Supracerebellar Infratentorial Approach, Indications, and Technical Pitfalls.

Posterior tentorial incisura not infrequently requires to be exposed for tumors of pineal gland, pulvinar, midbrain and cerebellum, aneurysms, arteriovenous malformations. Residing almost at the center of the brain, this area is almost equal distance to any point on the calvarium behind coronal sutures enabling alternative routes to encounter. Compared to supratentorial routes either subtemporal or suboccipital approach, infratentorial supracerebellar route has several advantages as providing shortest, most direct approach to the lesions of this area without encountering any important arteries and veins. Since its initial description at the early twentieth century, a wide range of complications arising from cerebellar infarction, air embolism, and neural tissue damage have been encountered. Working in a deep, narrow corridor without enough illumination and visibility under very limited anesthesiology support hindered popularization of this approach. In the contemporary era of neurosurgery, advanced diagnostic tools and surgical microscopes with state-of-the-art microsurgery techniques coupled with modern anesthesiology have eliminated almost all drawbacks of infratentorial supracerebellar approach.

Prognostic value of Ki-67 index in primary intracranial tumors of infants.

OBJECTIVE: Primary intracranial tumors are rare tumors in infants. They differ from those found in other pediatric age groups in terms of clinical presentation, histopathological diagnosis, adjuvant therapies, and outcome. Ki-67 index has also shown promising results as a prognostic factor in different types of intracranial tumors in children and adults. However, the importance and the best cutoff point of Ki-67 index in primary intracranial tumors of infants remains unclear. We aimed to analyze prognostic value of Ki-67 index in primary intracranial tumors of infants. METHODS: This study retrospectively reviewed the records of 28 infants undergoing surgical resection for primary intracranial tumors between April 2016 and March 2021. We analyzed clinical characteristics, tumor location, extent of resection, histopathological diagnosis, Ki-67 index, and overall survival (OS). To define the most relevant cutoff value for Ki-67 index, "Cutoff Finder" was used. RESULTS: The median age at diagnosis was 188 days for all patients. Fifteen of the patients were boys and 13 were girls. Tumors were located supratentorial in 13 patients and infratentorial in 15 patients. Gross total resection was performed in 7 of 13 supratentorial tumors and 9 of 15 infratentorial tumors. The mean Ki-67 index of the supratentorial tumors was 49.6%, the median was 55%; for infratentorial tumors, the mean was 49.9%, and the median was 70%. Tumor grade (p = 0.019) and Ki-67 index (p = 0.003) were found as significant predictors of OS in log-rank testing for Kaplan-Meier survival analysis. Univariate cox regression analysis identified high Ki-67 index as prognostic factor for worse OS, with hazard ratio of 8.852 (95% CI 1.95-64.80; p = 0.0108). High Ki-67 index was found as independent prognostic factor for worse OS in multivariate cox regression analysis (HR 7.036; 95% CI 1.229-65.82; p = 0.0457). CONCLUSION: High-grade and high Ki-67 index were associated with worse outcome. Ki-67 index did show a distinct prognostic value for OS within our cohort at a cutoff value of 72.5%.

Chordoid meningioma: report of 5 cases and review of the literature.

Chordoid meningioma is a rare, more aggressive subtype of meningioma. This study documents the histological, radiological and clinical features of seven tumours in five patients among 131 meningioma patients who were treated in the Department of Neurosurgery at Istanbul Medipol University between 2014 and 2019. There were two males and three females. All tumours were supratentorial. Surgical Simpson grade II resection was achieved in two cases, grade I in one and grade IV in two. One case relapsed and underwent further surgeries and adjuvant treatment. The chances of survival without recurrence after the Simpson grade I-II resection are high but close follow-up is recommended particularly if grade I cannot be achieved.

Human-derived hair follicle stem cells and hydrogen sulfide on focal cerebral ischemia model: A comparative evaluation of radiologic, neurobehavioral and immunohistochemical results.

