Surgical management of pseudotumor cerebri syndrome: A single center experience with endoscopic optic nerve decompression and CSF diversion procedures.

OBJECTIVES: Pseudotumor cerebri syndrome (PTC) is a chronic disorder, which is initially treated by conservative measures, yet surgery is inevitable in case of progressive worsening of vision or headache despite medical treatment. The surgical management is controversial including CSF diversion procedures and optic decompression. The purpose of this study was to evaluate the efficacy of different surgeries in PTC and to present surgical outcomes in a single center. METHODS: This retrospective study included the patients with PTC who were operated by endoscopic optic nerve decompression (EOND), ventriculoperitoneal (VP) and lumboperitoneal (LP) shunting. Surgical outcomes, i.e. visual acuity, visual field, papilledema and headache were compared according to type of surgery. Surgical complications were noted. RESULTS: Seventeen of 36 patients were treated with shunting, 14 with EOND and 5 patients with both EOND and shunting. No statistical significance was observed between CSF diversion procedures and EOND concerning clinical outcomes. The improvement rate of papilledema was higher with VPS (p = 0574) while more patients benefitted from LPS regarding visual field and acuity (p = 0471 and p = 0718, respectively). The best treatment response for headache was in shunt implemented patients (VPS and LPS) with a rate of 88.2% followed by EOND (78.6%) and both surgeries (60%)(p = 0.294). Gender and BMI were significant predictors of improved papilledema (p = 0.034). CONCLUSIONS: Our study demonstrated comparable results between shunting and EOND, regarding the efficacy on surgical outcomes. EOND is quite effective for headache besides its advantage on treatment-refractory visual loss. Shunting may offer sustained relief of symptoms when compared with EOND.

Factors affecting medical students' satisfaction with online learning: a regression analysis of a survey.

BACKGROUND: Medical education requires the implementation of different teaching methods and strategies for future doctors to achieve broad learning objectives. This wide range of methods and strategies includes the use of Information Technologies. For a long time, there was a call for a change in medical education for blending new teaching approaches to lessen medical students' class time. The COVID-19 pandemic then sped up the transition to the new way of medical education and classroom lectures were quickly moved to a virtual environment. We expect that these changes will continue, and online learning will be one of the main teaching strategies in medical education. Therefore, educational experiences during the COVID-19 pandemic will improve our understanding of online learning and will help to develop blended medical school curricula in the future. For this reason, we aimed to determine students' overall satisfaction with their online learning experience and to define the main factors affecting students' satisfaction with their online learning program at Cerrahpasa Medical Faculty. METHODS: A cross-sectional survey study was conducted to determine medical students' overall satisfaction with online learning methods and to identify factors associated with positive and negative satisfaction levels. A questionnaire, consisting of 24 questions to collect demographic characteristics, factors associated with online education experience and overall satisfaction levels was developed and distributed to 1600 medical students. Multivariable linear regression analysis was used to determine the factors associated with positive and negative satisfaction levels. RESULTS: Regression analysis showed that being familiar with online teaching techniques (ß = 0.19, 95% CI [0.07, 0.30], faculty members' higher online teaching skill levels (ß = 0.42, 95% CI [0.32, 0.51], interactive online teaching approaches (ß = 0.54, 95% CI [0.41, 0.67], having a personal workspace (ß = 0.43, 95% CI [0.19, 0.67], and a self-reported longer attention span (ß = 0.75, 95% CI [0.57, 0.92] were associated with higher overall satisfaction with online learning. The occurrence of technical problems (ß = -0.19, 95% CI [-0.26, -0.12] was associated with lower overall satisfaction. CONCLUSIONS: Higher online teaching skills of faculty members, use of interactive approaches, students' familiarity with online teaching techniques, provision of a personal workspace, and self-reported longer attention spans positively contributed to higher levels of student satisfaction with online learning. Considering the increasing significance of online educational methods, our study identified key components that affect students' level of satisfaction. This information might contribute to the development of online educational programs in the future.

