What is the restorative effect of VEGF inhibitor bevacuzimab against subarachnoid hemorrhage in an experimental model?

BACKGROUND: This study investigated the effect of vascular endothelial growth factor (VEGF) inhibitor bevacuzimab (BVZ) on the rabbit basilar artery using an experimental subarachnoid hemorrhage (SAH) model. METHODS: Eighteen adult male New-Zealand white rabbits were randomly divided into three groups: a control group (n = 6), SAH group (n = 6), and SAH+BVZ group (n = 6). Experimental SAH was created by injecting autologous arterial blood into the cisterna magna. In the treatment group, the subjects were administered a daily dose of 10 mg/kg, intravenous BVZ for 2 days after the SAH. Basilar artery diameters were measured with magnetic resonance angiography (MRA) 72 h after the SAH in all groups. After 72 h, whole brains, including the upper cervical region, were obtained from all the animals after perfusion and fixation of the animal. The wall thickness, luminal area, and the apoptosis at the basilar arteries were evaluated in all groups. RESULTS: BVZ significantly prevented SAH-induced vasospasm confirmed in vivo with MRA imaging with additional suppression of apoptosis on basilar artery wall. DISCUSSION: VEGF inhibition with BVZ has shown to have a vasospasm and apoptosis attenuating effect on basilar artery in a SAH model.

Dual-Ionomer-Based Device: Acetylcholine Transport and Nonenzymatic Sensing.

The malfunctioning in the release of acetylcholine (ACh+), leading to consequential damages in the neural system, has become an impulsion for the development of numerous progressive transport and detection gadgets. However, several challenges, such as laterality and complexity of transport devices, low precision of amperometric detection systems, and sumptuous, multistaged enzymatic quantification methods, have not yet been overcome. Herein, ionomers, because of their selective ion transporting nature, are chosen as suitable candidates for being implemented into both targeted ACh+ delivery and sensing systems. Based on these two approaches, for the very first time in the literature, the disulfonated poly(arylene ether sulfone) membrane is concurrently (i) used in the mimicry of transduction of the electrical-to-ionic signal in a neural network as "Acetylcholine Pen" (ACh+ Pen) and (ii) operated as a highly sensitive, conductivity-based ACh+ quantifier. Our dual device, being able to operate under an actual action potential of 55 mVbias, shows a strong potential of future applicability in real-time ionic delivery-and-sensing systems.

Prognostic Factors in Oligodendrogliomas: a Clinical Study of Twenty-Five Consecutive Patients.

BACKGROUND: The purpose of this study was to evaluate the prognostic significance of Ki-67 and subjective microvascular density (SMVD) indexes together with other factors in patients with oligodendroglioma. MATERIALS AND METHODS: In this retrospective study, oligodendroglioma specimens obtained from twenty-five consecutive patients were evaluated for Ki-67 and SMVD indices to help determine histological grading and investigate the fidelity of these markers in clinical prognosis. Other potentially prognostic factors were Karnofsky performance scale, tumor histological grade, and adjuvant radiotherapy. RESULTS: The Ki-67 proliferation index appeared to have a strong correlation with the grade of the tumor and the survival. Age, gender, adjuvant radiotherapy, surgical resection type (complete versus incomplete) did not have any influence on recurrence. The SMVD index correlated significantly with the 3 to 5-year survival. CONCLUSIONS: Ki-67 and MVD indexes are important and useful markers in estimating the prognosis of oligodendrogliomas.

Decrease in serine protease HtrA1 expression correlates with grade and recurrence in meningiomas.

PURPOSE: HtrA1 is a serine protease which was shown to be down-regulated in a variety of human cancers. It is considered to be a tumor suppressor and suggested as a prognostic marker and a therapeutic candidate. In order to investigate any possible implication of HtrA1 in meningioma we studied 100 cases. MATERIAL/METHODS: We used immunohistochemistry to determine HtrA1 expression in tumor tissue. Expression levels were evaluated with respect to tumor grade and recurrence. RESULTS: Our data revealed a strong association between decrease in HtrA1 expression and increase in meningioma grade (p=0.005). Most importantly, patients with higher HtrA1 expression had a lower rate of recurrence (p<0.001). CONCLUSIONS: According to our results HtrA1 appeared as an immunohistochemical marker to predict behaviour of the meningioma, mainly the recurrence. Although the exact mechanisms of HtrA1 are still largely unknown, we think that further in vivo and in vitro studies explaining the molecular targets of HtrA1 would have a great importance with regard to its role as a therapeutic agent for meningioma.

