Pathogenesis and Management in Cerebrovenous Outflow Disorders

Dehydration in cerebral venous sinus thrombosis

AIMS

This study aimed to unravel the dehydration status of patients with cerebral venous sinus thrombosis (CVST) to facilitate the understanding of dehydration in CVST.

METHODS

This was a multicenter retrospective study and three populations were recruited, namely, patients with CVST, CVST mimics, and healthy subjects. Blood samples were obtained 1-2 days after admission to assess dehydration status. Stata 15.1 was performed for statistical analysis.

RESULTS

A total of 208 patients were diagnosed with CVST, 237 with CVST mimics, and 200 healthy individuals were enrolled. The urine specific gravity (USG, 1.020 [1.014, 1.029] vs. 1.017 [1.011, 1.021]) was higher in patients with CVST than in those with mimics (all p < 0.001). The percentage of USG >1.03 was also higher in CVST (22.6%) than in its mimics (6.3%, p < 0.001). With the development of CVST, USG (acute vs. sub-acute vs. chronic, 1.022 [1.015, 1.033] vs. 1.021 [1.015, 1.031] vs. 1.019 [1.014, 1.025]) decreased. All dehydration-related markers could not differentiate CVST from its mimics and healthy populations, and they were not associated with CVST severity and prognosis (p > 0.05).

CONCLUSION

High levels of USG, especially USG >1.013, were more common in patients with CVST. Dehydration-related indices could not characterize CVST and were not associated with CVST severity and prognosis.

Cerebral venous congestion alters CNS homeostatic plasticity, evoking tinnitus-like behavior

BACKGROUND

Brain function and neuronal activity depend on a constant supply of blood from the cerebral circulation. The cerebral venous system (CVS) contains approximately 70% of the total cerebral blood volume; similar to the cerebral arterial system, the CVS plays a prominent role in the maintenance of central nervous system (CNS) homeostasis. Impaired venous autoregulation, which can appear in forms such as cerebral venous congestion, may lead to metabolic abnormalities in the brain, causing severe cerebral functional defects and even chronic tinnitus. However, the role of cerebral venous congestion in the progression of tinnitus is underrecognized, and its pathophysiology is still incompletely understood. This study elucidated the specific pathogenetic role of cerebral venous congestion in the onset and persistence of tinnitus and the possible neurophysiological mechanisms.

RESULTS

We found that a rat model of cerebral venous congestion exhibited tinnitus-like behavioral manifestations at 14 days postoperatively; from that point onward, they showed signs of persistent tinnitus without significant hearing impairment. Subsequent neuroimaging and neurochemical findings showed CNS homeostatic plasticity disturbance in rats with cerebral venous congestion, reflected in increased neural metabolic activity, ultrastructural synaptic changes, upregulated synaptic efficacy, reduced inhibitory synaptic transmission (due to GABA deficiency), and elevated expression of neuroplasticity-related proteins in central auditory and extra-auditory pathways.

CONCLUSION

Collectively, our data suggest that alternations in CNS homeostatic plasticity may play a vital role in tinnitus pathology caused by cerebral venous congestion. These findings provide a new perspective on tinnitus related to cerebral venous congestion and may facilitate the development of precise interventions to interrupt its pathogenesis.

Intensive mannitol slow infusion post-stenting may attenuate stenting-related early adverse effects in patients with cerebral venous sinus stenosis

AIMS

To analyze intensive slow mannitol poststenting on attenuating stenting-related early adverse effects in cerebral venous sinus stenosis (CVSS).

METHODS

This real-world study enrolled subacute or chronic CVSS patients from January 2017 through March 2022 and divided them into DSA only and stenting post-DSA groups. The later group was subdivided into control (without extra mannitol use) and intensive slow mannitol subgroup (immediate extra mannitol 250-500 mL, 2 mL/min infusion post-stenting) after signed informed consent. All data were compared.

