BACKGROUND:Approaching tumors involving the infratemporal fossa (ITF) is technically challenging due to the complex relationships between several neurovascular structures and the deep-seated location of these lesions.METHODS:The authors describe in detail a minimally invasive approach to the ITF, consisting on a single-nostril endoscopic endonasal transmaxillary approach aided by an anterior transmaxillary port (EEA-ATMa). Anatomical landmarks and surgical tenets of this approach are highlighted and reviewed with the goal to guarantee successful tumor resection and avoid operative complications.CONCLUSION:The EEA-ATMa is technically feasible and offers excellent surgical exposure to the anterior and lateral aspect of ITF, without the need of transecting the Vidian nerve or performing a wide septectomy.

Olfaction is an undervalued sense in neurosurgery. Attempted surgical resection of anterior cranial fossa meningiomas puts the olfactory pathway at risk. Preservation of olfaction may increase the postoperative quality of life. Objective assessment of olfaction may inform clinical decision-making and influence the selection of operative approaches for surgical resection. We reviewed all patients who underwent surgical resection for midline anterior skull base meningiomas from July 1, 2014, through December 31, 2017. Patient demographics, tumor size, operative approach, pre- and postoperative deficits, and Simpson grade were collected and analyzed. Postoperative olfaction was assessed by clinical evaluation as well as objective evaluation using the University of Pennsylvania Smell Identification Test (UPSIT). Twenty-eight patients (10 male, 18 female) were included with an average age of 53.8 years (range 27–80 years). Twenty-six patients underwent craniotomy for resection, while 2 patients had endoscopic approaches. Average tumor volume was 402.1 cm3 (6.6–2507.7 cm3). Preoperatively, five patients (17.8%) presented with olfactory impairment. Objectively, 50% of patients (14/28) consented and completed the UPSIT. The average postoperative UPSIT score was 25.8/40 (9/40–38/40). Two patients not identified on clinical assessment alone demonstrated postoperative olfactory deficit on UPSIT (2/14). There are limited published studies evaluating olfaction in patients who undergo skull-based approaches for anterior fossa meningiomas. Our series showed the highest olfaction preservation rate (87.5%) using a comprehensive strategy and multitude of surgical approaches based on the olfactory function and tumor characteristics.

STUDY DESIGN:Systematic review and meta-analysis. OBJECTIVES:This study aims to evaluate the effects of anterior cervical decompression and fusion (ACDF) on axial neck pain in adult patients receiving surgery for myelopathy, radiculopathy, or a combination of both. METHODS:Two independent reviewers completed a librarian-assisted search of 4 databases. Visual Analogue Scale (VAS) and Neck Disability Index (NDI) scores were extracted preoperatively and at 3, 6, 12, 24, 36, 48, and 48+ months postoperatively for ACDF groups and pooled using a random-effects model. RESULTS:Of 17 850 eligible studies, 37 were included for analysis, totaling 2138 patients analyzed with VAS and 2477 with NDI score. Individual VAS mean differences were reduced at 6 weeks (-2.5 [95% confidence interval (CI): -3.5 to -1.6]), 3 months (-2.9 [-3.7 to -2.2]), 6 months (-3.2 [-3.9 to -2.6]), 12 months (-3.7 [-4.3 to -3.1]), 24 months (-4.0 [-4.4 to -3.5]), 48 months (-4.6 [-5.5 to -3.8]), and >48 months (-4.7 [-5.8 to -3.6]) follow-up (P < .0001 for all endpoints). Individual NDI mean differences were reduced at 6 weeks (-26.7 [-30.9 to -22.6]), 3 months (-29.8 [-32.7 to -26.8]), 6 months (-31.2 [-35.5 to -26.8)], 12 months (-29.3 [-33.2 to -25.4]), 24 months (-28.9 [-32.6 to -25.2]), 48 months (-33.1 [-37.4 to -28.7]), and >48 months (-37.6 [-45.9 to -29.3]) follow-up (P < .0001 for all endpoints). CONCLUSIONS:ACDF is associated with a significant reduction in axial neck pain compared with preoperative values in patients being treated specifically for myelopathy or radiculopathy. This influences the preoperative discussions surgeons may have with patients regarding their expectations for surgery. The effects seen are stable over time and represent a clinically significant reduction in axial neck pain.

