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Meningiomas are the most common primary intracranial tumors. They have three pathologic grades. Surgical resection aiming Simpson I resection is the standard treatment for meningiomas. Radiotherapy and Gamma Knife radiosurgery are the main adjuvant and salvage treatments. Chemotherapy has limited use. Grade II, and III meningiomas have a higher recurrence rate, and adjuvant radiotherapy is usually the standard treatment for grade III meningiomas but there is not a consensus regarding grade II meningiomas. In this paper, we analyzed our meningioma series of 1401 patients and presented the treatment and follow-up results of 170 grade II meningioma cases. The median follow-up of grade II meningiomas was 61 (range = 1–231) months. The mean age of patients was 52.5 ± 15.0 years, 102 of them were female and 68 were male (female/male ratio = 1.5). The median progression-free survival (PFS) of them was 109 months, and the cumulative overall survival (OS) rate was 85% at 10 years. Meningiomas with gross total resection, non-skull base meningiomas, and primary grade II meningiomas had longer PFS with statistical significance, while non-skull base meningiomas, younger group of patients, and primary grade II meningiomas had longer OS with a statistical significance.

Background: The aim of this study was to understand how facet joint orientation (FJO) and facet joint tropism (FJT) affected severe intervertebral disc degeneration (IVDD) process at lower lumbar l...

Background Low back pain (LBP) may originate from different sources such as intervertebral disc degeneration (IVDD), end-plate and paraspinal muscle changes. Our aim is to explore the relevance of ...

There are case reports and small case series in the literature reporting gas-filled pseudocysts (GFP). However, a systematic review presenting overall view of the disease and its management is still lacking. In the present study, we aimed to make a systematic review of GFP cases, and present an exemplary case of ours. Our second aim was to discuss current theories for pathogenesis of GFP. A systematic review of GFP was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. Two large-scaled data search engines were used. A total of 53 articles were retrieved from the literature and presented with an exemplary case of ours. Mean age of the historical cohort was 59.47 years. There were 66 male (54.1%) and 56 female (45.9%) patients. The most prevalent clinical presentation was radicular sign/symptom in lower limbs with (29.1%) or without low back pain (LBP) (67%). Gas-filled pseudocyst has most commonly been diagnosed at the lower lumbar spine (L4-L5, 45.3%; L5-S1, 37.7%). Surgery was the treatment of choice in most of the patients (80%). In the whole cohort, 79.1% of the patients had complete recovery. Gas-filled pseudocysts are rarely observed in daily practice. They present mostly in men at the age of 60s. Precise differential diagnosis determination using appropriate imaging would help clinicians treat the patients properly. Gas-filled pseudocysts should be treated similarly to other spinal pathologies causing nerve root compression.

Background It is essential to localize the central sulcus in patients with lesions within or nearby the sensorial and/or motor cortex. The coronal suture is a valuable bony landmark in neurosurgical practice; it could be used to localize the central sulcus. There are scarce amount of literature about normal values of the distance between the central sulcus and the coronal suture. In the present study, the authors aimed to learn normative values of the distance between the central sulcus and the coronal suture in a patient sample representing Turkish population. The authors also aimed to look for any difference in values according to sex and age. Methods The authors retrospectively reviewed a prospectively collected database. Patients were evaluated on cranial computed tomography (CT) reformatted in 3 planes (axial, coronal, and sagittal). Intracranial and extracranial pathologies were scanned. If there was no pathology, the reviewed CT scan was added up to the database. The coronal suture and the central sulcus were identified at the midline location on axial and sagittal view CT images. Vertical distance between coronal suture and central sulcus was measured. Results Mean distance of the central sulcus to the coronal suture was 47.5 ± 7.6 mm (range = 26.2-67.3 mm). Conclusions Identifying the central sulcus relative to the coronal suture is essential to preserve the primary motor and/or sensory cortices in neurosurgical procedures. The distance of the central sulcus to the coronal suture is approximately 4.7 cm in adult patients from Turkey, which did not differ according to age or sex.

Background The aim of this study is to share our experiences on a series of 21 patients with intraventricular meningiomas (IVMs). Histopathologic examinations are reviewed in detail and the cell of origin of IVMs is discussed. Methods We retrospectively reviewed 1372 patients with intracranial meningioma who were surgically treated between September 1986 and July 2018. From this cohort, 21 patients with IVM were identified. The clinical, radiologic, surgical, and follow-up records were analyzed. The archival pathologic specimens were reviewed. Tissue microarray blocks were performed from the formalin-fixed, paraffin-embedded samples of all IVM cases, 2 choroid plexus tissue adjacent to the tumors, and 10 extraventricular fibrous meningioma cases selected as control randomly. Immunohistochemical staining with the antibodies S-100, SOX10, NGFR, and OTX2 was performed according to the protocols indicated by the manufacturers. Results Surgical complications included hemiparesis in 1 patient (5%), postoperative seizure in 1 patient (5%), sensorial aphasia in 1 patient (5%), and preexisting headache in 1 patient (5%). Seventeen (81%) of the IVMs had grade I pathology and 4 (19%) had grade II pathology. The immunoprofile of IVMs is identical to the immunoprofile of normal choroid plexus epithelium. Conclusions Transcortical approaches using intraoperative ultrasonography and intraoperative monitoring with avoidance of eloquent cortical areas can achieve good outcomes. Resection of the choroidal attachments should be attempted. Our results indicate that IVMs do not show arachnoid cap cell phenotype and the findings support that IVMs originate from the choroid plexus epithelium or the progenitors of the choroid plexus epithelium.

Background Meningiomas are heterogeneous, with differences in anatomical, histopathological, and clinical characteristics. Such spatial variability in meningioma biology is thought to result from differences in the expression of critical developmental regulators. We hypothesized that the variability in meningioma biology would follow gradients such as in embryology and tested a cohort of 366 meningiomas for histopathological and immunohistochemical gradients. Methods The medical records from 366 patients treated for meningiomas from 2003 to 2016 were retrospectively analyzed for age, gender, anatomical localization, recurrence-free survival, overall survival, histopathological diagnosis, and immunohistochemistry findings for 6 markers: epithelial membrane antigen (EMA), progesterone receptor (PR), CD34, S100, p53, and Ki-67 labeling index. Results EMA, PR, S100, p53, and CD34 were expressed in 94%, 73%, 49%, 26%, and 23% of the tumors, respectively. p53 expression correlated positively with Ki-67 and World Health Organization (WHO) grade (rτ = 0.31 and rτ = 0.4, respectively). PR positivity correlated inversely with S100, p53, Ki-67, and WHO grade (rτ = −0.19, rτ = −0.14, rτ = −0.15, and rτ = −0.16, respectively). All secretory meningiomas were positive for EMA and PR and negative for S100, and this pattern exhibited a rostrocaudal gradient. The overall proportion of EMA+PR+S100− cases was significantly lower in the cranial vault (30.3%) than in the skull base (45.89%; P = 0.021). The proportion of WHO grade II-III tumors was greater in cranial vault than in skull base meningiomas. Conclusions Unsupervised methods detected an association between the anatomical location and tumor biology in meningiomas. Unlike the categorical associations that former studies had indicated, the present study revealed a rostrocaudal gradient in both the cranial vault and the skull base, correlating with human developmental biology.

