Multiple skull base defects in the setting of spontaneous cerebrospinal fluid rhinorrhea; a dual institution view.

PURPOSE: Idiopathic intracranial hypertension (IIH) is a condition of high cerebrospinal fluid (CSF) pressure that presents with CSF leak. The implications of multiple skull base defects (SBD) and associated synchronous CSF leaks have not been previously explored. MATERIALS AND METHODS: A dual institutional case-control study examined multiple SBD's and encephaloceles on the risk of CSF leak and postoperative failures post-repair. IIH patients with CSF leaks and IIH controls without leaks were selected retrospectively. Chi square analysis evaluated for statistically significant alterations in probability with CSF leak development. RESULTS: 192 patients were selected with 108 IIH controls and 84 spontaneous CSF leak cases. Signs and symptoms for IIH controls and CSF leak cases respectively were pulsatile tinnitus (60.2 % and 29.8 %), headaches (96.3 % and 63.1 %), papilledema (74.1 % and 12.5 %), visual field defects (60.8 % and 13 %) (p < 0.001). Encephalocele formation in controls was 3.7 % compared to cases at 91.6 % (p < 0.001). Multiple SBD's in controls compared cases was 0.9 % and 46.4 % respectively (p < 0.001). Subgroup analysis of CSF leak cases showed 15 patients with two CSF leak repairs due to a recurrence. 27 (39.1 %) single leak cases had multiple SDB's while 12 (80 %) recurrent leaks had multiple SDB's (p = 0.004). CONCLUSIONS: Patients with radiographic evidence of multiple SBD's and encephaloceles represent a high-risk population with a propensity for CSF leaks. Secondary SBD's are common in patients with spontaneous CSF rhinorrhea and higher in patients with a recurrence.

Brain Atrophy and Leukoaraiosis Correlate with Futile Stroke Thrombectomy.

INTRODUCTION: Although mechanical thrombectomy (MT) is a proven therapy for acute large vessel occlusion strokes, futile recanalization in the elderly is common and costly. Strategies to minimize futile recanalization may reduce unnecessary thrombectomy transfers and procedures. We evaluated whether a simple and rapid visual assessment of brain atrophy and leukoaraiosis on a plain head CT correlates with futile stroke recanalization in the elderly. METHODS: Consecutive stroke patients admitted for thrombectomy, older than 65 years of age, all with TICI 2b/3 recanalization rates were retrospectively studied from multiple comprehensive stroke centers. Brain atrophy and leukoaraiosis were visually analyzed from pre-intervention plain head CTs using a simplified scheme based on validated scales. Baseline demographics were collected and the primary outcome measure was 90-day modified Rankin score (mRS). Cochran-Armitage trend test was applied in analyzing the association of the severity of brain atrophy and leukoaraiosis with 90-day mRS. RESULTS: Between 2017 and 2019, 175 patients > 65 years who underwent thrombectomy with TICI 2b/3 recanalization from two comprehensive stroke centers were evaluated. The median age was 77 years. IV-tPA was given in 59% of patients, average initial NIHSS was 19, average baseline mRS was 0.77 and median time to recanalization was 300 minutes. Age and severity of atrophy/leukoaraiosis was categorized into three groups of increasing severity and associated with 90 day mRS 0-3 rates of 62%, 49% and 41% (p=0.037) respectively. CONCLUSIONS: A simplified, visual assessment of the degree of brain atrophy and leukoaraiosis measured on plain head CT correlates with futile recanalization in patients age >65 years. Although additional validation is needed, these findings suggest that brain atrophy and leukoaraiosis may have value as a surrogate marker of prestroke functional status. In doing so, simplified visual plain head CT grading scales may minimize elderly futile recanalization.

Reduction in generalized conductance with increasing gain in amplifying Anderson-localized systems.