The present study investigated the effects of intracerebral human-derived hair follicle stem cells (HFBSCs), whether alone or in combination with hydrogen sulfide (H2S) in a rat model of focal cerebral ischemia. The rats were randomly assigned into 4 groups (n = 10): Control (phosphate buffered saline (PBS)), Group A (at 24 h post-middle cerebral artery occlusion(MCAo), stereotaxic intracerebral, 1,0 × 106, total 10 µL HFBSCs), Group B (3-14 d post-MCAo, intraperitoneal (i.p.), 25 µM/kg/day H2S), Group AB (HFBSCs + H2S). Cranial magnetic resonance images were recorded on postoperative 1st and 28th days. Three dimensional analysis was performed to calculate the infarct volumes. Rotarod and cylinder tests were performed after MCAo and finally all rats were euthanized by cardiac perfusion at 28 days after MCAo for immunohistochemical analysis. The reduction in infarct volumes of rats receiving HFBSC was significant. The cranial infarct volume on the postoperative 28th day was significantly higher in the group in which H2S was administered alone compared to the HFBSC alone group. All animals showed steadily improved spontaneous locomotor activity from day 7 post-MCAo on rotarod test, from day 1 on cylinder test, but showed no significant differences at all times. In all groups, the grading scores of CD34, CD5, CD11b and GFAP immunohistochemical markers did not differ significantly. In conclusion, intracerebral HFBSC treatment after 24 h of ischemic stroke may be an effective way to reduce the cranial infarct volume, whereas H2S treatment alone or in combination with HFBSC may not be sufficient for ischemic brain injury.

Intramedullary pancreatic adenocarcinoma metastasis: The first case in literature.

BACKGROUND: Pancreatic cancer is a common gastrointestinal malignancy, and is often associated with a poor prognosis. Although liver is generally seen as a distant metastasis point, it has been shown that it can metastasize to any organ, especially the gastrointestinal tract, and approximately 0.3% of metastases are observed in spinal cord. CASE DESCRIPTION: We report a 36-year-old woman with a prior history of pancreatic adenocarcinoma who presented to us with a thoracic intramedullary lesion and recent onset of neurological deficits. She underwent surgery with histological confirmation of a diagnosis of metastatic adenocarcinoma. CONCLUSION: To our knowledge there is no prior report of pure intramedullary spinal cord metastasis from a pancreatic adenocarcinoma in the literature. We report the present patient in view of the rarity of intramedullary spinal cord metastasis and its clinical significance. Although intramedullary metastases are rare, they should be investigated in every patient with malignancy and progressive neurological deficit. While its general prognosis is poor regardless of the type of treatment, early diagnosis and treatment is important in terms of quality of life and survival.

Pediatric brain tumors: a bibliometric analysis.

PURPOSE: The purpose of this study was to identify tendency and current issues in research on pediatric brain tumors over the past 20 years and to help researchers and investors explore new directions for future research in this subject. METHODS: Web of Science Core Collection was used for article selection and CiteSpace 5.8.R 1 was used for bibliometric analyses with these articles. RESULTS: The overall h-index was found to be 131 in the analysis made in a total of 4019 publications on the subject between the years 2000 and 2021. A total of 16,101 authors have published articles on pediatric brain tumors. The most active author in this field was Michael D. Taylor (h-index: 105). The publication which received the strongest citation burst among publications was published in 2016 by Louis et al. published in Acta Neuropathologica, and its content is the World Health Organization's classification of central nervous system tumors. Considering the country contribution, the USA is seen in the leading position. The most publications on the subject were followed by the Journal of Clinical Oncology. CONCLUSION: By examining the studies on childhood brain tumors carried out around the world, the subjects that can be determined as the focus were tried to be highlighted. And it has been seen that the scientific and industrial community should work together and the financial support for multidisciplinary studies should increase.

The Effect of the Number of Open Vertebral Segments on the Prognosis of Newborns with Midline Closure Defect: A Single Surgeon, Single Center Experience.

AIM: To investigate the effect of the number of open vertebral segments on the prognosis of newborns with midline closure defects (MCD), and the optimal timing for ventriculoperitoneal shunt (VPS) placement in those with MCD accompanied by hydrocephalus. MATERIAL AND METHODS: A total of 63 patients (35 girls and 28 boys) were admitted to the neonatal intensive care unit between April 2016 and January 2019. The patients? MCDs were examined in terms of type, localization, number of open vertebral segments, accompanying hydrocephalus (HC), surgical technique, and complications. RESULTS: The mean follow-up period was 12 months (6-24 months). Ten cases of meningocele (M) (15.9%), 41 cases of myelomeningocele (MM) (65%), and 12 cases of encephalocele (E) (19.1%) were identified. A VPS was inserted in 44 (69.8%) patients (E, 8; MM, 34; and M, 2), performed in 33 patients during the same admission, while 11 were shunted after discharge during the follow-up period. Thirty-four of the 41 cases of MM and all cases of M and E were primarily closed, while the remaining MMs required skin flaps. The M and MM cases were categorized according to the number of open vertebral segments and examined in terms of neurological deficit, length of hospital stay, and complications. CONCLUSION: In all pediatric cases, case-by-case evaluation, attention to hypothermia and meticulous hemostasis, protection of functional neural tissue, closing the defect as soon as possible, and treating accompanying HC during the same session, were considered. Additionally, the neural tissue density correlated with the number of open vertebral segments and it was considered prognostically more valuable.

