Risk factors for perianeurysmal vasogenic oedema (pavo) following embolization therapy: literature review.

Perianeurysmal vasogenic oedema (PAVO) is a rare complication associated post-embolisation of intracranial aneurysms. The prevalence, risk factors predisposing to susceptibility, and pathologic mechanisms underlying this process are not clearly understood. Since this complication may be associated with poor clinical outcomes, the authors designed this study to describe possible risk factors, underlying mechanisms, and management of PAVO through published case reports. Developing a priori protocol according to PRISMA guidelines, we searched MEDLINE/PubMed, Embase and Web of Science to identify case studies and reports of adult patients with intracranial aneurysms who developed perianeurysmal oedema following coil embolization therapy. Data extracted from these studies included patient demographics, aneurysm characteristics, coil type, PAVO characteristics, treatment, and outcomes. Quality was assessed using a standardized tool. 21 eligible studies of acceptable quality were identified, comprising 40 unique cases from 9 countries. The mean patient age was 56.4 years and 25 (62.5%) were female. Aneurysm size ranged from 6 to 30 mm, with a mean size of 15.2 mm; only 6 (15%) of cases were giant intracranial aneurysm (≥ 25 mm). The more frequent locations of intracranial aneurysms associated with PAVO were the ICA (50%) and posterior circulation (32.5%), with 7.5% and 10% of cases occurring in MCA and anterior circulation, respectively. 16 cases (40%) were treated with bare platinum coils, and 14 (35%) with a combination of BPCs and bioactive coils; in 10 cases (25%), the coil type was not mentioned. PAVO presented between 0 days and 8 years of coil embolization, with 23 (57.5% cases) presenting symptomatically in relation to brain region affected. Management strategies for PAVO included conservative, steroids, re-embolization, clipping, stenting, parent artery occlusion either as monotherapy or as combination therapy. Of reported studies, 26 treated cases (65%) resolved, with 8 (20%) remaining stable, and 4 (10%) deteriorating. PAVO can be associated with small or large intracranial aneurysms, bare and bioactive platinum coils, and all regions of the intracranial circulation. The understanding of the risk factors of this complication lies in the underlying mechanisms, which will ultimately guide appropriate patient follow-up and subsequent optimal management.

Radiological follow-up of endovascularly treated intracranial aneurysms: a survey of current practice in the UK and Ireland.

PURPOSE: Due to the risk of intracranial aneurysm (IA) recurrence and the potential requirement for re-treatment following endovascular treatment (EVT), radiological follow-up of these aneurysms is necessary. There is little evidence to guide the duration and frequency of this follow-up. The aim of this study was to establish the current practice in neurosurgical units in the UK and Ireland. METHODS: A survey was designed with input from interventional neuroradiologists and neurosurgeons. Neurovascular consultants in each of the 30 neurosurgical units providing a neurovascular service in the UK and Ireland were contacted and asked to respond to questions regarding the follow-up practice for IA treated with EVT in their department. RESULTS: Responses were obtained from 28/30 (94%) of departments. There was evidence of wide variations in the duration and frequency of follow-up, with a minimum follow-up duration for ruptured IA that varied from 18 months in 5/28 (18%) units to 5 years in 11/28 (39%) of units. Young patient age, previous subarachnoid haemorrhage and incomplete IA occlusion were cited as factors that would prompt more intensive surveillance, although larger and broad-necked IA were not followed-up more closely in the majority of departments. CONCLUSIONS: There is a wide variation in the radiological follow-up of IA treated with EVT in the UK and Ireland. Further standardisation of this aspect of patient care is likely to be beneficial, but further evidence on the behaviour of IA following EVT is required in order to inform this process.

Evaluating growth trends of residual sporadic vestibular schwannomas: a systematic review and meta-analysis.