Meningiomas are the most common primary intracranial tumors. They have three pathologic grades. Surgical resection aiming Simpson I resection is the standard treatment for meningiomas. Radiotherapy and Gamma Knife radiosurgery are the main adjuvant and salvage treatments. Chemotherapy has limited use. Grade II, and III meningiomas have a higher recurrence rate, and adjuvant radiotherapy is usually the standard treatment for grade III meningiomas. In this paper, we analyzed our meningioma series of 1401 patients and presented the treatment and follow-up results of 26 grade III meningioma cases. Median follow-up of grade III meningiomas was 40.5 (range, 1–154) months. The mean age of patients was 51.7 ± 15.7 years; 12 of them were female and 14 were male (female/male ratio = 0.9). The median progression-free survival (PFS) of them was 22 months, and overall survival (OS) was 62 months. Meningiomas with gross total resection (GTR), non-skull base meningiomas, and primary grade III meningiomas had longer PFS, while meningiomas with GTR, non-skull base meningiomas, and primary meningiomas had longer OS with a statistical significance.

Objective Robotic surgical systems are used worldwide in various fields. In this study, we present the advantages and disadvantages of the most common robotic surgical system, the da Vinci Xi system, in the supracerebellar transtentorial approach to the mesial temporal region and discuss options for its integration into neurosurgery. Methods Our study was conducted at the Advanced Simulation and Applied Endoscopic Surgery Training and Research Center and Anatomy Laboratory. Four formalin-fixed human cadaveric head specimens with red silicone dye injected into their arterial structures and blue silicone dye injected into their venous structures were used in the study. Dissections were performed in microscopic and robotic stages. All phases were photographed using a three-dimensional photographic technique. Results The mesial temporal lobe could be accessed via the supracerebellar transtentorial route with the use of the robotic system. We show that the robotic system can be used in difficult approaches and narrow regions with a wider exposure and superior image quality than with the microscopic approach, improving the ergonomics for the surgeon. The shortcomings of robotic systems are examined and innovative solutions are offered. Conclusions This study shows the advantages and disadvantages of the robotic surgical approach to the mesial temporal region via the supracerebellar transtentorial route. Robotic surgical systems can play a major role in neurosurgical practices with the tools designed and the innovative solutions determined in this study. Nevertheless, further research and development of these systems and related instruments are necessary to ensure their wider implementation in neurosurgery.

Aim Role of extrachromosomal DNA in cancer and the consequences of mutations are unclear. However, mitochondrial DNA (mtDNA) variants in the D-loop region have been suggested to be associated with different clinical parameters and proposed as controversial prognostic markers. Impaired function of mitochondria cannot be tolerated by highly energy requiring brain cells. Therefore, we have focused on the regulatory region D-loop which is thought to cause no growth disadvantage for cells. Our aim is to investigate the effect of mtDNA variants mainly in D-loop on glioma biology. Material and methods Sanger sequencing of D-loop (15971 - 16451 bp) for 52 glioma patients was performed and the variations were statistically analyzed for gender, WHO classification, morphological grade, IDH / TERT status. Results Total of 122 variations (51 unique) was identified in 52 patients. C16223T, T16189C, T16311C and T16126C variants were frequently detected. Total variation number was statistically non-significant among the analyzed categories. When individual variants were considered, T16311C and T16224C were statistically significant for WHO classification (p=0.033), morphological grade (p=0.036) and gender (p=0.039), respectively. Conclusion Total variation number in D-loop was not found to be related with clinical variables. Our data suggests that individual variants may play critical role in glioma biology.

Background Improved life expectancy and advanced diagnostic tools including computed tomography and magnetic resonance imaging have increased the awareness and diagnosis of intracranial meningiomas in the elderly population. The risk/benefit ratio of surgery in elderly patients with intracranial meningioma has not been clearly defined because of the lack of objective measurement tools. We aimed to understand the risk factors associated with postsurgical outcomes and how these risk factors affected postsurgical outcomes in elderly patients with intracranial meningioma. Methods We retrospectively evaluated 1372 patients, who were operated on for intracranial meningioma, using our prospectively collected database. The same senior author operated on all patients at 2 different tertiary clinics. Patients' clinical charts, presurgical postcontrast T1-weighted magnetic resonance images, operative reports, and pathology reports were reviewed. The relevant literature was also reviewed. Results Higher age, higher American Society of Anesthesiologists class, presence of comorbidities, tumor location, larger initial tumor size, and presence of peritumoral edema were all associated with postsurgical complications in elderly patients with intracranial meningioma. Age ≥50 years was the strongest predictor of postsurgical systemic complications, whereas higher American Society of Anesthesiologists class was the strongest predictor of postsurgical neurologic complications. A literature review showed higher morbidity and mortality of elderly patients with intracranial meningioma. Initial tumor size and postsurgical MIB-1 labeling index were higher in the elderly patients, both of which were predictors of tumor growth. Conclusions Even though elderly patients operated on for intracranial meningioma had higher morbidity and mortality compared with younger patients, surgery is still much more beneficial than wait-and-see strategy in elderly patients.

Background Serotonin syndrome (SS) is a common disease entity and could result in death if missed. The incidence of SS is underestimated due to misdiagnosis of many cases, especially the ones with less severe presentation. Many medications have been depicted as the source of SS. We present a case of SS in a patient who received intravenous tramadol and oral gabapentin as pain management after spine surgery. Case Description A 66-year-old man was admitted to our outpatient clinic with walking difficulties for 2 months. He was neurologically intact. However, he had neurologic claudication. He was on insulin, telmisartan-hydrochlorothiazide, amlodipine, and albuterol before the surgery, and these drugs were continued after the surgery. After he was diagnosed with lumbar spinal stenosis, he underwent total laminectomies of L3 and L4 and bilateral transpedicular screw placement from L1 to L5. He received tramadol 100 mg once daily intravenously and gabapentin 300 mg thrice daily orally after the spine surgery. He became confused, aggressive, and agitated during his stay in the hospital postoperatively. He became frustrated with even his children and wife. He started receiving haloperidol and quetiapine after psychiatry consultation. Because he worsened immediately after quetiapine and haloperidol, his medications were ceased in a step-by-step manner (first, tramadol and second, gabapentin). He became stable in a few hours, and his symptoms have improved since then. Conclusions Physicians treating spine patients should be alert about SS in patients using both tramadol and gabapentin.