The cadaveric perfusion and angiography as a teaching tool: imaging the intracranial vasculature in cadavers.

Background and Study Aim To enhance the visualization of the intracranial vasculature of cadavers under gross examination with a combination of imaging modalities. Material and Methods A total of 20 cadaver heads were used to test two different perfusion techniques. First, fixed cadaver heads were perfused with water; second, fresh cadavers were perfused with saline and 10% formalin. Subsequently, brains were removed and fixed. The compounds used were silicone rubber, silicone rubber mixed with powdered barium sulfate, and silicone rubber mixed with tantalum dioxide prepared by the first perfusion technique and gelatin mixed with liquid barium prepared with the second technique. Conventional X-ray imaging, computed tomography (CT), dynamic computed tomography (dCT), and postprocessing three-dimensional (3D) images were used to evaluate all the heads. Results Gelatinized barium was better visualized when compared with tantalum dioxide in conventional X-ray images. The blood vessels injected with either tantalum dioxide or gelatinized barium demonstrated a higher enhancement than the surrounding soft tissues with CT or dCT. The quality of the 3D reconstruction of the intracranial vasculature was significantly better in the CT images obtained from the gelatinized barium group. Conclusions Radiologic examinations of the heads injected with gelatinized barium facilitates the 3D understanding of cerebrovascular anatomy as an important tool for neuroanatomy training.

Osteopontin expressions correlate with WHO grades and predict recurrence in meningiomas.

Recurrence of meningiomas is a major prognostic issue. Although World Health Organization (WHO) histopathological grading correlates strongly with recurrence, it has some limitations, and predicting the biological behavior of grade I meningiomas is particularly difficult. Osteopontin (OPN) is a protein known to be involved in tumor progression. The purpose of this study is to determine expression of OPN in meningiomas and to investigate its correlation with WHO grades and tumor recurrence. Immunohistochemical (IHC) evaluation of expression of OPN was performed by two different methods to ensure reliability. OPN IHC and Allred scores were calculated on the basis of intensity and extent of staining. Both scores were in agreement and correlated significantly with meningioma grade and Ki-67 index. OPN scores were also significantly correlated with recurrence of WHO grade I meningiomas. Cut-off values for OPN IHC and OPN Allred scores between non-recurrent and recurrent grade I meningiomas were calculated as 70 and 5.5 respectively. We concluded that OPN is a valuable marker for grading meningiomas and for predicting the recurrence in WHO grade I tumors.

[Seroepidemiology of pertussis in 10-15 years old healthy children in Isparta province, Turkey]. / Isparta ilinde 10-15 yas grubu saglikli çocuklarda bogmaca seroepidemiyolojisi.

Pertussis, a highly contagious respiratory disease, commonly affects infants and young children and can be fatal, especially in babies less than one year of age. Bordetella pertussis continues to circulate even in populations where a high vaccine coverage of infants and children is achieved. Adults are reservoirs for infections in infants, in whom pertussis may be severe and life-threatening. Despite the rising rates of vaccination in our country and all over the world for the past 25 years, the number of pertussis cases among adolescents and adults has been increasing. To decrease the risk of pertussis infection and thus protect adults and adolescents against pertussis, booster doses should be administered to preschool children and adolescents. In order to decide when to administer the booster doses in a country, age-specific seropidemiology of the disease should be known. The aim of this study was to determine the pertussis toxin antibody levels of fully vaccinated healthy children in Isparta, Turkey, aged 10-15 years old. A total of 296 participants, that comprised fully vaccinated 254 healthy elementary-school students aged between 10-15 years (126 male, 128 female) and 42 adults between 18-39 years old (21 male, 21 female) were included in the study with informed consent. The sensitivities of subjects to pertussis were tested by the determination of pertussis toxin IgG levels with the use of commercial ELISA test (Genzyme Virotech, Germany). In our study, the seropositivity rate was found 12.6% (32/254) for 10-15 age group, however all the adult subjects were seronegative. Thus the total seropositivity rate was estimated as 10.8% (32/296). Pertussis toxin IgG seropositivity rate was 12.7% (16/126) for males and 12.5% (16/128) for females, and there was no significant gender difference (p> 0.05). The highest seropositivity rates were detected at 10(th) (23.8%) and 11(th) (19%) years in males, and 12(th) and 14(th) (23.8%) years in females. No seropositivity was detected in individuals over age 15 in our study. Since adults lose their immune protection gained by pertussis vaccination, they start becoming an infection source for infants. Therefore, a booster dose of acellular pertussis vaccine should be considered in preschool period and at ages 14-18. Further studies regarding diagnosis and surveillance of pertussis disease are required, as well as enhancement of vaccination rates.