Background: The role of extent of surgical resection (EOR) on clinical outcomes in patients with low-grade glioma requires further examination. Methods: We systematically searched MEDLINE, Embase, and the Cochrane Library for studies published between January 1, 1990 and January 5, 2018 on predefined patient outcomes regarding different EOR of low-grade glioma. Results: Our literature search yielded 60 studies including 13,289 patients. Pooled estimates of overall survival showed an increase from 3.79 years (95% CI, 2.37–5.22) in the biopsy group to 6.68 years (95% CI, 4.19–9.16) in STR to 10.65 years (95% CI, 6.78–14.52) in GTR. When compared to STR, GTR prolonged progression-free survival by 2.08 years (95% CI, 0.26–3.89; P=0.025). Pooled estimates of seizure control showed an improvement from 47.8% (95% CI, 26.7–69.6) with biopsy to 54.2% (95% CI, 48.7–59.6) with STR to 81.0% (95% CI, 74.6–86.2) with GTR. Compared to STR, GTR delayed malignant transformation (RR, 0.43; 95% CI, 0.20–0.93; P=0.032), without increasing postoperative mortality (RR, 0.38; 95% CI, 0.07–1.97; P=0.250) or morbidity (RR, 1.22; 95% CI, 0.65–2.28; P=0.540). Conclusions: Among patients with low grade gliomas, higher degrees of safe EOR, were associated with longer overall and progression-free survival, better seizure control, and delayed malignant transformation, without increased mortality or morbidity.

BACKGROUND: Anterior skull base meningiomas often grow to a large size (>= 4 cm) before detection. Their blood supply is mostly provided by the anterior and posterior ethmoidal arteries. Because of their vascularity, intraoperative bleeding can be a challenging prospect that increases the risk of perioperative complications. Preoperative ethmoidal arteries ligation has been used to aid in limiting blood loss. Our objective was to assess the effect of preoperative arterial ligation on the perioperative course of large (>= 4 cm) to giant (>= 6 cm) anterior skull base meningiomas. METHODS: We retrospectively searched our database for large anterior skull base meningiomas (>= 4 cm). We analyzed differences in intraoperative blood loss, operative time, intraoperative transfusion, and hematologic parameters between patients who did not undergo preoperative ethmoidal arteries ligation (Group 1) and those who did (Group 2). RESULTS: Average estimated blood loss (EBL) was 825 ml (Group 1) versus 350 mL. (Group 2) (P = 0.42), decrease in hemoglobin was 4 g/dL versus 3.2 g/dL (P = 0.53), decrease in hematocrit was 12.4% versus 9.6% (P = 0.64), and average operative time was 656 minutes versus 598 minutes (P = 0.58). EBL per volume yielded a ratio of 10.6 mL/cm(3) versus 4.1 ml/cm(3) (P = 0.06). CONCLUSIONS: Ethmoidal arteries ligation may have a benefit in large-to-giant anterior skull base meningiomas surgery. Our results showed a decrease in EBL and lesser decrease in pre- and postoperative hemoglobin and hematocrit levels as compared with cases in which no vascular ligation was performed when corrected for tumor volume.