BACKGROUND: Gross total resection remains the gold-standard approach for vestibular schwannomas (VS) when surgery is indicated. In select cases, incomplete resection (IR) becomes a desired alternative to preserve the facial nerve function and the patient's quality of life. While a lot of earlier studies described incompletely resected sporadic VSs as dormant, more recent studies reported a higher growth rate following IR, therefore an evaluation of the residual VS growth rates could have important implications for the follow-up treatment protocols and provide relevant information for neurosurgeons, neuro-otologists, neuropathologists, and radiologists. Although prognostic factors predicting preoperative VS growth have been previously investigated, these factors have not been investigated following IR. Our review aims to examine the growth rate of residual sporadic VS following IR and to examine variables associated with the regrowth of residual VS. METHODS: The review was conducted in accordance with the PRISMA guidelines. Six databases (MEDLINE (Ovid), Embase (Ovid), CINAHL Plus (EBSCO), Cochrane Central Register of Controlled Trials (CENTRAL), WHO International Clinical Trials Registry Platform and UK Clinical Trials Gateway (WHO ICTRP) were searched. Full-text articles analysing growth rates in at least ten patients who had residual VS after IR were assessed. We conducted a meta-analysis using a random-effects model via RevMan. RESULTS: 14 studies totalling 849 patients were included in the analysis. The mean planimetric growth rate was 1.57 mm/year (range 0.16-3.81 mm/year). The mean volumetric growth rate was 281.725 mm3/year (range 17.9-530.0 mm3/year). Age, sex, pre-operative tumour size/volume, cystic tumour sub-type, MIB-1 index, and intracanalicular tumour location were not associated with residual growth. Residual tumour size/volume was statistically significant to growth (OR = 0.65, 95% CI 0.47-0.90, p = 0.01). Radiological re-growth occurred in an average of 26.6% of cases (range 0-54.5%). CONCLUSION: From our analysis, only the residual tumour volume/size was associated with residual VS growth. Therefore, close postoperative surveillance for the first year, followed by an annual MRI scan for at least 5 years, and subsequently extended interval surveillance remains of utmost importance to monitor disease progression and provide timely surgical and adjuvant interventions. Our study shows that future work should be aimed at molecular and histological characteristics of residual VSs to aid prognostic understanding of growth.

Cavernous sinus haemangioma: systematic review and pooled analysis relating to a rare skull base pathology.

Cavernous sinus haemangiomas (CSHs) are rare malformations of the microcirculation arising from the cavernous sinus. A systematic review and pooled data analysis of the associated clinical features, diagnostic modalities, management, and outcomes for CSHs was done. In total, 68 articles (338 cases) were eligible for analysis based on our selection criteria. The primary outcome measures were the occurrence of (i) and (ii) symptom resolution/improvement. Categorical outcome variables were assessed by binary logistic regression at 5% significance level. With headaches (39.9%) and diplopia (36.5%) as the most common presenting symptoms reported, dynamic contrast-enhanced MRI was the most commonly used diagnostic modality and was the most definitive pre-treatment imaging modality for diagnosing CSH with a sensitivity of 89.5%. The majority of CSHs were managed with radiosurgery (47.9% of cases), 37.9% by surgical resection alone, and 14.2% by a combination of both. Compared to patients that were treated with surgical resection only, those treated solely with radiosurgery had a 100% decrease in the odds of developing post-treatment complications (adjusted OR: 0.00, 95% CI: 0.00-0.002, p < 0.001), with a 5.03 times greater odds of symptom resolution/improvement (adjusted OR: 5.03, 95% CI: 1.89-13.4, p = 0.001). Patients that underwent combined therapy had a 79% reduction in risk of developing post-treatment complications (adjusted OR: 0.21, 95% CI: 0.06-0.68, p = 0.01), with no statistically significant difference in the odds of symptom resolution/improvement, compared to those that had surgery only. In conclusion, radiosurgery offered the best outcomes with regards to symptom resolution/improvement and post-treatment complications in patients with CSH.

CSF rhinorrhoea after endonasal intervention to the anterior skull base (CRANIAL): proposal for a prospective multicentre observational cohort study.