Study the effects of zonisamide on fine structure of rabbit basilar artery and hippocampus in rabbit subarachnoid hemorrhage model.

BACKGROUND: In this study, we investigated the effect of a novel antiepileptic drug, zonisamide (ZNS), on the basilar artery and hippocampus in a rabbit subarachnoid hemorrhage (SAH) model. METHODS: Three groups of New Zealand white rabbits were used: a sham (non-SAH) group, an SAH + saline group, and SAH + drug treatment group that received ZNS. In the treatment group, the subjects were given ZNS for 3 days after the SAH. Hippocampal sections were evaluated for neural tissue degeneration. Basilar artery lumen areas and arterial wall thickness were also measured in all groups. RESULTS: The mean luminal area of the SAH + ZNS was significantly greater than the SAH + saline group. In addition, the arterial wall thickness of SAH + ZNS group was significantly thinner than the SAH + saline group. The neuronal degeneration scores of the hippocampal CA1 regions in the SAH + ZNS group were significantly lower than the SAH + saline treatment animals. CONCLUSIONS: These results indicate that ZNS has a vasodilatatory effect on the basilar artery and a neuronal protective effect in the CA1 region of the hippocampus in a rabbit SAH model.

Primary osteoma of the orbit with atypical facial pain: case report and literature review.

Osteoma is a benign, slowly growing tumor that mainly occurs in the bones and cavities of the middle third of the face, representing the most frequent benign tumor of the paranasal sinuses. It rarely originates primarily from the orbit. Most of these lesions develop in the fourth to fifth decades of life, and are more commonly encountered in males. In the English literature, there are so far three reported cases of primary osteoma of the orbit that originated from the sphenoid bone. Here we present another case of a primary osteoma of the orbit presenting with atypical facial pain and discuss the relevant literature.

Level I to III craniofacial approaches based on Barrow classification for treatment of skull base meningiomas: surgical technique, microsurgical anatomy, and case illustrations.

OBJECT: Although craniofacial approaches to the midline skull base have been defined and surgical results have been published, clear descriptions of these complex approaches in a step-wise manner are lacking. The objective of this study is to demonstrate the surgical technique of craniofacial approaches based on Barrow classification (Levels I-III) and to study the microsurgical anatomy pertinent to these complex craniofacial approaches. METHODS: Ten adult cadaveric heads perfused with colored silicone and 24 dry human skulls were used to study the microsurgical anatomy and to demonstrate craniofacial approaches in a step-wise manner. In addition to cadaveric studies, case illustrations of anterior skull base meningiomas were presented to demonstrate the clinical application of the first 3 (Levels I-III) approaches. RESULTS: Cadaveric head dissection was performed in 10 heads using craniofacial approaches. Ethmoid and sphenoid sinuses, cribriform plate, orbit, planum sphenoidale, clivus, sellar, and parasellar regions were shown at Levels I, II, and III. In 24 human dry skulls (48 sides), a supraorbital notch (85.4%) was observed more frequently than the supraorbital foramen (14.6%). The mean distance between the supraorbital foramen notch to the midline was 21.9 mm on the right side and 21.8 mm on the left. By accepting the middle point of the nasofrontal suture as a landmark, the mean distances to the anterior ethmoidal foramen from the middle point of this suture were 32 mm on the right side and 34 mm on the left. The mean distance between the anterior and posterior ethmoidal foramina was 12.3 mm on both sides; the mean distance between the posterior ethmoidal foramen and distal opening of the optic canal was 7.1 mm on the right side and 7.3 mm on the left. CONCLUSIONS: Barrow classification is a simple and stepwise system to better understand the surgical anatomy and refine the techniques in performing these complex craniofacial approaches. On the other hand, thorough anatomical knowledge of the midline skull base and variations of the neurovascular structures is crucial to perform successful craniofacial approaches.