A new ventricular index based on coronal brain magnetic resonance images in patients with idiopathic normal pressure hydrocephalus.

BACKGROUND: The aim of this study was to assess the effectiveness of a new quantitative index for the diagnosis of idiopathic normal pressure hydrocephalus. METHODS: This retrospective study was conducted at Istanbul University Cerrahpasa Medical Faculty between January 2016 and November 2022. A total of 31 patients diagnosed with idiopathic normal pressure hydrocephalus were included in the study group and 48 patients were included in the control group. Measurement via the new Index was performed on a coronal section of magnetic resonance imaging at the level of the anterior commissure. RESULTS: The new Index's mean diagnostic performance was 1.16 ± 0.08 in the study group, significantly lower (p < 0.0001) than the mean of 1.43 ± 0.10 in the control group. When a cutoff value of 1.23 was used for the new index, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rates were 96.1%, 90.7%, 80.6%, 98%, and 91.3%, respectively. DISCUSSION: The new Index described here is an effective, feasible, reproducible, highly sensitive, and specific quantitative method that can contribute to the improved diagnosis of patients with idiopathic normal pressure hydrocephalus.

Comparison of two surgical techniques in Chiari Malformation Type 1 Patients: Duraplasty alone vs duraplasty with arachnoid dissection.

OBJECT: Optimal surgical technique to restore the cerebrospinal fluid flow through the foramen magnum remains to be debated in Chiari malformation type 1 (CM-1) patients. METHOD: This study included 46 patients with CM-1 who underwent surgical treatment by one of two methods: posterior fossa bone decompression (BD) with arachnoid preserving duraplasty (Group 1) and BD with duraplasty and arachnoid dissection (Group 2). Complaints of the patient population and neurological findings were assessed with Neck Disability Index (NDI) and Europe Quality of Life 5 Dimensions (EQ-5D) in pre- and postoperative periods. RESULTS: NDI and EQ-5D scores improved in overall patient population and in each individual surgical group. Both groups showed a significant decrease in size of syringomyelia cavity. Complications resulting in recurrent treatments and re-operations occurred in 15% of patients (n = 7); six of them were from Group 2. CONCLUSION: CM-1 patients benefit significantly from surgical treatment. Duraplasty should be included to surgical technique. Avoiding arachnoid dissection may lead to better results regarding complication rates.

Intraoperative Fluorescein Sodium Videoangiography in Intracranial Aneurysm Surgery.

OBJECTIVE: Fluorescein sodium (FNa) videoangiography (VA) was performed to evaluate blood flow within vessels and exclusion of the aneurysm after surgical clipping of intracranial aneurysms. The aim of this study was to report results of FNa-VA in a case series, including benefits and limitations of the technique, and compare intraoperative findings with postoperative cerebral angiography to assess reliability of FNa-VA. METHODS: The study included 64 aneurysms in 50 consecutive patients. Following clip ligation of the aneurysm, 100 mg of FNa was administered intravenously. The microscope light was switched to the FL560 integrated fluorescence module. Aneurysm sac, parent arteries, and perforating arteries were observed. RESULTS: FNa-VA promoted real-time assessment of the surgical field in three-dimensional view through the binoculars with good image quality. In 79.68% of aneurysms, FNa-VA confirmed satisfactory clip application, as FNa did not penetrate into the aneurysm. In 14.06% of aneurysms, a homogeneous yellow-green color change occurred, which was accepted as a false-positive sign. In 6.25% of aneurysms, FNa seeped into the aneurysm emitting a heterogeneous green signal, which slowly dispersed throughout the sac. Postoperative angiography revealed satisfactory results. Small neck remnants were present in 5 patients, and mild parent artery stenosis was found in 3 patients. No ischemic event occurred secondary to parent artery or perforating artery occlusion. CONCLUSIONS: FNa-VA adds greatly to the safety of surgical treatment of intracranial aneurysms, particularly in lesions situated in deep locations, by enabling real-time inspection, which facilitates safer manipulation and evaluation of structures in question.