Intramedullary pancreatic adenocarcinoma metastasis: The first case in literature.

BACKGROUND: Pancreatic cancer is a common gastrointestinal malignancy, and is often associated with a poor prognosis. Although liver is generally seen as a distant metastasis point, it has been shown that it can metastasize to any organ, especially the gastrointestinal tract, and approximately 0.3% of metastases are observed in spinal cord. CASE DESCRIPTION: We report a 36-year-old woman with a prior history of pancreatic adenocarcinoma who presented to us with a thoracic intramedullary lesion and recent onset of neurological deficits. She underwent surgery with histological confirmation of a diagnosis of metastatic adenocarcinoma. CONCLUSION: To our knowledge there is no prior report of pure intramedullary spinal cord metastasis from a pancreatic adenocarcinoma in the literature. We report the present patient in view of the rarity of intramedullary spinal cord metastasis and its clinical significance. Although intramedullary metastases are rare, they should be investigated in every patient with malignancy and progressive neurological deficit. While its general prognosis is poor regardless of the type of treatment, early diagnosis and treatment is important in terms of quality of life and survival.

Flow Diverter Stents in the Treatment of Cerebral Aneurysms Less than 5 mm.

AIM: To evaluate the safety and efficacy of flow diverter (FD) stents in the treatment of intracranial aneurysms less than 5 mm. MATERIAL AND METHODS: We treated 66 aneurysms in 43 patients with aneurysms less than 5 mm. Of the patients, 29 were females and 14 males (mean age: 50.2 years). Headache was the most frequent symptom. In 8 patients, the aneurysms were recanalized and these had been treated with coils or stent-assisted coiling. All aneurysms were in the anterior circulation. In the treatment, one of the SILK, Pipeline, Derivo or FRED FD stents was used for each patient. Neurointerventional stent medication (double antiplatelet) was used. All patients were investigated for new ischemic lesions with diffusion-weighted imaging one day later. The first follow-up angiogram was planned 3-6 months later. RESULTS: The treatment was technically successful in all patients. Minor complications occurred in 3 patients (7%). In one patient, thrombus inside the SILK was seen and was relieved with tirofiban. The second patient bled from the right common femoral artery entrance, which was operated on. In the third patient, the complication was technical. All patients were discharged without any neurological deficit. The mean follow-up period was 26 (6-52) months. Of the aneurysms, 64 (97.0%) were completely closed. CONCLUSION: The FD treatment of cerebral, anterior circulation small aneurysms less than 5 mm is effective and safe.

Focal cortical dysplasia: etiology, epileptogenesis, classification, clinical presentation, imaging, and management.

BACKGROUND: Focal cortical dysplasia (FCD) is the most prevalent cause of intractable epilepsy in children. It was first described by Taylor et al. in 1971. In 2011, the International League against Epilepsy described an international consensus of classification for FCD. However, the exact mechanism causing this pathology remains unclear. The diagnosis and recognition of FCD increase with the advances in neuroradiology and electrophysiology. FOCUS OF REVIEW: In this paper, we discuss the literature regarding management of FCD with a focus on etiology, pathophysiology, classification, clinical presentation, and imaging modalities. We will also discuss certain variables affecting surgical outcome of patients with FCD. CONCLUSION: Based on our review findings, it is concluded that surgical management with complete resection of the lesion following preoperative localization of the epileptogenic zone in patients with FCD subtypes can provide a seizure-free outcome.

A comparison of the ultrasound-guided modified-thoracolumbar interfascial plane block and wound infiltration for postoperative pain management in lumbar spinal surgery patients.