Comparison of the effect of mexiletine and methylprednisolone on neural function and histopathological damage after transient spinal cord ischemia in rabbits.

AIM: The purpose of this study was to investigate the effect of mexiletine on the neural function and histopathological changes after ischemic spinal cord injury in rabbits. We also compared the effect of mexiletine to that of methylprednisolone. MATERIAL AND METHODS: Twenty six male New Zealand white rabbits were randomly divided into six groups. Group 1; sham operated group (n=3) underwent only the surgical exposure of infrarenal aorta. Group 2 (n=4) received neither intravenous (iv) nor intraperitoneal medication but the infrarenal aorta was cross-clamped. Group 3 (n=5) received intravenous infusion of 20 ml/kg/h normal saline. Group 4 (n=5) received 30 mg/kg intravenous methylprednisolone. Group 5 (n=3) received intraperitoneal 20mg/kg/h normal saline. Group 6 (n=6) received 50mg/kg mexiletine intraperitoneally. Temporary spinal cord ishemia was induced by infrarenal aortic occlusion for 25 minutes and followed by reperfusion. The neural status was scored using the Tarlov criteria at 24 hours after reperfusion. Immediately after the neurological scoring, the spinal cords of all animals were removed for histopathological study. RESULTS: Histopathological examination scores were significantly higher in group 6 compared to group 2 (p < 0.05). CONCLUSION: Mexiletine can significantly ameloriate the neural function and prevent histopathological damage after transient spinal cord ischemia in rabbits. This is the first research that investigates the neuron=protective effect of mexiletine in a spinal cord ischemia model.

Safe zone for C1 lateral mass screws: anatomic and radiological study.

OBJECTIVE: To evaluate the possible complications of overpenetrated C1 lateral mass screws and to identify and define a "safe zone" area anterior to the C1 vertebra. METHODS: The study was performed on 10 cadavers and 50 random patients who had undergone computed tomographic scanning with contrast medium of the neck for other purposes. Atlas lateral mass screw trajectories were plotted, and the safe zone for screw placement anterior to the atlas vertebra was determined for each trajectory. RESULTS: The trajectory of the internal carotid artery was measured from its medial wall. The trajectory of the internal carotid artery according to the ideal entrance point of the screw was 11.55 +/- 4.55 degrees (range, 2-22 degrees) in the cadavers and 9.78 +/- 4.55 degrees (range, -5 to 22 degrees) bilaterally in the patients. At 15 degrees (ideal screw trajectory), the thickness of the rectus capitis anterior muscle and longus capitis muscle was 6.69 +/- 0.83 mm (range, 5.32-7.92 mm) in the cadavers and 7.29 +/- 1.90 mm (range, 0.50-13.63 mm) bilaterally in the patients. The smallest distance from the internal carotid artery to the anterior cortex of the C1 vertebra was calculated as 4.33 +/- 2.03 mm (range, 1.15-8.40 mm) bilaterally in the cadavers and 5.07 +/- 1.72 mm (range, 2.15-8.91 mm) bilaterally in radiological specimens. CONCLUSION: The internal carotid artery trajectory is lateral to the ideal entrance point of C1 lateral mass screws. The medial angulation of a screw placed in the lateral mass of C1 seemed to increase the margin of safety for the internal carotid artery. The rectus capitis anterior and longus capitis muscles may be thought of as a safe zone area for C1 lateral mass screws. At more than 25 degrees of medial angulation, the risk of perforation of the oropharyngeal wall increases.

Freehand C1 lateral mass screw fixation technique: our experience.