RESULTS

A total of 95 eligible patients entered into final analysis, in which 37 cases underwent DSA only and 58 cases underwent stenting post-DSA. Finally, 28 patients were entered into intensive slow mannitol subgroup and 30 in control. Stenting group vs. DSA group, HIT-6 scores and WBC counts were higher in the former (both p < 0.001). Intensive slow mannitol subgroup vs. control on the third day post-stenting, a statistically significant reductions were noticed in the former on WBC counts (6.19 ± 1.86 × 109 /L vs. 9.59 ± 2.05 × 109 /L); HIT-6 scores (degree of headache) (40.00 (38.00-40.00) vs. 49.00 (41.75-55.25)) and brain edema surrounding the stent on CT maps (17.86% vs.96.67%), all p < 0.001.

CONCLUSIONS

Stenting-related severe headache, inflammatory biomarkers elevation, and brain edema aggravation can be attenuated by intensive slow mannitol infusion.

Development and Validation of a Clinical-Based Severity Scale for Patients with Cerebral Venous Thrombosis

Introduction

Cerebral venous thrombosis (CVT) is a rare subtype of stroke. However, existing scales were insufficient to evaluate the overall severity of CVT. The aim of this study is to develop and validate a CVT severity scale.

Methods

Items 1-11 were directly derived from NIHSS. New items were generated from a literature review and focus group discussion. A total of 170 CVT patients were prospectively recruited from 26 top tertiary hospitals in China Mainland from January 2021 to May 2022 to validate the CVT severity scale. The CVT severity scale, NIHSS, mRS and GCS were rated at admission. The lumbar puncture opening pressure was also recorded. Twenty randomly selected CVT patients were rated with the CVT severity scale again 24 hours later. The clinical outcome of CVT was evaluated by mRS at 6 months after baseline.

Results

We successfully established a CVT severity scale with 18 items. Exploratory factor analysis showed that 18 items were attributed to factor 1 (focal neurological deficits), factor 2 (diffuse encephalopathy), factor 3 (intracranial hypertension) and factor 4 (cavernous sinus syndrome). CVT severity scale was positively correlated with ICP, NIHSS and mRS, and negatively correlated with GCS at baseline. CVT severity scale >3 or factor 3 >2 indicated intracranial hypertension. CVT severity scale >10 indicated poor clinical outcome at 6 months of follow-up. Meanwhile, CVT severity scale showed high internal consistency and test-retest reliability.

Conclusion

The CVT severity scale included 18 items encompassing 4 domains of focal neurological deficits, diffuse encephalopathy, IH and cavernous sinus syndrome. CVT severity scale correlated well with ICP, NIHSS, mRS and GCS. Patients with CVT severity scale >10 can be defined as severe CVT. The CVT severity scale may serve as a valid and reliable tool for measuring the overall severity of CVT.

Long-term safety and efficacy of stenting on correcting internal jugular vein and cerebral venous sinus stenosis

OBJECTIVES

To compare the long-term safety and efficacy of stenting in correcting cerebral venous sinus stenosis (CVSS) and internal jugular venous stenosis (IJVS).

METHODS

Patients confirmed with CVSS or IJVS by imaging were enrolled in this real-world study from 2014 through 2021. Clinical characteristics and long-term outcomes of these two diseases entities post-stenting were followed up and compared.

RESULTS

Three hundred and nineteen patients were enrolled in this study, with a mean age of 48.83 years and a BMI of 25.08 on average. In which, 144 patients underwent stenting, the stenotic segments were corrected and the venous blood flow was restored immediately post-stenting. At 6.15 ± 1.67 days follow-up, significant improvement was observed in headache, tinnitus, insomnia, ICP, and mean pressure gradient in both groups (all p < 0.05). At 30.53 ± 4.41 months follow-up post-stenting, the headache, tinnitus, visual loss, papilledema, and insomnia were attenuated remarkably or even completely disappeared. The Frisen papilledema grade scores declined from 2 (0-4) to 1 (0-3) in IJVS group and from 4 (1-5) to 1 (0-4) in CVSS group compared to the baseline. One hundred and twenty-seven out of the 144 patients (95.5%) maintained sufficient blood flow verified by followed up computed tomographic venography or contrast-enhanced magnetic resonance angiography. Adverse events related to stenting included three cases of intraluminal restenosis and three cases of in-stent thrombosis, no intracranial hemorrhage, venous thromboembolisms, stent-adjacent stenosis, and stent displacement occurred.

