temporal gyrus, transverse temporal gyri, Heschl gyrus, genu and splenium of the corpus callosum, supramarginal gyrus, angular gyrus, calcarine sulcus, and sylvian fissure to cranial vault were evaluated. Results Three-fourths of the precentral gyrus and postcentral gyrus were in the superior parietal window. The inferior frontal gyrus extended to the inferior parietal window in 80%. The 3 important parts of this gyrus were located below the superior temporal line in all hemispheres. The orbital and triangular parts were in the inferior frontal window, and the opercular part was in the inferior parietal window. The superior temporal gyrus was usually located in the inferior parietal and temporal windows, whereas the supramarginal gyrus and angular gyrus were usually located in the superior and inferior parietal windows. The farthest anterior point of the Heschl gyrus was usually located in the inferior parietal window. The mean positions of arachnoid granulations were measured as 3.9 ± 0.39 cm anterior and 7.3 ± 0.51 cm posterior to the bregma. Conclusions Given that recognition of the gyral patterns underlying the craniotomies is not always easy, awareness of the coordinates and projections of certain gyri according to the craniometric points may considerably contribute to surgical interventions.

Pain, usually a response to tissue damage, is accepted as an unpleasant feeling generating a desire to escape from the causative stimulus. Although, in the early stages of malignant diseases, pain is seen in 5% to 10% of cases, this rate reaches nearly 90% in the terminal stage, and pain becomes a primary symptom. Cordotomy is one of the treatment choices in pain caused by malignancies localized unilaterally to the extremities as well as the thorax and the abdomen.The target of computed tomography (CT)-guided percutaneous cordotomy is the lateral spinothalamic tract located in the anterolateral region of the spinal cord at the C1-C2 level. Between 1987 and 2007, CT-guided percutaneous cordotomies were performed in 207 patients; most (193 patients) suffered from intractable pain related to malignancy. The patients' pain scores and Karnofsky Performance Scale scores were evaluated pre- and postoperatively.The initial success rate of CT-guided percutaneous cordotomy was 92.5%. The success rate was higher in the malignancy group. In the cancer group, selective cordotomy (pain sensation denervated only in the painful region of the body) was achieved in 83%. In 12 cases, bilateral selective percutaneous cordotomy was successfully applied.In the treatment of intractable pain, CT-guided cordotomy is an option in specially selected cases with malignancy. In this study, anatomic and technical details of the procedure and the experience gained from treating 207 patients over a 20-year period are discussed.

Endoscopic endonasal transsphenoidal approach to the sellar region yields an alternative to classical microsurgical approaches. Endoscopes provide images that differ from microscopic view. This study aimed to highlight surgical landmarks and their anatomical relationships for pituitary surgery through endoscopic perspective. Ten sides of five adult cadaveric heads with red-colored latex injected arteries were evaluated. Endoscopic dissections were performed and measurements were done in the sphenoid sinuses before and after the removal of bony structures in all the aspects. Endoscopic vision of the sellar region enabled a wide panoramic perspective and detailed inspection. The measurements, in general, indicated the variations in the bony structures and soft tissues. The width of the pituitary, which is the distance between the medial margins of the carotid prominences, was measured as 21 6 2.5 mm and the distance between the medial margin of the carotid prominences at the lower margin of the pituitary was 18 6 3.1 mm. After the bony structures were removed, further measurements were done. The width of the pituitary, which is the distance between the medial margins of the anterior curvature of the ICA, was measured as 23.2 6 3 mm, while the distance between the posterior curvature of the ICA was 19.7 6 4.9 mm. Endoscopic view provided superior detailed visualization of the close relationships between pituitary gland, internal carotid arteries, and optic nerves. This facilitated exact evaluation for variations, which could result in more effective and safe surgery. However, these variations again emphasize the necessity of preoperative radiological evaluation in each case. Clin. Anat. 21:627–632, 2008. V C 2008 Wiley-Liss, Inc.

Anterior cervical discectomy with or without fusion has been commonly used for cervical disc disease since the description by Smith and Robinson in 1958. In this report, surgical technique, advantages, and disadvantages of the posterior approach, known as the posterior keyhole laminotomy-foraminotomy, are reviewed and motion versus fusion surgery discussed. Between 1996 and 2004, the keyhole laminotomy-foraminotomy was performed on 84 patients suffering from lateral cervical soft disc herniation or osteophytes. All the procedures were performed under the surgical microscope. A high-speed drill was used for drilling the bone. In 49 patients (58%), soft disc herniation was removed, while in 35 patients (42%) there were osteophytes. Successful relief of radiculopathy symptoms was achieved in 80 patients (96%). In 4 patients the symptoms recurred. One patient (1.2%) developed kyphosis. The only complication observed intraoperatively was a partial root injury in one patient (1.2%). Mean hospitalization time was 48 hours. The posterior approach is particularly appropriate in patients whose root compression is located posterolaterally. Advantages of this surgery are minimal lamina resection, good visualization of the nerve root, postoperative early mobilization and minimal hospitalization. Microsurgery enables us to both preserve the motion of operated segment and avoid cervical instability.