BACKGROUND: Although C1 lateral mass fixation technique is frequently performed in upper cervical instabilities, it requires the guidance of fluoroscopic imaging. The fluoroscopy guidance is time-consuming and has the risks of accumulative radiation. Biplane fluoroscopy is also difficult in upper cervical pathologic conditions because of the use of cranial fixations. This study aimed to demonstrate that unicortical C1 lateral mass screws could be placed safely and rapidly without fluoroscopy guidance. METHODS: Between 2002 and 2008, 32 C1 lateral mass screws were inserted in 17 consecutive patients with various pathologic conditions involving either atlantoaxial or occipitocervical instability. RESULTS: C1 screw lengths ranged from 18 to 32 mm. The atlantoaxial fixation was performed in 13 patients, and C1 lateral mass screws were added to the occipitocervical construct in 3 patients, to the posterior cervical construct in 2 patients, and to the cervicothoracic construct in 1 patient. In 2 patients, because C1 lateral mass screws could not be inserted unilaterally, C1 pedicle screw analogs were inserted. There were no screw malpositions or neurovascular complications related to screw insertion. Operation time and intraoperative bleeding of the isolated atlantoaxial fixations were retrospectively evaluated. The mean follow-up was 32.3 months (range, 7-59 months). No screw loosening or construct failure was observed within this period. Postoperatively, 4 patients complained of hypoesthesia, whereas one patient had superficial wound infection. CONCLUSION: C1 lateral mass screws may be used safely and rapidly in upper cervical instabilities without intraoperative fluoroscopy guidance and the use of the spinal navigation systems. Preoperative planning and determining the ideal screw insertion point, the ideal trajections, and the lengths of the screws are the most important points.

Ideal screw entry point and projection angles for posterior lateral mass fixation of the atlas: an anatomical study.

Although various posterior insertion angles for screw insertion have been proposed for C1 lateral mass, substantial conclusions have not been reached regarding ideal angles and average length of the screw yet. We aimed to re-consider the morphometry and the ideal trajections of the C1 screw. Morphometric analysis was performed on 40 Turkish dried atlas vertebrae obtained from the Department of Anatomy at the Medical School of Ankara University. The quantitative anatomy of the screw entry zone, trajectories, and the ideal lengths of the screws were calculated to evaluate the feasibility of posterior screw fixation of the lateral mass of the atlas. The entry point into the lateral mass of the atlas is the intersection of the posterior arch and the C1 lateral mass. The optimum medial angle is 13.5 +/- 1.9 degrees and maximal angle of medialization is 29.4 +/- 3.0 degrees . The ideal cephalic angle is 15.2 +/- 2.6 degrees , and the maximum cephalic angle is 29.6 +/- 2.6 degrees . The optimum screw length was found to be 19.59 +/- 2.20 mm. With more than 30 degrees of medial trajections and cephalic trajections the screw penetrates into the spinal canal and atlantooccipital joint, respectively. Strikingly, in 52% of our specimens, the height of the inferior articular process was under 3.5 mm, and in 70% was under 4 mm, which increases the importance of the preparation of the screw entry site. For accommodation of screws of 3.5-mm in diameter, the starting point should be taken as the insertion of the posterior arch at the superior end of the inferior articular process with a cephalic trajection. This study may aid many surgeons in their attempts to place C1 lateral mass screws.

Removal of cavernous malformation of the Meckel's cave by extradural pterional approach using Heros muscle dissection technique.

BACKGROUND: We report on a patient with trigeminal neuralgia caused by an extraaxial cavernous malformation (CM) located within Meckel's cave. The lesion was removed via a pterional extradural approach with a modified temporalis muscle dissection technique, which was first described by Heros and Lee. Cadaveric dissections were performed to demonstrate the wider exposure gained by this approach. METHODS: A 56-year-old man presented with a history of episodic shocklike, right-sided facial pain for 10 years. Neurologic examination revealed diminished sensation in the mandibular division of the right trigeminal nerve. Magnetic resonance imaging showed an ipsilateral enhancing lesion in Meckel's cave. RESULTS: After placement of a lumbar drain, a right extradural pterional approach was undertaken. By reflecting the temporalis muscle posterolaterally, the craniotomy was extended so that the line of sight was level with the floor of the middle fossa. This allowed access to the lesion without needing to remove the zygoma. The lesion was resected with microsurgical technique. The patient's pain improved significantly after resection, and histopathologic examination confirmed the diagnosis of CM. CONCLUSIONS: Extraaxial middle fossa CMs arising solely from Meckel's cave are rare. These lesions are safely and simply approached by posteriorly deflecting the temporalis muscle during a pterional craniotomy, avoiding excessive elevation of the anterior temporal lobe or further bony removal.

