Patterns of chronic venous insufficiency in the dural sinuses and extracranial draining veins and their relationship with white matter hyperintensities for patients with Parkinson's disease

Nonarteritic anterior ischemic optic neuropathy and incidence of Parkinson's disease based on a nationwide population based study

This study aimed to investigate the association between nonarteritic anterior ischemic optic neuropathy (NAION) and Parkinson's disease (PD) using a retrospective, nationwide, population-based cohort in South Korea. This study utilized data from the Korean National Health Insurance database, including 43,960 NAION patients and 219,800 age- and sex-matched controls. Cox proportional hazards regression models were used to assess the risk of developing PD in the NAION group compared to the control group after adjusting for various confounding factors. Subgroup analyses were conducted based on sex, age, and comorbidities. The incidence rate of PD was higher in the NAION group (1.326 per 1000 person-years) than in the control group (0.859 per 1000 person-years). After adjusting for confounding factors, the risk of developing PD was significantly higher in the NAION group (adjusted hazard ratio [aHR] 1.516, 95% confidence interval [CI] 1.300-1.769). Subgroup analyses did not reveal a significant difference in the risk of PD development based on sex, age, or comorbidities. This retrospective, nationwide, population-based cohort study revealed a significant association between NAION and an increased risk of developing PD in a South Korean population. The incidence rate of PD was observed to be higher in individuals diagnosed with NAION than in age- and sex-matched controls even after adjusting for potential confounding variables, with the risk being approximately 51.6% higher in the NAION group. Further research is necessary to elucidate the underlying pathophysiological mechanisms linking NAION to PD and to determine whether similar associations exist in other ethnic and geographical populations.

Anatomic Asymmetry of Transverse Sinus May Be Irrelevant to the Prognosis of Intracerebral Hemorrhage

BACKGROUND

We investigate the probable effect of anatomic asymmetry of transverse sinus (TS) on the outcomes of acute intracerebral hemorrhage (ICH), to provide reference for customized treatment.

METHODS

Consecutive patients with imaging-confirmed acute ICH were enrolled from October 2015 through October 2019, and divided into 2 groups: symmetrical and unilateral (left or right) slender TS groups, based on the status of TS in imaging maps. Brain computed tomography (CT) maps of all patients at baseline and half-month post-ICH were obtained, and the volumes of hematoma and the perihematomal edemas (PHE), as well as the modified Rankin Scale (mRS) scores at the month-3 post-ICH between the 2 groups were assessed and analyzed.

RESULTS

A total of 46 eligible patients entered into final analysis, including 18 cases in the slender TS group (14 cases involved the left side while 4 cases involved the right side), and 28 cases in the symmetrical TS group. The mRS scores, hematoma absorption rates, and the residual volumes of PHE of all patients in the 2 groups at half-month post-ICH showed no statistical significance (all P >0.05), and all of the items mentioned above were related to the hematoma volume at baseline (all P <0.001). At the month-3 follow-up post-ICH, the mRS scores between the 2 groups showed no statistical significance as well ( P =0.551).

CONCLUSIONS

Anatomic asymmetry of TS may not affect the prognosis of PHE and clinical outcome after ICH.

Cerebrospinal fluid dynamics coupled to the global circulation in holistic setting: Mathematical models, numerical methods and applications

This paper presents a mathematical model of the global, arterio-venous circulation in the entire human body, coupled to a refined description of the cerebrospinal fluid (CSF) dynamics in the craniospinal cavity. The present model represents a substantially revised version of the original Müller-Toro mathematical model. It includes one-dimensional (1D), non-linear systems of partial differential equations for 323 major blood vessels and 85 zero-dimensional, differential-algebraic systems for the remaining components. Highlights include the myogenic mechanism of cerebral blood regulation; refined vasculature for the inner ear, the brainstem and the cerebellum; and viscoelastic, rather than purely elastic, models for all blood vessels, arterial and venous. The derived 1D parabolic systems of partial differential equations for all major vessels are approximated by hyperbolic systems with stiff source terms following a relaxation approach. A major novelty of this paper is the coupling of the circulation, as described, to a refined description of the CSF dynamics in the craniospinal cavity, following Linninger et al. The numerical solution methodology employed to approximate the hyperbolic non-linear systems of partial differential equations with stiff source terms is based on the Arbitrary DERivative Riemann problem finite volume framework, supplemented with a well-balanced formulation, and a local time stepping procedure. The full model is validated through comparison of computational results against published data and bespoke MRI measurements. Then we present two medical applications: (i) transverse sinus stenoses and their relation to Idiopathic Intracranial Hypertension; and (ii) extra-cranial venous strictures and their impact in the inner ear circulation, and its implications for Ménière's disease.

