Dimensions of Arachnoid Bulk Ratio: A Superior Optic Nerve Sheath Index for Intracranial Pressure.

Background Discrepancies in the literature regarding optimal optic nerve sheath diameter (ONSD) cutoffs for intracranial pressure (ICP) necessitate alternative neuroimaging parameters to improve clinical management. Purpose To evaluate the diagnostic accuracy of the dimensions of the perineural subarachnoid space to the optic nerve sheath ratio, measured using US, in predicting increased ICP. Materials and Methods In a prospective cohort study from April 2022 to December 2023, patients with suspected increased ICP underwent optic nerve US to determine the dimensions of arachnoid bulk (DAB) ratio and ONSD before invasive ICP measurement. Correlation between the parameters and ICP, as well as diagnostic accuracy, was assessed using area under the receiver operating characteristic curve (AUC) analysis. Results A total of 30 participants were included (mean age, 39 years ± 14 [SD]; 24 female). The DAB ratio and ONSD were significantly larger in participants with increased ICP (38% [0.16 of 0.42] and 14% [0.82 of 6.04 mm], respectively; P < .001). The DAB ratio showed a stronger correlation with ICP than ONSD (rs = 0.87 [P < .001] vs rs = 0.61 [P < .001]). The DAB ratio and ONSD optimal cutoffs for increased ICP were 0.5 and 6.5 mm, respectively, and the ratio had higher sensitivity (100% vs 92%) and specificity (94% vs 83%) compared with ONSD. Moreover, the DAB ratio better predicted increased ICP than ONSD, with a higher AUC (0.98 [95% CI: 0.95, 1.00] vs 0.86 [95% CI: 0.71, 0.95], P = .047). Conclusion An imaging ratio was proposed to predict ICP based on the relative anatomy of the cerebrospinal fluid space, demonstrating more accurate diagnosis of increased ICP and a strong correlation with ICP values, suggesting its potential utility as a neuroimaging marker in clinical settings. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Shepherd in this issue.

Burnout and dropout intention in medical students: the protective role of academic engagement.

INTRODUCTION: The influence of burnout, academic engagement, and their interaction in dropout intention among medical students should be further studied. Current research shows its consequences are relevant, however, there is little understanding on burnout and academic engagement moderation in dropout intention. The current study tested a model that relates the effects of coping strategies, social support satisfaction, general distress on academic engagement, burnout, and dropout intention, on medical students. METHODS: Through an online survey a non-probabilistic sample of one Medical Faculty's 1st- and 2nd-year students was recruited. Cross-sectional data were collected using psychometric instruments (Maslach Burnout Inventory - Student Survey, Social Support Satisfaction Scale for College Students, Brief COPE Scale for College Students, University Student Engagement Inventory, and Depression, Anxiety and Stress Scale), sociodemographic and academic variables, and analyzed using structural equation modeling. RESULTS: 532 students (76% response rate) enrolled in the study. Latent variables structural model presented a satisfactory fit to the data and confirmed the expected negative path between burnout and dropout intention (ßDI<-SB=0.430; p<.001) and the latent moderation burnout x engagement (ßDI<-SB*SE=-0.218; p<.001). CONCLUSION: Academic engagement attenuates the impact of burnout on dropout intention, working as a protective factor. Social support satisfaction and adaptive coping are associated with increased levels of academic engagement, and general distress and maladaptive coping are associated with burnout. Medical Schools should develop interventions to prevent dropout intention, tackle students' stress and academic challenges, and develop their academic engagement levels.

Early Recanalization in Patients With Cerebral Venous Thrombosis Treated With Anticoagulation.