Objective We aimed to develop a new scoring system for spinal degeneration including Modic changes, fatty infiltration (fi) in the paraspinal muscles, and intervertebral disc degeneration (IVDD), briefly Mo-fi-disc, using current radiological classification systems. We also aimed to understand whether Mo-fi-disc could predict patients with more intense low back pain (LBP). Patients and Methods We conducted a cross-sectional analysis of a retrospective database between March 2018 and July 2020. We evaluated patients in terms of Modic changes, fatty infiltration in the paraspinal muscles, and IVDD at all lumbar levels on lumbar spine MRI. We grouped patients based on their LBP intensity. Visual analog scale (VAS) scores were used for LBP intensity. Results We evaluated 134 patients (female: 66, male: 68; mean age: 35.44 ± 6.5 years). Patients with higher VAS scores had significantly higher ‘Mo-disc’ scores and higher ‘fi’ scores compared to those with lower VAS scores (3.54 ± 2.7 vs. 2.55 ± 2.8, p = 0.0075; 6.85 ± 3.2 vs. 5.25 ± 2.9, p = 0.0092). Patients with higher VAS scores had significantly higher ‘Mo-fi-disc’ scores compared to those with lower VAS scores (10.4 ± 4.2 vs. 7.94 ± 3.8, p = 0.0003). The most significant predictor for patients with higher VAS scores was ‘Mo-fi-disc’ scoring system with an OR of 1.193 (95 % CI: 1.055–1.349, p = 0.005). Conclusion Patients with more intense LBP had higher ‘Mo-fi-disc’ scores. This scoring system suggests an easy and objective classification to evaluate the spinal degeneration.

Objective The aim of our study was to determine any association between preservation of long latency response evoked by electrophysiological mapping of the caudal part of the pars opercularis (inferior frontal gyrus Broca area) and postoperative speech function after tumour removal in patients under general anesthesia. Patients and Methods Twelve native Turkish-speaking patients with tumors in the dominant left frontal lobe, near the Broca area, were included in a single-center prospective cohort study. Hooked-wire electrodes were placed in both cricothyroid muscles (CTHY) before anesthesia and a monopolar electrode was used to stimulate the caudal portion of the pars opercularis of the inferior frontal gyrus before and after tumor removal. A long latency response (LLR) elicited at the contralateral (CTHY) muscle was interpreted as a positive stimulation of the Broca area. Patients received one pre-op and two post-op cognitive assessments. The Montreal Cognitive Assessment (MoCA) was used to assess global cognition and a “Cookie Theft” picture description task from the Boston Diagnostic Aphasia Examination test was used in assessing the language functions. Results Electrical stimulation elicited a long latency response (LLR) in 9 (75 %) out of the 12 patients. The mean latency of the LLR was 50 ± 11 ms. Four (33.3 %) of the 12 patients showed temporary impairment in fluent speech postoperatively and all had full recovery during the 3-month follow-up period. Conclusions The use of electrophysiological mapping methods by using EMG recording from laryngeal muscles may help to identify the opercular part of the Broca area under general anesthesia in order to preserve fluent speech functions.

Aim: We report the preoperative and postoperative findings and also neurological follow-up results from 10 spinal cavernoma patients treated in our clinic. Several representative cases are presented in terms of clinical features, imaging results, and surgical outcomes. Material and methods: The data were retrospectively collected from patients' files in the hospital records and sorted with regards to clinical presentation, radiologic features, and operative findings. Patients received spinal MRI scans for the diagnosis of spinal cavernomas (SC) and postsurgical evaluation. Clinical presentation was evaluated via Ogilvy classification and symptoms were checked preoperatively and postoperatively at third month and first year using McCormick scale. Primary treatment was microsurgical operation aiming a gross total lesion resection. Results: 10 spinal cavernoma patients between the ages 30 and 63 were treated. Six (60\%) of the patients were diagnosed with cervical and four (40\%) others were diagnosed with thoracic SC. Among the patient group, mean preoperative Ogilvy classification score was 2.3 +/- 0.7.8 and McCormick score was 1.9 +/- 0.7. There was no residual mass or relapse after surgery. One patient developed surgery related left hemiparesis, which was normalized at 1 year follow-up. Conclusion: Patients must be diagnosed with MRI since it is nowadays a gold standard. Preoperative and postoperative scores are important in evaluating the patients' condition and improvement. The results from our patient series also reinforce the notion that immediate surgery should be the preferred treatment method for cavernomas. Intraoperative neurophysiologic monitarization should assist the surgery in order to prevent complications. In conclusion, microsurgery is a gold standard method that we recommend for cases of cavernomas, which will not recur if gross total resection is achieved.

Schwannomas are the most frequent primary tumors of the spine with an incidence of 0.3-0.5/100,000 person per year. Current treatment for non-syndromic spinal schwannomas is total resection of the tumor with preservation of neurovascular structures. This study aims to report neurologic and radiologic outcome following treatment of non-syndromic spinal schwannomas along with a novel tumor classification used in our clinic. A retrospective case series was carried out with a patient sample of 82 male and female patients with non-syndromic spinal schwannomas. All patient data were retrospectively collected from the hospital records. As a routine procedure, after admittance and primary evaluation, patients' tumors were classified using CT or MRI in accordance with our proposed classification method, which employs a dual designation method with tree groups (A, B, and C) for tumor volume and four types (I, II, III, and IV) for tumor localization. Subsequent resection surgery was followed by neurological assessments and follow up at 45th, 180th, and 360th postoperative day. Along with Karnofsky performance status scale, pain, sensory deficits, and motor weakness were scored to assess neurologic recovery. Our finding indicates that patients with different tumor types significantly differ in their neurological scores and show consistent but differential neurological recovery at early and late time points postsurgery. Complications during and postsurgery were minimal, occurring only in two patients. Our findings further reinforce the established safety of total resection operations and indicate that our proposed classification is a simple, effective tool that has proven helpful in preoperative planning and avoiding unnecessary surgical approaches.

Objective Clinical characteristics and management of hemangioblastomas of the spinal cord associated with von Hippel-Lindau syndrome have been extensively covered in the literature. This report aims to analyze the characteristics and surgical treatment results of sporadic spinal hemangioblastomas (SSHB). Methods This is a retrospective analysis of 14 patients with SSHB (8 men and 6 women) operated on during a span of 23 years. The median age was 41.5 years (24–70 years). von Hippel Lindau syndrome was excluded by imaging in all patients. The median follow-up was 4 years (1–23 years). We also conducted a meta-analysis of all 271 SSHB cases reported in the English-speaking language literature from 1967 to 2011. Results Nine (64.3%) lesions were cervical, 3 (28.5%) were thoracic, and 1 (7.1%) was lumbar. Eight (57.1%) tumors were dorsal intramedullary, 4 (28.6%) were exophytic, 1 (7.1%) was intradural extramedullary, and 1 (7.1%) was completely extradural. Diffuse segmental cord enlargement was present in 7 patients (50%) and a cyst/syrinx was present in 7 (50%). These 14 patients underwent 15 operations, and gross total resection was achieved in all operations. There was no mortality. Symptoms improved after 8 (53.3%) of 15 operations, remained the same after 5 (33.3%), and worsened after 2 (13.3%). The mean Karnofsky performance score improved from 79.3 (± 17.5) to 87.3 (± 12.2) after 6 months of follow-up. There was one recurrence 15 years after magnetic resonance imaging confirmed total resection. Conclusions The SSHBs occur most often in the upper spinal cord. Excellent surgical results and long-term outcome can be achieved using microsurgery alone with only rare recurrences.

