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This is the case of a 14-year-old female who presented with headache and seizures. Cranial magnetic resonance imaging revealed an arteriovenous malformation (AVM) located at the posterior portion of the right-sided fusiform gyrus. Cerebral angiography showed that the AVM was fed mainly by branches from the inferior temporal trunk of the posterior cerebral artery. The main venous drainage was to the right transverse sinus through the tentorial vein. The AVM was totally excised through the paramedian supracerebellar-transtentorial approach with the patient in a semisitting position. Postoperative MRI and cerebral angiography confirmed the total resection. The patient was discharged on the 5th postoperative day without neurological deficit. The video can be found here: https://youtu.be/QPrUl8AP7G8 .

Objective A challenging step of the paramedian supracerebellar-transtentorial approach is to expose the anterior portion of the mediobasal-temporal region (MTR), a step that seems most affected by the steepness of the tentorium. The objective of this study was to define magnetic resonance imaging measurements that can predict the level of challenge in exposing the anterior portion of the MTR. Methods Cranial magnetic resonance imaging studies of 100 healthy individuals were examined. The tentorial and occipital angles were measured, and the amount of brain tissue that remained hidden on the microscopic view in front of the petrous apex was indirectly estimated. These measurements were statistically compared with the cephalic index of each person. Results The mean values for the tentorial and occipital angles were 42° (range 25°-53°) and 98° (range 69°-122°), respectively. The results proved that the higher the tentorial angle, the higher the occipital angle and the greater the amount of hidden brain tissue. Of 100 persons, 3 (3%) were found to be dolichocephalic, 23 (23%) were mesocephalic, and 74 (74%) were brachycephalic. Statistical analysis proved that individuals with a dolichocephalic cranial shape have lower tentorial and occipital angles. Conclusions The results provide strong evidence proving that the lesser the tentorial and occipital angles, the easier the exposure of the anterior portion of the MTR during the paramedian supracerebellar-transtentorial approach. The tendency of the cranial shape toward dolichocephaly seems to have the same practical value in choosing the approach. It is easier to expose the anterior portion of the MTR in these individuals. © 2015 Elsevier Inc. All rights reserved.

Objective One significant drawback during a cranial reoperation is the presence of meningocerebral adhesions. The appearance of connective tissue bridges between the inner surface of the dura and the pia-arachnoid is mostly related to dural closure and the condition in which the surgical field was left in the previous surgery. This study was done to determine the benefit of placing a thin-layer gelatin sponge of polypeptides subdurally to prevent meningocerebral adhesions. Methods From September 2005 through May 2012, 902 craniotomies were performed for various lesions by the senior author (U.T.). Beginning in February 2009, we began placing a gelatin sponge under the dural flap to isolate the dural healing process from the cortical surface. To compare the degree of meningocerebral adhesions statistically, reoperation cases between February 2009 and May 2012 were divided into 2 groups as group G (gelatin) and group C (Control) in which the dural closure was made with and without subdural application of the gelatin sponge, respectively. Results In all patients of group G (n = 15), a neomembrane was found when the dura was opened. This layer was easily dissected and showed no or minimal attachment to the underlying cerebral cortex. However, in group C (n = 14), meningocerebral adhesions in various degrees were detected. Adhesion scores were significantly greater in group C than in group G (P < 0.001). Conclusion This study proves that, during the dural closure, placing a thin layer of gelatin sponge in the subdural space is a safe and effective method for preventing meningocerebral adhesions. © 2015 Elsevier Inc. All rights reserved.

OBJRCT: The goal in this study was to explore and further refine comprehension of the anatomical features of the temporal loop, known as Meyer's loop. METHODS: The lateral and inferior aspects of 20 previously frozen, formalin-fixed human brains were dissected under the operating microscope by using fiber microdissection. RESULTS: A loop of the fibers in the anterior temporal region was clearly demonstrated in all dissections. This temporal loop, or Meyer's loop, is commonly known as the anterior portion of the optic radiation. Fiber microdissection in this study, however, revealed that various projection fibers that emerge from the sublentiform portion of the internal capsule (IC-SL), which are the temporopontine fibers, occipitopontine fibers, and the posterior thalamic peduncle (which includes the optic radiation), participate in this temporal loop and become a part of the sagittal stratum. No individual optic radiation fibers could be differentiated in the temporal loop. The dissections also disclosed that the anterior extension and angulation of the temporal loop vary significantly. CONCLUSIONS: The fiber microdissection technique provides clear evidence that a loop in the anterior temporal region exists, but that this temporal loop is not formed exclusively by the optic radiation. Various projection fibers of the IC-SL, of which the optic radiation is only one of the several components, display this common course. The inherent limitations of the fiber dissection technique preclude accurate differentiation among individual fibers of the temporal loop, such as the optic radiation fibers. © AANS, 2015.