The contribution of SPECT/CT in patients with radionuclide shuntography through shunt dysfunction.

OBJECTIVE: Radionuclide CSF study is a simple, effective, and low-radiation-dose procedure for the assessment of shunt patency. With the help of CT image of single-photon emission computed tomography/computed tomography (SPECT/CT), the interpretation becomes more accurate and easier.The aim of this study was to compare the classical methods and 2D planar scintigraphic images with radionuclide shuntography fused SPECT/CT. METHODS: Between 2015-2019 all hydrocephalic patients who underwent radionuclide shuntography and classical methods (cranial CT, USG and/or direct X-rays), for suspected VP shunt malfunction at our hospital were retrospectively enrolled in the study. Fusion with SPECT/CT is provided in all radionuclide shuntographies. Approximately 0.5-1 mCi diethylene-triaminepentaaceticacid (DTPA) was intrathecally injected. Images were collected as 5-second frames for the first minute, and 1-min frames for the second to the 30th min. Static whole body images were obtained as early (30 min) and delayed (120 min) images. SPECT/CT was performed in 120 min. RESULTS: When the classical methods were evaluated in the operated patients, according to the direct radiographic findings, in only 17 patients had shunt dysfunction due to disconnection-kinking or laceration, was obtained.On the other hand,while67 shuntography were evaluated,65 of these patients (97%) whose intraoperative and shuntography findings were found to be compatible with each other. CONCLUSION: The 3D SPECT images combined with the two-dimensional planar images added to the CT provide more accurate information and also provide detailed anatomical information. The patient's operation was performed successfully in one session in cooperation with the other surgical branches when needed.

Investigation of Survivin Gene Polymorphism and Serum Survivin Levels in Patients with Brain Tumors.

BACKGROUND/AIM: The single nucleotide polymorphism -31C/G identified in the survivin gene promoter seems to be associated with over-expression of survivin, an anti-apoptotic protein. In gliomas, increased survivin expression correlated with decreased survival. The aim of the study was to investigate whether survivin gene polymorphism associates with benign and malignant brain tumors and whether it affects survivin serum levels. PATIENTS AND METHODS: Survivin polymorphism -31C>G was genotyped in 82 patients with brain tumors and 65 healthy controls by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and survivin levels were evaluated by enzyme-linked immuno sorbent assay (ELISA) in patients and controls. RESULTS: Serum survivin levels in patients with malignant tumors were higher than patients with benign tumors (p<0.001). Survivin levels in patients with malignant glial tumors and the frequency of the GG genotype were higher than in patients with benign tumors (p=0.04) and controls (p=0.05). The prevelance of the survivin gene promoter polymorphism -31C>G did not differ between patients and controls. CONCLUSION: Survivin promoter -31C>G gene polymorphism seems to be associated with serum survivin levels in brain tumors of different grades and histologies.

Endoscopic Endonasal Transethmoidal Approach for the Management of a Traumatic Brain Abscess and Reconstruction of the Accompanying Anterior Skull Base Defect.

Skull base endoscopy in the treatment of brain abscesses has been rarely published. Moreover, endoscopic endonasal transethmoidal approach (EETA) for the treatment of brain abscess following a head trauma has been reported only in a few case reports. We report the management of a patient of intracerebral abscess and reconstruction of the accompanying anterior skull base defect through an EETA.Thirty-year-old male with a frontal lobe abscess due to a penetrating skull base trauma was operated via EETA. After drainage of the abscess, dural and bony defects were repaired to prevent any recurrence. Postoperative radiological imaging revealed prominent decrease in abscess size. The patient did not need any further surgical intervention, and antibiotherapy was adequate.EETA is safe and effective in the management of brain abscesses. Skull base endoscopy provides direct visualization of the abscess cavity through a minimal invasive route, facilitates wide exposure of surrounding neurovascular structures within the operative field, and enables concurrent closure of the skull base defect.

Association between FAS and FASL genetic variants and risk of primary brain tumor.