OBJECTIVE: The cervical carotid segment is used routinely as donor site for high-flow bypass procedures. The horizontal petrous segment would offer a shorter graft distance, complete graft protection intracranially, and avoid the need for surgical neck exposure. In a morpho-metric cadaveric study, we aimed to investigate variations of the petrous carotid anatomy, especially the incidence of bony dehiscence of the roof of the horizontal petrous carotid segment canal, which may facilitate exposure of the vessel and thereby potentially lower the morbidity of high-flow bypass procedures. METHODS: A subtemporal approach was used to expose the horizontal petrous internal carotid artery (ICA) on each side of 4 alcohol-embedded, silicone-injected human cadaver heads to perform a morphometric analysis of the vessel segment and surrounding bony anatomy. RESULTS: The following measurements were obtained of the horizontal petrous ICA (millimeters): long axis mean 9.6 (standard deviation [SD] 4.4, MIN 4.2, MAX 19.5), diameter mean 4.9 (SD 0.6, MIN 4, MAX 5.7), thickness of canal roof mean 2.1 (SD 1.7, MIN 0, MAX 5), and distance from temporal squama mean 22.5 (SD 6, MIN 17, MAX 35). Dehiscence of the bony roof of the horizontal petrous carotid canal was found in 25% of specimen investigated. CONCLUSIONS: A dehiscent bony roof of the horizontal petrous carotid canal potentially facilitates exposure of the vessel for high-flow bypass procedures and was observed in 25% of specimens. This feature could be identified on preoperative high-resolution imaging and thus aid in patient selection.

This is a case of an extensive tuberculum sella meningioma involving the circle of Willis down to the basilar artery that presented with bilateral visual loss worse on the right than left side. A one-piece right orbitopterional approach along the worse eye was used to gain access to the three cranial fossae. The orbitotomy facilitates access to the midline structures and contralateral base of the tumor with minimal brain retraction. Tumor resection is initiated by first identifying the tumor capsule, followed by piecemeal debulking via ultrasonic aspiration. Early decompression of the ipsilateral optic nerve was performed. Gross total resection of the tumor was achieved through multiple windows as follows: prechiasmatic, opticocarotid, and carotid oculomotor. Sharp dissection is performed around critical neurovascular structures to reduce strain and vascular injury. The circle of Willis including the small perforators was completely preserved. Postoperative examination at follow-up demonstrated improvement in vision less on the right side and resolution of postoperative partial third nerve palsy. The link to the video can be found at: https://youtu.be/XfEh8CjkvA0 .

The tremendous advances in endoscopic skull base surgery added a new set of intricate less invasive approaches to the neurosurgical armamentarium. The new generations of neurosurgeons face the challenge of adopting the ever-changing technology and quickly learning modern surgical techniques beyond the traditional neurosurgery comfort zone. The future skull base surgeon must be well trained and knowledgeable in all surgical portals to the skull base in order to select the safest, least invasive, most direct approach that offers the optimum exposure to handle a complex skull base pathology. The multi-portal/corridor philosophy is often adopted in order to achieve superior surgical and clinical outcomes. Neurosurgeons need to consider such an approach when appropriate as it may offer a superior outcome while minimizing the morbidity associated with large exposures.

Vestibular schwannoma is a benign tumor that affects 3% of the population, but accounts for 85% of tumors occurring at the cerebellopontine angle (CPA). In this case, we present a 48-year-old female with history of cholesteatoma on the right and chronic suppurative otitis media on the left who presented with an 18 month history of bilateral hearing loss, worse on the right. Investigations revealed a right sided vestibular schwannoma measuring 1.6 cm in diameter. Audiogram revealed an AAO-HNS (American Academy of Otolaryngology-Head and Neck Surgery) class C hearing on the right and class B on the left. There are several management options for this size of vestibular schwannoma including observation and radiosurgery. However, preserving cochlear nerve function remains a challenging enterprise. Furthermore, the ideal management that confers the highest chance of hearing preservation remains heavily debated. Given the patient's young age, the goal of hearing preservation and the tumor size/extension into the CPA, surgery was decided through a right retrosigmoid transmeatal approach for tumor resection with intraoperative brain auditory evoked responses monitoring. For hearing preservation, we emphasize few important dissection techniques: tumor debulking from the top first to avoid early manipulation of the cochlear nerve at the bottom of the tumor, sharp dissection from medial to lateral off the vestibular nerve which is kept intact as a tension band to minimize cochlear nerve manipulations, and limit the drilling of the posterolateral wall of the internal auditory canal (IAC) medial to the labyrinth and endolymphatic apparatus. Postoperatively, the patient was discharged home within 2 days, with imaging showing a gross total resection. Follow-up audiogram shows unchanged pure tone thresholds. The link to the Video can be found at: https://youtu.be/Z5ftkpJN5k8 .