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Object. Chordomas are locally aggressive bone tumors known to arise from the remnants of the notochord. Because chordomas are rare, molecular studies aimed at developing new therapies are scarce and new approaches are needed. Chordoma cells and cancer stem-like cells share similar characteristics, including self-renewal, differentiation, and resistance to chemotherapy. Therefore, it seems possible that chordomas might contain a subpopulation of cancer stem-like cells. The aim of this study is to determine whether cancer stem-like cells might be present in chordomas. Methods. In this study, the authors used gene expression analysis for common cancer stem-like cellmarkers, including c-myc, SSEA-I, oct4, klf4, sox2, nanog, and brachyury, and compared chordoma cells and tissues with nucleus pulposus tissues (disc degenerated nontumorigenic tissues). Differentiation through agents such as all-trans retinoic acid and osteogenic differentiation medium was induced to the chordoma cells. Additionally, U-CH I cells were sorted via magnetic cell sorting for stem cell markers CD133 and CD15. After separation, positive and negative cells for these markers were grown in a nonadherent environment, soft agar, to determine whether the presence of these cancer stem-like cells might be responsible for initiating chordoma. The results were compared with those of untreated cells in terms of migration, proliferation, and gene expression by using reverse transcriptase polymerase chain reaction. Results. The results indicate that chordoma cells might be differentiating and committing into an osteogenic lineage when induced with the osteogenic differentiation agent. Chordoma cells that are induced with retinoic acid showed slower migration and proliferation rates when compared with the untreated cells. Chordoma cells that were found to be enriched by cancer stem-like cell markers, namely CD133 and CD15, were able to live in a nonadherent soft agar medium, demonstrating a self-renewal capability. To the authors' knowledge, this is the first time that cancer stem-like cell markers were also found to be expressed in chordoma cells and tissues. Conclusions. Cancer stem-like cell detection might be an important step in determining the recurrent and metastatic characteristics of chordoma. This finding may lead to the development of new approaches toward treatments of chordomas. (http://thejns.org/doi/abs/10.3171/2011.12.JNS11430) Yeditepe UniversityYeditepe University This study was supported by Yeditepe University Research Funding.

Aim: We aimed to investigate the stages of surgical procedure at which venous air embolism might occur, and complications related to echocardiography probe, anesthesia and position of the patient, and also to determine the incidence of venous air embolism during craniotomy performed in the sitting position under monitorization with transesophagial echocardiography (TEE) using our standard anaesthesia protocol. Material and Methods: Sixty ASA I- II patients, aged 18-70 years scheduled for elective craniotomy in the sitting position were enrolled into the study. TEE was used for monitorization of venous air embolism in patients receiving standard anesthesia protocol. Air embolism seen on the monitor of TEE was classified as mild, moderate, severe and very severe (mild: If only air can be seen on screen, moderates if end-tidal carbon dioxide value falls >3 mmHg accompanied with air observed on the screen, severe: increase in heart rate or reduction in blood pressure accompanied with air seen on the screen, and very severe: hemodynamic deterioration requiring cardiopulmonary resuscitation). During the operation, air embolism, as well as any associated hemodynamic changes, precautions taken to prevent entry of air, therapeutic approaches to remove air embolism, and complications of anesthesia were recorded. The findings were expressed as means±SD. Results: In all patients, vena cava, right atrium, right ventricle and venous air entry could be easily monltorlzed echocardiographically. The frequency of air embolism was determined as 35% (n:21) (mild, n=12; moderate, n=9) in 14 of these patients, air entry was detected.during more than one surgical stage. During the postoperative period, pneumocephalus (n=1 ), and discoloration secondary to TEE probe (n=1 ) were found. Conclusions: In this study, air embolism could be detected easily with TEE, which is used for monitoring air embolism during craniotomy in the sitting position in all patients. Minor side effects related to TEE were reported.