Background and Purpose- The hypothesis that venous recanalization prevents progression of venous infarction is not established in patients with cerebral venous thrombosis (CVT). Evidence is also scarce on the association between residual symptoms, particularly headache, and the recanalization grade. We aimed to assess, in patients with CVT treated with standard anticoagulation, (1) the rate of early venous recanalization, (2) whether lack of early recanalization was predictor of parenchymal brain lesion progression, and (3) the prevalence and features of persistent headache according to the recanalization grade achieved. Methods- PRIORITy-CVT (Pathophysiology of Venous Infarction - Prediction of Infarction and Recanalization in CVT) was a multicenter, prospective, cohort study including patients with newly diagnosed CVT. Standardized magnetic resonance imaging was performed at inclusion (≤24 hours of therapeutic anticoagulation), days 8 and 90. Potential imaging predictors of recanalization were predefined and analyzed at each anatomical segment. Primary outcomes were rate of early recanalization and brain lesion progression at day 8. Secondary outcomes were headache (days 8 and 90) and functional outcome (modified Rankin Scale at days 8 and 90). Results- Sixty eight patients with CVT were included, of whom 30 (44%) had parenchymal lesions. At the early follow-up (n=63; 8±2 days), 68% (n=43) of patients had partial recanalization and 6% (n=4) full recanalization. Early recanalization was associated both with early regression (P=0.03) and lower risk of enlargement of nonhemorrhagic lesions (P=0.02). Lesions showing diffusion restriction (n=12) were fully reversible in 66% of cases, particularly in patients showing early venous recanalization. Evidence of new or enlarged hemorrhagic lesions, headache at days 8 and 90, and unfavorable functional outcome at days 8 and 90 were not significantly different in patients achieving recanalization. Conclusions- Venous recanalization started within the first 8 days of therapeutic anticoagulation in most patients with CVT and was associated with early regression of nonhemorrhagic lesions, including venous infarction. There was an association between persistent venous occlusion at day 8 and enlargement of nonhemorrhagic lesions.

Headache at the Chronic Stage of Ischemic Stroke.

BACKGROUND: Headache in ischemic stroke survivors after the acute stage is incompletely described. OBJECTIVE: We aimed to prospectively describe the characteristics of headache and the predictors of headache at the chronic stage after ischemic stroke. METHODS: We conducted a prospective observational cohort study including 102 acute ischemic stroke patients admitted to a Stroke Unit. Patients were interviewed at the acute and the chronic stage (12 months after stroke). Characteristics of those headaches were collected using a previously validated headache questionnaire enabling headache classification following the International Headache Society criteria. Pre-stroke headache history was registered using the same instrument. RESULTS: Forty-five patients out of 89 with completed follow-up (51%) reported headache at the chronic stage. In most of the patients, headache was sporadic, mild, pressure-like, with a duration of minutes to hours, with characteristics of tension-type headache in 51% (n = 23/45). Headache was a reactivation of pre-stroke headache in 33% (n = 15/45), different from pre-stroke headache in 44% (n = 20/45), and of new-onset in 22% (n = 10/45). Only 1 patient had a new-onset headache at the acute stage that persisted with the same characteristics at the chronic stage. Pre-stroke headache (OR = 5.3; 95% CI [2.01-13.98] P = .001) and female sex (OR = 3.5; 95% CI [1.3-9.4] P = .013) predicted headache at the chronic stage after stroke, controlling for age, severity, and location of stroke. CONCLUSIONS: Headache in ischemic stroke survivors at the chronic stage is more frequent in women and in patients with pre-stroke headache. It is most frequently a headache with different characteristics of the pre-stroke headache and only rarely a new-onset headache starting at the acute stage and persisting at the chronic stage.

Brush Sign Is Associated With Increased Severity in Cerebral Venous Thrombosis.