BACKGROUND: The endonasal transsphenoidal approach (TSA) has emerged as the preferred approach in order to treat pituitary adenoma and related sellar pathologies. The recently adopted expanded endonasal approach (EEA) has improved access to the ventral skull base whilst retaining the principles of minimally invasive surgery. Despite the advantages these approaches offer, cerebrospinal fluid (CSF) rhinorrhoea remains a common complication. There is currently a lack of comparative evidence to guide the best choice of skull base reconstruction, resulting in considerable heterogeneity of current practice. This study aims to determine: (1) the scope of the methods of skull base repair; and (2) the corresponding rates of postoperative CSF rhinorrhoea in contemporary neurosurgical practice in the UK and Ireland. METHODS: We will adopt a multicentre, prospective, observational cohort design. All neurosurgical units in the UK and Ireland performing the relevant surgeries (TSA and EEA) will be eligible to participate. Eligible cases will be prospectively recruited over 6 months with 6 months of postoperative follow-up. Data points collected will include: demographics, tumour characteristics, operative data), and postoperative outcomes. Primary outcomes include skull base repair technique and CSF rhinorrhoea (biochemically confirmed and/or requiring intervention) rates. Pooled data will be analysed using descriptive statistics. All skull base repair methods used and CSF leak rates for TSA and EEA will be compared against rates listed in the literature. ETHICS AND DISSEMINATION: Formal institutional ethical board review was not required owing to the nature of the study - this was confirmed with the Health Research Authority, UK. CONCLUSIONS: The need for this multicentre, prospective, observational study is highlighted by the relative paucity of literature and the resultant lack of consensus on the topic. It is hoped that the results will give insight into contemporary practice in the UK and Ireland and will inform future studies.

Endoscopic skull base neurosurgical practice in the United Kingdom.

Background: Endoscopic skull base surgery (ESBS) is a new subspecialty area that has become more popular over the past 20 years. It is fast evolving and the indications are getting increasingly diverse. The skill-sets also continue to significantly improve, hence, we, the authors aim to assess the current status of this unique sub-specialty within the United Kingdom. Objective: Our objectives included identifying the proportion of neurosurgeons within the United Kingdom who utilize endoscopic skull base approaches, the background training involved and how much of the overall neurosurgical workload is constituted by endoscopic skull base neurosurgery. There was also a focus on the technical nuances involved with ESBS. Materials and methods: 45 neurosurgeons were included in this study, and a 47% response rate (n = 21) was obtained. Results: 7 (33%) had training in ESBS during residency and 8 (38%) had some fellowship exposure to ESBS. Each respondent did an average of 1.9 endoscopic skull base courses prior to commencing their practice. The length of practice ranged from 3 to 15 years (mean - 7.2 years). Although most of the surgeons had mixed sub-specialty interests, the most commonly associated sub-specialty with ESBS was lateral skull base surgery (38%). Conclusion: In the United Kingdom, ESBS appears to be commonly combined with a lateral/open skull base neurosurgical practice. Most of the surgeons had their ESBS training after formal residency. Collaboration with ENT occurs more commonly for extended transphenoidal procedures.

Decision-making algorithm for minimally invasive approaches to anterior skull base meningiomas.