The consequences of a nonconservative environment on the transport of photons under conditions of Anderson localization in a disordered system are a topic of great interest. In this work, we experimentally demonstrate the systematic decrease in the localization length of a quasi-one-dimensional localizing system when gain is added to it. We quantify the generalized conductance of the system using the variance of the fluctuations in the localized eigenfunctions and show a decrease in conductance with gain. We theoretically model this system using a combination of transfer matrix calculations and rate equations for a two-level lasing system and find very good qualitative agreement with the experimental results. We show that the generalized conductance in higher disorder can be emulated in weak disorder using the appropriate gain. The decreasing conductance is explained using the reduced probability of outcoupling of photons relative to their peak position within the system.

Stereotactic Radiosurgery for Unruptured Versus Ruptured Pediatric Brain Arteriovenous Malformations.

Background and Purpose- The effects of prior hemorrhage on stereotactic radiosurgery (SRS) outcomes for pediatric arteriovenous malformations (AVMs) are not well defined. The aim of this multicenter, retrospective cohort study is to compare the SRS outcomes for unruptured versus ruptured pediatric AVMs. Methods- The International Radiosurgery Research Foundation pediatric AVM database from 1987 to 2018 was reviewed retrospectively. Favorable outcome was defined as AVM obliteration, no post-SRS hemorrhage, and no permanently symptomatic radiation-induced changes. Associations between prior hemorrhage and outcomes were adjusted for baseline differences, inverse probability weights, and competing risks. Results- The study cohort comprised 153 unruptured and 386 ruptured AVMs. Favorable outcome was achieved in 48.4% and 60.4% of unruptured and ruptured AVMs, respectively (adjusted odds ratio, 1.353; P=0.190). Cumulative AVM obliteration probabilities were 51.2%, 59.4%, 64.2%, and 70.0% for unruptured and 61.0%, 69.3%, 74.0%, and 79.3% for ruptured AVMs at 4, 6, 8, and 10 years, respectively (subhazard ratio, 1.311; P=0.020). Cumulative post-SRS hemorrhage probabilities were 4.5%, 5.6%, 5.6%, and 9.8% for unruptured and 4.7%, 6.1%, 6.1%, and 10.6% for ruptured AVMs at 4, 6, 8, and 10 years, respectively (subhazard ratio, 1.086; P=0.825). Probabilities of AVM obliteration (adjusted subhazard ratio, 0.968; P=0.850) and post-SRS hemorrhage (adjusted subhazard ratio, 1.663; P=0.251) were comparable between the 2 cohorts after inverse probability weight adjustments. Symptomatic (15.8% versus 8.1%; adjusted odds ratio, 0.400; P=0.008) and permanent (9.2% versus 5.0%; adjusted odds ratio, 0.441; P=0.045) radiation-induced change were more common in unruptured AVMs. Conclusions- The overall outcomes after SRS for unruptured versus ruptured pediatric AVMs are comparable. However, symptomatic and permanent radiation-induced change occur more frequently in pediatric patients with unruptured AVMs.

Transarterial and transvenous approaches for embolization of tentorial dural arteriovenous fistula.

Tentorial dural arteriovenous fistulas (DAVFs) are uncommon, complex fistulas located between the leaves of the tentorium cerebelli with a specific anatomic and clinical presentation characterized by high hemorrhagic risk. They have an extensive arterial supply and complex venous drainages, making them difficult to treat. There is recent literature favoring treatment through an endovascular transarterial route. The authors present an uncommon tentorial/ambient cistern region DAVF with feeders arising from the external and internal carotid arteries. The patient underwent a combined transarterial and transvenous approach with successful obliteration of the DAVF. The authors discuss the management challenges faced in this case.The video can be found here: https://youtu.be/VXDD8zUvsSQ.

Endovascular management of complex superior sagittal sinus dural arteriovenous fistula.

Superior sagittal sinus (SSS) dural arteriovenous fistulas (DAVFs) are rare and present unique challenges to treatment. Complex, often bilateral, arterial supply and involvement of large volumes of eloquent cortical venous drainage may necessitate multimodality therapy such as endovascular, microsurgical, and stereotactic radiosurgery techniques. The authors present a complex SSS DAVF associated with an occluded/severely stenotic SSS. The patient underwent a successful endovascular transvenous approach with complete obliteration of the SSS. The authors discuss the management challenges faced on this case.The video can be found here: https://youtu.be/-rztg0_cBXY.