The purpose of this study was to investigate whether functional polymorphisms of apoptosis pathway genes FAS and FASL are associated with the development of primary brain tumors. The study constituted 83 patients with primary brain tumor and 108 healthy individuals. In the present case-control study, the primary brain tumors were divided into two groups: gliomas and meningiomas. Evaluation of FAS -1377 G/A and FASL -844 T/C gene polymorphisms were performed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). To confirm the genotyping, results were examined by DNA sequencing method. Our results were analyzed by SPSS. The frequency of the FAS -1377 AA genotype was significantly lower in meningioma and glioma patients compared to controls (p = 0.023; p = 0.001, respectively). Multivariate logistic regression analysis revealed that FAS -1377 AA genotype was associated with decreased risk of meningioma and glioma (OR = 0.092, 95% CI: 0.012-0.719, p = 0.023 for meningiomas; OR = 0.056, 95% CI: 0.007-0.428, p = 0.006 for gliomas). However, there was no significant differences in FASL -844 T/C genotype frequencies between patients with primary brain tumors and controls (p > 0.05). In this study, combined genotypes were evaluated for association with primary brain tumors. Combined genotype analysis showed that the frequencies of AATC and AACC were significantly lower in glioma patients in comparison with those of controls (p = 0.023; p = 0.022, respectively). This study provides the first evidence that FAS -1377 AA genotype may have a protective effect on the developing primary brain tumor in a Turkish population.

Investigation of ICAM-1 and ß3 integrin gene variations in patients with brain tumors.

BACKGROUND: Primary brain tumors constitute a small percent of all malignant cancers, but their etiology remains poorly understood. ß3 integrin (ITGB3) has been recognized to play influential roles in angiogenesis, tumor growth and metastasis. Intercellular adhesion molecule-1 (ICAM-1) is a surface glycoprotein important for tumor invasion and angiogenesis. The aim of this study was to investigate whether specific genetic polymorphisms of ICAM-1 and ITGB3 could be associated with brain cancer development and progression in a Turkish population. Our study is the first to our knowledge to investigate the relationship between brain tumor risk and ICAM-1 and ß3 integrin gene polymorphisms. MATERIALS AND METHODS: The study covered 92 patients with primary brain tumors and 92 age-matched healthy control subjects. Evaluation of ß3 integrin (Leu33Pro (rs5918)) and ICAM-1 (R241G (rs1799969) and K469E (rs5498)) gene polymorphisms was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: According to results of our research, the A allele of the ICAM-1 R241G gene polymorphism appeared to be a risk factor for primary brain tumors (p<0.001). Similarly, the frequency of the A mutant allele of ICAM-1 R241G was statistically significant in patients with brain tumors classified as glioma (p<0.001). When allele and genotype distributions of ICAM- 1 K469E, ICAM-1 R241G and ß3 integrin Leu33Pro gene polymorphisms were evaluated with age, sex, and smoking, there were no statistically significant differences. Haplotype analysis revealed that the frequencies of GAC (rs1799969-rs5498-rs5918) and GAT (rs1799969-rs5498-rs5918) haplotypes were significantly lower in patients as compared with controls (p=0.001; p=0.036 respectively). CONCLUSIONS: This study provides the first evidence that ICAM-1 R241G SNP significantly contributes to the risk of primary brain tumors in a Turkish population. In addition, our results suggest that ICAM-1 R241G in combination ICAM-1 K469E may have protective effects against the development of brain cancer.

Cyclin D1 gene G870A variants and primary brain tumors.