OBJECTIVE Anterior skull base meningiomas are benign lesions that cause neurological symptoms through mass effect on adjacent neurovascular structures. While traditional transcranial approaches have proven to be effective at removing these tumors, minimally invasive approaches that involve using an endoscope offer the possibility of reducing brain and nerve retraction, minimizing incision size, and speeding patient recovery; however, appropriate case selection and results in large series are lacking. METHODS The authors developed an algorithm for selecting a supraorbital keyhole minicraniotomy (SKM) for olfactory groove meningiomas or an expanded endoscopic endonasal approach (EEA) for tuberculum sella (TS) or planum sphenoidale (PS) meningiomas based on the presence or absence of olfaction and the anatomical extent of the tumor. Where neither approach is appropriate, a standard transcranial approach is utilized. The authors describe rates of gross-total resection (GTR), olfactory outcomes, and visual outcomes, as well as complications, for 7 subgroups of patients. Exceptions to the algorithm are also discussed. RESULTS The series of 57 patients harbored 57 anterior skull base meningiomas; the mean tumor volume was 14.7 ± 15.4 cm3 (range 2.2-66.1 cm3), and the mean follow-up duration was 42.2 ± 37.1 months (range 2-144 months). Of 19 patients with olfactory groove meningiomas, 10 had preserved olfaction and underwent SKM, and preservation of olfaction in was seen in 60%. Of 9 patients who presented without olfaction, 8 had cribriform plate invasion and underwent combined SKM and EEA (n = 3), bifrontal craniotomy (n = 3), or EEA (n = 2), and one patient without both olfaction and cribriform plate invasion underwent SKM. GTR was achieved in 94.7%. Of 38 TS/PS meningiomas, 36 of the lesions were treated according to the algorithm. Of these 36 meningiomas, 30 were treated by EEA and 6 by craniotomy. GTR was achieved in 97.2%, with no visual deterioration and one CSF leak that resolved by placement of a lumbar drain. Two patients with tumors that, based on the algorithm, were not amenable to an EEA underwent EEA nonetheless: one had GTR and the other had a residual tumor that was followed and removed via craniotomy 9 years later. CONCLUSIONS Utilizing a simple algorithm aimed at preserving olfaction and vision and based on maximizing use of minimally invasive approaches and selective use of transcranial approaches, the authors found that excellent outcomes can be achieved for anterior skull base meningiomas.

Double pituitary adenomas are most commonly associated with GH- and ACTH-secreting tumors: systematic review of the literature.

INTRODUCTION: Double adenomas in the pituitary gland are a rare occurrence. The ability to cure a hormone-producing adenoma with surgery is dependent on the ability to identify and completely remove the correct adenoma. The relative frequency of each subtype of hormone-secreting adenomas confirmed with magnetic resonance image (MRI), surgery and immunohistochemistry is not defined. METHODS: Following PRISMA guidelines, we performed a systematic review of PubMed Central, Google Scholar, Scopus Database, Cochrane database and Science Research, using the key-words: "double pituitary adenomas", "multiple pituitary adenomas" and only papers where multiple or truly separate double pituitary adenomas were identified pre-surgically by MRI and/or confirmed by pathology/immunohistochemistry staining were included. RESULTS: We reviewed papers from 1975 to 2016 and found 17 cases with two pituitary adenomas and 1 with three pituitary adenomas. The ages ranged from 22 to 67 years old, and there were twelve females and five males. Immunohistochemical staining showed that the most common double pituitary adenomas were growth hormone (GH)- followed by adrenocorticotropic (ACTH)-secreting. CONCLUSION: Double pituitary adenomas are rare but most commonly found with GH- or ACTH-producing tumors. It is critical to remove all identified possible adenomas to achieve biochemical cure and clinicians should have heightened sensitivity in patients with acromegaly or Cushing's Disease.

Frontal skull osteoblastoma with aneurysmal bone cyst-like changes associated with trauma during pregnancy: a case report.

We report the case of a large osteoblastoma arising in the frontal bone of a 20-year-old female. The lesion was first noted after a fall, and grew steadily in size following further head injury during pregnancy. Initial plain radiography demonstrated an area of radiolucency, with subsequent cross-sectional imaging revealing the extent of the lesion. Following successful surgical resection, histological features were suggestive of an aggressive osteoblastoma with aneurysmal bone cyst-like changes. We consider the influence of pregnancy and trauma on osteoblastoma behavior.

A rare case of multifocal craniospinal leptomeningeal melanocytoma: A case report and scoping review.