Vascular compression of the trigeminal nerve is generally accepted as the primary source causing TN. To date, skull base bone deformity associated with ITN has been reported in only a number of case reports. The aim of the present study was to investigate one such skull base deformity, platybasia, in ITN patients in comparison with a randomized control population.Basal angle values reflecting the development of platybasia were measured in 25 patients with ITN and compared with the measurements in 25 control subjects.Basal angle measured to investigate the existence of platybasia was found significantly wider in the ITN group (t = 3.90; P.001), although platybasia was present in only 10 patients. Moreover, the average angle was also greater in the study group than in the control group, and the difference was statistically significant. Platybasia was found in 10 patients, whereas it was detected in only 2 control individuals; difference in platybasia incidence between the 2 groups was also statistically significant (chi(2) = 7.01; P.01).Our data demonstrated that platybasia affecting the bony walls of the posterior fossa may play an important role in the pathogenesis if vascular abnormalities causing TN.

Objective : Glioblastoma multiforme (GBM) is an incurable and the most common type of lethal brain tumors. A transmembrane glycoprotein CD133 has been used as a marker in cancer stem cell analysis...

Background Atypical facial pain (AFP) is a throbbing pain situated deep in the eye and malar region, often radiating to the ear, neck, and shoulders. The pain generally is not within any dermatomal or anatomical boundaries. Atypical facial pain is distinct from trigeminal neuralgia and its variants. Therefore, the treatment of AFP should be specified. There is also no consensus in the treatment of AFP. Two different treatment procedures on the trigeminal tract and nucleus in a series of cases with AFP are presented. Methods Between 1989 and 2005, 17 patients with AFP, in whom previous therapies had failed, underwent computed tomography (CT)-guided percutaneous trigeminal tractotomy-nucleotomy (TR-NC). One patient with unfavorable response to TR-NC underwent trigeminal dorsal root entry zone (DREZ) operation. Results In the series with AFP, pain relief was achieved in all of the 17 cases. TR-NC provided maximum to inadequate degrees of pain relief in 16 of 17 patients. Dorsal root entry zone operation provided partial relief in 1 case. Neither mortality nor serious permanent complication was observed in the series. Conclusion Neurosurgical procedures such as TR-NC or trigeminal DREZ operation may be effective in the treatment of intractable AFP. The primary choice of operation should be TR-NC because this procedure is minimally invasive. Trigeminal DREZ operation, which affects a larger spread area, may follow if TR-NC fails. The indications and procedure of choice should be individually tailored, depending on the type of pain, underlying pathology, and experience of the surgeon.

Background The precentral gyrus (PG) is the primary motor area and is one of the most eloquent brain regions of neurosurgical interest. Although the arterial supply to the PG is generally known, contributions from different arterial branches such as the anterior cerebral artery (ACA), posterior cerebral artery (PCA), and middle cerebral artery (MCA) have not been comprehensively studied. The aim of the present study was to provide detailed information about the arteries of the PG. Methods Twenty adult human brains (40 hemispheres) were obtained, and ACA, MCA, and PCA were separately cannulated and injected with latex. The PG was identified. Results The ACA supplied the medial one third and the MCA supplied the lateral two thirds of the PG. The PCA did not reach the PG in any of the hemispheres. In 16 hemispheres (40%), the callosomarginal artery and, in 13 hemispheres (32.5%), the pericallosal artery were dominant for the medial one third of the PG. In 11 hemispheres (27.5%), equal dominance was observed. MCA branches at the lateral tip of the PG were classified into precentral, central, and postcentral groups. In 29 hemispheres (72.5%), the central group, and in 4 hemispheres (10%), the precentral group were dominant for the lateral two thirds of the PG. In 7 hemispheres (17.5%), the precentral and central groups were equally dominant. No dominance was identified for the postcentral group. Conclusion In each hemisphere, the PG was supplied by different vascularization patterns of ACA and MCA. The present study is the first to describe and discuss these details. Therefore, awareness of this pattern will provide a great contribution to surgical interventions.