Objective: The aim of this study was to evaluate the analgesic efficacy of intravenous PCA using tramadol in patients, undergoing supratentorial tumor resection with craniotomy. Material and Method: One hundred and fifty patients with ASA I-II between 18 and 70 years of age scheduled for an elective supratentorial craniotomy for tumor resection, were assigned to receive standardized general anesthesia. Postoperative pain was assessed at standard time intervals using a visual analogue scale (VAS) score. When the VAS score was >3, 1 to 1.5 mg/kg of tramadol was administered intravenously and PCA using tramadol was started. For 48 h postoperatively, the VAS, Glasgow coma, sedation, comfort, and nausea and vomiting scores were assessed. Results: During the first 48 hours, 46% of the patients needed analgesic therapy and PCA with tramadol was adequate for these patients. Most patients needed analgesic drugs at 2 hours and their mean analgesic usage was higher at that point than at other periods in the first 2 h (p

Bilimsel Zemin: Santral sulkus çevresindeki cerrahi girişimlerde; sensorimotor korteks, operasyon sırasında cerrah tarafından anatomik olarak lokalize edilmektedir. Motor defisit gelişme riski yüksek olan bu bölge cerrahilerinde, preoperatif dönemde fonksiyonel MRG ve traktografi, operasyon sırasında ise faz dönüşümlü somatosensoriyel uyarılmış potansiyeller (FD-SEP) ve/veya kortikal uyarı gibi elektrofizyolojik tekniklerin kullanılması, postoperatif nörolojik defisit gelişim oranını azaltmaktadır. FD-SEP santral sulkusun kesin lokalizasyonu amacıyla kullanılan kolay ve güvenilir bir tekniktir. Amaçlar: Bu çalışmada amaç merkezimizde motor korteks yakınında bulunan tümör operasyonları sırasında yapılan FD-SEP sonuçlarını sunmaktır. Gereç ve Yöntemler: Yeditepe Üniversitesi Hastanesi, Nörolojik Bilimler bölümünde Şubat 2006- Şubat 2008 tarihleri arasında yaşları 11-68 arasında değişen 11 erkek, 4 kadın olguda FD-SEP uygulaması yapılmıştır. Sonuçlar: On üç olguda (% 86,6) FD-SEP çalışması sonucunda santral sulkus lokalize edilmiş ve hiç bir olgumuzda yeni motor defisit gelişmemiştir. İki olguda (%13,3) santral sulkus lokalizasyonu gerçekleştirilememiştir. Yorumlar: Uygulanımı kolay olan FD-SEP ile olguların %80-90'ında santral sulkus'un doğru olarak lokalize edilebildiği daha önce yapılan çalışmalarda bildirilmiştir. Bizim çalışmamızda da literatür ile uyumlu olarak %86 olguda başarılı sonuç elde edilmiştir. FD-SEP; motor korteks yakınındaki cerrahi girişimlerde kullanılan; fonksiyonel MRG ve operasyon sırasındaki anatomik lokalizasyona ek olarak cerrahiye yardımcı olan ve postoperatif motor defisit gelişme riskini azaltan kolay ve güvenilir bir yöntemdir. Scientific Background: During surgeries near the motor cortex the sensori-motor cortex is commonly identified with anatomical markers by the surgeon. These surgeries may be associated with a high risk of motor deficits and preoperative functional magnetic resonance imaging, tractography, or intraoperative electrophysiological techniques such as phase reversal somatosensorial evoked potential (PR-SEP) monitoring and/or cortical stimulation methods may be used to decrease the rate of postoperative deficits. PR-SEP has been reported to be an easy and reliable technique to exactly localize the central sulcus. Objectives: The aim of this study is to report the results of PR-SEP studies performed in our enstitution in surgeries near the motor cortex. Material and Methods: Eleven male and 4 female patients with ages between 11-68 were monitorized with PR-SEP during the period of February 2006-2008 at Yeditepe University Hospital, Neurological Sciences Department. Results: In 13 patients (%86,6) the central sulcus was localized with PR-SEP, and none of our patients had a new postoperative motor deficit. In 2 patients (%13,3) the central sulcus localization was not successful. Conclusions: It has been reported that, PR-SEP is an easy method to localize the central sulcus and is successful in 80-90 % of the cases. Similarly in our study this method was succesfull in 86% of the patients. We conclude that as an addition to the preoperative imaging techniques and intraoperative anatomical localization, PR-SEP is an easy and reliable method to guide the surgeon for the surgeries near the motor cortex in order to decrease the postoperative motor deficits.