Study Design: Questionnaire. Objectives: Iatrogenic dural tear is a complication of spinal surgery with significant morbidity and cost to the health care system. The optimal management is unclear, and therefore we aimed to survey current practices among Canadian practitioners. Methods: A questionnaire was administered to members of the Canadian Neurological Surgical Society designed to explore methods of closure of iatrogenic durotomy. Results: Spinal surgeons were surveyed anonymously with a 55% response rate (n = 91). For pinhole-sized tears, there is no agreement in the methods of closure, with a trend toward sealant fixation (36.7%). Medium-and large-sized tears are predominantly closed with sutures and sealant (67% and 80%, respectively). Anterior tears are managed without primary closure (40.2%), or using sealant alone (48%). Posterior tears are treated with a combination of sutures and sealant (73.8%). Nerve root tears are treated with either sealant alone (50%), or sutures and sealant (37.8%). Tisseal is the preferred sealant (79.7%) over alternatives. With the exception of pin-hole sized tears (39.5%) most respondents recommended bed rest f or at least 24 hours in the setting of medium (73.2%) and large (89.1%) dural tears. Conclusions: This study elucidates the areas of uncertainty with regard to iatrogenic dural tear management. There is disagreement regarding management of anterior and nerve root tears, pinhole-sized tears in any location of the spine, and whether patients should be admitted to hospital or should be on bed rest following a pinhole-sized dural tear. There is a need for a robust comparative research study of dural repair strategies.

BACKGROUND: Endoscopic third ventriculostomy (ETV) is a safe and effective treatment for hydrocephalus. An entry point located 4 cm anterior to the coronal suture, 3 cm anterior to Kocher point, and approximately 9 cm from the pupil at the midpupillary line has been used successfully for the last 20 years in our center. We aimed to evaluate this alternative anterior entry point routinely used for ETV, with or without concurrent endoscopic biopsy.METHODS: Patients undergoing this proposed entry point were examined to evaluate its safety and efficacy. Factors such as patients' age, sex, hydrocephalus etiology, tumor location and pathology, and complication rate were examined through regression analyses to evaluate their impact on tumor biopsy and ETV success rates, and the need for subsequent ventricular shunting.RESULTS: A total of 131 patients were included in the study. ETV was successful in 125 (95.4%) patients. Of these, 26 (19.8%) patients required a biopsy, which was successful in 21 (80.8%) cases. A complication was observed in 10 (7.6%) patients, with a trend toward complications occurring after ETV failure. There was no association between ETV success rate and patients' age (P = 0.5) or sex (P = 0.99).CONCLUSIONS: The anterior entry point is a safe and effective method for ETV, especially when considering concurrent ventricular tumor biopsy. This entry point may be considered as a more minimally invasive procedure when using rigid endoscopy and may also eliminate the need for a flexible scope.

Atlantoaxial procedures have been developed in an effort to ensure solid C1-C2 fusion. However, techniques that involve sublaminar wiring have the potential for neural structure injury. We present the management of a patient who previously underwent Gallie fusion 10 years ago and is presenting with a dislodged titanium wire that has migrated into the medulla oblongata. A 52-year-old female patient known with rheumatoid arthritis presented with truncal ataxia and food regurgitation 10 years after undergoing a C1-C2 Gallie fusion. A computerized tomography (CT) scan revealed that a wire from her Gallie fusion procedure migrated into the medulla oblongata. The patient underwent foramen magnum decompression with C1 bilateral laminectomy, instrumentation, and removal of a migrated wire. Six months later, a CT scan showed that all occipital screws were pulled out. In the revision surgery, new occipital screws were placed with a resultant significant improvement in patient’s gait postoperatively. Wire migration as a differential diagnosis should be considered in patients presenting with neurological dysfunction who underwent surgical treatment with sublaminar wire fusion techniques.