Background and Purpose- The brush sign (BS) is an abnormally accentuated signal drop of the subependymal and deep medullary veins in paramagnetic-sensitive magnetic resonance sequences, previously described in acute ischemic stroke. We aimed to describe the BS in patients with thrombosis of the cerebral veins and sinuses and explore its association with clinical severity, thrombosis extent, parenchymal brain lesion, and clinical prognosis. Methods- We assessed consecutive adult patients admitted to 2 university hospitals with diagnosis of acute thrombosis of the cerebral veins and sinuses and imaging assessment with magnetic resonance imaging, including paramagnetic-sensitive sequences. Demographics, imaging findings, clinical presentation, and functional outcome at 3 months were analyzed according to the presence of BS. Results- In 118 patients included, BS was observed in gradient-echo T2*weighted (T2*WI) in 16% and susceptibility-weighted imaging in 13% of cases. All patients with BS had thrombosis of the superior sagittal sinus, straight sinus, or deep venous system. BS was associated with ipsilateral parenchymal lesion (odds ratio, 6.4; 95% CI, 1.9-21.1; P=0.002) and higher thrombus load (median [interquartile range] 5 [4-6] versus 2 [2-4]); P<0.0001). BS was also associated with focal neurological deficits (OR 4.2; 95%CI, 1.4-12.7, P=0.01). The functional outcome at 3 months was not significantly different in patients with BS. Conclusions- BS in T2*WI and susceptibility-weighted imaging was observed in approximately one in 7 patients with acute thrombosis of the cerebral veins and sinuses. BS was significantly associated with ipsilateral parenchymal brain lesion, extent of thrombosis, and manifestation with focal neurological deficits. This suggests that BS can represent a marker of severity in thrombosis of the cerebral veins and sinuses.

Recanalization in Cerebral Venous Thrombosis.

Background and Purpose- The role of recanalization of the occluded dural sinus or vein in the outcome of patients with cerebral venous thrombosis (CVT) is not established. We aimed to systematically review, in patients with CVT, (1) the recanalization rate and its association with (2) clinical outcome and (3) CVT recurrence. Methods- Systematic search in MEDLINE (Medical Literature Analysis and Retrieval System Online), Cochrane Library, and clinicaltrials.gov (inception to September 2017). We considered cohort studies reporting the recanalization rate in adult patients with CVT treated with anticoagulation. Reported rates of venous recanalization at the last follow-up, functional outcome defined using the modified Rankin scale at last follow-up dichotomized for favorable (0-1) and unfavorable (2-6) outcome, and recurrence rate of CVT according to recanalization status were extracted independently by 2 authors. Meta-analyses of proportions were performed using Freeman-Tukey double arcsine transformation. Functional outcomes according to the recanalization status were compared using meta-analysis and ordinal logistic regression. We conducted sensitivity analyses for time to assessment of recanalization and study quality. Results- Four hundred sixty-eight studies were identified, and 19 studies were included. (1) We found report of 694 patients with recanalization in the follow-up among 818 cases of CVT. The overall pooled proportion of patients achieving recanalization was 85% (95% confidence interval, 80-89; I2=58%). In studies with higher methodological quality, the recanalization rate was 77% (95% confidence interval, 70-82; I2=0%). (2) There was a significant increase in the chance of favorable outcome (modified Rankin scale, 0-1) in patients with recanalization with a pooled odds ratio of 3.3 (95% confidence interval, 1.2-8.9; I2=32%) in the random effects meta-analysis and a common odds ratio of 3.3 (95% confidence interval, 1.7-6.3) in the ordinal logistic regression. (3) Data on CVT recurrence according to recanalization was scarce. Conclusions- The overall rate of recanalization in patients receiving anticoagulation was 85%, but exclusion of severe patients from follow-up imaging is a plausible source of bias. Lack of venous recanalization was associated with worse clinical outcome.

Advanced MR Imaging of the Human Nucleus Accumbens--Additional Guiding Tool for Deep Brain Stimulation.