Objective: One significant drawback during a cranial reoperation is the presence of meningo-cerebral adhesions. The appearance of these connective tissue bridges between the inner surface of the dura and the pia-arachnoid is directly related to the dural closure in the previous surgery. This study was[for full text, please go to the a.m. URL], 65. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)

Objective The dense and complex distribution of neural structures in the brainstem makes it challenging to understand their real configuration. We used the fiber microdissection technique to show the course of the medial and lateral lemnisci within the brainstem. Although these structures seem anatomically alike, they are functionally distinct. Methods Fifteen human brainstems and 8 brain hemispheres (formalin-fixed and previously frozen) were dissected and studied under the operating microscope by applying the fiber microdissection technique. Results We delineated and described the medial and lateral lemnisci, noting their gross elaborate arrangement. These structures are intimately compact and closely related to one another in their common trajectory through the tegmenta of the pons and midbrain. However, we were not able to identify the exact origin and termination of their fibers or the accurate delimitation between the medial lemniscus, spinothalamic tract, and lateral lemniscus along their course in the brainstem. Conclusions Using the fiber microdissection technique, we were able to define a general perspective of the topography and architecture of the medial and lateral lemnisci in the brainstem. This perspective should be incorporated into interpretations of magnetic resonance imaging techniques, recognizing both their benefits and limitations. It should also be applied to surgical planning and strategies to achieve a safer and more precise microsurgical procedure. © 2016 Elsevier Inc.

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Accurate digital representation of major white matter bundles in the brain is an important goal in neuroscience image computing since the representations can be used for surgical planning, intra-patient longitudinal analysis and inter-subject population connectivity studies. Reconstructing desired fiber bundles generally involves manual selection of regions of interest by an expert, which is subject to user bias and fatigue, hence an automation is desirable. To that end, we first present a novel anatomical representation based on Neighborhood Resolved Fiber Orientation Distributions (NRFOD) along the fibers. The resolved fiber orientations are obtained by generalized q-sampling imaging (GQI) and a subsequent diffusion decomposition method. A fiber-to-fiber distance measure between the proposed fiber representations is then used in a density-based clustering framework to select the clusters corresponding to the major pathways of interest. In addition, neuroanatomical priors are utilized to constrain the set of candidate fibers before density-based clustering. The proposed fiber clustering approach is exemplified on automation of the reconstruction of the major fiber pathways in the brainstem: corticospinal tract (CST); medial lemniscus (ML); middle cerebellar peduncle (MCP); inferior cerebellar peduncle (ICP); superior cerebellar peduncle (SCP). Experimental results on Human Connectome Project (HCP)’s publicly available “WU-Minn 500 Subjects + MEG2 dataset” and expert evaluations demonstrate the potential of the proposed fiber clustering method in brainstem white matter structure analysis. © 2018 Türkiye Bilimsel ve Teknolojik AraÅ?tirma Kurumu: 112E320 Funding: This work was supported by TÜBİTAK (The Scientific and Technological Research Council of Turkey) Grant No. 112E320.