OBJECTIVES: Pain management is an important issue following lumbar spinal surgery. Wound infiltration is a technique that a local anesthetic solution is infiltrated into the tissues around the surgical area. Previous studies reported that US-guided modified thoracolumbar interfacial plane (mTLIP) block after lumbar spinal surgery provided effective analgesia. In this study, we aimed to compare the analgesic efficacy of the US-guided mTLIP block and wound infiltration following lumbar disc surgery. METHODS: 60 patients aged 18-65 years, ASA classification I-II, and scheduled for lumbar disc surgery under general anesthesia were included in the study. US-guided mTLIP block was performed via the lateral approach in group T (n=30), and wound infiltration was performed in group W (n=30). Opioid consumption, postoperative pain scores and adverse effects of opioids, such as allergic reactions, nausea, and vomiting, were recorded. RESULTS: Opioid consumption and the use of rescue analgesia were significantly lower in group T in all the postoperative periods (1, 2, 4, 8, 16, and 24 h) (p<0.05). The VAS scores for pain during mobility and while at rest were significantly lower in group T than those in group W 8 h after the surgery (p<0.05). The incidences of nausea, vomiting, and itching in group W were higher than the incidences in group T. CONCLUSION: The mTLIP block provides effective analgesia for the first 24 h following lumbar disc surgery, and it may be an alternative to wound infiltration for pain management.

Giant Sacral Schwannoma Causing Bilateral Hydronephrosis: Case Report and Review of the Literature.

BACKGROUND: Giant sacral schwannomas are very rare, and less than 1%-5% of spinal schwannomas are found in the sacral region. These frequently grow to considerable size because of permissive anatomic location and benign, slow growth of tumor. They can be unnoticed before reaching a huge size. CASE DESCRIPTION: We report a rare case of a giant sacral schwannoma in a 46-year-old man. The patient presented with difficulty in passing urine, episodic constipation, and swelling of the right lower extremity for 6 months. Magnetic resonance imaging revealed 160 x 110 x 110 mm encapsulated heterogenous solid mass originated from left S1 spinal nerve extending into the pelvis and abdomen. Sigmoid colon and rectum were displaced to the right side, and bladder was displaced anteriorly. Left side of the S1 and S2 vertebral bodies, left S1 and S2 neural foramen were also eroded. It also compressed ureters causing bilateral hydronephrosis. The patient underwent a 2-stage procedure in which complete resection was achieved. CONCLUSIONS: We report the second case of a completely resected giant sacral schwannoma with bilateral hydronephrosis in the literature. Performing a 2-stage procedure is important in giant sacral schwannomas. Morbidity can be minimized, and extent of resection can be maximized with the help of combined anterior/posterior approach.

Assessment of the MRI and Behavioral Test Results in a Focal Cerebral Ischemia-Reperfusion Model in the Rat after Separate and Combined Use of Mouse-Derived Neural Progenitor Cells, Human-Derived Neural Progenitor Cells and Atorvastatin.

AIM: To assess the efficacy of Neural progenitor cell (NPC) transplantation in ischemic stroke, and to investigate whether atorvastatin enhances therapeutic potency of NPC after stroke. MATERIAL AND METHODS: The focal cerebral ischemia-reperfusion model was performed by transient occlusion of middle cerebral artery. Rats were assigned randomly to receive intracerebral transplantation of mouse NPC alone (mNPC), human NPC alone (hNPC), mouse NPC plus oral atorvastatin (mNPC+A), human NPC plus oral atorvastatin (hNPC+A), oral atorvastatin alone, or intracerebral Dulbecco"s Modified Eagle"s medium injection (control group). Adhesive removal, rotarod, cylinder tests, and magnetic resonance imaging (MRI) were used for assessment of rats during 4 weeks. After sacrification on 28th day, rats were investigated by immunofluorescent staining. RESULTS: The hNPC and mNPC groups showed significantly improved functional outcome and reduced infarct area ratio compared with the control group. The hNPC group had significantly better performance and lower infarct area ratio than the mNPC group. Addition of atorvastatin to stem cell therapy significantly improved functional outcome, although it did not affect the infarct area ratio on MRI. Anti-inflammatory response in the infarct area was higher in the mNPC group. NPC transplantation significantly reduced the amount of microglia and a significant increase in the amount of astrocytes. CD8a+ T lymphocyte and granzyme B activities were not detected in any of the subjects. CONCLUSION: Both hNPC and mNPC treatments significantly improved functional outcome, and reduced infarct area ratio after stroke. Atorvastatin enhanced the therapeutic potency of NPCs, including neurological improvement.