OBJECTIVE: The human nucleus accumbens (Acc) has become a target for deep brain stimulation (DBS) in some neuropsychiatric disorders. Nonetheless, even with the most recent advances in neuroimaging it remains difficult to accurately delineate the Acc and closely related subcortical structures, by conventional MRI sequences. It is our purpose to perform a MRI study of the human Acc and to determine whether there are reliable anatomical landmarks that enable the precise location and identification of the nucleus and its core/shell division. METHODS: For the Acc identification and delineation, based on anatomical landmarks, T1WI, T1IR and STIR 3T-MR images were acquired in 10 healthy volunteers. Additionally, 32-direction DTI was obtained for Acc segmentation. Seed masks for the Acc were generated with FreeSurfer and probabilistic tractography was performed using FSL. The probability of connectivity between the seed voxels and distinct brain areas was determined and subjected to k-means clustering analysis, defining 2 different regions. RESULTS: With conventional T1WI, the Acc borders are better defined through its surrounding anatomical structures. The DTI color-coded vector maps and IR sequences add further detail in the Acc identification and delineation. Additionally, using probabilistic tractography it is possible to segment the Acc into a core and shell division and establish its structural connectivity with different brain areas. CONCLUSIONS: Advanced MRI techniques allow in vivo delineation and segmentation of the human Acc and represent an additional guiding tool in the precise and safe target definition for DBS.

The nucleus accumbens beyond the anterior commissure: implications for psychosurgery.

INTRODUCTION: The nucleus accumbens (Acc) is a basal forebrain structure integrated in the dopaminergic cerebral rewarding circuits and implicated in some neuropsychiatric disorders. It has become a target for deep brain stimulation for some of these disorders when refractory to medical treatment. However, it is controversial as to which target is the best and similar results have been achieved with the stimulation of neighboring structures such as the bed nucleus of the stria terminalis (BNST). Previous studies have established the stereotactic anatomy of the human Acc, but some difficulties remain concerning its precise posterior limit, which is assumed to be at the level of the anterior commissure (AC). It is our purpose to clarify the anatomy of this zone, given the importance of its exact identification in psychosurgery. METHODS: A total of 16 Acc were collected by autopsy, fixed, dissected, embedded and cut in coronal 5-µm slices. The slices were stained with hematoxylin and eosin, marked with anti-D1 and anti-D2 antibodies and analyzed under a microscope. RESULTS: The human Acc has the same cellular structure as the dorsal striatum, except in its posterior subcommissural part where voluminous neurons prevail, similar to and contiguous with the BNST. CONCLUSIONS: The Acc is longer than previously described, with a sub- and postcommissural extension behind the AC, continuous with the BNST.

Internal carotid artery rupture during endovascular thrombectomy in patients with tandem occlusion: A two-case report.

Endovascular thrombectomy in patients with tandem occlusions can rarely result in the rupture of the internal carotid artery, leading to subarachnoid haemorrhage and death. However, this complication and its causes are rarely reported and discussed in the literature. We describe two cases of internal carotid artery rupture during endovascular thrombectomy in patients with tandem occlusion. It is hypothesised that the primary approach to the distal lesion, before recanalization, creates a blind alley that faces an intraluminal pressure increase upon manual contrast injection, surpassing the vessel's resistance and resulting in arterial wall rupture. To prevent this complication, approaches such as treating the proximal occlusion first, injecting the contrast through a microcatheter or retracting the endovascular support catheter proximally to the stenosis of the cervical internal carotid artery have been suggested and are discussed.

Corrigendum: Direct oral anticoagulants for the treatment of cerebral venous thrombosis - a protocol of an international phase IV study.

[This corrects the article DOI: 10.3389/fneur.2023.1251581.].

Reducing the global burden of cerebral venous thrombosis: An international research agenda.

BACKGROUND: Due to the rarity of cerebral venous thrombosis (CVT), performing high-quality scientific research in this field is challenging. Providing answers to unresolved research questions will improve prevention, diagnosis, and treatment, and ultimately translate to a better outcome of patients with CVT. We present an international research agenda, in which the most important research questions in the field of CVT are prioritized. AIMS: This research agenda has three distinct goals: (1) to provide inspiration and focus to research on CVT for the coming years, (2) to reinforce international collaboration, and (3) to facilitate the acquisition of research funding. SUMMARY OF REVIEW: This international research agenda is the result of a research summit organized by the International Cerebral Venous Thrombosis Consortium in Amsterdam, the Netherlands, in June 2023. The summit brought together 45 participants from 15 countries including clinical researchers from various disciplines, patients who previously suffered from CVT, and delegates from industry and non-profit funding organizations. The research agenda is categorized into six pre-specified themes: (1) epidemiology and clinical features, (2) life after CVT, (3) neuroimaging and diagnosis, (4) pathophysiology, (5) medical treatment, and (6) endovascular treatment. For each theme, we present two to four research questions, followed by a brief substantiation per question. The research questions were prioritized by the participants of the summit through consensus discussion. CONCLUSIONS: This international research agenda provides an overview of the most burning research questions on CVT. Answering these questions will advance our understanding and management of CVT, which will ultimately lead to improved outcomes for CVT patients worldwide.