Introduction: Leptomeningeal melanocytomas are rare tumours originating from neural crest derived melanocytes. They are usually solitary and presentation with multifocal meningeal melanocytoma is very rare and indicative of potentially more aggressive behaviour. This case report and scoping review sought to evaluate the presentation, and key radiological features that can help differentiate multifocal meningeal melanocytoma from other differentials and provide a discussion of the key management and prognostic points once these tumours are diagnosed. Case presentation: A 26 year old male presented with neck pain radiating to both shoulders and subjective weakness in left shoulder movement. MRI demonstrated a large enhancing C2-C3 intradural-extramedullary lesion with further lesions at the T7/T8 level, left cerebellopontine angle and midline suprachiasmatic region. Whilst the imaging appearances were initially thought be indicative of a phacomatosis such as NF2-related schwannomatosis, surgical excision of the cervical tumour confirmed a melanocytic tumour of leptomeningeal origin, consistent with multifocal meningeal melanocytoma. Patient made a good post-operative recovery and remains under half yearly radiological surveillance, with repeat MRI 6 months after surgery demonstrating subtle growth of the untreated intracranial and spinal lesions. Literature review and conclusions: This is the first description, to our knowledge, of a multifocal meningeal melanocytoma associated with both cerebellopontine angle and suprasellar lesions. This case and included scoping review highlight the need to consider this rare diagnosis whenever multifocal craniospinal lesions are encountered, and the need to consider aggressive management through surgical resection and adjuvant craniospinal radiotherapy once these tumours are diagnosed.

Perianeurysmal vasogenic oedema (PAVO): A single centre 10-year retrospective review.

INTRODUCTION: Perianeurysmal Vasogenic Oedema (PAVO) is a rare but important complication of endovascular treatment of intracranial aneurysms. Many potential risk factors have been identified including age, aneurysm size, aneurysm location, immunological profile, type of coil used, diabetes, hypertension, and smoking. PAVO can cause persistent post-procedural symptoms, subsequently increasing post-embolization morbidity. METHODS: A 10-year retrospective review was conducted between 2011 and 2021 at Royal Preston Hospital, Preston, UK. RESULTS: We identified 8 patients that fit our inclusion criteria. This included 6 (75%) females and 2 (25%) males. The mean age was 64. All patients had anterior circulation aneurysms with the middle cerebral artery (MCA) being the most common site. The mean aneurysm size was 12 mm. Our patients were managed with a range of endovascular techniques. One patient had pre-treatment PAVO while 7 patients had post-embolization PAVO. Five patients were symptomatic, and 3 cases were asymptomatic with only radiological evidence of PAVO. Five patients were managed with varying courses of dexamethasone. PAVO resolution was achieved in 4 cases. The oedema significantly improved in 3 cases, but transiently progressed in 1 case. CONCLUSIONS: PAVO is a rare but important complication of endovascular management of intracranial aneurysms. We have shown that patients can be effectively managed with steroids with resultant oedema regression and symptomatic improvement. Many risk factors have been associated with PAVO, but further research is needed to better understand their role in PAVO development and help develop other therapeutic options.

Representation of minorities in European neurosurgical leadership.

Introduction: Ethnic diversity has significantly increased within European countries since World War II for several reasons. However, there continues to be a contrasting lag in leadership positions within healthcare circles, and neurosurgery is no exception. Under-representation of minorities is a contributory factor to recurring problems of healthcare inequality. Research question: The European Association of Neurosurgical Societies (EANS) Diversity Committee (DC) set out to examine trends in underrepresented minority (URM) representation in leadership positions across Europe. Material and methods: Data on the race and ethnicity of departmental heads across the units in the European nations was collated. We defined the term 'ethnic minority' in line with the criteria set by the European Commission against Racism and Intolerance (ECRI). The percentage of URM among the European neurosurgical units was analysed against the demographics of the respective countries to assess whether there was a corresponding association. Results: The percentage of URM representation was low across most European countries. Countries with the highest immigration rates e.g. Great Britain and Germany had the highest rates of representation within the neurosurgical leadership in comparison to other countries. The Balkan states had zero rates of URM representation within the neurosurgical leadership. Discussion and conclusion: Our findings demonstrate that URM representation in neurosurgical leadership across European countries is significantly low. Selection policies, training curricula and recruitment processes aimed at improving health inequality are necessary. Further studies are needed to elucidate the factors contributing to the low participation of URM in neurosurgical leadership.

