A Morphometric Study of Cadavers for the Anterior Approach to the Lower Lumbar Spine.

AIM: To explore the relationship between the retroperitoneal vasculature and anterior surface of the lower spine, and to establish values for aiding in prediction of the pertinence of anterior approach at the L4-L5 and L5-S1 intervertebral discs. MATERIAL AND METHODS: The study included 13 fresh human cadavers. After exploration of the abdominal cavity and removal of the visceral organs, the vasculature, and anterior spinal surface were revealed beneath the lower extension of the perirenal fascia. Morphometric measurements of the great vessels and the intervertebral discs were obtained. All measurements were analyzed and presented as mean and standard deviation. Differences in the values between sexes were assessed. RESULTS: The anterior height of the L4-L5 and L5-S1 intervertebral disc was 6.8 ± 0.81 mm and 6.7 ± 0.99 mm, respectively. The widths of the aorta, inferior vena cava, right and left common iliac arteries, and right, and left common iliac veins were 16.4 ± 3.58, 20.6 ± 3.36, 11.5 ± 2.32, 11.5 ± 2.43, 14.7 ± 3.13, and 15.5 ± 3.27 mm, respectively. The mean aortic bifurcation angle was 45.5°. The aortic bifurcation was located above the lower endplate of the L4 vertebrae in 53.8% of the cadavers. The area of the interarterial and interiliac trigones was 14.6 ± 5.33 cm < sup > 2 < /sup > and 7.1 ± 4.35 cm2, respectively. No statistically significant differences were noted between the sexes. CONCLUSION: An elaborate radiological examination of the vasculature should be performed prior to surgery to avoid unwanted vascular complications during the anterior approach. Knowing the area of the interarterial and interiliac triangles and the aortic bifurcation location could be aid in assessing the safe working zone.

The Effect of Halofuginone Use on Epidural Fibrosis After Spinal Surgery: An Animal Experiment.

AIM: To investigate the effectiveness of local halofuginone application for spinal epidural fibrosis (EF) after lumbar laminectomy in rats. MATERIAL AND METHODS: Forty rats were equally divided into four groups (Groups I-IV; 10 rats in each group), and lumbar laminectomy was performed under general anesthesia. After laminectomy, Group I received saline (NaCl 0.9%) locally (control), Group II received spongostan, Group III received 0.5 mL of halofuginone-impregnated spongostan, and Group IV received 0.5 mL of halofuginone. Spongostan was used to prolong the exposure period of halofuginone. All rats were sacrificed after four weeks and evaluated according to histopathological criteria. A p-value of < 0.05 was considered statistically significant. RESULTS: Fibrosis was significantly lower in Group IV than in Group I (p < 0.05). There was no significant difference in fibrosis between Group II/III and Group I. It was observed that spongostan increased fibrosis. CONCLUSION: Halofuginone helps prevent EF after spinal surgery. However, further clinical and experimental studies are needed to assess its safety in humans.

Full-Endoscopic Surgery for Hypothalamic Hamartoma Resection.

Hypothalamic hamartomas (HH) are rare developmental anomalies of the inferior hypothalamus that often cause refractory epilepsy, including gelastic seizures. Surgical resection is an effective method to treat drug-resistant epilepsy and endocrinopathy in a suitable patient group. Open surgery, endoscopic surgery, ablative procedures, and stereotactic radiosurgery can be utilized. In this study, we aimed to describe the full-endoscopic approach for HH resection. The technique involves the use of an intraoperative ultrasonography (USG) system, a 30° rigid endoscope system that has an outside diameter of 2.7 mm with two working channels, a stylet that has an outer diameter of 3.8 mm, a monopolar coagulation electrode, a fiberoptic light guide, and the endovision system. Microforceps and monopolar electrocautery are the two main surgical instruments for HH removal. The protocol is easy to apply after a particular learning curve has been passed and shorter than open surgical approaches. It leads to less blood loss. Full-endoscopic surgery for HH is a minimally invasive technique that can be applied safely and effectively with good seizure and endocrinological outcomes. It provides low surgical site pain and early mobilization.

Effectiveness and Safety of Epilepsy Surgery for Pediatric Patients with Intractable Epilepsy: A Clinical Retrospective Study from a Single-Center Experience.