The role of optic nerve sheath ultrasonography in increased intracranial pressure: A systematic review and meta analysis.

OBJECTIVES: To review the optimal diagnostic cut-off of ultrasonographic optic nerve sheath diameter (ONSD) in the diagnosis of increased intracranial pressure (IICP). METHODS: A systematic search was conducted of available studies assessing the use of ONSD ultrasonography in patients with suspected IICP. Meta-analysis of diagnostic accuracy of ultrasonographic ONSD was performed using a bivariate model of random effects to summarize pooled sensitivity and specificity. A summary receiver operating characteristics (SROC) curve was plotted. Accuracy measures associated with ONSD cut-off and predefined covariates were investigated with meta-regression. RESULTS: We included 38 studies, comprising a total of 2824 patients. A total of 21 studies used invasive techniques as a reference standard estimation of IICP and meta-analysis revealed a pooled sensitivity of 0.90 (95% CI 0.85-0.93) and specificity of 0.87 (95% CI 0.80-0.91). Optimal ONSD cut-off values ranged between 4.1 mm and 7.2 mm. Meta-regression analysis showed that ONSD cut-off values of 5.6 to 6.3 mm were associated with higher pooled specificity compared to cut-off values of 4.9 to 5.5 mm (0.93, 95% CI 0.85-0.97 vs. 0.78, 95% CI 0.65-0.87; p = 0.036). CONCLUSIONS: Ultrasonography of ONSD shows a high diagnostic accuracy for IICP, with high pooled sensitivity and specificity. Additionally, larger cut-off values seem to significantly increase specificity without compromising sensitivity, which support their use as optimal ONSD cut-off. The overall high sensitivity of ultrasonographic ONSD suggests its usefulness as a screening tool for IIC, which may provide an estimate of when invasive methods are warranted. CLINICAL RELEVANCE: ONSD ultrasonography is a fast and cost-effective method with a high diagnostic accuracy to detect IICP. The optimum ONSD cut-off hasn't been established before, but we suggest the 5.6 to 6.3 mm range as the best for the diagnosis of IICP.

Direct oral anticoagulants for the treatment of cerebral venous thrombosis - a protocol of an international phase IV study.

Introduction: Current guidelines recommend that patients with cerebral venous thrombosis (CVT) should be treated with vitamin K antagonists (VKAs) for 3-12 months. Direct oral anticoagulants (DOACs), however, are increasingly used in clinical practice. An exploratory randomized controlled trial including 120 patients with CVT suggested that the efficacy and safety profile of dabigatran (a DOAC) is similar to VKAs for the treatment of CVT, but large-scale prospective studies from a real-world setting are lacking. Methods: DOAC-CVT is an international, prospective, observational cohort study comparing DOACs to VKAs for the prevention of recurrent venous thrombotic events after acute CVT. Patients are eligible if they are 18 years or older, have a radiologically confirmed CVT, and have started oral anticoagulant treatment (DOAC or VKA) within 30 days of CVT diagnosis. Patients with an absolute contra-indication for DOACs, such as pregnancy or severe renal insufficiency, are excluded from the study. We aim to recruit at least 500 patients within a three-year recruitment period. The primary endpoint is a composite of recurrent venous thrombosis and major bleeding at 6 months of follow-up. We will calculate an adjusted odds ratio for the primary endpoint using propensity score inverse probability treatment weighting. Discussion: DOAC-CVT will provide real-world data on the comparative efficacy and safety of DOACs versus VKAs for the treatment of CVT. Clinical trial registration: ClinicalTrials.gov, NCT04660747.