A 45-year old female was admitted complaining of double vision. A CT scan revealed a mass originating from the petrous part of the temporal bone with infiltration of the cavernous sinus. The patient was operated and a subtotal excision of the tumor was achieved. Pathological examination revealed benign osteoblastoma. During an 18 year follow up period, no progression of tumor has been detected.

Several medical and surgical procedures have been presented for treatment of dystonia. Thalamotomy, pallidotomy, and campotomy are some of the surgical choices. This study presents a patient with dystonia who underwent a cervical dorsal root entry zone (DREZ) operation after thalamotomy and campotomy. A 23-year-old man who was resistant to medical treatment presented with left hemidystonia. Thalamotomy and campotomy were performed. The patient remarkably benefited from the procedure but dystonic complaints in his left arm continued. A cervical DREZ operation was performed 5 years after the first operation and the dystonic complaints decreased after the surgery. This article presents a new aspect for the treatment of dystonia. Based on the outcomes of the treatment, DREZ operation may be suggested as an alternative surgical treatment for patients with segmental dystonia located in the extremities.

The fossa navicularis is a relatively rare anatomic variation of the skull base. Awareness of its existence will avoid misinterpretations of radiological images and unnecessary investigations. This study describes the appearance of the fossa navicularis, and investigates its incidence and whether it is related to pathology at the basiocciput. We studied 492 dry human skulls and 525 computer tomography (CT) images of patients. Dry skulls showing a fossa navicularis were investigated by CT scan, whereas patients identified as having a fossa navicularis were further examined with magnetic resonance imaging (MRI). To document the position of the fossa more precisely, measurements were made between the fossa navicularis and certain anatomic landmarks such as the foramen ovale, the pharyngeal tubercle, the posterior border of the vomer, the foramen lacerum, the carotid canal, and the occipital condyle. Upon examination, 26 of 492 skulls (5.3%) were found to have a fossa navicularis. Twelve were

Damage to the olfactory bulb and tract is a frequently described complication of brain surgery in the frontal region, and it seems to be influenced by the surgical approaches. Eighty cerebral hemispheres and 5 formalin-fixed cadavers filled with colored latex were used. Parameters were directly measured, and after olfactory bulb and tract were mobilized with careful dissections, retraction of the frontal lobe was noted. The anterior border of the olfactory bulb is 22.21 (SD, 5.45) mm posterior to the frontomarginal sulcus, and arachnoidal dissection should be performed parallel to olfactory structures using sharp instruments to allow early visualization. Overall mobilization of the olfactory bulb and tract as 29.3 (SD, 6.4) mm in length is possible without disrupting the structures and enables a greater degree of the frontal-lobe elevation window up to 13.1 (SD, 3.2) mm. Using the morphometric data and anatomic knowledge may prevent unwanted anosmia complication during surgical approaches.

Objective: In this study we aimed to determine a landmark that can be measured through the skin with nasal mid-point (bregma) to coronal suture, and additionally an average value was calculated. We report, to our knowledge, the distance between the nasion-coronal sutures is reported for the first time in Turkish population. Methods: The study included 30 craniums and 30 frontal bones. Each skull from midline nasal suture to coronal suture curved up at the distance was measured with tape measure. Results: Mean values were determined. Nasal suture between coronal suture distance average 12,2 cm (min10,3 cm, up to 13,5 cm) were detected. Conclusion: Nasal suture is an easily palpable area through the skin. A small incision is carried down through skin to bone at the spot 12 cm back from the nasion 3 cm lateral to the midline for ventricular drainage operation. This data provide practical information for neurosurgeon and is available everywhere. J Clin Exp Invest 2014; 5 (3): 368-370

Complex Regional Pain Syndrome Type I (CRPS-I) is a debated health problem concerning its pathophysiology and treatment strategies. A 12-year-old boy and a 35-year-old woman were diagnosed with CRPS-I at different times. They had previously undergone various types of interventions with no success. After one year of follow-up and observation, DREZ lesioning operation was performed. Afterwards, both cases had transient lower extremity ataxia. The first case was followed for 60 months with no recurrence and total cure. The second case was pain-free until the 6th month, when she required psychological support; she was followed for 33 months with partial satisfactory outcome. Although not a first-line option, DREZ lesioning procedure can be chosen and may be a curative option in selected cases of CRPS-I who are unresponsive to conventional therapies.