Alterations of cyclin D1, one of the main regulators of the cell cycle, are known to be involved in various cancers. The CCDN1 G870A polymorphism causes production of a truncated variant with a shorter half-life and thus thought to impact the regulatory effect of CCDN1. The aim of the present study was to contribute to existing results to help to determine the prognostic value of this specific gene variant and evaluate the role of CCDN1 G870A polymorphism in brain cancer susceptibility. A Turkish study group including 99 patients with primary brain tumors and 155 healthy controls were examined. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism analysis. The CCDN1 genotype frequencies in meningioma, glioma and control cases were not significantly different (p>0.05). No significant association was detected according to clinical parameters or tumor characteristics; however, a higher frequency of AG genotype was recorded within patients with astrocytic or oligoastrocytic tumors. A significant association between AG genotype and gliobilastoma multiforme (GBM) was recorded within the patients with glial tumors (p value=0.048 OR: 1.87 CI% 1.010-3.463). According to tumor characteristics, no statistically significant difference was detected within astrocytic, oligoasltrocytic tumors and oligodentrioglias. However, patients with astrocytic astrocytic or oligoastrocytic tumors showed a higher frequency of AG genotype (50%) when compared to those with oligodendrioglial tumors (27.3%). Our results indicate a possible relation between GBM formation and CCDN1 genotype.

The vitamin D receptor (VDR) gene polymorphisms in Turkish brain cancer patients.

Objective. It has been stated that brain cancers are an increasingly serious issue in many parts of the world. The aim of our study was to determine a possible relationship between Vitamin D receptor (VDR) gene polymorphisms and the risk of glioma and meningioma. Methods. We investigated the VDR Taq-I and VDR Fok-I gene polymorphisms in 100 brain cancer patients (including 44 meningioma cases and 56 glioma cases) and 122 age-matched healthy control subjects. This study was performed by polymerase chain reaction-based restriction fragment length polymorphism (RF LP). Results. VDR Fok-I ff genotype was significantly increased in meningioma patients (15.9%) compared with controls (2.5%), and carriers of Fok-I ff genotype had a 6.47-fold increased risk for meningioma cases. There was no significant difference between patients and controls for VDR Taq-I genotypes and alleles. Conclusions. We suggest that VDR Fok-I genotypes might affect the development of meningioma.

Primary fourth ventricular meningioma: case report and review of the literature.

Primary fourth ventricle meningiomas are extremely rare, and they are defined as meningiomas arising from the choroid plexus and lying strictly within the fourth ventricle. In this report we present a 61-year-old man with progressive worsening vertigo and gait disturbance, and new onset of diplopia. Neurological examination revealed bilateral abducens nerve paralysis, horizontal nystagmus, and gait disturbance with truncal ataxia. Neuroimaging revealed a mass lesion in the fourth ventricle with brain stem compression, and obstructive hydrocephalus. The patient was operated in the prone position with suboccipital craniotomy and splitting the lower vermis. Total resection of the tumor was achieved with no intra- or post-operative complications. Histopathologic examination revealed fibroblastic type meningioma (WHO grade I).

Surgical treatment of trigonocephaly: technique and long-term results in 48 cases.

OBJECT: The authors present their experience in the surgical treatment of metopic synostosis by orbital bandeau remodeling and frontal bone rotation. The pitfalls and advantages of the surgical technique are discussed, along with the long-term clinical results in 48 consecutive cases. METHODS: Forty-eight consecutive patients in whom trigonocephaly was diagnosed between 1990 and 2009 were treated with frontal bone rotation and frontoorbital bandeau remodeling. Of these patients, 38 (79%) were boys and 10 (21%) were girls. The age at the time of surgical treatment ranged between 4 and 42 months (mean ± SD 11.4 ± 8.7 months). The average follow-up period was 5.5 ± 4.2 years (range 5 months-19 years). The preoperative and latest postoperative photographs of the patients were evaluated for the following features: 1) shape of the forehead; 2) hypotelorism; and 3) temporal depression. Scores of 0, 1, or 2 were assigned for each item: 0 was normal, 1 meant moderate deformity, and 2 denoted severe deformity. RESULTS: In the early postoperative period, no complications were documented. The average hospitalization period was 4 days. Follow-up radiographs or 3D CT scans were obtained at regular intervals. The mean preoperative scores for the evaluated items were 1.38 ± 0.49 for the shape of the forehead, 1.33 ± 0.48 for hypotelorism, and 1.7 ± 0.46 for the temporal depression. The mean postoperative scores were 0.06 ± 0.24 for the shape of the forehead, 0.21 ± 0.4 for hypotelorism, and 0.67 ± 0.48 for the temporal depression. Overall, the total preoperative score dropped from 4.4 to 0.93 postoperatively (p < 0.05). All the patients were contented with the cosmetic results. CONCLUSIONS: Early detection and treatment of metopic suture synostosis has a significant, favorable influence on the outcomes. Good understanding of the structural abnormality and the pathophysiological mechanisms of the possible complications is very important for performing proper surgical reconstruction.