OBJECTIVEThe semisitting position of a patient confers numerous advantages in various neurosurgical procedures, but venous air embolism is one of the associated complications of this position. To date, no prospective studies of the relationship between the degree of head elevation and the rate and severity of venous air embolism for patients undergoing a procedure in this position have been performed. In this study, the authors compared changes in the severity of venous air embolism according to the degree of head elevation (30° or 45°) in patients undergoing an elective cranial neurosurgical procedure in the semisitting position.METHODSOne hundred patients undergoing an elective infratentorial craniotomy in the semisitting position were included, and each patient was assigned to 1 of 2 groups. In Group 1, each patient’s head was elevated 30° during surgery, and in Group 2, each patient’s head elevation was 45°. Patients were assigned to their group according to the location of their lesion. During surgery, the standard anesthetic protocol was used with total intravenous anesthesia, and transesophageal echocardiography was used to detect air in the blood circulation. Any air embolism seen on the echocardiography screen was classified as Grade 0 to 4. If multiple events occurred, the worst graded attack was used for statistical analysis. During hemodynamic changes caused by emboli, fluid and vasopressor requirements were recorded. Surgical and anesthetic complications were recorded also. All results were compared statistically, and a p value of < 0.05 was considered statistically significant.RESULTSThere was a statistically significant difference between groups for the total rates of venous air emboli detected on transesophageal echocardiography (22.0% [n = 11] in Group 1 and 62.5% [n = 30] in Group 2; p < 0.0001). The rate and severity of air embolism were significantly lower in Group 1 than in Group 2 (p < 0.001). The rates of clinically important venous air embolism (Grade 2, 3, or 4, venous air embolism with decreased end-tidal carbon dioxide levels and/or hemodynamic changes) were 8.0% (n = 4) in Group 1 and 50.0% (n = 24) in Group 2 (p < 0.0001). There was no association between the rate and severity of venous air embolism with patient demographics (p > 0.05). An association was found, however, between the rate of venous air embolism and the type of surgical pathology (p < 0.001); venous embolism occurred more frequently in patients with a meningioma. There were no major surgical or anesthetic complications related to patient position during the postoperative period.CONCLUSIONSFor patients in the semisitting position, an increase in the degree of head elevation is related directly to a higher rate of venous air embolism. With a 30° head elevation and our standardized technique of positioning, the semisitting position can be used safely in neurosurgical practice.

Fixed atlantoaxial dislocations are difficult to treat and there is no consensus in the treatment protocol. Unilateral enlargement of the atlas-axis facet complex in fixed atlantoaxial dislocations is a very rare condition. These pathologies are usually quite unstable and surgical treatment is necessary in unreductable cases. A 52-year-old woman with a diagnosis of irreducible-fixed rotatory atlantoaxial dislocation presented with acute onset of dizziness, loss of balance, and tetraparesis. She was under 8 years of conservative follow-up. Review of radiology revealed unilateral C2 superior facet hypertrophy compressing the medulla and obstructing the vertebral artery. To treat this condition, we have used a posterior midline approach and removed the lateral portions of the posterior rim of the foramen magnum and the assimilated posterior arch of C1. The V3 segments of the vertebral arteries were exposed bilaterally. The atlantoaxial joint complex on the left was hypertrophied compressing V3. We have removed hypertrophied lateral mass of the atlas and the hypertrophic superior articular facet of C2 for decompression. Patency of both vertebral arteries were checked intraoperatively by Doppler and indocyanine green angiography. We have fixated craniocervical junction on the same session. Patient was neurologically intact and she had confirmed fusion on the surgical site after three years of follow-up. This is a rare case of unilateral hypertrophy of the C2 superior articular facet in a fixed atlantoaxial rotatory dislocation. Progressive compression of medulla and the left vertebral artery leaded to clinical worsening of neurology in this case after 8 years of follow-up. Surgical treatment was necessary for neurological decompression and to establish stability. © 2013 Springer-Verlag.

WOS: 000396449400059, PubMed ID: 27725299, OBJECTIVE: To describe the topographic anatomy of surgically accessible surfaces of the human thalamus as a guide to surgical exploration of this sensitive area. METHODS: Using the operating microscope, we applied the fiber microdissection technique to study 10 brain specimens. Step-by-step dissections in superior-inferior, medial-lateral, and posterior-anterior directions were conducted to expose the surfaces and nuclei of the thalamus and to investigate the relevant anatomic relationships and visible connections. RESULTS: There were 4 distinct free surfaces of the thalamus identified: lateral ventricle surface, velar surface, cisternal surface, and third ventricle surface. Each is described with reference to recognizable anatomic landmarks and to the underlying thalamic nuclei. The neural structures most commonly encountered during the surgical approach to each individual surface are highlighted and described. CONCLUSIONS: Observations from this study supplement current knowledge, advancing the capabilities to define the exact topographic location of thalamic lesions. This improved understanding of anatomy is valuable when designing the most appropriate and least traumatic surgical approach to thalamic lesions. These proposed surface divisions, based on recognizable anatomic landmarks, can provide more reliable surgical orientation.