INTRODUCTION: Pediatric epilepsy surgery is an effective treatment modality for patients with drug-resistant epilepsy (DRE). Early pediatric surgery yields favorable results for DRE in terms of seizure control and neurophysiological outcome. In this study, pediatric patients were categorized based on their age (above 3 years old and below 3 years old) to demonstrate the effectiveness and safety of surgical procedures. METHODS: In this retrospective, single-center study, 60 pediatric patients who underwent epilepsy surgery at Istanbul Faculty of Medicine between 2002 and 2018 were evaluated. Overall morbidity and mortality rates, as well as seizure outcomes of the patients, were assessed and compared based on two age groups: those aged 3 years old or younger and those older than 3 years old. The effectiveness of invasive monitoring was also evaluated in relation to pathological results. The postoperative seizure outcome rates were evaluated using Engel's classification, with an average follow-up period of 8.7 years. RESULTS: Out of the total number of patients, 47 (78.4%) underwent resective surgery, while 13 (21.6%) had palliative surgery. Ten patients (16.6%) had invasive monitoring. Among all patients, 34 were classified as Engel I and II (56.6%), while 26 were classified as Engel III and IV (43.4%) postoperatively. 47% of patients who were under 3 years old, 60.4% of patients who were over 3 years old, and 50% of patients who underwent invasive monitoring had a favorable seizure outcome (Engel I-II). Postoperative morbidity and mortality rates were 35% (n = 21) and 1.6% (n = 1), respectively. CONCLUSION: Pediatric epilepsy surgery is an important treatment modality for preserving cognitive abilities and providing effective treatment for pediatric DRE. In our study, we claim that both invasive monitoring and epilepsy surgery lead to favorable seizure outcomes for all age groups. Further clinical studies should be conducted to provide more reliable data on the safety and effectiveness of the surgery, particularly in patients under the age of three.

Full-Endoscopic Technique for Posterior Fossa Decompression in Chiari Malformation.

BACKGROUND AND IMPORTANCE: Full-endoscopic techniques are well-described for spinal procedures. Although endoscopic-assisted techniques are reported for posterior fossa decompression (PFD) in Chiari malformation (CM), a full-endoscopic technique is yet to be reported in these patients. The aim of this study was to present and describe a full-endoscopic technique for PFD in patients with CM. CLINICAL PRESENTATION: Two patients diagnosed with CM were operated on by the full-endoscopic PFD technique. The patients consented to the procedure and to the publication of their image. An endoscope with an oval shaft cross-section with a diameter of 9.3 mm, a working length of 177 mm, a viewing angle of 20°, and a working channel of 5.6 diameters were used. Operative videos were recorded. The surgical steps were easily applied after the clear anatomic landmarks, such as the C1 posterior tubercle and the rectus capitis posterior minor muscles. The patients were followed up for 6 months. Both patients were symptom-free with a significant decrease in Visual Analog Scale score and a good functional outcome assessed by Chicago Chiari Outcome Scale after surgery without any complications. CONCLUSION: All the steps of the full-endoscopic technique for PFD described by the authors in their previous human cadaveric study were also feasible on patients with CM.

Corrigendum: Full-endoscopic removal of third ventricular colloid cysts: technique, results, and limitations.

[This corrects the article DOI: 10.3389/FSURG.2023.1174144.].

Full-endoscopic removal of third ventricular colloid cysts: technique, results, and limitations.

Introduction: Colloid cysts (CCs) are rare benign lesions that usually arise from the roof of the third ventricle. They may present with obstructive hydrocephalus and cause sudden death. Treatment options include ventriculoperitoneal shunting, cyst aspiration, and cyst resection microscopically or endoscopically. This study aims to report and discuss the full-endoscopic technique for removing colloid cysts. Materials and methods: A 25°-angled neuroendoscope with an internal working channel diameter of 3.1 mm and a length of 122 mm is used. The authors described the technique of resecting a colloid cyst by a full-endoscopic procedure and evaluated the surgical, clinical, and radiological results. Results: Twenty-one consecutive patients underwent an operation with a transfrontal full-endoscopic approach. The swiveling technique (grasping the cyst wall and rotational movements) was used for CC resection. Of these patients, 11 were female, and ten were male (mean age, 41 years). The most frequent initial symptom was a headache. The mean cyst diameter was 13.9 mm. Thirteen patients had hydrocephalus at admission, and one needed shunting after cyst resection. Seventeen patients (81%) underwent total resection; 3 (14%), subtotal resection; and 1 (5%), partial resection. There was no mortality; one patient had permanent hemiplegia, and one had meningitis. The mean follow-up period was 14 months. Conclusion: Even though microscopic resection of cysts has been widely used as a gold standard, successful endoscopic removal has been described recently with lower complication rates. Applying angled endoscopy with different techniques is essential for total resection. Our study is the first case series to show the outcomes of the swiveling technique with low recurrence and complication rates.