Background: Multiple myeloma (MM) as a cause of spontaneous intracranial hemorrhage has not been well established. Methods: We report a patient who developed a spontaneous intracerebral hemorrhage secondary to MM and conduct a systematic review of the literature. In addition, we discuss the underlying pathophysiology. Results: A 67-year-old relatively healthy female with a recent history of low back pain presented with an altered level of consciousness and left sided hemiplegia. CT demonstrated a large right temporal intracerebral hemorrhage. CT angiogram ruled out a vascular abnormality; however, multiple abnormal bony lesions were incidentally noted. Other causes for intracranial bleed were ruled out. She underwent a craniotomy for hematoma evacuation. Intra-operatively, the skull was noted to be abnormal and hematoma was not associated with a mass lesion. In addition, serum and urine electrophoresis were found to be positive for monoclonal free kappa light chains. Subsequent bone biopsy confirmed the diagnosis of MM. Our literature search identified 2 reported cases of spontaneous subdural hematomas and 2 patients with spontaneous intracerebral hematomas secondary to MM. Moreover, only 4 reports in the literature document intracranial hemorrhage secondary to a mass developed from MM. Conclusions: Multiple myeloma is perhaps an under-reported possible cause for spontaneous intracerebral hematoma.

Background: Cervical spine clearance protocols are controversial for unconscious patients after blunt traumatic injury and negative findings on computed tomography (CT). Purpose: To review evidence about the utility of different cervical spine clearance protocols in excluding significant cervical spine injury after negative CT results in obtunded adults with blunt traumatic injury. Data Sources: MEDLINE, EMBASE, CINAHL, Google Scholar, and the Cochrane Library were searched from January 2000 through November 2014. Study Selection: English-language studies that examined patients with negative CT results having confirmatory routine testing with magnetic resonance imaging (MRI), dynamic radiography, or clinical examination and that reported outcome measures of missed cervical spine injury, need for operative stabilization, or prolonged use of cervical collars. Data Extraction: Independent reviewers evaluated the quality of studies and abstracted the data according to a predefined protocol. Data Synthesis: Of 28 observational studies (3627 patients) that met eligibility criteria, 7 were prospective studies (1686 patients) with low risk of bias and well-interpreted, high-quality CT scans. These 7 studies showed that 0% of significant injuries were missed after negative CT results. The overall studies using confirmatory routine testing with MRI showed incidence rates of 0% to 1.5% for cervical spine instability (16 studies; 1799 patients), 0% to 7.3% for need for operative fixation (17 studies; 1555 patients), and 0% to 29.5% for prolonged collar use (16 studies; 1453 patients). Limitations: Most studies were retrospective. Approaches to management of soft tissue changes with collars varied markedly. Conclusion: Cervical spine clearance in obtunded adults after blunt traumatic injury with negative results from a well-interpreted, high-quality CT scan is probably a safe and efficient practice. Primary Funding Source: None.

The minimal access retrosigmoid endoscopic approach to vestibular schwannoma (VS) resection has been used with promising results. However, it has not been compared with the standard open approach in the literature. We performed a meta-analysis review for all articles describing both approaches for VS from 1996 to 2011. We found 1861 articles. After review and discussion, we narrowed our study to 25 articles, 4 endoscopic and 21 open. The total number of patients was 3026 for open and 790 for endoscopic. The mean tumor sizes in the open and endoscopic series were 2.5 cm and 2.7 cm, respectively. Good facial nerve outcome was achieved in 67% of the open series patients and in 94% of the endoscopic series patients. Other outcomes in the open and endoscopic series were the following: gross total resection, 91% versus 97%; functional hearing, 22.6% versus 46%; wound infection, 1.3% versus 2.6%; and recurrence, 5.4% versus 2.2%. We acknowledge the limitations of our study, but we can state that the endoscopic approach is not inferior to the standard open approach. In expert hands the endoscopic approach can offer as good a result as the open, with potential benefits such as less pain and a shorter length of stay in the hospital. There is a need for more controlled studies for a definitive comparison.