Effects of Levodopa Therapy on Cerebral Arteries and Perfusion in Parkinson's Disease Patients

BACKGROUND

Levodopa is the most-commonly used therapy for Parkinson's Disease (PD). Imaging findings show increased cerebral blood flow (CBF) response to levodopa, but the artery morphological change is less studied.

PURPOSE

To investigate the effect of levodopa on cerebral arteries and CBF.

STUDY TYPE

Prospective.

POPULATION

57 PD patients (56 ± 10 years, 26 males) and 17 age-matched healthy controls (AMC, 57 ± 9 years, 9 males) were scanned at baseline (OFF). Patients were rescanned 50 minutes after taking levodopa (ON).

FIELD STRENGTH AND SEQUENCE

3 T; Simultaneous noncontrast angiography intraplaque imaging (SNAP) based on turbo field echo; Pseudo-continuous arterial spin labeling (PCASL) based on echo-planner imaging.

ASSESSMENT

The Unified Parkinson's Disease Rating Scale (UPDRS-III) was used to assess the disease severity. Length and radius of arteries were measured from SNAP images. CBF was calculated from PCASL images globally and regionally.

STATISTICAL TESTS

Mann Whitney U tests were conducted in comparing PD vs. AMC. Wilcoxon matched-pairs signed rank tests were used in comparing OFF vs. ON, and the more-affected vs. the less-affected hemisphere in PD. Linear regressions were performed to test the correlations of neuroimaging findings with behavioral changes. Significance threshold was P < 0.05 with Bonferroni correction.

RESULTS

PD patients were identified with significantly lower CBF (PD OFF Mean = 40.15 ± 5.99, AMC Mean = 43.48 ± 6.21 mL/100 g/min) and shortened total artery length (PD OFF Mean = 5851.07 ± 1393.45, AMC Mean = 7479.16 ± 1335.93 mm). Levodopa elevated CBF of PD brains (PD ON Mean = 41.48 ± 6.32 mL/100 g/min) and expanded radius of proximal arteries. Artery radius change significantly correlated with CBF change in corresponding territories (r = 0.559 for Internal Carotid Arteries, r = 0.448 for Basilar Artery, and r = 0.464 for Middle Cerebral Artery M1). Global CBF significantly related to UPDRS-III (r = -0.391) post-levodopa.

DATA CONCLUSION

Levodopa can increase CBF by dilating proximal arteries.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY STAGE: 4.

Numerical modeling of blood flow in the internal jugular vein with the use of computational fluid mechanics software

OBJECTIVES

To determine the site and nature of altered hemodynamics in pathological internal jugular veins.

METHOD

With the use of computational fluid mechanics software we simulated blood flow in 3 D models of the internal jugular veins that exhibited different morphologies, including nozzle-like strictures in their upper parts and valves in the lower parts.

RESULTS

In a majority of models with nozzle-like strictures, especially those positioned asymmetrically, abnormal flow pattern was revealed, with significant flow separation and regions with reversed flow. Abnormal valves had no significant impact on flow in a case of already altered flow evoked by stricture in upper part of the vein.

CONCLUSIONS

In our jugular model, cranially-located stenoses, which in clinical practice are primarily caused by external compression, cause more significant outflow impact respect to endoluminal defects and pathological valves located more caudally.

Pathogenesis and Management in Cerebrovenous Outflow Disorders

In keeping with its status as one of the major causes of disability and mortality worldwide, brain damage induced by cerebral arterial disease has been the subject of several decades of scientific investigation, which has resulted in a vastly improved understanding of its pathogenesis. Brain injury mediated by venous etiologies, however, such as cerebral, jugular, and vertebral venous outflow disturbance, have been largely ignored by clinicians. Unfortunately, this inattention is not proportional to the severity of cerebral venous diseases, as the impact they exact on the quality of life of affected patients may be no less than that of arterial diseases. This is evident in disease sequelae such as cerebral venous thrombosis (CVT)-mediated visual impairment, epilepsy, and intracranial hypertension; and the long-term unbearable head noise, tinnitus, headache, dizziness, sleeping disorder, and even severe intracranial hypertension induced by non-thrombotic cerebral venous sinus (CVS) stenosis and/or internal jugular venous (IJV) stenosis. In addition, the vertebral venous system (VVS), a large volume, valveless vascular network that stretches from the brain to the pelvis, provides a conduit for diffuse transmission of tumors, infections, or emboli, with potentially devastating clinical consequences. Moreover, the lack of specific features and focal neurologic signs seen with arterial etiologies render cerebral venous disease prone to both to misdiagnoses and missed diagnoses. It is therefore imperative that awareness be raised, and that as comprehensive an understanding as possible of these issues be cultivated. In this review, we attempt to facilitate these goals by systematically summarizing recent advances in the diagnosis and treatment of these entities, including CVT, CVS stenosis, and IJV stenosis, with the aim of providing a valid, practical reference for clinicians.