Full Endoscopic Interlaminar Approach for Paracentral L5-S1 Disc Herniation.

The full endoscopic interlaminar approach (FEILA) is a minimally invasive technique for lumbar discectomy. It has multiple advantages over other conventional discectomy methods, including less traumatization of the soft tissues, fewer complication rates (dural injury, bleeding), rapid rehabilitation, quick return to daily life activities, and preferable cosmetic results. FEILA is a surgery with a relatively steep learning adaptation. Endoscopic surgery is a closed tubular approach, and all surgical maneuvers are performed within a uniportal single working channel. Also, the technique has not yet been standardized and well-documented. Therefore, the early learning stages of this technique may not be easy for most surgeons. Despite these, FEILA is easy, and the operation length is comparable to and even shorter than other techniques of lumbar discectomy. FEILA for lumbar discectomy could be considered a safe and effective alternative procedure for paracentral L5-S1 disc herniation. Here, we describe the technique of FEILA, including every cutoff step required to reach technical proficiency for surgeons who want to start applying this approach.

Surgical management of interhemispheric subdural empyemas: Review of the literature and report of 12 cases.

BACKGROUND: Subdural empyemas (SDEs) are rare intracranial infections mostly secondary to sinusitis. Incidence of SDEs is 5-25%. Interhemispheric SDEs are even rarer, which makes their diagnosis and treatment difficult. Aggressive surgical interventions and wide-spectrum antibiotics are needed for treatment. In this retrospective clinical study, we intended to evaluate the results of surgical management supported by antibiotics in patients with interhemispheric SDE. METHODS: Clinical and radiological features, medical and surgical management and outcomes of 12 patients treated for interhemi-spheric SDE have been evaluated. RESULTS: 12 patients were treated for interhemispheric SDE between 2005 and 2019. Ten (84%) were male, two (16%) were female. Mean age was 19 (7-38). Most common complaint was headache (100%). Five patients were diagnosed with frontal sinusitis prior SDE. Initially, three patients (27%) underwent burr hole aspiration and ten patients (83%) underwent craniotomy. In one patient both were done in the same session. Six patients were reoperated (50%). Weekly magnetic resonance imaging and blood tests were used for follow-up. All patients received antibiotics for at least 6 weeks. There was no mortality. Mean follow-up period was 10 months. CONCLUSION: Interhemispheric SDEs are rare, challenging intracranial infections that have been related to high morbidity and mor-tality rates in the past. Both antibiotics and surgical interventions play role in treatment. Careful choice of surgical approach and repeated surgeries if necessary, accompanied by appropriate antibiotic regimen, leads to good prognosis reducing morbidity and mortality.

A series of post-traumatic midline epidural hematoma and review of the literature.

BACKGROUND: Supratentorial midline epidural hematoma is rare but challenging in diagnosis and management. Indication for surgery can arise even following hospital admission. Being familiar to the presentation and watching out for direct and indirect signs on axial computed tomography (CT) such as suture diastasis or fracture traversing midline are essential to plan multi-planar CT enabling exact diagnosis including form and mass effect of hematoma. METHODS: Nine patients with midline epidural hematoma including two pediatric patients underwent surgery between 2013 and 2018. Pre-operative and post-operative patient status, radiological features, and surgical technique were analyzed. RESULTS: Four patients had deteriorating consciousness levels and two patients had paraparesis. All had fractures traversing midline and epidural hematomas with significant mass effect. They were operated through separated craniotomies around the midline and midline bone strip was used for dural tenting and as support for natural closure of bone flaps. No post-operative complications were developed. All patients were discharged with Glasgow Outcome Score of 5. CONCLUSION: Because of the rarity of the lesion and small number of patients, definitive conclusions may be misleading but we think that, in experienced hands, midline epidural hematomas can safely be operated on and, preservation of midline bone strip pro-vides easier bleeding control.