Endovascular management of basilar artery occlusion secondary to fusiform aneurysm with intraluminal thrombus.

Acute basilar artery occlusion is one of the most devastating subtypes of ischemic stroke with an extremely high morbidity and mortality rate. The most common causes include embolism, large-artery atherosclerosis, penetrating small-artery disease, and arterial dissection. The heart and vertebral arteries are the main source of emboli in embolic basilar occlusions. The authors present an uncommon acute basilar occlusion secondary to a fusiform aneurysm with intraluminal thrombus. The patient underwent a mechanical thrombectomy with successful recanalization, but persistent intraluminal thrombus. The authors discuss the management dilemma and describe their choice for placement of flow diverter stents.The video can be found here: https://youtu.be/XzBdgxJPSWQ.

Stent-assisted coil embolization of MCA aneurysm via a trans-posterior communicating artery access.

External carotid artery (ECA) to internal carotid artery (ICA) bypass is a well-established procedure for the treatment of chronic ischemic diseases of the carotid artery. Rarely de novo aneurysms can develop at the site of anastomosis. The treatment of these aneurysms can be very challenging due to various factors, including the presence of graft, previous craniotomy, atherosclerotic vessels, and lack of direct access. In this video the authors report and discuss the management of a right middle cerebral artery (MCA) wide-necked de novo aneurysm by stent-assisted coiling through a retrograde trans-posterior communicating artery access.The video can be found here: https://youtu.be/MBKolPvOErU.

Fractionated Gamma Knife radiosurgery for skull base meningiomas: a single-institution experience.

OBJECTIVEGamma Knife radiosurgery (GKRS) has been successfully used for the treatment of intracranial meningiomas given its steep dose gradients and high-dose conformality. However, treatment of skull base meningiomas (SBMs) may pose significant risk to adjacent radiation-sensitive structures such as the cranial nerves. Fractionated GKRS (fGKRS) may decrease this risk, but until recently it has not been practical with traditional pin-based systems. This study reports the authors' experience in treating SBMs with fGKRS, using a relocatable, noninvasive immobilization system.METHODSThe authors performed a retrospective review of all patients who underwent fGKRS for SBMs between 2013 and 2018 delivered using the Extend relocatable frame system or the Icon system. Patient demographics, pre- and post-GKRS tumor characteristics, perilesional edema, prior treatment details, and clinical symptoms were evaluated. Volumetric analysis of pre-GKRS, post-GKRS, and subsequent follow-up visits was performed.RESULTSTwenty-five patients met inclusion criteria. Nineteen patients were treated with the Icon system, and 6 patients were treated with the Extend system. The mean pre-fGKRS tumor volume was 7.62 cm3 (range 4.57-13.07 cm3). The median margin dose was 25 Gy delivered in 4 (8%) or 5 (92%) fractions. The median follow-up time was 12.4 months (range 4.7-17.4 months). Two patients (9%) experienced new-onset cranial neuropathy at the first follow-up. The mean postoperative tumor volume reduction was 15.9% with 6 patients (27%) experiencing improvement of cranial neuropathy at the first follow-up. Median first follow-up scans were obtained at 3.4 months (range 2.8-4.3 months). Three patients (12%) developed asymptomatic, mild perilesional edema by the first follow-up, which remained stable subsequently.CONCLUSIONSfGKRS with relocatable, noninvasive immobilization systems is well tolerated in patients with SBMs and demonstrated satisfactory tumor control as well as limited radiation toxicity. Future prospective studies with long-term follow-up and comparison to single-session GKRS or fractionated stereotactic radiotherapy are necessary to validate these findings and determine the efficacy of this approach in the management of SBMs.

Giant posterior fossa dural cavernoma in a child.