INTERPRETATION

Using stents to correct IH and related neurological issues has shown to be a safe and effective approach for both IJVS and CVSS.

Absence of the torcular, review of venous sinus anatomy, and the simplified dural sinus classification

BACKGROUND

Classically, the torcular Herophili is described as the symmetric junction between the superior sagittal sinus (SSS), transverse sinuses (TSs), and straight sinus (SS). However, finding this pattern in practice is not standard. Anatomical variations are common, and different drainage patterns should be expected. Existing literature proposes highly detailed descriptions and classifications of this region. Still, a simplified and practical categorization is not available.

METHODS

We present an anatomical finding of the torcular Herophili discovered on a cadaveric dissection. Then, we conducted a retrospective study examining the 100 most recent cranial magnetic resonance venographies (MRVs) from the Mayo Clinic, labeling them with a new proposed dural sinus classification system. Images were initially classified by two authors and further validated by a board-certified neurosurgeon and a board-certified neuroradiologist from our institution. To measure consistency in image identification, two additional international neurosurgeons were asked to classify a subset of the same MRV images, and their answers were compared.

RESULTS

Of the MRV cohort, 33 patients were male and 67 were female. Their ages ranged from 18 to 86 years, with a mean of 47.35 years and a median of 49 years. Upon examination, 53 patients presented as confluent (53%), 9 as SSS divergent (9%), 25 as SS divergent (25%), 11 as circular (11%), and 2 as trifurcated (2%). The inter-rater reliability ranked very good; agreement between the two neurosurgeons was 83% (κ = 0.830, p < 0.0005).

CONCLUSION

The confluence of the venous sinuses is a highly variable anatomical area that is rarely evaluated with neuroimaging before surgery. The classic textbook configuration is not the rule. Using a simplified classification system may increase awareness and hopefully patient safety by preparing the physician for anatomical variations that they will encounter in a surgical or clinical scenario.

Inflammatory Markers Differentiate Cerebral Venous Sinus Thrombosis from Mimics

Imaging tests always misdiagnose anatomical variants of cerebral sinuses as cerebral venous sinus thrombosis (CVST). Anatomical variants of cerebral sinuses are called CVST mimics. This study aimed to identify the role of inflammatory markers in differentiating CVST from mimics. A total of 146 patients diagnosed as CVST and 93 patients with mimics were recruited in this study. Receiver operating characteristic (ROC) analysis was performed to demonstrate the sensitivity and specificity of inflammatory markers for diagnosing CVST. Rank logistic regression analysis was performed to identify the association of markers to CVST severity and prognosis. CVST presented higher inflammatory reactions compared with mimics, demonstrated by the neutrophil count (5.11 [3.97-6.80] vs. 3.06 [2.34-3.86]), interleukin (IL)-6 (7.42 [3.85-14.22] vs. 2.47 [1.50-4.00]), and neutrophil-to-lymphocyte ratio (NLR; 3.19 [2.18-4.62] vs. 1.66 [1.16-2.22]). ROC analysis showed markers with area under the curve (AUC) >0.8, including IL-6 (optimal cutoff: 3.790; kappa value: 0.499), neutrophil count (3.975; 0.522), and NLR (2.070; 0.476). After propensity score matching, only IL-6 had an AUC >0.8, with an optimal cutoff of 3.060 and a kappa value of 0.636. Ranked logistic regression showed that IL-6 (odds ratio, 95% confidence interval: 1.063, 1.026-1.101; 1.029, 1.009-1.050), cerebrospinal fluid (CSF) immunoglobulin (Ig) A (0.279, 0.110-0.706; 0.398, 0.162-0.974), CSF IgM (22.399, 3.004-167.001; 9.545, 1.382-65.928), and CSF IgG (1.287, 1.124-1.473; 1.232, 1.091-1.392) were independently correlated with the baseline and follow-up mRS. In conclusion, inflammatory markers in CVST were different from those in mimics. These markers, especially IL-6, could not only differentiate CVST from its mimics, but also evaluate CVST severity and prognosis.

