Dural Venous Sinus Variations in Idiopathic Subarachnoid Hemorrhage: A New Indicator of the Venous Origin with Diagnostic Usefulness?

OBJECTIVE: Venous hypertension associated with a primitive basal vein of Rosenthal (BVR) has been noted as the most likely cause of idiopathic subarachnoid hemorrhage (iSAH). Other types of venous drainage variations have been scarcely studied but may further explain the cases not associated with a BVR anomaly. Our aim was to investigate if dural venous sinus (DVS) anomalies are related with iSAH. METHODS: A total of 76 patients diagnosed with iSAH were identified from a prospectively maintained database and their angiographic findings compared with 76 patients diagnosed with aneurysmal subarachnoid hemorrhage. RESULTS: On top of the BVR variations, our data showed a higher prevalence of transverse sinus hypoplasia (47.4% vs. 28.9%; P = 0.019), superior petrosal sinus hypoplasia (32.9% vs. 13.2%; P = 0.003), and clival plexus hyperplasia (65.8% vs. 43.4%; P = 0.005) in patients with iSAH. Analyzing by total number of angiograms, the iSAH group showed also a higher prevalence of inferior petrosal sinus hyperplasia (36.2% vs. 25%; P = 0.003). Of the patients with iSAH without a primitive BVR, 84% harbored ≥1 perimesencephalic DVS variation and the overall number of venous drainage variations was significantly higher in patients with iSAH. CONCLUSIONS: In addition to the well-documented BVR anomalies, there seems to be a significant relationship of other DVS variations in patients with iSAH. Transverse sinus hypoplasia, superior petrosal sinus hypoplasia, inferior petrosal sinus hyperplasia, and clival plexus hyperplasia were significantly more frequent in patients with iSAH. The presence of ≥3 of those variations would increase the suspicion of a nonaneurysmatic subarachnoid hemorrhage and could help avoid a second angiogram.

Women's role in neurosurgical research: is the gender gap improving?

OBJECTIVE: The percentage of women publishing high-impact neurosurgical research might be perceived as a representation of our specialty and may influence the perpetuation of the existing gender gap. This study investigated whether the trend in women taking lead roles in neurosurgical research has mirrored the increase in female neurosurgeons during the past decade and whether our most prestigious publications portray enough female role models to stimulate gender diversity among the new generation of neurosurgeons. METHODS: Two of the most prominent neurosurgical journals-Journal of Neurosurgery and Neurosurgery-were selected for this study, and every original article that was published in 2009 and 2019 in each of those journals was investigated according to the gender of the first and senior authors, their academic titles, their affiliations, and their institutions' region. RESULTS: A total of 1328 articles were analyzed. The percentage of female authors was significantly higher in Europe and Russia compared with the US and Canada (first authors: 60/302 [19.9%] vs 109/829 [13.1%], p = 0.005; and senior authors: 32/302 [10.6%] vs 57/829 [6.9%], p = 0.040). Significantly increased female authorship was observed from 2009 to 2019, and overall numbers of both first and senior female authors almost doubled. However, when analyzing by regions, female authorship increased significantly only in the US and Canada. Female authors of neurosurgical research articles were significantly less likely to hold an MD degree compared with men. Female neurosurgeons serving as senior authors were represented in only 3.6% (48/1328) of articles. Women serving as senior authors were more likely to have a female colleague listed as the first author of their research (29/97 [29.9%] vs 155/1231 [12.6%]; χ2 = 22.561, p = 0.001). CONCLUSIONS: Although this work showed an encouraging increase in the number of women publishing high-impact neurosurgical research, the stagnant trend in Europe may suggest that a glass ceiling has been reached and further advances in equity would require more aggressive measures. The differences in the researchers' profiles (academic title and affiliation) suggest an even wider gender gap. Cultural unconscious bias may explain why female senior authors have more than double the number of women serving as their junior authors compared with men. While changes in the workforce happen, strategies such as publishing specific issues on women, encouraging female editorials, and working toward more gender-balanced editorial boards may help our journals to portray a more equitable specialty that would not discourage bright female candidates.

Iatrogenic Intracranial Aneurysm After External Ventricular Drain Placement: Traumatic or Mycotic Origin? Case Report and Literature Review.