Venous dysfunction plays a critical role in "normal" white matter disease of aging

A ubiquitous finding on MRI in older individuals, age-related cerebral white matter hyperintensities (WMHs) are associated with cognitive decline, dementia, disability, and death. Currently, these findings are thought to represent small infarcts secondary to lipohyalinotic arteriosclerosis. Commonly though, the anatomic distribution of WMHs is often non-arterial, and parallel the deep venous system. Furthermore, there is discrepant evidence for the role of conventional vascular risk factors such as hypertension, carotid atherosclerosis and diabetes for the development and progression of these. Interventions targeting conventional vascular risk factors lack consistency in preventing the progression of WMHs. There is evidence for age-related hemodynamic cervical venous dysfunction resulting in reduced internal jugular vein venous compliance, venous dilatation, and venous reflux. Similarly, venous collagenosis increases with age. Increased blood-brain barrier (BBB) permeability is also noted with aging. Both hemodynamic venous dysfunction, venous sclerosis, and increased BBB permeability are associated with WMHs. We propose that age-related WMHs are a sequalae of venous dysfunction. Venous dysfunction results initially in increased transmission of venous pressures to the brain. Subsequent BBB disruption leads to increased permeability with progression to end-stage findings of age-related WMHs.

Clinical Classification and Collateral Circulation in Chronic Cerebrospinal Venous Insufficiency

Background: As an indispensable part of the cerebral venous system, the extracranial cerebrospinal venous system is not fully recognized. This study aimed to analyze the clinical classification and imaging characteristics of chronic cerebrospinal venous insufficiency (CCSVI) quantitatively.

Methods: A total of 128 patients, who were diagnosed as CCSVI by jugular ultrasound and contrast-enhanced magnetic resonance venography (CE-MRV), were enrolled from May 2018 through May 2019. For the patients with possible extraluminal compression, computed tomography venography (CTV) was applied to estimate the degree of internal jugular venous stenosis (IJVS) and rank the vertebral venous collateral circulation.

Results: The causes of extraluminal compression induced IJVS included osseous compression (78.95%), carotid artery (24.21%), sternocleidomastoid muscle (5.79%), swollen lymph node (1.05%), and unknown reasons (5.26%). The subtypes of non-compression CCSVI included the high jugular bulb (77.27%), fenestration of the internal jugular vein (IJV) (7.27%), internal jugular phlebectasia (2.73%), tortuous IJV (0.91%), IJV thrombosis (14.55%), and elongated venous valves with/without erythrocyte aggregation (13.64%). For extraluminal compression induced IJVS, the ratio of severe vertebral venous expansion was higher in the severe IJVS group than that in the mild IJVS group (p < 0.001). The IJVS degree was higher in the severe vertebral venous expansion group than in the mild vertebral venous expansion group (p < 0.001).

Conclusions: A multimodal diagnostic system is necessary to improve the diagnostic accuracy of CCSVI. The vertebral venous system is an important collateral circulation for CCSVI, which may be a promising indicator for evaluating IJVS degree.

Anatomical Morphology Analysis of Internal Jugular Veins and Factors Affecting Internal Jugular Vein Size

Background and objectives: There is a paucity of research on the shape of internal jugular vein (IJV) and their association with an individual's morphology and various chronic diseases. Therefore, this study aimed to analyze the anatomy of the IJV across various patients and to relate the differences in anatomy to basic patient characteristics. Materials and Methods: This retrospective study included a total of 313 patients who underwent contrast-enhanced neck computed tomography between January 2017 and December 2018. The circumferences of the right and left IJVs were measured at three locations (hyoid bone, cricoid cartilage, and first thoracic vertebra) and parameters affecting the size of the IJV were analyzed. Results: The right IJV was significantly larger than the left IJV at each position (p < 0.001), and the area of the lumen was the largest at the cricoid cartilage level (p < 0.001). After dividing the right IJV data into two groups (above and below the median area), multivariate logistic regression analysis showed that age (odds ratio (OR) 1.040; 95% confidence interval (CI) 1.022-1.058, p < 0.001) and body mass index (BMI, OR 1.080; 95% CI 1.011-1.154, p = 0.0.23) affected size. Conclusions: The right IJV is larger than the left and has a rhomboid morphology. Age and BMI are significant factors affecting the IJV size.