The treatment of anaplastic astrocytoma (AA) is controversial. New chemotherapeutic approaches are needed for AA treatment. Temozolomide (TMZ) is one of the chemotherapeutic drugs for the treatment of AA. The cytotoxic effects of TMZ can be removed by the MGMT (O(6)-methylguanine-DNA methyltransferase) enzyme. Then, chemotherapeutic resistance to TMZ occurs. MGMT inhibition by MGMT inactivators (such as lomeguatrib) is an important anticancer therapeutic approach to circumvent TMZ resistance. We aim to investigate the effect of TMZ–lomeguatrib combination on MGMT expression and TMZ sensitivity of SW1783 and GOS-3 AA cell lines. The sensitivity of SW1783 and GOS-3 cell lines to TMZ and to the combination of TMZ and lomeguatrib was determined by a cytotoxicity assay. MGMT methylation was detected by MS-PCR. MGMT and p53 expression were investigated by real-time PCR after drug treatment, and the proportion of apoptotic cells was analyzed by flow cytometry. When the combination of TMZ–lomeguatrib (50 μM) was used in AA cell lines, IC50 values were reduced compared to only using TMZ. MGMT expression was decreased, p53 expression was increased, and the proportion of apoptotic cells was induced in both cell lines. The lomeguatrib–TMZ combination did not have any effect on the cell cycle and caused apoptosis by increasing p53 expression and decreasing MGMT expression. Our study is a pilot study investigating a new therapeutic approach for AA treatment, but further research is needed.

It has been increasingly reported that traumatic and ischemic insults to the spinal cord may produce tissue damage through both direct and indirect mechanisms. In spite of many theories about post-traumatic spinal cord injury, there is still no satisfactory account of the exact mechanism. Vasospasm may be related to the trauma and release of vasoconstrictor or vasoactive amines. This study aims at studying the possible protective mechanisms of iloprost, a stable analogue of prostacyclin, after spinal cord injury on the rabbit. Forty-two adult male rabbits (New Zealand albino) were inflicted injuries by epidural application of an aneurysm clip to the spinal cord. Twenty-one rabbits received an i.v. infusion of 25 microg kg(-1) x h(-1) iloprost. The remaining twenty-one rabbits received an i.v. infusion of saline as the control group. Intravenous treatment started immediately after the infliction of the spinal cord injury and lasted for 1 h. Iloprost treatment had no side effects on the general physiological parameters in the rabbits. Control and iloprost treatment groups were divided into three sub-groups. The first group of animals was deeply anesthetized and spinal cords were removed 15 min after treatment. Second and third group animals were sacrificed in the 3rd and 24th hours respectively. All spinal cords were removed for light and electron microscopic examination. The width of anteriolar smooth muscle cells and the ultrastructural analysis of sulcal arterioles and venules in the ventral median fissure of spinal cords treated by iloprost revealed less thickening in all groups especially on the 24th hour group (p < 0.01), but less thickening was observed on the 3rd hour group. Iloprost-treated groups had limited edema and moderate protection of myelin and axons. These results suggest that iloprost treatment after spinal cord injury has a highly protective effect, and the possible protective effect of iloprost is resolution of vasospasm due to spinal cord injury.

This anatomic study investigated the thoracic pedicle and its relations. The objective was to emphasize the importance of the thoracic pedicle for transpedicular screw fixation to avoid complications during surgery. Twenty cadavers were used to observe the cervical pedicle and its relations. The isthmus of the pedicle was exposed after removal of whole-posterior bony elements, including spinous processes, laminas, lateral masses, and the inferior and superior facets. The pedicle width and height, interpedicular distance, pedicle-inferior nerve root distance, pedicle-superior nerve root distance, pedicle-dural sac distance, root exit angle, and nerve root diameter were measured. There was no distance between the pedicle and dural sac in eight specimens. There was, however, a short distance in 12 remaining specimens in the upper and lower thoracic regions. The distances between the thoracic pedicle and the adjacent nerve roots ranged from 1.5 to 6.7 mm and 0.8 to 6.0 mm superiorly and inferiorly at all levels. The mean pedicle height and width at T1-T12 ranged from 2.9 to 11.4 mm and 6.2 to 21.3 mm, respectively. The interpedicular distance decreased gradually from T1 to T5 and then increased gradually to T12. The mean root exit angle decreased consistently from 104 degrees to 60 degrees. The nerve root diameter was between 2.3 and 2.5 mm at the T1-T5 level and then increased consistently from 2.5 to 3.7 mm. All significant differences were noted at p < 0.05 and p < 0.01. The following suggestions are made based on these results. 1) More care should be taken when a transpedicular screw is placed in the horizontal plane. 2) Improper medial placement of the pedicle screw, especially in the middle thoracic spine, should be avoided, and the anatomic variations between individuals should be considered. 3) Because of substantial variations in the size of thoracic pedicles, utmost attention should be given to the findings of a computed tomographic evaluation before thoracic transpedicular fixation is begun.