Fully endoscopic interlaminar and transforaminal lumbar discectomy: Analysis of 47 complications encountered in a series of 835 patients.

OBJECTIVE: To report perioperative complications in fully endoscopic lumbar discectomy (FELD). METHODS: From September 2010 to November 2016, 835 patients underwent FELD. In total, 865 disc levels were operated on. Of the 835 patients, the transforaminal (TF) approach was used in 174 patients, while 691 patients were operated on using the interlaminar (IL) approach. Surgical complications occurred in 47 patients, which were retrospectively analyzed. RESULTS: Neurological deficits occurred in six patients. In four of these six patients, deficits resolved spontaneously. In one patient, symptoms resolved after a laminectomy procedure. In only one case, the neurological deficit was permanent. Seven patients complained of dysesthesia, which resolved spontaneously with medical treatment in four patients. In the remaining two patients, dysesthesia symptoms improved after epidural and foraminal injections. Dural tears were encountered in 26 patients. Pudendal neuralgia occurred in three patients. Two cases showed wound infection. The other complications comprised one disc infection, one retroperitoneal hematoma and one wrong level surgery. CONCLUSION: The FELD procedure has a steep learning curve and it is a difficult procedure to master. Surgeons should be aware of complications that can occur with the FELD procedure, most of which resolve spontaneously.

Percutaneous Fully Endoscopic Interlaminar Approach to the Filum Terminale: A Cadaveric Study.

OBJECTIVE: To investigate the utility, safety, and feasibility of a novel endoscopic technique for the visualization and surgical manipulation of the filum terminale in fresh postmortem adult human cadavers. METHODS: The filums from 18 fresh postmortem adult human cadavers were explored with a percutaneous fully endoscopic interlaminar approach. After the filum was identified and the nerve roots were dissected away from it, the filum was cut. A specimen was sent for histopathologic examination. RESULTS: In 15 of 18 (83%) cadavers, the filum terminale could be visualized. A specimen for histopathologic examination was obtained from 11 of 15 (73%) visualized filums. Histopathologic examination revealed that 2 of them were fatty filums, 7 were normal filums, and 2 were peripheral nerves. CONCLUSIONS: We have described a successful and feasible percutaneous fully endoscopic interlaminar approach to the filum terminale. This technique provides a smaller skin incision, narrow durotomy, and minimal tissue damage. Animal studies are necessary to prove the feasibility and safety of our method before clinical use.

Use of Antifibrotics to Prevent Ventriculoperitoneal Shunt Complications Due to Intra-abdominal Fibrosis: Experimental Study in a Rat Model.

BACKGROUND: Cerebrospinal fluid shunt operations have reduced the morbidity and mortality of hydrocephalus, but have potential complications. Ventriculoperitoneal (vp) shunt obstruction is one of the common complications of shunt surgery. The obstruction is caused by fibrosis and is usually located on the tip of the ventricular and/or peritoneal catheter. OBJECTIVE: In our study, we aimed to demonstrate the known antifibrotic effects of heparin, hyaluronate/carboxymethylcellulose, and icodextrin on peritoneal catheter obstruction in a vp shunt model in rats. METHODS: Thirty-two male Sprague-Dawley rats were used in this study. A shunt catheter was placed in the abdominal cavity. In the control group, isotonic solution, in the study groups, heparin, sodium hyaluronate/carboxymethylcellulose (HA/CMC), and icodextrin were intraperitoneally applied. The severity of adhesions and inflammation around the peritoneal catheter was evaluated after the rats were killed on day 30. RESULTS: One animal in the heparin group died due to intra-abdominal hemorrhage. We found the most adhesions in the control group. All three drugs (heparin, HA/CMC, icodextrin) were effective for adhesion prevention. HA/CMC was more effective than heparin, and icodextrin was most effective. There was a statistically significant difference between the icodextrin and the control group (p = 0.007). CONCLUSION: The intra-abdominal instillation of icodextrin, HA/CMC, and heparin, especially icodextrin, can decrease the rate of vp shunt dysfunction by preventing formation of intraperitoneal fibrosis.