Idiopathic intracranial hypertension in patients with cerebral small vessel disease: A case report

INTRODUCTION

Idiopathic intracranial hypertension (IIH) is a clinical syndrome characterized by increased intracranial pressure (ICP) without any identifiable cause. However, restrictions of cerebrospinal fluid absorption from the cerebral venous system, the glymphatic system overflow, and the cerebrospinal fluid's lymphatic pathways may be involved in the pathophysiology of IIH. Furthermore, an impaired glymphatic system is also implicated in the initiation and progression of cerebral small vessel disease (CSVD). Here, we reported a case of CSVD with concomitant IIH, possibly associated with the brain's glymphatic and lymphatic system dysfunction.

CASE CONCERN

A 39-year-old male presented with worsening headaches over the bilateral parietal areas during the past year and nausea for 2 days. Fundus examination revealed bilateral papilledema and lumbar puncture suggestive of elevated ICP, laboratory results showed hyperhomocysteinemia and mutation of methylenetetrahydrofolate reductase C677T. On magnetic resonance imaging, subcortical small infarct, white matter lesions, lacunes, enlarged perivascular spaces and dilatation of the optic nerve sheaths was detected, and right transverse sinus stenosis and a hypoplastic left sinus were showed on contrast-enhanced magnetic resonance venography.

DIAGNOSIS

The diagnoses of IIH, CSVD, transverse sinus stenosis, and hyperhomocysteinemia were performed.

INTERVISION AND OUTCOMES

The patient received antihypertensive, antiplatelet, anti-atherosclerotic, and homocysteine-lowering therapies. Finally, the patient's symptoms remised, and the increased ICP returned to normal; however, the bilateral TSS persisted after 3 months of follow-up.

CONCLUSIONS

In this case, we speculate that the normal glymphatic outflow pathway may serve as a compensatory mechanism for regulating increased ICP in patients with bilateral venous sinus obstruction, indicating impaired venous outflow pathway, possibly associated with dysfunction of the glymphatic and lymphatic systems in patients with CSVD.

Cerebral Venous-Associated Brain Damage May Lead to Anxiety and Depression

Background and purpose: Anxiety and depression are common in patients with Cerebral venous outflow disturbance (CVOD). Here, we aimed to explore possible mechanisms underlying this phenomenon. Methods: We enrolled patients diagnosed with imaging-confirmed CVOD, including internal jugular venous stenosis (IJVS) and cerebral venous sinus stenosis (CVSS) between 2017 and 2020. All of them had MRI/PWI scans. The Hamilton Anxiety Scale (HAMA) and 24-item Hamilton Depression Scale (HAMD) were used to evaluate the degree of anxiety and depression at the baseline and three months post-stenting. In addition, the relationships between the HAMA and HAMD scores, white matter lesions, and cerebral perfusion were analyzed using multiple logistic regressions. Results: A total of 61 CVOD patients (mean age 47.95 ± 15.26 years, 59.0% females) were enrolled in this study. Over 70% of them reported symptoms of anxiety and/or depression. Severe CVOD-related anxiety correlated with older age (p = 0.046) and comorbid hyperlipidemia (p = 0.005). Additionally, head noise, sleep disturbances, and white matter lesions (WMLs) were common risk factors for anxiety and depression (p < 0.05). WMLs were considered an independent risk factor for anxiety based on multiple regression analysis (p = 0.029). Self-contrast displayed that CVOD-related anxiety (p = 0.027) and depression (p = 0.017) scores could be corrected by stenting, as the hypoperfusion scores in the limbic lobes of patients with anxiety and depression were significantly higher than those in patients without. Conclusions: CVOD-induced hypoperfusion-mediated changes in the white matter microstructure may represent an underlying mechanism of anxiety and depression in patients with chronic CVOD.