The interpeduncular cistern is a difficult region to approach through conventional methods due to its deep location and important adjacent neurovascular structures. Therefore, it is usually difficult to expose the region sufficiently. Technical problems associated with various surgical approaches have led to emergence of combined approaches and their modifications (i.e., the removal of the zygomatic arch). In addition, a frontotemporal craniotomy is reported to provide a wide exposure of the anterior temporal base, thus allowing oblique access to the interpeduncular cistern with minimal brain retraction. This study describes clinicians' experience and the surgical results of 24 patients who underwent a zygomatic anterior subtemporal approach.

OBJECTIVE Although several clinical applications of transpedicular screw fixation in the cervical spine have been documented recently, few anatomic studies concerning the cervical pedicle are available. This study was designed to evaluate the anatomy and adjacent neural relationships of the middle and lower cervical pedicle (C3–C7). The main objective is to provide accurate information for transpedicular screw fixation in the cervical region and to minimize complications by providing a three-dimensional orientation. METHODS Twenty cadavers were used to observe the cervical pedicle and its relationships. After removal of the posterior bony elements, including spinous processes, laminae, lateral masses, and inferior and superior facets, the isthmus of the pedicle was exposed. Pedicle width, pedicle height, interpedicular distance, pedicle-inferior nerve root distance, pedicle-superior nerve root distance, pedicle-dural sac distance, medial pedicle-dural sac distance, mean angle of the pedicle, root exit angle, and nerve root diameter were measured. RESULTS The results indicate that there was no distance between the pedicle and the superior nerve root and between the pedicle and the dural sac in 16 specimens, whereas there was a slight distance in the lower cervical region in the 4 other specimens. The mean distance between the pedicle and the inferior nerve root for all specimens ranged from 1.0 to 2.5 mm. The mean distance between the medial pedicle and the dural sac increased consistently from 2.4 to 3.1 mm. At C3–C7, the mean pedicle height ranged from 5.2 to 8.5 mm, and the mean pedicle width ranged from 3.7 to 6.5 mm. Interpedicular distance ranged from 21.2 to 23.2 mm. The mean root exit angle ranged from 69 to 104 degrees, with the largest angle at C3 and the smallest at C6. The mean angle of the pedicle ranged from 38 to 48 degrees. The nerve root diameter increased consistently from 2.7 mm at C3 to 3.8 mm at C6 and then decreased to 3.7 mm at the C7 level. Differences in measurements were considered statistically significant at levels ranging from P < 0.05 to P < 0.01. CONCLUSION This study indicates that improper placement of the pedicle screw medially and superiorly in the middle and lower cervical spine should be avoided and that the anatomic variations between individuals should be established by measurement.

Two patients presented with congenital basilar invagination manifesting as progressive myelopathy. Both patients underwent surgery using a neuronavigation-assisted transoral-transpharyngeal approach. The Brain-LAB Vector Vision navigation system was used for image guidance. The registration accuracies were 0.9 and 1.3 mm. After decompression, posterior stabilization was performed. Both patients had an uneventful postoperative course. The transoral-transpharyngeal approach with the neuronavigation system provides safe exposure and decompression for basilar invagination.

Temozolomide (TMZ) is commonly used in the treatment of glioblastoma (GBM). The MGMT repair enzyme (O (6)-methylguanine-DNA methyltransferase) is an important factor causing chemotherapeutic resistance. MGMT prevents the formation of toxic effects of alkyl adducts by removing them from the DNA. Therefore, MGMT inhibition is an interesting therapeutic approach to circumvent TMZ resistance. The aim of the study was to investigate the effect of the combination of lomeguatrib (an MGMT inactivator) with TMZ, on MGMT expression and methylation. Primary cell cultures were obtained from GBM tumor tissues. The sensitivity of primary GBM cell cultures and GBM cell lines to TMZ, and to the combination of TMZ and lomeguatrib, was determined by a cytotoxicity assay (MTT). MGMT and p53 expression, and MGMT methylation were investigated after drug application. In addition, the proportion of apoptotic cells and DNA fragmentation was analyzed. The combination of TMZ and lomeguatrib in primary GBM cell cultures and glioma cell lines decreased MGMT expression, increased p53 expression, and did not change MGMT methylation. Moreover, apoptosis was induced and DNA fragmentation was increased in cells. In addition, we also showed that lomeguatrib-TMZ combination did not have any effect on the cell cycle. Finally, we determined that the sensitivity of each primary GBM cells and glioma cell lines to the lomeguatrib-TMZ combination was different and significantly associated with the structure of MGMT methylation. Our study suggests that lomeguatrib can be used with TMZ for GBM treatment, although further clinical studies will be needed so as to determine the feasibility of this therapeutic approach.