Potential Mechanism of Venous System for Leukoaraiosis: From post-mortem to in vivo Research

BACKGROUND

Leukoaraiosis (LA), widely accepted as a feature of cerebral small vessel disease, significantly increases the incidence of stroke, dementia, and death. Cerebral small artery disease has been considered as one of the main causes of LA. However, since the term "venous collagenosis" (VC) was proposed in an atrophy research in 1995, there have been pathological and neuroimaging studies proving the association between the venous system and LA in aging, Alz-heimer's disease (AD), and Parkinson's disease.

SUMMARY

Autopsy studies confirmed that thickening of the lumen wall in venules, which results from the deposition of collagen I and III, leading to vessel stenosis or occlusion, is closely associated with LA. Susceptibility-weighted imaging research revealed a controversial association of deep medullary veins and LA in vivo, regarding which there are no standard criteria currently. Nevertheless, retinal venous changes had been reported to increase the risk of LA development, providing a novel way for in vivo evaluation. As for the internal jugular vein, jugular venous reflux could double the LA score in aging and modulate circulation of cerebral spinal fluids. Key Messages: Disruption of the venous system was notably associated with LA in aging, AD, and Parkinson's disease post-mortem and in in vivo models. The venous pathological changes may induce cerebral hypoperfusion, drainage system disruption, and vasogenic oedema in the veins around the periventricular white matter. The clarification of VC in LA may provide an early prevention and early treatment strategy for LA patients.

Clinical characteristics and neuroimaging findings in eagle syndrome induced internal jugular vein stenosis

Background

Eagle syndrome is a condition that causes pharyngeal pain, facial pain, swallowing difficulties, and symptoms of arterial impingement due to the elongated styloid process. However, few reports were about eagle syndrome with venous compression up to now. This study aimed to identify the clinical profiles of the internal jugular vein stenosis (IJVS) related eagle syndrome comprehensively.

Methods

A total of 27 patients, who were diagnosed as IJVS induced by styloid process compression were enrolled. The clinical manifestations and imaging features were analyzed.

Results

Styloid process compression was presented in all of the 27 IJVS patients, in which, the top three symptoms included insomnia (81.5%), tinnitus (63.0%) and head noises (63.0%). The most vulnerable segment of internal jugular vein (IJV) was J3 segment (96.3%). The average styloid process length in our study was 3.7 cm. Hearing impairment was more common in bilateral IJVS (68.8% vs. 18.2%, P=0.018). One patient reported significant relief of symptoms at 1 year follow-up after underwent styloidectomy combined with stenting.

Conclusions

Neurological symptoms of eagle syndrome induced IJVS were various, including either arterial or venous issues. Better understanding of this disease entity may be helpful for clinical diagnosis and treatment.

Probable risk factors of internal jugular vein stenosis in Chinese patients-A real-world cohort study

OBJECTIVES

Extracranial venous anomalies, especially internal jugular vein stenosis (IJVS), have recently received increasing attention, however, its etiologies are uncertain. This study aimed to explore the probable risk factors of IJVS in Chinese PATIENTS AND METHODS: Eligible patients with IJVS confirmed by contrast-enhanced magnetic resonance venography (CE-MRV) were enrolled from October 2017 through October 2018. Probable risk factors were analyzed, including the conditions that may result in IJV wall damage, extraluminal compression, gender and age.