Object The goal of surgery in high-grade gliomas is to maximize the resection of contrast-enhancing tumor without causing additional neurological deficits. Intraoperative MRI improves surgical results. However, when using contrast material intraoperatively, it may be difficult to differentiate between surgically induced enhancement and residual tumor. The purpose of this study was to assess the usefulness of intraoperative dynamic contrast-enhanced T1-weighted MRI to guide this differential diagnosis and test it against tissue histopathology. Methods Preoperative and intraoperative dynamic contrast-enhanced MRI was performed in 21 patients with histopathologically confirmed WHO Grade IV gliomas using intraoperative 3-T MRI. Standardized regions of interest (ROIs) were placed manually at 2 separate contrast-enhancing areas at the resection border for each patient. Time-intensity curves (TICs) were generated for each ROI. All ROIs were biopsied and the TIC types were compared with histopathological results. Pharmacokinetic modeling was performed in the last 10 patients to confirm nonparametric TIC analysis findings. Results Of the 42 manually selected ROIs in 21 patients, 25 (59.5%) contained solid tumor tissue and 17 (40.5%) retained the brain parenchymal architecture but contained infiltrating tumor cells. Time-intensity curves generated from residual contrast-enhancing tumor and their preoperative counterparts were comparable and showed a quick and persistently increasing slope (“climbing type”). All 17 TICs obtained from regions that did not contain solid tumor tissue were undulating and low in amplitude, compared with those obtained from residual tumors (“low-amplitude type”). Pharmacokinetic findings using the transfer constant, extravascular extracellular volume fraction, rate constant, and initial area under the curve parameters were significantly different for the tumor mass, nontumoral regions, and surgically induced contrast-enhancing areas. Conclusions Intraoperative dynamic contrast-enhanced MRI provides quick, reproducible, high-quality, and simply interpreted dynamic MR images in the intraoperative setting and can aid in differentiating surgically induced enhancement from residual tumor.

Rarely, spinal gunshot injuries result in migrating intraspinal bullets. Use of MRI is controversial and other radiographic imaging might mimic an extradural bullet, even though it is intradural and migratory. Here, we present a case of spinal missile injury resulting in an intraoperatively mobile intradural bullet. The challenges faced during diagnosis and surgical removal are described. We also show that intraoperative ultrasonography may be useful in clarifying whether the bullet is intradural. A 32-year-old male presented with weakness and paraesthesia in his right leg following an accidental gunshot injury to his spine. Facet joint destruction and an intraspinal bullet were detected. Immediate surgical removal and transpedicular instrumentation was performed. The surgical procedure was complicated by lack of an identifying dural perforation at the bullet entry point and a gliding bullet inside the spinal canal during surgery. Gliding of the bullet was caused by the pushing effect of the bone rongeur and further gliding was avoided by performing the next laminectomy with an electric drill. Where other modalities indicated for a possible extradural location, intraoperative USG clearly showed the intradural position of the bullet and provided clear images without major artifacts. Surgical treatment of a mobile intradural bullet is challenging and open to surprises. Location of the bullet may shift as result of surgical procedure itself. Laminectomy should be performed with a power drill. Where fluoroscopy was inadequate and MRI not available, intraoperative USG proved useful in ascertaining the intradural versus extradural position of the bullet and allowed for a tailored dural opening.

Aim Chordomas are rare, slow growing but locally aggressive malignancies of the axial skeleton. Skull base chordomas, due to their intricate anatomical localization, pose significant challenges to managing physicians. In classical and chondroid chordomas, the disease course cannot be reliably determined using only morphological criteria. Brachyury (T Gene) was shown to play a central role in chordoma pathogenesis and several studies also showed that this gene also carries potential as a prognostic biomarker. This study aims to correlate Brachyury expression with the clinical course in surgically treated skull base chordomas. Material and methods Chordoma tumor samples from 14 patients with skull base chordomas, diagnosed using histopathological and immunohistochemistry criteria (epithelial membrane antigen (EMA), S100, pan cytokeratin (panCK)) were retrospectively analyzed for Brachyury expression using immunohistochemistry. Brachyury expression was graded using a 4 point semi-quantitative scoring system. Focal (grade II) and diffuse staining (grade III) were considered as overexpression. Patient recurrence-free survival and total survival were compared between Brachyury overexpressing and non-overexpressing groups using Kaplan-Meier survival analysis. Results Among the stained tumor samples, 85.7% were positive for brachyury expression. In both groups, there was one sample that was negative. We did not observe any significant difference among the groups for staining, grade and percentage of brachyury positive cells. Conclusion Brachyury expression in tumor samples is not a sensitive indicator of prognosis in chordomas.

Jugular foramen schwannomas are very rare tumors. Advances in skull base surgery have led to more aggressive resection of these tumors, but surgery may associate with development of new neurological deficits. In this report, we analyze the long-term results for 17 patients with newly diagnosed or residual/recurrent jugular foramen schwannoma who underwent gamma-knife treatment. During a mean 64 months of follow-up, magnetic resonance imaging revealed reduced tumor size in 13 cases and no size change in four cases. The tumor growth control rate was 100% and only one patient had transient hoarseness. For patients who have small- to moderate-sized jugular foramen schwannomas, gamma-knife radiosurgery is associated with good tumor control and carries minimal risk of adverse radiation effects.

BACKGROUND: Experimental models to study cerebrovascular malformations are limited therefore we used the neonatal rodent retina as a model to study cerebral angiogenesis. OBJECTIVE: We performed a gene expression analysis to define temporal changes in the expression of 96 angiogenesis-related genes during retinal vascularization. METHODS: A total of 72 retinas from 36 newborn C57BL/6 mice were used. Sets of neonatal mouse retinas were surgically isolated by 2-day intervals starting from postnatal day 0 to day 20 and at the 32nd day (representing adult retinas). For each of these 12 time points in the postnatal developmental period of mouse retinas, separate sets of 6 retinas from 3 mice were pooled, and their RNA was hybridized to an angiogenesis-specific gene array. Temporal expression patterns of each of the 96 angiogenesis-related genes were analyzed. For confirmation, vascular endothelial growth factor protein expression was also studied by immunohistochemistry. RESULTS: Twenty-two of the 96 genes analyzed displayed a significantly different temporal expression profile, and the rest exhibited a static expression, as compared to the human glyceraldehyde-3-phosphate dehydrogenase gene. Among these genes, the temporal pattern of expression was variable, but peaks were seen mostly on days 8, 10, 12, and 16. This timing corresponds well to morphologic changes that occur in the retina during different stages of angiogenesis. CONCLUSION: The neonatal rodent retina, which has a cellular architecture similar to that of the brain, has active and quantifiable angiogenic activity during the neonatal period and can be used as a simple and convenient model to study cerebral angiogenesis.