Object. Information pertaining to the natural history of intramedullary spinal cord cavernous malformations (ISCCMs) and patient outcomes after surgery is scarce. To evaluate factors associated with favorable outcomes for patients with surgically and conservatively managed ISCCMs, the authors performed a systematic review and metaanalysis of the literature. In addition, they included their single-center series of ISCCMs. Methods. The authors searched MEDLINE, EMBASE, CINAHL, Google Scholar, and The Cochrane Library for studies published through June 2013 that reported cases of ISCCMs. Data from all eligible studies were used to examine the epidemiology, clinical features, and neurological outcomes of patients with surgically managed and conservatively treated ISCCMs. To evaluate several variables as predictors of favorable neurological outcomes, the authors conducted a meta-analysis of individual patient data and performed univariate and multivariate logistic regression analyses. Variables included patient age, patient sex, lesion spinal level, lesion size, cerebral cavernomas, family history of cavernous malformations, clinical course, presenting symptoms, treatment strategy (operative or conservative), symptom duration, surgical approach, spinal location, and extent of resection. In addition, they performed a meta-analysis to determine a pooled estimate of the annual hemorrhage rate of ISCCMs. Results. Eligibility criteria were met by 40 studies, totaling 632 patients, including the authors' institutional series of 24 patients. Mean patient age was 39.1 years (range 2-80 years), and the male-to-female ratio was 1.1:1. Spinal levels of cavernomas were cervical (38%), cervicothoracic (2.4%), thoracic (55.2%), thoracolumbar (0.6%), lumbar (2.1%), and conus medullaris (1.7%). Average cavernoma size was 9.2 mm. Associated cerebral cavernomas occurred in 16.5% of patients, and a family history of cavernous malformation was found for 11.9% of evaluated patients. Clinical course was acute with stepwise progression for 45.4% of patients and slowly progressive for 54.6%. Symptoms were motor (60.5%), sensory (57.8%), pain (33.8%), bladder and/or bowel (23.6%), respiratory distress (0.5%), or absent (asymptomatic; 0.9%). The calculated pooled annual rate of hemorrhage was 2.1% (95% CI 1.3%-3.3%). Most (89.9%) patients underwent resection, and 10.1% underwent conservative management (observation). Outcomes were better for those who underwent resection than for those who underwent conservative management (OR 2.79, 95% CI 1.46-5.33, p = 0.002). A positive correlation with improved neurological outcomes was found for resection within 3 months of symptom onset (OR 2.11, 95% CI 1.31-3.41, p = 0.002), hemilaminectomy approach (OR 3.20, 95% CI 1.16-8.86, p = 0.03), and gross-total resection (OR 3.61, 95% CI 1.24-10.52, p = 0.02). Better outcomes were predicted by an acute clinical course (OR 1.72, 95% CI 1.10-2.68, p = 0.02) and motor symptoms (OR 1.76, 95% CI 1.08-2.86, p = 0.02); poor neurological recovery was predicted by sensory symptoms (OR 0.58, 95% CI 0.35-0.98, p = 0.04). Rates of neurological improvement after resection were no higher for patients with superficial ISCCMs than for those with deep-seated ISCCMs (OR 1.36, 95% CI 0.71-2.60, p = 0.36). Conclusions. Intramedullary spinal cord cavernous malformations tend to be clinically progressive. The authors' findings support an operative management plan for patients with a symptomatic ISCCM. Surgical goals include gross-total resection through a more minimally invasive hemilaminectomy approach within 3 months of presentation.