Skull Base Neurosurgery Eponyms: A Review of Notable Anatomical Landmarks.

Eponyms highlight the contributions made to medicine over the years, and celebrate individuals for their work involving diseases, pathologies, and anatomical landmarks. We have compiled an in-depth report of eponyms used in skull base neurosurgery, as well as the historical contexts of the personalities behind the names. A literature search identified 36 eponyms of the bones, foramina and ligaments of the skull base named after anatomists and physician-scientists. The 36 eponymous structures pinpointed include Arnold's canal, the foramen of Arnold, Bill's bar, Bertin's bones, Civinini's canal, Civinini's ligament, Civinini's process, sinodural angle of Citelli, Clivus of Blumenbach, Dorello's canal, the Eustachian tube, the eponymous cavernous sinus triangles of Parkinson, Kawase, Mullan, Dolenc, Glasscock and Hakuba, the Fallopian canal, the Glasserian fissure, Gruber's ligament, Haller cells, the spine of Henle, Highmore's antrum, the foramen of Huschke, Hyrtl's fissure, the Ingrassia process, Jacobson's canal, the MacEwen triangle, Meckel's cave, the Onodi air cell, the Pacchionian foramen, Fossa of Rosenmuller, the foramen of Vesalius, the Vidian canal, Trautman's triangle and the annular tendon of Zinn. Knowledge of the relevant eponyms enables succinct descriptions of important skull base structures, provides an understanding of associated clinical implications, and reminds us of the vast history of contributions to neurosurgery made by prominent figures in the field.

The Role of Endoscopy in the Resection of Sporadic Vestibular Schwannomas: A Systematic Review of Surgical Outcomes.

BACKGROUND: Vestibular schwannomas (VS) are benign intracranial tumors originating from the vestibular division of the eighth cranial nerve. Treatment options include microsurgery, radiotherapy, and surveillance. Endoscopy is becoming more widely used as an adjunct in skull base surgery and may influence outcomes in surgically managed VS. METHODS: A systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies involving endoscope-assisted and fully endoscopic procedures for sporadic VS resection were identified. Facial nerve function, hearing preservation, extent of resection, and complications were analyzed. RESULTS: Thirty-one studies were included (27 endoscope-assisted, four fully endoscopic). Subgroup analyses were performed to assess outcomes according to tumor size and surgical approach. Overall, endoscopic facial nerve preservation rates were comparable to microsurgical treatment. A subgroup analysis suggested that functional facial nerve preservation rates may be higher when endoscopic assistance is used for smaller (Koos I-II) tumors using the retrosigmoid or translabyrinthine approach. The gross total resection rate for small tumors was higher in retrosigmoid ES-assisted microsurgery (96.2%) compared to rates in the literature for the standard, open retrosigmoid approach. Hearing outcomes were more variable and were under-reported. CONCLUSIONS: Current data suggest that ES-assisted resection of sporadic VS is not inferior to microsurgical resection with respect to facial nerve outcomes and extent of resection. However, some ES series report poor hearing outcomes, which are under-reported in the literature. Further prospective studies are required to ascertain if endoscopic assistance can improve outcomes for VS resection, particularly for smaller (Koos I-II) tumors.

Deep Learning in the Management of Intracranial Aneurysms and Cerebrovascular Diseases: A Review of the Current Literature.