Objective We planned a cross-sectional analysis to determine the frequency and severity of metabolic acidosis in patients taking topiramate while awaiting craniotomy. Methods Eighty patients (18 – 65 years) taking topiramate to control seizures while awaiting elective craniotomy were enrolled. Any signs of metabolic acidosis or topiramate-related side effects were investigated. Blood chemistry levels and arterial blood gases, including lactate, were obtained. The severity of metabolic acidosis was defined according to base excess levels as mild or moderate. Results Blood gas analysis showed that 71% ( n = 57) of patients had metabolic acidosis. The frequency of moderate metabolic acidosis was 56% ( n = 45), while that of mild metabolic acidosis was 15% ( n = 12). A high respiratory rate was reported in only 10% of moderately acidotic patients. Conclusions In patients receiving topiramate, baseline blood gas analysis should be performed preoperatively to determine the presence and severity of metabolic acidosis.

Gabapentin is an anticonvulsant drug that has analgesic properties for acute postoperative pain. However, the analgesic effect of gabapentin as an antiepileptic prophylactic drug on patients undergoing craniotomy is unclear. In this study, we evaluated the postoperative effectiveness of gabapentin on acute postoperative pain when it is used for antiepileptic prophylaxis in patients undergoing craniotomy for supratentorial tumor resection.Eighty patients undergoing craniotomy for supratentorial tumor resection were randomly assigned into two groups. Patients in Group G (n = 40) received oral gabapentin (3 x 400 mg), and patients in Group P (n = 40) received oral phenytoin (3 x 100 mg) for 7 days before the operation and postoperatively. An identical anesthesia protocol was performed for both the groups. Anesthesia was maintained with propofol and remifentanil infusion. Patient-controlled analgesia with morphine was used, and pain levels were measured. The antiepileptic-related side effects, anesthetic consumption, duration of anesthesia and surgery, tracheal extubation time, postoperative pain scores, morphine consumption, and sedation scores were recorded.Thirty-seven patients in Group G and 38 patients in Group P completed the study. During the preoperative period in Group G, one patient had severe fatigue, one had severe dizziness, and one patient's surgical procedure was changed. The median plasma levels of gabapentin were 34 micromol/mL (range, 23-51 micromol/mL) in 34 patients. In Group P, one patient withdrew from the study preoperatively and one developed transient neurological symptoms postoperatively. The demographic data and mean duration of anesthesia and surgery were similar in both the groups. The total propofol and remifentanil consumption in Group G (1847 +/- 548 mg/3034 +/- 1334 microg) was significantly less than that of Group P (2293 +/- 580 mg/4287 +/- 1282 microg) (P = 0.01). However, tracheal extubation could be done earlier in Group P (4.5 +/- 2 min) than in Group G (16.6 +/- 22 min) (P0.001). Pain scores were significantly higher in Group P at 15 min, 30 min, and 1 h (P0.001). The total morphine consumption was also significantly higher in Group P (33 +/- 17 mg vs 24 +/- 19 mg) (P = 0.01). The postoperative sedation scores were significantly higher in Group G at 15 min, 30 min, 1 h, and 2 h (P0.001).The administration of gabapentin to patients undergoing craniotomy for supratentorial tumor resection was effective for acute postoperative pain. It also decreased analgesic consumption after surgery. However, it may lead to side effects such as delayed tracheal extubation and increased sedation postoperatively.

The role of intraoperative monitoring of lower cranial nerves is not well established. In this study, the authors retrospectively analyzed the intraoperative monitoring data and the clinical outcome of the spinal accessory nerve (SAN) in patients who have undergone posterior fossa surgery. SAN was monitored in 19 patients. Subcutaneous needle electrodes were placed in the trapezius, and any abnormal spontaneous activity was documented for duration and amplitude. A bipolar stimulation probe was used for triggered electromyogram, with a maximum stimulation intensity of 3 mA. All patients were clinically evaluated for SAN dysfunction postoperatively 24 hours and 7 days. Neurotonic discharges, lasting between 3 and 90 minutes were seen in 84% of the patients. Continuous discharges lasting longer than 5 minutes were seen in 36% of the patients. The SAN was stimulated in 57.8% of the patients. With clinical examination, none of our patients had postoperative SAN dysfunction. Long lasting dense neurotonic discharges and high stimulation thresholds have been correlated with postoperative facial nerve injury; however, this does seem be true in the case of SAN monitoring. Neurotonic discharges are commonly false-positive and stimulation intensity up to 3 mA can be related with a good outcome. The intraoperative monitoring of SAN may not be valuable as much as facial nerve monitoring. Copyright © 2008 American Clinical Neurophysiology Society.