Endoscopic treatment of cavum vergae cyst: case report and review.

A 3.5-year-old boy was admitted with febrile convulsion for the first time. The patient had a medical history of in vitro fertilization (IVF) and premature delivery in the 21st week of pregnancy. Further, he suffered from neonatal germinal matrix hemorrhage and intraventricular hematoma (IVH). The patient was treated in the pediatric intensive care unit. Cranial magnetic resonance imaging (MRI) showed resorption of the hematoma with the presence of cavum vergae (CV) variation. The new brain MRI revealed progression of the cavum to a large CV cyst compared with the previous imagings, causing pressure upon both lateral ventricles. Endoscopic fenestration of the lateral walls of the cyst with lateral ventricles was performed. The postoperative period was uneventful and the patient was discharged the next day. Followup MRI one year after surgery showed normal ventricle size, shrinkage of the cyst and cerebrospinal fluid (CSF) flow between the cyst and the lateral ventricles. This is an interesting demonstration of the progression over years of a CV anatomical variation to a large CV cyst in a premature birth case that experienced germinal matrix hemorrhage.

Endoscopic management of posterior fossa arachnoid cyst in an adult: case report and technical note.

The authors report a case of large arachnoid cysts of the posterior fossa treated by endoscopic surgery. A 40-year-old man was admitted with a 3-month history of headache and progressive gait imbalance, with no significant medical history. At the time of admission, neurological examination revealed no abnormalities except for tandem imbalance. Brain computerized tomography (CT) scan and magnetic resonance imaging (MRI) revealed a posterior fossa arachnoid cyst (PFAC) causing brain stem compression accompanied by hydrocephalus. The patient was treated by endoscopic fenestration of the cyst with a paramedian suboccipital transcortical approach. Postoperatively the patient's complaints showed improvement and he was discharged with no complications. Follow up MRI showed a decrease in the cyst's size and the hydrocephalus with decompression of the brain stem.

Endoscopic endonasal anatomy and approaches to the anterior skull base: a neurosurgeon's viewpoint.

OBJECTIVES: The objective of this study was to review the endoscopic anatomy of the anterior skull base, defining the pitfalls of endoscopic endonasal approaches to this region. Recently, these approaches are gaining popularity among neurosurgeons, and the details of the endoscopic anatomy and approaches are highlighted from the neurosurgeons' point of view, correlated with demonstrative cases. MATERIALS AND METHODS: Twelve fresh adult cadavers were studied (n = 12). We used Karl Storz 0 and 30 degrees, 4 mm, 18- and 30-cm rod lens rigid endoscope in our dissections. After preparation of the cadaveric specimens, we approached the anterior skull base by the extended endoscopic endonasal approach. RESULTS: After resection of the superior portion of the nasal septum, bilateral middle and superior turbinates, and bilateral anterior and posterior ethmoidal cells, we could obtain full exposure of the anterior skull base. The distance between optic canal and the posterior ethmoidal artery ranged from 8 to 16 mm (mean, 11.08 mm), and the distance between posterior ethmoidal artery and the anterior ethmoidal artery ranged from 10 to 17 mm (mean, 13 mm). After resecting the anterior skull base bony structure and the dura between the 2 medial orbital walls, we could visualize the olfactory nerves, interhemispheric sulcus, and gyri recti. With dissecting the interhemispheric sulcus, we could expose the first (A1) and second (A2) segments of the anterior cerebral artery, anterior communicating artery, and Heubner arteries. CONCLUSIONS: This study showed that extended endoscopic endonasal approaches are sufficient in providing wide exposure of the bony structures, and the extradural and intradural components of the anterior skull base and the neighboring structures providing more controlled manipulation of pathologic lesions. These approaches need specific skill and learning curve to achieve more minimally invasive interventions and less postoperative complications.