Posterior reversible encephalopathy syndrome in the pediatric population: a pictorial essay.

Posterior reversible encephalopathy syndrome (PRES) is a rare disease attributed to an increase in blood pressure that exceeds the autoregulatory capabilities of the cerebral vasculature, resulting in brain edema. Although PRES primarily affects adults, the pediatric population is also at risk. Radiologists must be aware of that risk because the imaging features on brain MRI are often atypical, especially in pediatric patients. Over a 6-year period, nine pediatric patients were diagnosed with PRES at our institution. Here, those patients are evaluated retrospectively regarding demographic characteristics, clinical profiles, imaging aspects, and outcomes. In this pictorial essay, we review the typical and atypical imaging findings of PRES in pediatric patients, demonstrating that it should be considered in patients with a clinical profile suggestive of the diagnosis, given that prompt, effective treatment is important for full recovery, thus avoiding major morbidity and mortality in such patients.

A síndrome de encefalopatia posterior reversível (PRES) é uma doença rara relacionada com uma falha no mecanismo autorregulatório vascular, resultando em edema cerebral. Apesar de primariamente descrita em adultos, a população pediátrica encontra-se em igual risco de desenvolver esta condição e o radiologista deve estar atento porque frequentemente a ressonância magnética apresenta características de imagem atípicas. Em um período de seis anos, nove pacientes pediátricos com o diagnóstico de PRES foram avaliados, retrospectivamente, no que diz respeito a sua demografia, antecedentes médicos, características de imagem e prognóstico. Neste ensaio analisamos características de imagem típicas e atípicas de pacientes pediátricos com o diagnóstico de PRES, mostrando que este diagnóstico deve ser considerado quando está presente um quadro clínico adequado, uma vez que o tratamento rápido e eficaz é importante para a recuperação completa, evitando morbimortalidade maior neste grupo etário.

Posterior reversible encephalopathy syndrome in the pediatric population: a pictorial essay / Síndrome de encefalopatia posterior reversível na população pediátrica: uma revisão de imagens

Abstract Posterior reversible encephalopathy syndrome (PRES) is a rare disease attributed to an increase in blood pressure that exceeds the autoregulatory capabilities of the cerebral vasculature, resulting in brain edema. Although PRES primarily affects adults, the pediatric population is also at risk. Radiologists must be aware of that risk because the imaging features on brain MRI are often atypical, especially in pediatric patients. Over a 6-year period, nine pediatric patients were diagnosed with PRES at our institution. Here, those patients are evaluated retrospectively regarding demographic characteristics, clinical profiles, imaging aspects, and outcomes. In this pictorial essay, we review the typical and atypical imaging findings of PRES in pediatric patients, demonstrating that it should be considered in patients with a clinical profile suggestive of the diagnosis, given that prompt, effective treatment is important for full recovery, thus avoiding major morbidity and mortality in such patients.

Resumo A síndrome de encefalopatia posterior reversível (PRES) é uma doença rara relacionada com uma falha no mecanismo autorregulatório vascular, resultando em edema cerebral. Apesar de primariamente descrita em adultos, a população pediátrica encontra-se em igual risco de desenvolver esta condição e o radiologista deve estar atento porque frequentemente a ressonância magnética apresenta características de imagem atípicas. Em um período de seis anos, nove pacientes pediátricos com o diagnóstico de PRES foram avaliados, retrospectivamente, no que diz respeito a sua demografia, antecedentes médicos, características de imagem e prognóstico. Neste ensaio analisamos características de imagem típicas e atípicas de pacientes pediátricos com o diagnóstico de PRES, mostrando que este diagnóstico deve ser considerado quando está presente um quadro clínico adequado, uma vez que o tratamento rápido e eficaz é importante para a recuperação completa, evitando morbimortalidade maior neste grupo etário.