High cervical disc herniations (C2-C3) are extremely rare, and various approaches have been used to treat C2-C3. In this report, we recommend the anterolateral extradural approach as an alternative to treat C2-C3 disc herniation. A 72-year-old woman was referred to us with severe pain in the left side of her neck and occipital region. She had been taking high doses of analgesics but had no myelopathic symptoms. Magnetic resonance imaging of the cervical spine revealed that left paramedian, extruded C2-C3 disc material was compressing the spinal cord and the left C3 nerve root. A left-sided anterolateral extradural approach was done to remove the extruded disc material at the C2-C3 level. After resection of the transverse processes of C1 and C2, the V3 segment of the vertebral artery was mobilized posteromedially. The extruded disc material was carefully removed, and the vertebral artery was freed and repositioned. The anterolateral extradural approach to a C2-C3 disc herniation is a good alternative, especially in patients with thick or short necks. © 2007 Springer-Verlag.

BACKGROUND: During surgery for intrinsic brain lesions, it is important to distinguish the pathological gyrus from the surrounding normal sulci and gyri. This task is usually tedious because of the pia-arachnoid membranes with their arterial and venous complexes that obscure the underlying anatomy. Moreover, most tumors grow in the white matter without initially distorting the cortical anatomy, making their direct visualization more difficult. OBJECTIVE: To create and evaluate a simple and free surgical planning tool to simulate the anatomy of the surgical field with and without vessels. METHODS: We used free computer software (OsiriX Medical Imaging Software) that allowed us to create 3-dimensional reconstructions of the cerebral surface with and without cortical vessels. These reconstructions made use of magnetic resonance images from 51 patients with neocortical supratentorial lesions operated on over a period of 21 months (June 2011 to February 2013). The 3-dimensional (3-D) anatomic images were compared with the true surgical view to evaluate their accuracy. In all patients, the landmarks determined by 3-D reconstruction were cross-checked during surgery with high-resolution ultrasonography; in select cases, they were also checked with indocyanine green videoangiography. RESULTS: The reconstructed neurovascular structures were confirmed intraoperatively in all patients. We found this technique to be extremely useful in achieving pure lesionectomy, as it defines tumor's borders precisely. CONCLUSION: A 3-D reconstruction of the cortical surface can be easily created with free OsiriX software. This technique helps the surgeon perfect the mentally created 3-D picture of the tumor location to carry out cleaner, safer surgeries. © 2014 by the Congress of Neurological Surgeons.

Achille Louis Foville's atlas of brain anatomy (1844) is one of the most artistic and detailed works on neuroanatomy in the medical literature. The outstanding drawings by the 2 artists, Emile Beau and Frederic-Michel Bion, highlight all the philosophy, ability, and sensibility of A.L. Foville in carefully dissecting the superficial and deep structures of the brain and spinal cord. Several plates show true brain fiber dissections of high artistic and academic value. As a result of an early misrecognition in the medical literature, "inferior Foville syndrome" has been wrongly attributed to Achille Louis Foville rather than his son, Achille Louis Francois Foville (1832-1887), also called Defoville. Therefore, we suggest that Defoville, who actually described the pontine syndrome for the first time in the neurological literature, deserves to be credited for this syndrome and that the syndrome should be called the Defoville syndrome. Through analyzing the political and scientific events in France in the 19th century, we highlight the invaluable contributions of A.L. Foville and his son to the history of neuroanatomy and neurology.

Introduction Cerebral cavernous malformations (cavernomas) are one of the four types of cerebrovascular malformations. The other three are arteriovenous malformations, capillary telangiectases, and venous malformations [1]. A sporadic and a hereditary form of cavernous malformations have been described [2]. These lesions are well-circumscribed, consisting of closely packed and enlarged capillary-like vessels. They do not contain intervening parenchyma and, histologically, the vascular channels (which resemble dilated capillaries) are lined by a single layer of vascular endothelium surrounded by a layer of dense fibrous tissue [3, 4]. Cavernous malformations account for 5% to 10% of vascular malformations in the central nervous system. Eighty percent are located supratentorially, with a mostly superficial preference, and these histopathologically benign lesions occur in 0.1% to 0.9% of the population [5–8]. © Cambridge University Press 2011.