PURPOSE: Extra-axial (dural) cavernomas are rare and constitutes 5% of all cavernomas. They are thought to arise from the venous plexus of the dura. They can reach large sizes before diagnosis and can have an aggressive presentation. METHODS: The authors report a rare case of giant cavernoma based on the posterior fossa dura adjacent to the sigmoid sinus (sino-dural angle) in an 8-year-old boy which was excised with good outcome. The authors describe its clinico-radiological profile and outcome characteristics along with a comprehensive review of relevant literature. RESULTS: This child underwent retromastiod craniectomy and complete excision of the dural cavernoma. The dural attachment was coagulated. Histopathological examination confirmed the diagnosis. CONCLUSION: We report cavernoma needs to be considered in the differential diagnosis of a dural-based posterior fossa lesion in paediatric population as complete excision is possible.

Intracerebellar malignant nerve sheath tumor in a child: case report and review of literature.

PURPOSE: Intracerebellar malignant nerve sheath tumor (ICMNST) is an extremely rare entity, only two cases have been reported previously, and this is the first case to be reported in a child. The histogenesis, diagnosis, and management of this entity are very ambiguous, and natural history in a child is unknown. METHODS: The authors report a 7-year-old girl who presented with ataxia and signs of raised intracranial pressure and discuss the challenges in diagnosis, surgical strategy, and treatment. RESULTS: Following gross total resection and radiation to tumor bed, the patient had unremarkable recovery and is recurrence free at 1-year follow-up. CONCLUSION: ICMNSTs are extremely rare tumors of the cerebellum. Preoperative radiological diagnosis is not possible due to its close radiological resemblance to other common posterior fossa tumors. Immunohistochemistry plays a pivotal role in clinching the diagnosis. Though the reported adult counterparts have shown dismal prognosis, the pediatric counterparts may fare better with good surgical resection followed by radiotherapy.

The vanishing shunt valve.

PURPOSE: Ventriculoperitoneal (VP) shunt is one of the most commonly performed procedures by a neurosurgeon. It is occasionally fraught with the most bizarre complications. Understanding the pathophysiology of these complications can help us make the procedure safe and more effective. METHODS: The authors report a case of 8-year-old boy, previously operated for lumbar myelomeningocele and hydrocephalus with an intra diploic migration of shunt tube and shunt dysfunction, and discuss the pathophysiology, diagnosis, and surgical strategy. RESULTS: After diagnosis of shunt malfunction, shunt revision was done with placement of new system and removal of the old apparatus. Patient had a remarkable recovery after the surgery. CONCLUSION: Intradiploic migration is an extremely rare cause of shunt malfunction and has never been reported in literature before. Possible mechanism is that prolonged pressure on the valve due to recumbent head position in a paraplegic child might have led to new bone formation and subsequent intradiploic migration of the valve. Careful planning the position of shunt valve in relation to head position, especially in children who are recumbent due to paraplegia might avoid this untoward complication.

Intrafistula pressure measurement in traumatic carotid cavernous fistulas--key to increasing safety and effectiveness of endovascular coiling.

BACKGROUND: Very few diseases demostrate the tremendous variation and capricious results common with the clinical ensemble of carotid cavernous fistulas (CCFs). The treatment modality for CCFs has changed from surgical to endovascular therapy. Many options exist in endovascular therapy ranging from balloons to coils and liquid embolization agents like Onyx. This study was undertaken to assess the role of recording intra-fistula pressure (IFP) during endovascular coiling of CCFs in order to help us better understand the angiodynamics of the fistula and to make coiling safer and effective. METHODS: IFP measurement was done in 15 cases of traumatic CCF undergoing endovascular coiling. Patients were prospectively analyzed by pre- and post- procedural clinical profile, degree of recovery and time until fistula occlusion. Univariate analysis was used to find the correlation between the reduction in IFP, the degree of fistula obliteration and time until occlusion. RESULTS: Of the 15 patients who underwent endovascular coiling 13 had total occlusion of the fistula, 1 patient had subtotal occlusion and 1 patient had no occlusion of the fistula. There was 100 % internal carotid artery (ICA) patency. Univariate analysis showed a strong correlation between the degree of reduction in IFP and time required for fistula occlusion (p < 0.001). Patients with a significant drop in IFP were also preceived as having a higher chance of fistula occlusion after waiting 30 min. CONCLUSION: To our knowledge this is the largest series in published literature focused on using only detachable coils as the first line embolizing agent in treatment of traumatic CCFs. We conclude that IFP monitoring will play an important role in making treatment of CCFs safer and more effective. The aim of coiling the fistula is not to tightly pack the fistula as during treatment of aneurysms; rather it is to reduce flow across the fistula leading to thrombosis thus reducing the requirement of coils.