Analysis of the Prognosis of High-Grade gliomas in the View of New Immunohistochemistry Markers and 2016 WHO Classification.

AIM: To evaluate isocitrate dehydrogenase (IDH) mutation status and Ki67 percentages of tumors that were treated in our institution to determine whether these markers affected the initial diagnosis and survival rates. MATERIAL AND METHODS: High-grade glioma patients, who were operated in our department between 2013 and 2018, were enrolled in the study and retrospectively reviewed. New immunohistochemistry staining studies were conducted and survival analyses were performed. RESULTS: Of 135 patients and 136 tumors, 117 were glioblastoma multiforme (GBM), 8 were grade III-IV glioma, 4 were anaplastic astrocytoma and 7 were anaplastic oligodendroglioma. One patient had two different lesions, which were GBM and anaplastic astrocytoma respectively. Mean age was 55 (7-85) years, and 88 (65%) were male and 47 (35%) were female. The most common complaint was motor deficit (56%). Fourteen patients underwent reoperation due to recurrent disease. Tumors were most commonly found in the frontal lobe (53, 39%). Magnetic resonance imaging (MRI) features showed that existence of necrosis is strongly related to GBM (p < 0.01). Approximately 126 patients were found to be IDH-wildtype, which changed 6 patients? diagnosis to GBM, IDH wildtype from grade III-IV glioma. Five patients, who were diagnosed with anaplastic astrocytoma and anaplastic oligodendroglioma initially were found to be IDH wildtype. IDH mutation status, extend of resection, and age were found to affect survival. CONCLUSION: IDH mutation status is important in classifying high-grade gliomas, as well as its effects on prognosis. This mutation is related to several radiological features of tumors. Extent of resection and patient age are also profoundly affect survival. Detailing the diagnosis with molecular features will help physicians to shape targeted adjuvant therapies, which would better outcomes.

Surgical Treatment in Refractory Epilepsy: Seizure Outcome Results Based on Invasive EEG Monitorization.

AIM: To discuss seizure outcomes of patients with invasive electroencephalography (EEG) monitorization (IEM) following their epilepsy surgery at our centre. MATERIAL AND METHODS: Forty-seven patients suffering from refractory epilepsy and who were evaluated by invasive EEG were included in this retrospective study at Istanbul Faculty of Medicine from 2003 to 2017. We examined the Video EEG and invasive EEG monitorization, cranial MRI, SPECT, PET and neuropsychological tests of all patients. Postoperative seizure outcome results were evaluated according to Engel classification. The factors affecting seizure outcomes were discussed. RESULTS: Twenty-six of the patients were female (55.3%), 21 were male (44.7). The average age was 32.0 (± 12.4). Forty-three patients had surgery and the average age of these patients was 26,6 (±11.15). 38.3% of the patients had hippocampal sclerosis (HS), 23.4% had focal cortical dysplasia (FCD), 8.5% had a tumor, 14.9% had sequela lesion and 14.9% had unknown etiology. Postoperative seizure status according to the Engel classification showed that 81.6% of the patients were class I, 10.5% were class II, 2.6% were class III and 5.3% were class IV. CONCLUSION: A significant relation was statistically determined between structural MRI lesion and favorable seizure outcome (p < 0.05). The most frequent etiology was HS in our patients. Of the patients with Engel I, the averages of their ages, ages at onset of epilepsy and ages at surgery were lower than other groups, but the difference was not statistically significant (p > 0.05). We argue that IEM is an essential examination for favorable outcomes for determining the epileptogenic zone and/or the proximity of the functional structures.

Versatile Use of Intraoperative Ultrasound Guidance for Brain Puncture.