Intracranial aneurysms are a common asymptomatic vascular pathology, the rupture of which is a devastating event with a significant risk of morbidity and mortality. Aneurysm detection and risk stratification before rupture events are, therefore, imperative to guide prophylactic measures. Artificial intelligence has shown great promise in the management pathway of aneurysms, through automated detection, the prediction of rupture risk, and outcome prediction after treatment. The complementary use of these programs, in addition to clinical practice, has demonstrated high diagnostic and prognostic accuracy, with the potential to improve patient outcomes. In the present review, we explored the role and limitations of deep learning, a subfield of artificial intelligence, in the aneurysm patient journey. We have also briefly summarized the application of deep learning models in automated detection and prediction in cerebral arteriovenous malformations and Moyamoya disease.

Development and Growth of Intracranial Meningiomas in Transgender Women Taking Cyproterone Acetate as Gender-Affirming Progestogen Therapy: A Systematic Review.

Background: Gender-affirming hormone therapy is critical to the management of transgender persons. Cyproterone acetate (CPA) is a synthetic, progesterone-like compound commonly used in high doses as gender-affirming progestogen therapy in transgender women. An association between high-dose CPA and the development and growth of intracranial meningioma, including case reports in transgender women, has been described. This systematic review summarizes these cases at the patient level and discusses their management. Methods: This systematic review was registered with PROSPERO (CRD42020191965). A detailed search of the PubMed, EMBASE, and Web of Science electronic bibliographic databases was performed (inception-December 20, 2020). Two review authors independently completed screening, data extraction, and risk of bias assessment in duplicate. Results: Nine records were included describing (n=12) individual case reports and (n=35) intracranial meningiomas. The median age at presentation was 48 years (interquartile range [IQR], 43-55 years), most frequent daily CPA doses were 50 mg/day (n=5) and 100 mg/day (n=5), and the median duration of CPA use was 9.5 years (IQR, 6.5-17.5 years). Multiple meningiomas were common (n=7). For most cases (n=10), surgical resection was the initial preferred management strategy, but two were successfully managed by CPA cessation. Conclusions: Transgender women receiving high doses of CPA may be at increased risk of intracranial meningioma development and/or growth, although this remains a rare disease. For presumed CPA-associated meningioma, drug cessation appears to be an appropriate management strategy when surgery is not imminently required to manage raised intracranial pressure or prevent neurological deterioration. Given the importance of gender-affirming hormone therapy to transgender persons, a suitable alternative hormone regimen should be offered, although the use of CPA in both high doses and for prolonged periods of time is now in decline.

State of African Neurosurgical Education: An Analysis of Publicly Available Curricula.

BACKGROUND: Africa bears more than 15% of the global burden of neurosurgical disease; however, it has the lowest neurosurgical workforce density worldwide. The past decade has seen an increase in neurosurgery residency programs on the continent. It is unclear how these residency programs are similar or viable. This study highlights the current status and interdepartmental and regional differences, with the main objective of offering a template for improving the provision of neurosurgical education on the continent. METHODS: PubMed and Google Scholar were searched using keywords related to "neurosurgery," "training," and "Africa" from database inception to October 13, 2021. The residency curricula were analyzed using a standardized and validated medical education curriculum viability tool. RESULTS: Curricula from 14 African countries were identified. The curricula differed in resident recruitment, evaluation mode and frequency, curriculum content, and length of training. The length of training varied from 4 to 8 years, with a mean of 6 years. The Eastern African region had the highest number of examinations, with a mean of 8.5. Few curricula had correlates of viability: ensuring that the instructors are competent (64.3%), prioritization of faculty development (64.3%), faculty participation in decision making (64.3%), prioritization of resident support services (50%), creating a conducive environment for quality education (42.9%), and addressing student complaints (28.6%). CONCLUSIONS: There are significant differences in the African postgraduate neurosurgical education curriculum warranting standardization. This study identifies areas of improvement for neurosurgical education in Africa.

Identifying Factors Associated with the Growth of Vestibular Schwannomas: A Systematic Review.