Objective To analyze pituitary adenoma volume changes after gamma knife radiosurgery (GKRS) in patients with 3 years of follow-up and to investigate factors that might affect these changes. Methods Between January 1997 and March 2004, a total of 1930 patients were treated in the Gamma Knife Unit of the Marmara University Department of Neurosurgery in Istanbul, Turkey. Three hundred sixty of these patients had pituitary adenomas (PAs). This prospectively designed clinical study documents the radiological-volumetric analysis for the first 100 of these patients with PAs who had a minimum of 3 years of follow-up and met the study requirements. Each tumor was assessed with serial magnetic resonance imaging scans after radiosurgery; at each time point, adenoma volume was expressed as a percentage of the tumor's initial volume. Volume changes were investigated relative to margin dose, the cavernous sinus infiltration, and endocrinological type of adenoma. Results At the end of the first year after GKRS, the PA volumes had decreased to approximately 90% of the initial volume on average. The corresponding approximate averages for the ends of Years 2 and 3 were 80 and 70% of the initial volume, respectively. At 3 years after GKRS, the PAs in the group with a peripheral dose of less than 17 Gy were reduced to approximately 80% of the initial volume on average. In contrast, the tumors in the patients with marginal doses of 21 to 23 Gy were reduced to approximately 60% of the initial volume at this stage. The adenomas treated with the highest marginal doses (>27 Gy) showed the earliest volume decreases after GKRS (6-9 mo after the procedure). Cavernous sinus noninfiltrating adenomas showed greater volume decreases after GKRS; on average, these masses were reduced to approximately 50% of their initial volume at 3 years. In contrast, the PAs that had infiltrated the cavernous sinus had only dropped to approximately 80% of their initial volume at this stage. The growth hormone-secreting PAs showed the maximum volume decrease with GKRS. On average, these lesions were approximately 60% of their initial volume at the 3-year stage. The nonfunctioning tumors and the prolactin-secreting adenomas showed similar volume changes over time. On average, these tumors had dropped to approximately 75 and 70% of the initial volume, respectively, by 3 years after GKRS. Conclusion Gamma knife radiosurgery halts the growth of pituitary adenomas. Cavernous sinus extension and margin dose are the most important determinants of adenoma volume after this type of therapy.

Objective The aim of this study was to evaluate the microanatomy of the central myelin-peripheral myelin transitional zone (TZ) in trigeminal nerves from cadavers. Methods One hundred trigeminal nerves from 50 cadaver heads were examined. The cisternal portion of the nerve (from the pons to Meckel's cave) was measured. Horizontal sections were stained and photographed. The photomicrographs were used to measure the extent of central myelin on the medial and lateral aspects of the nerve and to classify TZ shapes. Results The cisternal portions of the specimens ranged from 8 to 15 mm long (mean, 12.3 mm; median, 11.9 mm). The data from the photomicrographs revealed that the extent of central myelin (distance from pons to TZ) on the medial aspect of the nerve (range, 0.1-2.5 mm; mean, 1.13 mm; median, 1 mm) was shorter than that on the lateral aspect (range, 0.17-6.75 mm; mean, 2.47 mm; median, 2.12 mm). Conclusion The data definitively prove that the root entry zone (REZ, nerve-pons junction) and TZ of the trigeminal nerve are distinct sites and that these terms should never be used interchangeably. The measurements showed that the central myelin occupies only the initial one-fourth of the trigeminal nerve length. If trigeminal neuralgia is caused exclusively by vascular compression of the central myelin, the problem vessel would always have to be located in this region. However, it is well known that pain from trigeminal neuralgia can resolve after vascular decompression at more distal sites. This suggests that the effects of surgical decompression are caused by another mechanism.

PubMed ID: 16256845, Background: Oncological treatment of a neoplasm is more than surgical removal of the tumor. Probably, this truth is the reason for the ongoing discussion on cavernous sinus meningiomas in the last decade. Debate on optimal management of cavernous sinus meningiomas aims to compare the different treatment strategies: (a) radical surgical resection and (b) conservative surgical resection complemented with radiosurgical treatment. Materials and Methods: Natural history of the change in the management strategy of cavernous sinus meningiomas in our department before and after GK facility became available in 1997 allowed us to compare the 2 aforementioned strategies. Before installation of a Leksell GK unit at the hospital in 1997, the neurosurgical team at Marmara University Institute of Neurological Sciences and Faculty of Medicine (Istanbul, Turkey) treated patients with cavernous sinus meningioma using radical resection (radical strategy, group A, 10 patients). After 1997, the same neurosurgical team used understanding of surgical removal of the extracavernous sinus tumor component with GK irradiation of the intracavernous part (conservative strategy, group B, 12 patients). Another group of patients, who were treated with GK as a first-step treatment, was analyzed (GK group, group C, 26 patients). Results: At the end of the third year, more stable tumor volume control was achieved in groups B and C; after the second year, an incline in the tumor volume-time graph was detected. Group B resulted in less cranial nerve-related complications; a certain degree of improvement in cranial nerve deficits was observed. Conclusion: Comparing 2 different management strategies for cavernous sinus meningiomas in the same hospital setting using the same neurosurgical group, we conclude that extracavernous resection followed by GK is as effective as radical surgery. Considering cranial nerve complications and third-year tumor volume control achievement, conservative approach yielded better results. Longer follow-up with larger series is necessary. © 2005 Elsevier Inc. All rights reserved., Scientific activities of Türker Kılıç, MD, PhD, have been financially supported by Turkish Academy of Sciences.

Background Allopurinol is a xanthine oxidase inhibitor that prevents the generation of free radicals and may play a role in the protection of the cells during cerebral ischemia. Methods We evaluated the protective and therapeutic effect of allopurinol on reversible focal cerebral ischemia-reperfusion model in rats. Cerebral blood flow to the left hemisphere of adult Sprague-Dawley rats (n = 40) was temporarily interrupted by middle cerebral artery (MCA) and bilateral common carotid artery (CCA) occlusion for 3 hours in 5 groups of 8 rats each. Allopurinol (50 mg/kg) was given intraperitoneally 2 hours and immediately before ischemia and immediately and 2 hours after reperfusion in 4 different groups of rats, respectively. Animals were kept alive 24 hours after reperfusion. After sacrifice, infarction volumes and ratios of the brain slices were calculated, and the results were compared with those of the control group. Results The difference between the allopurinol-administered group and the control group 2 hours before for both infarction volumes and infarction ratios achieved statistical significance. Regarding the allopurinol-administered group immediately before ischemia, infarction volumes and infarction ratios were diminished, but there was no statistically significant difference. The difference between allopurinol-administered and control group immediately after and 2 hours after reperfusion for both infarction volumes and infarction ratios achieved no statistical significance. Conclusion This study showed that allopurinol has a protective effect, but not a therapeutic effect, on cerebral ischemia.