The BE COOL Treatments (Batroxobin, oxygEn, Conditioning, and cOOLing): Emerging Adjunct Therapies for Ischemic Cerebrovascular Disease

Ischemic cerebrovascular disease (ICD), the most common neurological disease worldwide, can be classified based on the onset time (acute/chronic) and the type of cerebral blood vessel involved (artery or venous sinus). Classifications include acute ischemic stroke (AIS)/transient ischemic attack (TIA), chronic cerebral circulation insufficiency (CCCI), acute cerebral venous sinus thrombosis (CVST), and chronic cerebrospinal venous insufficiency (CCSVI). The pathogenesis of cerebral arterial ischemia may be correlated with cerebral venous ischemia through decreased cerebral perfusion. The core treatment goals for both arterial and venous ICDs include perfusion recovery, reduction of cerebral ischemic injury, and preservation of the neuronal integrity of the involved region as soon as possible; however, therapy based on the current guidelines for either acute ischemic events or chronic cerebral ischemia is not ideal because the recurrence rate of AIS or CVST is still very high. Therefore, this review discusses the neuroprotective effects of four novel potential ICD treatments with high translation rates, known as the BE COOL treatments (Batroxobin, oxygEn, Conditioning, and cOOLing), and subsequently analyzes how BE COOL treatments are used in clinical settings. The combination of batroxobin, oxygen, conditioning, and cooling may be a promising intervention for preserving ischemic tissues.

Differentiation between anatomical slenderness and acquired stenosis of the internal jugular veins

Background and Purposes

Differentiating between acquired stenosis (pathologic) and anatomical slenderness (physiologic) of internal jugular vein (IJV) remain ambiguous. Herein, we aimed to compare the similarities and differences between the two entities.

Methods

Patients who underwent head and neck computer tomography (CT) and brain magnetic resonance imaging (MRI) were enrolled in this case‐control study from January 2016 through October 2021.

Results

1487 eligible patients entered final analysis totally. 803 patients had bilateral IJVs imaging without IJV stenosis‐related symptoms and presented in three ways: right IJV slenderness (10.5%, n = 85), left IJV slenderness (48.4%, n = 388), and symmetric IJVs (41.1%, n = 330). In patients with asymmetric IJVs, their bilateral jugular foramina were also asymmetric. All involved asymmetric IJVs presented as slenderness without surrounding abnormal collaterals and credible cloudy‐like white matter hyper‐intensity (WMH). Their cerebral arterial perfusion statuses on brain MR‐PWI maps were normal.

In contrast, the major patients with IJV stenosis presented with signs and symptoms such as headaches, head noise, etc. In CE‐MRV maps, local stenosis of the IJV was surrounded by abnormal venous collaterals in contrast to the lack of abnormal venous collaterals for patients with IJV slenderness. And in CTV maps, the caliber of jugular foramina was mismatched with the transverse diameter of IJV. Moreover, in MRI maps of most of these patients, a cloudy‐like WMHs were distributed symmetrically in bilateral periventricular and/or centrum semi vales. These patients also had symmetrical cerebral arterial hypo‐perfusion. Seven patients underwent stenting of the IJV stenosis correction, their WMHs attenuated or disappeared subsequently.

Conclusions

Imaging features in addition to clinical symptoms can be used to differentiate between physiologic IJV slenderness and pathologic IJV stenosis. Notable imagine‐defining features for IJV stenosis include local stenosis surrounded by abnormal venous collaterals, cloudy‐like WMHs, and mismatch between the transverse diameter of IJV and the caliber of the jugular foramina.

Effects of low molecular weight heparin combined with hyperbaric oxygen on neurologic function and coagulation factors in patients with intracranial venous thrombosis

OBJECTIVE

To investigate the effects of low molecular weight heparin (LMWH) combined with hyperbaric oxygen (HBO) on the neurologic function and coagulation factors of patients with intracranial venous thrombosis (ICVT).

METHODS

The clinical data of 80 patients with ICVT admitted to the No. 2 Hospital of Baoding from February 2020 to January 2021 were retrospectively analyzed. Patients were assigned to a control group (n=32) and a research group (n=48) according to different treatment methods. The neurological function score, and the levels of D-dimer (D-D), fibrinogen (FIB), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) were compared between the two groups. The two groups were also compared regarding the curative effect, toxic and side effects, as well as quality of life (QoL).

RESULTS

After treatment, the National Institutes of Health Stroke Scale (NIHSS) score was significantly lower in the research group compared to the control group. At 1, 2 and 3 weeks after treatment, the levels of D-D and FIB, as well as inflammatory factors TNF-α and CRP were lower in the research group compared to the control group. The overall response rate was significantly higher in the research group compared to the control group, while there was no significant difference in the total incidence of toxic and adverse effects between the two groups. After treatment, the QoL of patients assessed by the Generic Quality of Life Inventory-74 (GQOLI-74) from the domains of physical, social, and psychological function as well as material life status was significantly better in the research group.