BACKGROUND: Surveillance imaging is a valid management option for selected vestibular schwannomas (VS). An ideal protocol for radiologic monitoring would highlight growth-related risk factors and tailor management accordingly. This study aims to identify variables associated with the growth of sporadic VS to enhance surveillance imaging, enable early intervention, and optimize outcomes. METHODS: The review was conducted according to the PRISMA guidelines. A systematic review of 5 databases (PubMed, Ovid, Cochrane Library, Web of Science, and Google Scholar) was performed to identify negative and positive growth predictors of sporadic vestibular schwannomas. The search was limited to studies reported between January 2015 and January 2020. We conducted an individual patient data meta-analysis using a 1-stage multivariate mixed-effect logistic regression model. RESULTS: A total of 437 studies were identified, of which 25 met our criteria for full-text analysis. Articles that measured VS with comparable methods were determined eligible for meta-analysis inclusion. The selected articles were highly heterogeneous in their use of grading scales and assessment of tumor size. Our review showed that size at diagnosis (odds ratio, 1.15; 95% confidence interval, 1.11-1.18; P < 0.0001) and intracanalicular localization (odds ratio, 0.49; 95% confidence interval, 0.26-0.90; P = 0.023) were associated with VS growth. CONCLUSIONS: The factors most frequently reported as being associated with growth within the literature were size of VS at diagnosis and localization of an intracanalicular component. Greater attention should be placed on these criteria within the surveillance imaging algorithm for VS.

State of Neurosurgical Education in Africa: A Narrative Review.

BACKGROUND: There is no comprehensive report of neurosurgery postgraduate education in Africa. This narrative review aimed to map out the landscape of neurosurgery training in Africa and highlight similarities and differences in training. METHODS: The keywords "neurosurgery," "education," and "Africa" were searched on PubMed and Google Scholar from inception to January 17, 2021. Next, a complementary hand search was conducted on Google using the keywords "neurosurgery," "residency," and the individual African countries in English and official languages. The relevant data were extracted and compiled into a narrative review. RESULTS: A total of 76 African training programs that recruit more than 168 trainees each year were identified. Less than half (40.7%, n = 22) of African countries have at least 1 neurosurgery training program. Egypt (n = 15), Algeria (n = 14), and Nigeria (n = 10) have the highest number of training programs, whereas Algeria (0.33), Egypt (0.15), and Libya (0.15) have the highest number of training programs per 1 million inhabitants. The College of Surgeons of East, Central, and Southern Africa has 16 programs in 8 countries, whereas the West African College of Surgeons has 17 accredited programs in 3 countries. The duration of training varies between 4 and 8 years. There is limited information available in the public domain and academic literature about subspecialty fellowships in Africa. CONCLUSIONS: This review provides prospective applicants and African and global neurosurgery stakeholders with information to advocate for increased investment in African neurosurgery training programs.

De Novo Cavernoma Formation in a Patient With Cowden Syndrome and Lhermitte-Duclos Disease.

BACKGROUND: Cowden syndrome (CS) is an autosomal dominant genodermatosis with a predisposition for the development of multiple cancers, benign hamartomas, and extracranial vascular malformations. Rarely, intracranial lesions like meningiomas and vascular malformations can also be present with CS. These vascular malformations include developmental venous anomalies, arteriovenous fistulae and cavernomas. Most cases of cavernomas are thought to be congenital, although in recent literature they have been shown to occur de novo with other conditions (e.g., other vascular malformations, trauma, postcranial surgery, viral infection, and genetic disorders). CASE DESCRIPTION: We present a 29-year-old woman who was diagnosed with Lhermitte-Duclos disease after episodes of persistent generalized headaches. She underwent a foramen magnum decompression and was subsequently diagnosed with CS. Ten years, later she was also diagnosed with 2 cerebral cavernomas that were not present on her prior monitoring scans. CONCLUSIONS: We present a case of a patient with CS and LDD who had de novo cavernoma development several years after the initial diagnosis, as well as a review of the literature. We highlight the need of surveillance neuroimaging for patients with CS, as there is the risk of new development of vascular abnormalities (particularly cavernomas).