BACKGROUND: In this study, we investigated the effects of propofol infusion on hepatic and pancreatic enzymes and acid-base status compared with baseline values in children undergoing craniotomy who were receiving phenytoin for antiepileptic prophylaxis. METHODS: In this prospective clinical study, we measured the serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), ?-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP), pancreatic amylase, lipase, and triglyceride levels of 30 children ranging from 4 to 12 yr. All children received propofol anesthesia and were taking phenytoin for antiepileptic prophylaxis. Patients already receiving phenytoin were continued on their medication. Peroral 5 mg • kg • d phenytoin was started in patients who were not receiving phenytoin. Serum AST, ALT, GGT, ALP, bilirubin, pancreatic amylase, lipase, and triglyceride levels were studied on admission to the hospital, 1 day before surgery, and on postoperative Days 1, 3, 5, and 7. Arterial blood gas samplings were taken after tracheal intubation, during the operation (2nd and 4th h), just after extubation, and 1, 2, 6, and 12 h after extubation. RESULTS: Serum AST, ALT, GGT, ALP, pancreatic amylase, lipase, and triglyceride levels were increased significantly in the postoperative period compared with baseline with a peak value on postoperative Day 1 and returned to normal values within a week. Base excess levels after extubation were significantly decreased compared with baseline. They were in the normal range, however, and returned to baseline values by 6 h after surgery. There were no clinical signs of hepatitis or pancreatitis. Bilirubin levels were normal. None of the children developed complications related to the liver or pancreas during the 4-6 mo after surgery. CONCLUSIONS: Despite the slightly increased pancreatic and hepatic enzyme levels during the postoperative period, anesthesia maintenance with propofol in children undergoing craniotomy had no significant clinical effect on the acid-base status or pancreas or liver enzymes. Copyright © 2009 International Anesthesia Research Society.

OBJECTIVE: We investigated the membranous architecture of the abducens nerve at the petroclival region and describe the characteristics of this area in cadaveric specimen and two children with hydrocephalus and sixth nerve palsy using magnetic resonance imaging (MRI). MATERIALS AND METHODS: Five adult cadaver heads were used to investigate the petroclival part of the abducens nerve. The heads were injected with colored latex for microsurgical dissection, and the length of the dural sleeve of the abducens nerve and its width at the apex were measured. In one cadaver head, the area between the petroclival entrance porus of the abducens nerve and the cavernous sinus was histologically studied under light microscopy. In two patients with hydrocephalus and abducens nerve palsy, the petroclival area was screened by using the MRI fat suppression technique. RESULTS: In the cadavers, the arachnoid membrane on the clivus extended within the dural sleeve as far as the petrous apex, as an extension of the subarachnoid space. The average length of the dural sleeve was 9.5 mm and the average width was 1.5 mm at the apex, where the nerve entered the cavernous sinus. MRI scans showed that the cerebrospinal fluid distance of the petroclival region was 5 mm in the first patient and 7 mm in the second. CONCLUSION: The subarachnoid space inside the dural sleeve of the abducens nerve can be defined by using thin-slice MRI scans. Enlargement of the dural sleeve at the petroclival region may coexist with the abducens nerve palsy. It has been documented in this study that the arachnoid membrane forms a membraneous barrier between the subarachnoid and subdural spaces within Dorello's canal. Copyright © by the Congress of Neurological Surgeons.

WOS: 000240398700024 PubMed: 16906438 The injection of cadaver brains is invaluable for anatomic study, but cadavers that have been properly handled are not easy to obtain. A large number of cadavers pass through forensic departments around the world, and these cadavers could provide hundreds of research specimens, though they remain in the forensic unit for only a short time. The injection of a silicone mixture that quickly solidifies during autopsy would provide greater numbers of fresh specimens for study. The authors describe a technique for injecting a self-curing silicone mixture that can be used on autopsy specimens in a forensic unit. This technique does not interfere with routine autopsy findings. We describe the preparation of the mixture and autopsy specimens, the injection process, and the method for removing injected brains from cadavers. The solidifying process took a 1-h duration in this injection method and was in accord with autopsy procedure. The arterial bed was satisfactorily filled, and even small perforating branches and pial anastomoses were well demonstrated. Injecting autopsy specimens with the quick-solidifying silicone mixture allows anatomical studies of specimens even from cadavers admitted to forensic departments for only a short time. This method can provide neurosurgery laboratories with sufficient numbers of specimens appropriate for various studies.