Recent reports indicate that cerebellar hemorrhage after spinal surgery is infrequent, but it is an important and preventable problem. This type of bleeding is thought to occur secondary to venous infarction, but the exact pathogenetic mechanisms are unknown. This report details the case of a 48-year-old woman who developed remote cerebellar hemorrhage after spinal surgery. The patient presented with a herniated lumbar disc, spinal stenosis, and spondylolisthesis, and underwent multiple-level laminectomy, discectomy, and transpedicular fixation. The dura mater was opened accidentally during the operation. There were no neurologic deficits in the early postoperative period; however, 12 h postsurgery the patient complained of headache. This became more severe, and developed progressive dysarthria and vomiting as well. Computed tomography demonstrated small sites of remote cerebellar hemorrhage in both cerebellar hemispheres. The patient was treated medically, and was discharged in good condition. At 6 months after surgery, she was neurologically normal. The case is discussed in relation to the ten previous cases of remote cerebellar hemorrhage documented in the literature. The only possible etiological factors identified in the reported case were opening of the dura and large-volume cerebrospinal fluid loss.

We report 2 patients with suprasellar haemangioblastoma (HBL). The first, a 54-year-old man, presented with headache and gradually worsening bilateral visual field defects that had progressed to complete blindness on the right side. Computed tomography (CT) and magnetic resonance imaging (MRI) of the brain demonstrated a suprasellar mass. The mass was removed through a pterional craniotomy. The postoperative course was uneventful. He had no stigmata of von Hippel-Lindau (VHL) disease. After 5 years follow-up, vision in the left eye is normal but the right eye remains blind and MRI reveals no recurrence. The second, a 38-year-old man presented with a 2-month history of severe headaches and complete visual loss in the left eye. He had had surgery for excision of a cerebellar HBL, 5 years prior to this presentation. CT and MRI revealed a residual mass in the posterior fossa and a new suprasellar mass. He underwent craniotomy and subtotal excision of the suprasellar tumour. The histological diagnosis was HBL in both patients. HBL in the sellar and suprasellar region are rare and may be sporadic or occur in association with VHL disease. The literature is reviewed and diagnosis and treatment options discussed.

OBJECTIVE AND IMPORTANCE The C3 level is the transition zone between the upper and lower cervical spine. Because of its high position and anatomic relationships to significant structures, exposing C3 is challenging, and the surgical approach is controversial. CLINICAL PRESENTATION A 16-year-old girl was admitted to our institution with a 3-year history of neck pain and progressive quadriparesis. Neuroradiological examination revealed severe spinal cord compression from kyphosis at the C3 level. TECHNIQUE We used the lateral approach to resect the C3 corpus and realign the cervical spine. Resecting the transverse processes of C2-C4 and mobilizing the V2 segment of the vertebral artery adequately exposed C3 for resection. Bilateral occipitocervical fusion was performed in a second procedure, and no postoperative complications occurred. The patient's neurological status improved drastically after surgery, and she has had no craniocervical instability during the follow-up period. CONCLUSION The lateral approach to the C3 corpus offers the greatest degree of cord decompression and easy access to the lesion in a wide and sterile operative field. We describe the surgical technique of this approach as an alternative to the anterior transmucosal or anterolateral retropharyngeal approach.

Objective and importance Schwannomas of the central nervous system usually originate from the vestibular nerve and occasionally originate from the trigeminal nerve. Sympathetic plexus schwannomas are extremely rare and have never been noted within the cavernous sinus. Clinical presentation A 23-year-old man experienced occasional double vision for a period of 6 months. Magnetic resonance imaging studies revealed an isointense lesion, with enhancement after gadolinium administration, located inferomedial to the internal carotid artery within the left cavernous sinus. Intervention We explored the cavernous sinus via a left-sided extradural-pterional approach and found the tumor inferomedial to the cavernous segment of the internal carotid artery. Microsurgical gross total resection of the tumor was performed. The IIIrd (oculomotor) to VIth (abducens) cranial nerves within the cavernous sinus were not related to the tumor and were preserved. The operative findings and the anatomic location of the tumor demonstrated that it originated from the internal carotid plexus within the cavernous sinus. The patient's postoperative course was uneventful, and he exhibited no cranial nerve deficits. However, incomplete Horner's syndrome was present on the treated side. Conclusion We present the first reported case of an internal carotid plexus schwannoma, and we describe in detail its anatomic and neuroradiological characteristics. The microneurosurgical resection of this unusual tumor within the cavernous sinus was successful and without morbidity.

Objective To test the hypothesis that the expression of certain growth factors and/or structural proteins is correlated with the biological behavior of cranial base chordomas. Methods The study investigated 14 pathological specimens of cranial base chordomas from patients who were monitored for at least 2 years after their initial operations. Some cases involved multiple tumor recurrences and multiple operations. For those patients, the time to recurrence after each operation was recorded and a mean value was calculated. Nine patients with mean times to recurrence of 24 months or more or with 24 months of follow-up monitoring without recurrence after single operations were designated the "good-prognosis" group. Five patients with mean times to recurrence of less than 24 months were designated the "poor-prognosis" group. In each case, only the specimen from the initial operation was studied. Multiple sequential sections were cut from paraffin-embedded blocks of tissue and immunohistochemically prepared for detection of three growth factors and three structural proteins, i.e., basic fibroblast growth factor, transforming growth factor alpha, vascular endothelial growth factor, fibronectin, collagen III, and collagen IV. Intensity of expression was graded by using a four-tier system (Grades 0, 1, 2, and 3). Levels of expression of the molecules in the two groups were evaluated and compared. Results The mean transforming growth factor alpha expression intensity grades for the good- and poor-prognosis groups were 0.8 and 2.6, respectively, and the corresponding mean basic fibroblast growth factor grades were 1.4 and 2.6. For both groups, the mean grade for vascular endothelial growth factor expression was 0.6. For fibronectin, the mean staining grades for the good- and poor-prognosis groups were 2.2 and 3.0, respectively. The corresponding mean intensities for collagen III were 1.1 and 0.8, and those for collagen IV were 2.5 and 2.6. Conclusion Our descriptive data from immunohistochemical analyses of chordomas suggest that high levels of transforming growth factor alpha and basic fibroblast growth factor expression are linked to higher rates of recurrence. Strong fibronectin expression may also be a marker of aggressive biological behavior.