BACKGROUND: Intracranial iatrogenic aneurysms (IIAs) developing after external ventricular drain (EVD) placement or removal have been only rarely reported. Most of these reports assumed a traumatic etiology; however, some have demonstrated an inflammatory origin. We have presented the case of an IIA that developed after an EVD had been inserted to treat acute hydrocephalus secondary to a ruptured arteriovenous malformation. We also performed a literature review and discussed how these IIAs might have an inflammatory rather than a traumatic etiology and how they might lie behind some of the cases of idiopathic hemorrhage observed after EVD manipulation. CASE DESCRIPTION: A 48-year-old woman had presented with acute hydrocephalus secondary to bleeding from a vermian arteriovenous malformation. The EVD inserted for hydrocephalus management required several revisions because of malfunction. Four weeks later, a diagnostic arteriogram had incidentally revealed the existence of a 5-mm aneurysm in an anterior branch of the right callosomarginal artery, coincidental to the EVD trajectory. The patient underwent emergent endovascular treatment of the aneurysm, with complete occlusion and no complications deriving from the procedure. CONCLUSIONS: IIAs associated with EVD placement or removal have been described as a rare complication of the procedure. Despite the scarce number of cases reported and the lack of histological examinations, common features such as a distal location, an incidental diagnosis, and a benign clinical course might suggest a mycotic or inflammatory origin rather than a traumatic etiology. Considering the high volume of EVDs placed annually, this complication might be more frequent than reported. Further studies investigating the association of risk factors for inflammatory aneurysms and hemorrhage incidence after EVD could provide information on this intriguing topic.

Amateur Endurance Athletes: At Higher Risk of Suffering Dural Arteriovenous Fistulas? Report of 3 Cases.

BACKGROUND: The present study aims to draw attention to the fact that endurance sport could be a risk factor for dural arteriovenous fistula (DAVF) development. DAVFs have been correlated with acquired dural venous sinus anomalies owing to trauma, infection, neoplasia, or other classic risk thrombogenic factors. Here we report 3 cases of intracranial DAVF in young healthy patients who had no known thrombogenic risk factors other than amateur intensive sports practice. CASE DESCRIPTION: Three young healthy individuals not fitting into the classical clinical picture of a DAVF patient presented to our institution. One was a 40-year-old man with an acute subdural hematoma secondary to an ethmoidal DAVF. Another 41-year-old man presented with a cerebellar hematoma due to a tentorial DAVF. A third 41-year-old man presented with numbness of his right arm in relationship to a superior sagittal sinus DAVF. None of them had a relevant medical history. All the usual thrombogenic risk factors for DAVF development were ruled out. Interestingly, the 3 patients had outstanding training and practice routines for endurance sports. CONCLUSIONS: Dehydration, microfractures, muscular contractures, low heart rate, long distance travel, and high altitudes are all well documented thrombogenic risk factors affecting endurance sports amateur athletes and might represent a plausible mechanism for the development of DAVF. Despite its limitations, to our knowledge, this is the first work suggesting a possible link between such sport practice and DAVF development. Further prospective research from larger dedicated vascular centers might shed further light on this hypothetic but intriguing link.

Growth prediction in asymptomatic meningiomas: the utility of the AIMSS score.

BACKGROUND: Management of asymptomatic meningiomas represents a challenge due to the absence of a solid consensus on which is the best management strategy. There are various known factors predicting meningiomas growth risk. However, the Asian Intracranial Meningioma Scoring System (AIMSS) is the only described score to quantify such risk thus emerging as a potential tool for management decisions. This study aims to validate this score on our series of asymptomatic meningiomas. METHOD: We performed a retrospective review of asymptomatic meningiomas diagnosed at our institution between January 2008 and October 2016 and followed by an annual cerebral Magnetic Resonance Imaging (MRI). For each lesion, the AIMSS score was calculated thus classifying them in low (0-2), intermediate (3-6) or high risk (7-11) of rapid growth (>2cm3/year). We investigated the correlation between the expected Average Growth Rate (AGR) according to the score and the one obtained in our study. The mean growth velocity over the different risk groups was also compared. RESULTS: Overall, 69 asymptomatic meningiomas found incidentally in 46 patients were included in the study; 31 were assigned to the low-risk group, 34 to the intermediate-risk group and 4 to the high-risk group. Attending to the AGR, 0% showed rapid growth in the low-risk group, 12% in the intermediate-risk group, and 25% in the high-risk group. The mean growth velocity showed a significant difference over the different risk groups (p < 0,001). CONCLUSIONS: According to our finding, the AIMSS score is a valid tool to estimate the risk of rapid growth of asymptomatic meningiomas. It is especially useful distinguishing between low- and intermediate-risk meningiomas. This feature would allow physicians to adjust the periodicity of radiological and clinical controls. Adding more known risk factors of rapid growth to the score might improve its predictive capabilities with the high-risk group.