Topiramate attenuates hippocampal injury after experimental subarachnoid hemorrhage in rabbits.

OBJECTIVE: The aim of this study was to investigate the ability of topiramate (TPM) to prevent neural injury in a rabbit model of subarachnoid hemorrhage (SAH). The effect of TPM on cerebral vasospasm was also evaluated. METHODS: Fifty-three New Zealand white rabbits were allocated into three groups randomly. SAH was induced by injecting autologous blood into the cisterna magna. The treatment groups were as follows: (1) sham operated (no SAH (n=18); (2) SAH only (n=17); (3) SAH + TPM (n=18). Hippocampal sections were evaluated for neural tissue degeneration, using the previously described neural degeneration scoring system. The ApopTag peroxidase in situ apoptosis detection kit (Serologicals Corp., former Intergen) was used to assess apoptosis in the hippocampal sections and the effect of TPM on the apoptotic response. Basilar artery lumen areas and arterial wall thickness were also measured in all groups. RESULTS: There was a statistically significant difference between the mean degeneration scores of the control and SAH only groups (p<0.05). The level of neural degeneration in TPM treated group was significantly lower compared with SAH only group (p<0.05), but not significantly higher than the control group (p>0.05). There were no statistically significant differences between arterial cross-sectional area and arterial wall thickness measurements of the SAH group and SAH + TPM group. CONCLUSION: These findings demonstrate that TPM has marked neuroprotective effect in an experimental model of SAH in rabbits. This observation may have clinical implications suggesting that this antiepileptic drug could be used as a possible neuroprotective agent in patients without major adverse effects.

Crossed Wernicke's aphasia after aneurysmal subarachnoid hemorrhage: a case report.

Crossed aphasia (CA) refers to aphasia occurring after right brain damage in right handers. In the literature, numerous CA cases following cerebral ischemia have been reported, but few met the criteria for a prompt diagnosis. The authors present the case of a 52-year-old woman with SAH caused by a right middle cerebral artery (MCA) saccular aneurysm who developed non-fluent aphasia characterized by reduced verbal output, word-finding disturbances and phonemic paraphasias in both oral and written language. 99mTc-HMPAO SPECT was also consistent with right parieto-temporal and frontoparietal ischemia with crossed cerebellar diaschisis on the right cerebellum. A diagnosis of CA was made. One year follow-up showed improvement in communication skills but persistent right fronto-temporo-parietal ischemia. Cerebral vasospasm after aneurysmal SAH symptomatology may vary from motor and sensory disturbances to cognitive disabilities. Aphasia developing after cerebral ischemia of the right hemisphere in a right-hand dominant patient following vasospasm may be a misleading symptom for the localization of the insult. Keeping a high index of suspicion may help in making the correct diagnosis. The changes in the perfusion patterns of cerebellum as assessed by SPECT study during the acute and recovery phases suggests the involvement of cerebellum in language functions.

Microsurgical anatomy of the posterior spinal artery via a far-lateral transcondylar approach.