Terminal syringomyelia mimicking an intramedullary tumor: case report.

In this report, the authors present a 14-year-old male patient admitted with progressive paraparesis and urinary incontinence that developed in a 3-month period. Thoracolumbar MRI revealed an intramedullary lesion starting from the level of the T10 vertebra and extending to fill the sacral spinal canal. Based on the radiological findings an intramedullary tumor was suspected. Exploratory operation with right L5 hemilaminectomy was done and the intraoperative finding was syringomyelia which was punctured with releasing of the tethered cord. The patient was followed for 3 years with clinical and radiological regression of the pathology and no symptoms and sings have remained. Syringomyelia can mimic intramedullary tumors clinically and radiologically. That is why it is useful to consider exploratory hemilaminectomy to confirm diagnosis.

Treatment of symptomatic interhemispheric arachnoid cysts by cystoperitoneal shunting.

Arachnoid cysts (AC) located within the interhemispheric fissure are rare, frequently associated with agenesis or hypogenesis of the corpus callosum. The optimal method for surgical treatment is under debate. In this study, we retrospectively reviewed the clinical results of seven infants (five males, two females; mean age, 5.1 months) with large interhemispheric AC who underwent cystoperitoneal shunting (CP) and evaluated the long-term efficacy in terms of clinical data, psychomotor development and neuroimaging. All patients were symptomatic and operated on before they reached 1 year of age. In three patients, additional ventricular catheters were inserted due to concomitant hydrocephalus. The additional catheters were joined with the cyst catheters and the peritoneal catheters with Y-shaped connectors in the same session. The patients were followed up for an average of 57 months (range 24-120 months). The clinical and developmental outcome was good in most patients with complete resolution of symptoms and signs. The developmental outcome scale, which included cognitive and psychomotor development, was "good" (normal) or "fair" (near normal) for six of seven patients. Radiologically, the cyst was completely or nearly totally resolved in five patients, and partially resolved in two. In these symptomatic patients with interhemispheric AC, CP shunting provided favorable treatment outcomes with complete or near-total resolution of symptoms and reduction in cyst size or disappearance of the cyst.

Endoscopic anatomy of the oculomotor nerve: defining the blind spot during endoscopic skull base surgery.

OBJECTIVE: The objective of this study is to define the endoscopic anatomy of the oculomotor nerve (CN III) and its neurovascular relations in order to facilitate surgical procedures and avoid injury to this nerve during endoscopic endonasal approach to the skull base. MATERIALS AND METHODS: Endoscopic anatomy of the cavernous sinus was studied in seven fresh adult cadavers bilaterally and the basal cisterns in five fresh adult cadavers. Extended endoscopic endonasal suprasellar approach was performed to expose the oculomotor nerve in the interpeduncular cistern and the endoscopic endonasal transethmoidopterygoidosphenoidal approach to expose the oculomotor nerve within the cavernous sinus. RESULTS: The extraorbital part of the oculomotor nerve can be divided into three segments in regard to the cisterns and venous spaces that are being transected: the interpeduncular segment, the cisternal segment, and the intercavernous segment. Of these segments, only the cisternal segment could not be exposed since this segment was located at the initial part of the roof of the cavernous sinus, anterolateral to the posterior clinoid, and posteroinferior to the anterior clinoid processes. Thus, cisternal segment of the oculomotor nerve was considered a blind spot during endoscopic approaches to the skull base. CONCLUSION: We defined the endoscopic anatomy of the CN III and the related neurovascular structures and proposed a new segmental classification of extraorbital oculomotor nerve. Awareness of the endoscopic anatomy and the new segmental classification of the CN III may prove helpful in avoiding the risk of nerve injury during endoscopic endonasal surgery for skull base pathologies.