Object. Various approaches have been described for resection of the dens of the axis, each of which has potential advantages and disadvantages. Anterior approaches such as the transoral route or its modifications are the most commonly used for resection of this structure. The transcondylar approach, however, which allows the surgeon to view the craniovertebral junction (CVJ) from a lateral perspective, has been introduced by Al-Mefty, et al., as an alternative approach. In this report, the authors describe the surgical technique of the extreme lateral—transatlas approach and their clinical experiences. Methods. The authors first examined the surgical approach to the dens from a lateral perspective in five cadaveric heads. They found that removal of the lateral mass of the atlas provided adequate exposure for resection of the dens. Following this cadaveric study, the extreme lateral—transatlas approach was successfully performed at the authors' institution over a 1-year period (September 1998–August 1999) in five patients with basilar invagination due to congenital anomaly of the CVJ and rheumatoid arthritis. Furthermore, during the same procedure, unilateral occipitocervical fusion was performed following resection of the dens. In all cases complete resection of the dens was achieved using the extreme—lateral transatlas approach. This procedure provides a sterile operative field and the ability to perform occipitocervical fusion immediately following the resection. No postoperative complications or craniocervical instability were observed. The mean follow-up period was 17.2 months (range 13–24 months). Conclusions. The extreme lateral—transatlas approach for resection of the dens was found to be safe and effective. Knowledge of the anatomy of this region, especially of the V3 segment of the vertebral artery, is essential for the success of this procedure.

The trigemino-cardiac reflex (TCR) is a well-known reflexive response in which bradycardia, hypotension, and gastric hypermotility are induced by stimulation of a peripheral or central portion of the trigeminal nerve. This reflex occurs during craniofacial surgery and other operations on or near the cerebellopontine angle, petrosal sinus, orbit and trigeminal ganglion. TCR is a well-known, although not well documented, phenomenon commonly observed during trans-sphenoidal surgery for resection of pituitary adenomas. We report a case in which asystole occurred during trans-sphenoidal surgery on a pituitary adenoma that was infiltrating the right cavernous sinus. When the anesthesiologist reported asystole, the team stopped manipulation and administered intravenous atropine. Intra-operative MRI showed a small tumour remnant in the right cavernous sinus. The operation was terminated but subsequent radiosurgery was planned for the residual tumor. Although TCR is rare and usually self-limiting, this case led us to change our treatment strategy. Surgeons who perform trans-sphenoidal surgery should be aware of this potential problem. Invasive pituitary adenomas should be removed gently and the risk of triggering TCR should be kept in mind.

BACKGROUND Focal cerebral ischemia secondary to cerebral vessel occlusion is still an important cause of mortality and morbidity. Excitatory neurotransmitters are gathered in the extracellular space during ischemia and initiate or stimulate a series of pathophysiological biochemical processes and consequently lead to neuronal death. Tizanidine (Sandoz compound DS 103–282, 5-chloro-4,2 (2-imidazolin-2-yl-amino)-2,1,3-benzothiazol hydrochloride) is a selective α 2 adrenoreceptor agonist which shows its effect by stimulating presynaptic α 2 adrenoreceptors in central ASPergic and GLUergic system by inhibiting aspartic acid and glutamic acid release. In this study, the effect of Tizanidine on reversible focal cerebral ischemia was evaluated. METHODS Cerebral blood flow to the left hemisphere of adult Sprague-Dawley rats ( n = 48) was temporarily interrupted by middle cerebral artery and bilateral common carotid artery occlusion for 3 hours in eight rats of each group. Tizanidine was given to each group of rats intraperitoneally before the ischemic insult, 2 hours after ischemia, right after the reperfusion, 2 h after reperfusion, and 4 hours after reperfusion; the animals survived for 24 hours after the reperfusion. After killing and triphenyltetrasoliumchloride staining of brain slices, infarction volumes and ratios of the brains were calculated and the results were compared with those of the control group. RESULTS Infarction volumes and infarction ratios of the Tizanidine group 1/2 hours before ischemia (143.7 ± 6.34 mm 3 and 10.1 ± 0.43%) and the Tizanidine group 2 hours after ischemia (145.6 ± 6.32 mm 3 and 10.3 ± 0.43%) were found to be significantly lower in favor of the Tizanidine groups when compared with those of the control group (173.9 ± 6.38 mm 3 and 12,4 ± 0.41%). Tizanidine is not effective if used just after reperfusion or later. CONCLUSION This study shows that Tizanidine pretreatment before the ischemic insult and the administration of the drug within the 2 hours after ischemia reduces ischemic damage significantly. Therefore, this drug can be used as a protective and therapeutic agent in ischemic diseases.

Superficial siderosis of the central nervous system is a rare, progressive, irreversible and debilitating neurological disease characterized by the deposition of haemosiderin in the leptomeninges and the subpial layers of the brain and spinal cord. The main clinical findings are progressive bilateral sensorineural hearing loss, cerebellar ataxia and pyramidal tract signs. The present report describes a 49-year-old woman who presented with intermittent headache of 5 years duration. The pain had become more severe in the previous 6 months. Neurological examination revealed nothing abnormal. Computed tomography showed a cystic mass with apparent internal haemorrhage in the right frontal lobe and T(2)-weighted magnetic resonance imaging showed material of low signal intensity coating the entire surface of the brain. The mass was completely excised via craniotomy. A histopathological study identified the mass as a papillary glioneuronal tumour. The patient recovered well and is still neurologically normal 1 year later. This is the first documented case of superficial siderosis caused by this type of tumour.

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is an autosomal-recessive disease associated with multiple deletions of mitochondrial DNA in skeletal muscle. MNGIE is a multisystem syndrome affecting muscle, peripheral, and central nervous systems and the gastrointestinal tract. A 25-year-old man is presented with 3 years history of right sided trigeminal neuralgia. He has been diagnosed as MNGIE based on clinical, neurophysiological and pathological findings. He had also received medical therapy and two radiofrequency thermocoagulations for the treatment of trigeminal neuralgia. Gamma Knife radiosurgery was performed and resulted in partial relief. To our knowledge, this is the first case in the literature of MNGIE with trigeminal neuralgia. An analogy is suggested between multiple sclerosis and MNGIE as a cause for trigeminal neuralgia in this patient.