BACKGROUND: Intraoperative ultrasound (iUS) is an effective guidance and imaging system commonly used in neuro-oncological surgery. Despite the versatility of iUS, its utility for single burr hole puncture guidance remains fairly underappreciated. OBJECTIVE: To highlight the simplicity, versatility, and effectiveness of iUS guidance in brain puncture by presenting the current case series and technical note collection. METHODS: We present 4 novel uses of iUS guidance for single burr hole brain puncture: cannulation of normal-sized ventricles, endoscopic third ventriculostomy (ETV) guidance, evacuation of interhemispheric empyema, and stereotactic biopsy assistance. RESULTS: All techniques were performed successfully in a total of 16 patients. Normal-sized ventricles were cannulated in 7 patients, among whom 5 underwent Ommaya reservoir placement and 2 underwent ventriculoperitoneal shunt placement for idiopathic intracranial hypertension. No more than 1 attempt was needed for cannulation. All ventricular tip positions were optimal as shown by postoperative imaging. iUS guidance was used in 5 ETV procedures. The working cannula was successfully introduced to the lateral ventricle, providing the optimal trajectory to the third ventricular floor in these cases. Interhemispheric subdural empyema was aspirated with iUS guidance in 1 patient. Volume reduction was clearly visible, allowing near-total evacuation of the empyema. iUS guidance was used for assistive purposes during stereotactic biopsy in 3 patients. No major perioperative complications were observed throughout this series. CONCLUSION: iUS is an effective and versatile guidance system that allows for real-time imaging and can be easily and safely employed for various brain puncture procedures.

A single-center experience of transsphenoidal endoscopic surgery for acromegaly in 73 patients: results and predictive factors for remission.

BACKGROUND: Transsphenoidal endoscopic surgery is the first-line treatment for growth hormone-secreting adenomas. OBJECTIVE: To analyse the results of the transsphenoidal endoscopic approach for acromegaly and to determine the predictive factors of remission. METHODS: A single-centre retrospective review was performed in patients who underwent endoscopic transsphenoidal surgery for acromegaly between January 2009 and January 2019. Demographic features, clinical presentation, histopathology records, complications and pre- and postoperative radiologic and endocrinological assessments were evaluated. The factors that influenced the remission rates were investigated. RESULTS: A total of 73 patients underwent surgery via the transsphenoidal endoscopic approach. Cavernous sinus invasion was detected in 32 patients (43.8%); and macroadenoma, in 57 (78%). The pathology specimens of the 27 patients (36.9%) showed dual-staining adenomas with prolactin. A total of 51 patients (69.8%) attained biochemical remission 1 year after surgery. A second operation was performed in 10 patients (13.6%) with residual tumours without biochemical remission in the first year. Six (60%) of the patients attained remission at the last follow-up. Transient diabetes insipidus was observed in 18 patients (24.6%); and rhinorrhoea, which was resolved with conservative treatment, in 4 (5.4%). None of the patients developed panhypopituitarism. The presence of cavernous sinus invasion and preoperative IGF-1, immediate postoperative GH and third-month IGF-1 levels were predictive of remission. CONCLUSION: Transsphenoidal endoscopic surgery is a safe and effective treatment for acromegaly. Reoperation should be considered in patients with residual tumours without remission.

Effect of Intraoperative Computed Tomography on Ventriculoperitoneal Shunt Survival.

BACKGROUND: In patients with hydrocephalus who undergo ventriculoperitoneal shunt placement, the ventricular catheter tip position is one of the most important prognostic factors influencing shunt survival. The aim of this study was to present our findings of ventriculoperitoneal shunt placement performed with intraoperative computed tomography (CT) and to evaluate the effect of intraoperative CT-based image guidance on optimal catheter positioning and overall shunt survival. METHODS: Of the study enrolled 345 patients with hydrocephalus who underwent ventriculoperitoneal shunt placement for the first time between 2008 and 2018. Ventricular catheters were inserted freehand via the Kocher point into the lateral ventricle in all patients. In 163 patients, intraoperative CT was performed to confirm the tip position. In this group of patients, if the tip position was nonoptimal, the catheter was ejected and reinserted during the surgery. In the remaining 182 patients, the tip position was assessed with routine postoperative CT. The effect of performing intraoperative CT on catheter tip positioning and shunt failure was investigated. RESULTS: Nonoptimal tip position was significantly correlated with shunt dysfunction even when excluding nonobstructive causes (P < 0.001). In the intraoperative CT group, 11 ventricular catheters (6.7%) were intraoperatively repositioned. The repositioning significantly improved the optimal tip position rate from 54% to 58.3% (P = 0.007). Intraoperative CT usage also showed direct correlation with shunt survival (P = 0.006). CONCLUSIONS: Intraoperative CT is an effective tool for increasing the rate of optimal tip positioning and thereby overall shunt survival.