Surgical Strategies in the Treatment of Giant Pituitary Adenomas.

BACKGROUND AND OBJECTIVES: The management of giant pituitary adenomas (GPAs) is challenging due to associated endocrinopathies and the close proximity of these tumors to critical structures, such as the optic nerves, structures of the cavernous sinus, and hypothalamus. The objective of this review article was to summarize the current management strategies for giant pituitary adenomas, including the role of open and endoscopic surgical approaches and the role of medical and radiation therapy in conjunction with surgery. METHODS: We conducted a retrospective review of GPAs operated at our institute between January 2010 and March 2023. Surgical approaches, extent of resection, and associated complications were documented. Furthermore, we conducted a thorough literature review to identify relevant studies published in the past decade, which were incorporated along with insights gained from our institutional case series of GPAs to analyze and integrate both the existing knowledge base and our institution's firsthand experience in the management of GPAs. RESULTS: A total of 46 giant pituitary adenomas (GPAs) were operated on, using various surgical approaches. Transsphenoidal approach was used in 25 cases and a staged approach using transsphenoidal and pterional was used in 15 cases. Other approaches included transcortical-transventricular, transcallosal, pterional/orbitozygomatic, and subfrontal approaches. Complications and technical nuances were reported. CONCLUSION: The management of giant pituitary adenomas remains complex, often involving several modalities-open or endoscopic resection, radiosurgery, and medical management of both the tumor and associated endocrinopathies. Surgical resections are often challenging procedures that require careful consideration of several factors, including patient characteristics, tumor location, and size, and the experience and skill of the surgical team.

Comparison of Radial Versus Femoral Access for Neuroendovascular Procedures in Very High Body Mass Index Individuals.

BACKGROUND: Femoral access (TFA) for neuroendovascular procedures may present a challenge in very high body mass index (BMI) individuals. Whether radial access (TRA) confers a comparative benefit in this specific population has not been studied. METHODS: We retrospectively identified all patients undergoing neuroendovascular procedures at our center between 2017 and 2021 with BMI ≥35 kg/m2. A total of 335 patients met our inclusion criteria, with 224 undergoing femoral access and 111 undergoing radial access. Electronic medical records were reviewed for baseline clinical and angiographic characteristics and procedural outcomes. RESULTS: The primary outcome of any bleeding complication occurred in 7% of the femoral group and 2% of the radial group (odds ratio 4.2, 95% confidence interval 1.0-18.6, P = 0.0421). Radial access was also associated with significantly shorter mean procedure times (median 43 minutes for radial, median 58 minutes for femoral, P = 0.0009) and mean fluoroscopy exposure times (median 15 minutes for radial, median 20 minutes for femoral, P = 0.0003). There were no significant differences in nonaccess site complications, procedural failure, length of stay, or deaths during hospitalization. CONCLUSIONS: When compared to TRA, TFA was associated with a significantly greater rate of bleeding complications in very high BMI patients undergoing neuroendovascular procedures. Procedure time and fluoroscopy time were both significantly longer when using TFA compared to TRA in this patient population.

Clinical relevance of intracranial hemorrhage after thrombectomy versus medical management for large core infarct: a secondary analysis of the SELECT2 randomized trial.