Object The authors had previously shown that 3-T intraoperative MRI (ioMRI) detects residual tumor tissue during low-grade glioma and that it helps to increase the extent of resection. In a proportion of their cases, however, the ioMRI disclosed T2-hyperintense areas at the tumor resection border after the initial resection attempt and prompted a differential diagnosis between residual tumor and nontumoral changes. To guide this differential diagnosis the authors used intraoperative long-TE single-voxel proton MR spectroscopy (ioMRS) and tested the correlation of these findings with findings from pathological examination of resected tissue. Methods Patients who were undergoing surgery for hemispheric or insular WHO Grade II gliomas and were found to have T2 changes around the resection cavity at the initial ioMRI were prospectively examined with ioMRS and biopsies were taken from corresponding localizations. In 14 consecutive patients, the ioMRS diagnosis in 20 voxels of interest was tested against the histopathological diagnosis. Intraoperative diffusion-weighted imaging (ioDWI) was also performed, as a part of the routine imaging, to rule out surgically induced changes, which could also appear as T2 hyperintensity. Results Presence of tumor was documented in 14 (70%) of the 20 T2-hyperintense areas by histopathological examination. The sensitivity of ioMRS for identifying residual tumor was 85.7%, the specificity was 100%, the positive predictive value was 100%, and the negative predictive value was 75%. The specificity of ioDWI for surgically induced changes was high (100%), but the sensitivity was only 60%. Conclusions This is the first clinical series to indicate that ioMRS can be used to differentiate residual tumor from nontumoral changes around the resection cavity, with high sensitivity and specificity.

Objective To introduce the authors of 6 prominent Ottoman surgical treatises, to present the chapters that relate to present-day neurosurgery, and to discuss their influence on the establishment of modern Turkish neurosurgery. Methods Neurosurgery-related chapters of 6 prominent Ottoman surgical treatises and their role i the establishment of modern neurosurgery in Turkey are discussed. Results Neurosurgery-related chapters of “Hulasa-i Tibb” by Surgeon Mesud (Summary of Medicine), “Cerrahhiyet-al Haniyye” by Serefeddin Sabuncuoglu (Imperial Surgery), “Cerrahname” by an unknown author (Surgical Treatise), “Ala'im-i Cerrahin” by Surgeon Ibrahim (Wonders of Surgeons) “Cerrahname” by Ali Munsi of Bursa (Surgical Treatise), and “The law of surgeons” by Sanizade Ataullah Mehmed Efendi (Kanun-al Cerrahin) were analyzed. Conclusions These treatises, including sections on neurosurgery-related topics, were important influences on the establishment of contemporary neurosurgery in modern Turkey.

The transition from the medieval universities to the secular, second generation universities in Turkey occurred in the period from 1773 to 1945. The Ottoman Empire's efforts to establish a higher education system in the eighteenth and nineteenth centuries only aimed at modernization of the armed forces, and the civil effects on the general society were only secondary. After the Turkish Republic was founded in 1923, complete modernization of all institutions of society, including political, social, educational, economic, and law reforms, were initiated by the President Mustafa Kemal Ataturk. His establishment of the modern Istanbul University in Turkey was an experiment unforeseen in the history of education. Step by step, he created a new language, a new alphabet, achieved unified and secular education under government supervision, formed primary and secondary education to support higher education, took expert opinion on forming the new university, and finally established the modern university. German-speaking academicians have played a very important role during the creation of the modern secular university in Turkey. This is a short analysis of this period.

BACKGROUND The primary treatment for craniopharyngiomas is total excision, but recurrence is common. However, current knowledge on the mechanisms of recurrence is limited. OBJECTIVE We hypothesized that recurrence is linked to the angiogenesis of the tumor. Recurrent and nonrecurrent tumor samples were compared with regard to expression of angiogenesis-related factors and angiogenic capacity in a corneal angiogenesis model. METHODS Specimens of 4 recurrent and 6 nonrecurrent tumors were selected from 57 patients with adamantinomatous craniopharyngiomas. Sections were immunohistochemically stained with antibodies for vascular endothelial growth factor (VEGF), fibronectin, fibroblast growth factor (FGF)-2, platelet-derived growth factor (PDGF)-A, PDGF-B, platelet-derived growth factor receptor (PDGFR)-alpha, and PDGFR-beta. Expression levels were graded using a 4-point scoring system and were compared. For corneal angiogenesis assay, tissue samples were inoculated in a micropocket created on the rat eye, and microvessels were counted on days 3, 5, 7, and 9 to evaluate angiogenic potential. RESULTS Expression of PDGFR-alpha and FGF-2 were significantly higher for recurrent tumors (P = .02 and P = .01). However, recurrent and nonrecurrent tumors did not differ in the expressions of other ligands and receptors (PDGF-A, PDGF-B, and PDGFR-beta). Recurrent tumors displayed a higher angiogenic potential starting from the fifth day of corneal angiogenesis assay. CONCLUSION These findings suggest a relationship between recurrence of craniopharyngiomas and angiogenesis. New treatment modalities with selective PDGFR-alpha blockers may represent a novel and effective therapeutic option for the treatment of craniopharyngiomas.

This study aimed to examine the association between time to tumor recurrence, angiogenic potential and tumor contrast-enhancement. Tumor samples were taken from 20 patients with low-grade oligodendroglioma and examined for their angiogenic potential using an in vivo rat corneal model of angiogenesis. Patients were evaluated for tumor contrast enhancement prior to surgical excision using MRI and they were followed for tumor recurrence. Patients who had tumors without contrast enhancement had longer disease-free survival (median time to tumor recurrence, 72 months) compared to those who had tumors with contrast enhancement (median, 42 months; p = 0.0068). Based on corneal angiogenesis assay results, a high angiogenic potential was associated with a significantly shorter disease-free survival. Our findings suggest that radiological contrast enhancement and a high angiogenic potential based on an in vivo corneal angiogenesis assay were related to a shorter disease-free survival. This might have important prognostic implications in patients with low-grade oligodendrogliomas.

Objective To compare the angiogenic potentials of embolized, gamma knife-treated or untreated cerebral arteriovenous malformations (AVMs), using a rat cornea angiogenesis model. Methods Tissue samples from cerebral AVM patients who were either untreated or had previously been treated with embolization or gamma knife radiosurgery and who had undergone operations for hemorrhage at the Neurosurgery Department or the Neurological Sciences Institute of Marmara University were used. For the macroscopic evaluation of angiogenesis, tissue samples were inoculated in a micropocket created on the rat eye, and the level of angiogenic activity was graded macroscopically for 15 days, with glioblastoma multiforme and normal brain artery tissues serving as positive and negative controls, respectively. For the other part of the experiment, eyes of another set of rats were inoculated with the study samples only using the same cornea angiogenesis model, in which microvessel count and vascular endothelial growth factor assessment was done at days 3, 7, 11, and 15. Results Based on our macroscopic findings in the cornea angiogenesis model, embolized AVMs exhibited the highest angiogenic activity, followed by untreated AVMs and gamma knife-treated AVMs. Evaluations of vascular endothelial growth factor expression and microvessel counts showed a similar relation among the 3 tissue groups with regard to the level of angiogenic activity, supporting the results of macroscopic examinations. Conclusion This study, for the first time, provides experimental semiquantitative data to compare the angiogenic potentials of embolized and gamma knife-treated AVM tissues. Embolization may increase angiogenic activity, and gamma knife radiosurgery may decrease it when compared with activity in previously untreated AVMs. These data can be useful to understand why recurrence of AVMs after angiographically demonstrated endovascular occlusion is common but after gamma knife occlusion is rare.