Effect of Sarcopenia on Mortality after Percutaneous Vertebral Augmentation Treatment for Osteoporotic Vertebral Compression Fractures in Elderly Patients: A Retrospective Cohort Study.

OBJECTIVE: The aim to evaluate central sarcopenia, as measured by psoas cross-sectional area on admission imaging, is associated with outcomes in patients with vertebral compression fractures (VCFs) treated with percutaneous vertebral augmentation treatment. METHODS: We evaluated the records of patients aged >60 years treated with vertebroplasty or kyphoplasty between 2009 and 2018 for osteoporotic VCFs. The Social Security Death Index was used to determine death. We used the psoas:lumbar vertebral index (PLVI), calculated using the cross-sectional area of the L4 vertebral body and the left and right psoas muscles, to assess for sarcopenia. A multivariate Cox algorithm was applied to recognize factors independently associated with survival. RESULTS: A total of 103 patients were included with an average age of 72.3 years. During the study period, 22 (21.4%) patients were deceased, whereas 81 (78.6%) were alive. The survival rates at 1 month, 6 months, and 1 year after surgery were 99%, 94.1%, and 88.4%, respectively. PLVI measurements ranged from 0.24-1.19 with a mean of 0.59 ± 0.17 and a median of 0.603. A total of 51 patients with a median value of 0.603 were defined as low PLVI group, and 52 patients with a median value of ≥0.603 were defined as the high PLVI group. PLVI was significantly low in patients who died. Age, American Society of Anesthesiologists score, and PLVI value were independently associated with a poor overall survival. CONCLUSIONS: There is a significant correlation between sarcopenia and postoperative mortality after vertebral augmentation procedure in patients with VCFs.

Comprehensive Anatomic and Morphometric Analyses of Triangular Working Zone for Transforaminal Endoscopic Approach in Lumbar Spine: A Fresh Cadaveric Study.

OBJECTIVE: The aim of this study is to provide essential information for endoscopic transforaminal approach by performing morphometric analysis of the triangular working zone (TWZ) in fresh cadavers. METHODS: Fifteen fresh human cadavers (9 women and 6 men) with no history of spinal surgery were used in this study. Anatomic dissection of 150 foraminal levels were performed. Significant surgical landmarks constructing TWZ were measured bilaterally from L1-2 to L5-S1 on 15 fresh cadavers. The relationship between traversing roots and intervertebral discs was defined. RESULTS: Base, height, and hypotenuse measurements of TWZ were longer as the level lowered. Mean base height and hypotenuse of TWZ were 12.15 mm, 11.29 mm, and 16.69 mm (L1-2); 17.94 mm, 17.18 mm, and 28.03 mm (L5-S1), respectively. TWZ was triangular shaped at the upper lumbar levels (L1-2, L2-3, and L3-4), and trapezoid at the lower lumbar levels (L4-5 and L5-S1). Going down the levels, the exiting root angle was narrower, the mean exiting angle of the L5 root being 28.23°. All L2 and L3 traversing roots and nearly all L4 traversing roots (86.7%) originated from below the disc level. Forty percent of L5 traversing roots originated above the disc level, and 53.3% originated at the disc level. Most S1 traversing roots originated at the proximal margin of the disc level (80%). CONCLUSIONS: Our study reveals a detailed morphometric analysis of TWZ. Understanding the foraminal anatomy is crucial for safely performing transforaminal endoscopic surgery. The learning curve of transforaminal surgery can be reduced by garnering knowledge of TWZ anatomy.

Clinical Study of Decompressive Craniectomy in Children.