BACKGROUND: The incidence of intracerebral hemorrhage (ICH) and its effect on the outcomes after endovascular thrombectomy (EVT) for patients with large core infarcts have not been well-characterized. METHODS: SELECT2 trial follow-up imaging was evaluated using the Heidelberg Bleeding Classification (HBC) to define hemorrhage grade. The association of ICH with clinical outcomes and treatment effect was examined. RESULTS: Of 351 included patients, 194 (55%) and 189 (54%) demonstrated intracranial and intracerebral hemorrhage, respectively, with a higher incidence in EVT (134 (75%) and 130 (73%)) versus medical management (MM) (60 (35%) and 59 (34%), both P<0.001). Hemorrhagic infarction type 1 (HBC=1a) and type 2 (HBC=1b) accounted for 93% of all hemorrhages. Parenchymal hematoma (PH) type 1 (HBC=1c) and type 2 (HBC=2) were observed in 1 (0.6%) EVT-treated and 4 (2.2%) MM patients. Symptomatic ICH (sICH) (SITS-MOST definition) was seen in 0.6% EVT patients and 1.2% MM patients. No trend for ICH with core volumes (P=0.10) or Alberta Stroke Program Early CT Score (ASPECTS) (P=0.74) was observed. Among EVT patients, the presence of any ICH did not worsen clinical outcome (modified Rankin Scale (mRS) at 90 days: 4 (3-6) vs 4 (3-6); adjusted generalized OR 1.00, 95% CI 0.68 to 1.47, P>0.99) or modify EVT treatment effect (Pinteraction=0.77). CONCLUSIONS: ICH was present in 75% of the EVT population, but PH or sICH were infrequent. The presence of any ICH did not worsen functional outcomes or modify EVT treatment effect at 90-day follow-up. The high rate of hemorrhages overall still represents an opportunity for adjunctive therapies in EVT patients with a large ischemic core.

Plant breeding can be made more efficient by having fewer, better crosses.

BACKGROUND: Crop yields have to increase to provide food security for the world's growing population. To achieve these yield increases there will have to be a significant contribution from genetic gains made by conventional plant breeding. However, the breeding process is not efficient because crosses made between parental combinations that fail to produce useful varieties consume over 99% of the resources. RESULTS: We tested in a rice-breeding programme if its efficiency could be improved by using many fewer, but more judiciously chosen crosses than usual. In a 15-year programme in Nepal, with varietal testing also in India and Bangladesh, we made only six crosses that were stringently chosen on complementary parental performance. We evaluated their success by the adoption and official release of the varieties they produced. We then modelled optimum cross number using assumptions based on our experimental results.Four of the six crosses succeeded. This was a fifty-fold improvement over breeding programmes that employ many crosses where only about one, or fewer, crosses in 200 succeed. Based on these results, we modelled the optimum number of crosses by assuming there would be a decline in the reliability of the breeder's prediction of the value of each cross as more crosses were made (because there is progressively less information on the traits of the parents). Fewer-cross programmes were more likely to succeed and did so using fewer resources. Making more crosses reduced the overall probability of success of the breeding programme. CONCLUSIONS: The efficiency of national and international breeding programmes would be increased by making fewer crosses among more carefully chosen parents. This would increase the number of higher yielding varieties that are delivered to farmers and hence help to improve food security.

Technical Challenges in Endovascular Treatment of Ruptured Aneurysm in a Patient with Body Mass Index >100.

BACKGROUND: Morbid obesity can pose unique challenges in the endovascular treatment of cerebrovascular diseases, particularly in the management of ruptured aneurysms. CASE DESCRIPTION: This technical report discusses the challenges faced during the treatment of a ruptured aneurysm in a morbidly obese patient with a body mass index of 101. The technical adaptations used included the utilization of Dyna CT for routine imaging, vacuum assist devices for patient transfer, and a transradial approach to avoid groin complications. The technical adaptations used in the management of the ruptured aneurysm in the morbidly obese patient were effective in overcoming the challenges posed by the patient's obesity. CONCLUSION: This technical report and literature review can serve as a guide for physicians treating morbidly obese patients with cerebrovascular diseases. Utilization of advanced technology and innovative approaches can aid in overcoming the challenges posed by obesity and improving patient outcomes.