CONCLUSIONS

LMWH combined with HBO can effectively improve the clinical efficacy and neurologic function of patients with ICVT and reduce the levels of coagulation factors and inflammatory factors.

Animal Models of Epilepsy: A Phenotype-oriented Review

Epilepsy is a serious neurological disorder characterized by abnormal, recurrent, and synchronous discharges in the brain. Long-term recurrent seizure attacks can cause serious damage to brain function, which is usually observed in patients with temporal lobe epilepsy. Controlling seizure attacks is vital for the treatment and prognosis of epilepsy. Animal models, such as the kindling model, which was the most widely used model in the past, allow the understanding of the potential epileptogenic mechanisms and selection of antiepileptic drugs. In recent years, various animal models of epilepsy have been established to mimic different seizure types, without clear merits and demerits. Accordingly, this review provides a summary of the views mentioned above, aiming to provide a reference for animal model selection.

Pathogeneses and Imaging Features of Cerebral White Matter Lesions of Vascular Origins

White matter lesion (WML), also known as white matter hyperintensities or leukoaraiosis, was first termed in 1986 to describe the hyperintense signals on T2-weighted imaging (T2WI) and fluid-attenuated inversion recovery (FLAIR) maps. Over the past decades, a growing body of pathophysiological findings regarding WMLs have been discovered and discussed. Currently, the generally accepted WML pathogeneses mainly include hypoxia-ischemia, endothelial dysfunction, blood-brain barrier disruption, and infiltration of inflammatory mediators or cytokines. However, none of them can explain the whole dynamics of WML formation. Herein, we primarily focus on the pathogeneses and neuroimaging features of vascular WMLs. To achieve this goal, we searched papers with any type published in PubMed from 1950 to 2020 and cross-referenced the keywords including “leukoencephalopathy”, “leukoaraiosis”, “white matter hyperintensity”, “white matter lesion”, “pathogenesis”, “pathology”, “pathophysiology”, and “neuroimaging”. Moreover, references of the selected articles were browsed and searched for additional pertinent articles. We believe this work will supply the robust references for clinicians to further understand the different WML patterns of varying vascular etiologies and thus make customized treatment.

Nonthrombotic internal jugular venous stenosis may facilitate cerebral venous thrombosis

AIMS

To explore the effect of nonthrombotic internal jugular venous stenosis (IJVS) exerted on cerebral venous thrombosis (CVT).

METHODS

Patients with imaging confirmed CVT were enrolled into this real-world case-control study consecutively from January 2018 through April 2021, and were divided into CVT and IJVS-CVT groups, according to whether or not with non-thrombotic IJVS. Chi-square and logistic regression models were utilized for between-group comparison of thrombotic factors.

RESULTS

A total of 199 eligible patients entered into final analysis, including 92 cases of CVT and 107 cases of IJVS-CVT. Chi-square revealed that thrombophilic conditions were found in majority of CVT, while only minority in the IJVS-CVT group (83.7% vs. 20.6%, p < 0.001). Multivariate logistic regression indicated that most identified thrombophilia were negatively related to IJVS-CVT (all p < 0.05), including oral contraceptive use (β = -1.38), hyperhomocysteinemia (β = -1.58), hematology (β = -2.05), protein C/S deficiency (β = -2.28), connective tissue disease (β = -1.18) and infection (β = -2.77). All recruited patients underwent standard anticoagulation, 10 cases in IJVS-CVT group also received jugular angioplasty for IJVS correction. Most participants obtained alleviations during 1-year follow-up. However, both clinical and imaging outcomes in IJVS-CVT group were not as good as those in CVT group (both p < 0.05). Moreover, 8 cases with CVT and 7 cases with IJVS-CVT were rehospitalized for CVT recurrences and underwent customized treatment.

CONCLUSION

Nonthrombotic IJVS may be one of the risk factors of CVT. Anticoagulation might need to be suggested for IJVS patients.