AIM: To evaluate the clinical characteristics of children who recently underwent decompressive craniectomy (DC) due to elevated intracranial pressure (ICP) correlated to head trauma or other causes, such as ischemic insult. MATERIAL AND METHODS: Twelve patients aged ≤17 years who underwent DC due to elevated ICP between 2013 and 2018 were included in the study. The clinical status of the participants, radiological characteristics, type and timing of surgery, and outcomes were recorded. RESULTS: Three female and nine male patients with a mean age of 10 years were included. The initial average Glasgow Coma Scale score was 6 (3-12). All patients presented with signs of diffuse cerebral edema and subdural hematoma of various sizes along with other intracranial pathologies. Only one patient required bilateral frontal craniectomy. In the postoperative period, three patients died, and three had severe disability. CONCLUSION: With the increasing use and success of DC in adults, this procedure can also be effective in children. Considering brain differences in children, large and well-structured clinical trials must be conducted to prevent complications and to identify the best technique, timing, and benefits of DC for children.

Endoscope-Assisted Surgery for Petrous Bone Cholesteatoma with Hearing Preservation.

OBJECTIVES: Petrous bone cholesteatoma is a rare pathologic entity and may be a difficult surgical challenge because of potential involvement of the facial nerve, carotid artery, dura mater, otic capsule and superior petrosal or lateral sinus. The objective of this article is to present the endoscope-assisted surgery for petrous bone cholesteatoma. MATERIALS AND METHODS: Eight patients (nine ears) who underwent endoscope-assisted petrous bone surgery for cholesteatoma. Pure tone audiogram, magnetic resonance imaging were performed at preoperatively, and at approximately 12 months postoperatively. RESULTS: Endoscope assisted surgery was performed in 8 patients and 9 ears. Of these patients, 6 were male and 2 were females. Median age was 19,5 (range 7-52) years. Hearing was able to preserved in 8 ears (8/9). Recurrence disease was observed one ear in long term follow up (1/9). In another one patient, cholesteatoma pearl was removed in the office. CONCLUSION: Endoscope-assisted surgery can allow removal of cholesteatoma of petrous apex with preserving hearing. It also provides to remove the cholesteatoma via transmastoid approach for perilabyrinthine space as "minimally invasive surgery" instead of middle fossa approach that is standard surgical procedure. In apical and peri-labyrinthine cholesteatomas, endoscopes allow to preserve hearing with middle fossa approach instead of trans-otic/ trans-labyrinthine/trans-cochlear approach.

Characterization of Hand Clenching in Human Sensorimotor Cortex Using High-, and Ultra-High Frequency Band Modulations of Electrocorticogram.

Functional mapping of eloquent cortex before the resection of a tumor is a critical procedure for optimizing survival and quality of life. In order to locate the hand area of the motor cortex in two patients with low-grade gliomas (LGG), we recorded electrocorticogram (ECoG) from a 113 channel hybrid high-density grid (64 large contacts with diameter of 2.7 mm and 49 small contacts with diameter of 1 mm) while they executed hand clenching movements. We investigated the spatio-spectral characteristics of the neural oscillatory activity and observed that, in both patients, the hand movements were consistently associated with a wide spread power decrease in the low frequency band (LFB: 8-32 Hz) and a more localized power increase in the high frequency band (HFB: 60-280 Hz) within the sensorimotor region. Importantly, we observed significant power increase in the ultra-high frequency band (UFB: 300-800 Hz) during hand movements of both patients within a restricted cortical region close to the central sulcus, and the motor cortical "hand knob." Among all frequency bands we studied, the UFB modulations were closest to the central sulcus and direct cortical stimulation (DCS) positive site. Both HFB and UFB modulations exhibited different timing characteristics at different locations. Power increase in HFB and UFB starting before movement onset was observed mostly at the anterior part of the activated cortical region. In addition, the spatial patterns in HFB and UFB indicated a probable postcentral shift of the hand motor function in one of the patients. We also compared the task related subband modulations captured by the small and large contacts in our hybrid grid. We did not find any significant difference in terms of band power changes. This study shows initial evidence that event-driven neural oscillatory activity recorded from ECoG can reach up to 800 Hz. The spatial distribution of UFB oscillations was found to be more focalized and closer to the central sulcus compared to LFB and HFB. More studies are needed to characterize further the functional significance of UFB relative to LFB and HFB.