OBJECT: The posterior spinal artery (PSA) is a clinically significant vessel that may frequently be encountered during the far-lateral transcondylar approach. There have been a limited number of reports on the specific origin of the PSA in the literature. The aim of this study was to demonstrate the origin of the PSA. METHODS: Thirteen cadaveric heads (26 sides) were injected with colored silicon. A bilateral far-lateral transcondylar approach was performed on each side. In every specimen the site of the origin of the PSAs, as well as their course, branching pattern and anastomoses, external diameters, and neighboring vascular and nervous structures were recorded. Microanatomical dissections were performed using the surgical microscope. In addition, 8 surgical cases in which the far-lateral approach was used were collected prospectively to record the course and origin of the PSA. Altogether, a total of 34 sides were analyzed for their PSA origin and course. RESULTS: In the cadaveric specimens, the PSA was found to originate from the vertebral artery (VA) in 25 sides (96%). In 13 specimens (50%) the PSA originated from the V(4) segment of the VA intradurally. In 12 specimens (46%) the PSA originated from the V(3) segment of the VA extradurally. In 1 specimen (4%), in whom the posterior inferior cerebellar artery (PICA) had an early origin from the VA extradurally at the C-1 level, the PSA originated from the PICA. Of the 8 surgical cases, 2 patients had extradural origin of the PSA from the V(3) segment of the VA, whereas 6 patients had intradural origin of the PSA from the V(4) segment. CONCLUSIONS: Although the usual origin of the PSA is from the VA either intra- or extradurally, its origin is closely related to the origin of the PICA. The PSA originates from the PICA in cases in which the PICA originates extradurally from the VA. In the far-lateral transcondylar approach, the dura is opened in close proximity to the VA. Knowledge of the origin and course of the PSA is critically important when executing the far-lateral approach to avoid its injury.

Supracerebellar transtentorial transcollateral sulcus approach to the atrium of the lateral ventricle: microsurgical anatomy and surgical technique in cadaveric dissections.

BACKGROUND: Access to lesions located in the atrium of the lateral ventricle without causing neurologic deficit can be challenging. Here, we demonstrate the supracerebellar transtentorial transcollateral sulcus (STTS) approach as an alternative route to the atrium of the lateral ventricle using anatomical dissections in cadavers. METHODS: Suboccipital craniotomy with extension above the transverse sinus was performed in 5 arterial and venous latex-injected cadaveric heads (10 hemispheres). After the dural opening, arachnoidal dissection of the supracerebellar space was performed, and the tentorium cerebelli was cut from lateral to medial. This revealed the parahippocampal and fusiform gyri and collateral sulcus (CS). The distance from the CS to the atrium was measured. RESULTS: The atrium of the lateral ventricle was entered through the CS in each specimen. The cerebral hemispheres were removed from each cadaveric specimen, and dissections were performed. The distance from the CS to the atrium was 1.30 cm on the right side and 1.31 cm on the left. The CS was bifurcated in 62% of the hemispheres, whereas it was single in 38%. Through this approach, only the "u" fibers of the CS were damaged, and the fibers of the optic radiation in the inferolateral wall of the atrium were preserved. CONCLUSION: The STTS approach may be an effective alternative approach to lesions located in the medioposterior aspect of the atrium of the lateral ventricle in selected cases. Further clinical studies to evaluate the safety and efficacy of this approach are needed.

Neuroprotective effects of mesenchymal stem cells derived from human embryonic stem cells in transient focal cerebral ischemia in rats.

Embryonic mesenchymal stem cells (eMSCs) were first derived from human embryonic stem cells (hESCs) overexpressing green fluorescence protein (GFP). They expressed CD29, CD44, CD73, CD105, CD166 and nestin, but not CD34, CD45, CD106 SSEA-4 or Oct3/4. Twenty million eMSCs in 1 mL of phosphate-buffered saline (PBS) were injected into the femoral veins of spontaneously hypertensive rats after transient middle cerebral artery occlusion. The migration and differentiation of the eMSCs in the ischemic brain were analyzed. The results revealed that eMSCs migrated to the infarction region and differentiated into neurons, which were positive for beta-tubulin III, microtubule-associated protein 2 (MAP2), HuC, neurofilament and human nuclear antibody, and to vascular endothelial cells, which were positive for von Willebrand factor (vWF). The transplanted cells survived in the infarction region for at least 4 weeks. Adhesive removal function significantly improved in the first week after cell transplantation, and rotarod motor function significantly improved starting from the second week. The infarction volume in the eMSC group was significantly smaller than that in the PBS control group at 4 weeks after infusion. The results of this study show that when administered intravenously, eMSCs differentiated into neuronal and endothelial cells, reduced the infarction volume, and improved behavioral functional outcome significantly in transient focal cerebral ischemia.