RESULTS

A total of 133 patients enrolled in the final analysis, including 73 females and 60 males, the mean age were 54.83 ± 15.25 years. In this IJVS cohort, the top two risks were previous hepatitis B virus (HBV) infection (48.9 %) and osseous compression (41.4 %). The IJVS cohort was divided into two subsets: extraluminal compression and non-compression. In the former, osseous compression (80.9 %) was the top risk factor, other risks including arterial (22.1 %) and lymph node compression (2.9 %). While, in the latter subset, the most common risk factor was previous HBV infection (46.2 %). In addition, cerebral venous sinus thrombosis (CVST) in non-compression subset was more common than that in extraluminal compression subset (21.5 % VS. 2.9 %, p = 0.001). When considered the gender (Male vs. Female), the ratios were 28.3 % vs. 0 % of smoking, p < 0.001, 16.67 % vs. 1.37 % of hyperhomocysteinemia, p = 0.002, and 11.67 % vs. 1.37 % of hyperuricemia, p = 0.023. In the subset with age less than 45 years, the top three risks included CVST (56.25 %), immunological diseases (55.56 %), and hyperhomocysteinemia (50.00 %), while, in the subset with the ages over 60 years, type-2 diabetes (66.66 %), carotid artery compression (53.33 %), previous HBV infection (52.31 %), and osseous compression (49.09 %) were more common than others.

CONCLUSION

This study illustrates the probable risks of IJVS may be diverse, in which osseous compression and previous HBV infection may be the top two probable risks of IJVS in Chinese. This is the biggest difference from previous reports based on Caucasian.

Probable factors affecting clinical outcomes of internal jugular vein stenosis

Background

Internal jugular vein stenosis (IJVS) has recently aroused increasing interests, whereas, the factors affecting its clinical outcomes are not clear. This study aims to explore the probable factors affected clinical prognosis by evaluating the IJVS with different etiologies and strategies.

Methods

Patients with IJVS confirmed by contrast-enhanced magnetic resonance venography (CE-MRV) were enrolled from October 2017 through October 2018. One-year clinical outcomes of the IJVS cases enrolled in this study were assessed by outpatient and telephone follow-up using the Patient Global Impression of Change (PGIC) scores. According to the etiologies, patients were divided into thrombotic IJVS and non-thrombotic IJVS groups. And further, non-thrombotic IJVS group was divided into external compression and non-external compression subgroups. Outcomes of IJVS with different etiologies and strategies were compared and the probable prognostic factors were analyzed.

Results

A total of 118 eligible patients enrolled in this study, including 76 females and 42 males, mean aged 55.07±14.61 years. The average follow-up duration after discharge was 13.22±3.80 months. According to the PGIC scores, we categorized patients as good outcome and poor outcome groups. For thrombotic IJVS, patients underwent standard anticoagulant obtained remarkable PGIC improvement (100.0% vs. 33.3%, P=0.038). For non-thrombotic IJVS, stenting showed benefit in non-external compression subgroup (26.9% vs. 3.3%, P=0.019) but not in external compression subgroup. In addition, we found that in this Chinese IJVS cohort, poor outcomes involved old age (P=0.004), type 2 diabetes mellitus (P=0.036), previous hepatitis B virus (HBV) infection (P=0.027), and head noises (P=0.002). Multivariate logistic regression analysis indicated that continuous head noises [P=0.045, odds ratio (OR): 2.412, 95% confidence interval (CI): 1.019-5.711], as a unique symptom of IJVS may be significantly related to poor outcomes.

Conclusions

In this Chinese cohort, elderly degenerative bone compression, type 2 diabetes mellitus, and previous HBV infection are the top-three probable etiologies of non-thrombotic IJVS and may involve poor outcome. Long-term head noises may predict IJVS and with poor outcome. Thrombosis-induced IJVS may get benefit from standard anticoagulation. Non-external compression IJVS can be corrected by stenting.

Vascular aspects of multiple sclerosis: emphasis on perfusion and cardiovascular comorbidities

INTRODUCTION

Multiple sclerosis (MS) is a chronic inflammatory, demyelinating, and neurodegenerative disease of the central nervous system. Over the last two decades, more favorable MS long-term outcomes have contributed toward increase in prevalence of the aged MS population. Emergence of age-associated pathology, such as cardiovascular diseases, may interact with the MS pathophysiology and further contribute to disease progression. Areas covered: This review summarizes the cardiovascular involvement in MS pathology, its disease activity, and progression. The cardiovascular health, the presence of various cardiovascular diseases, and their effect on MS cognitive performance are further explored. In similar fashion, the emerging evidence of a higher incidence of extracranial arterial pathology and its association with brain MS pathology are discussed. Finally, the authors outline the methodologies behind specific perfusion magnetic resonance imaging (MRI) and ultrasound Doppler techniques, which allow measurement of disease-specific and age-specific vascular changes in the aging population and MS patients. Expert opinion: Cardiovascular pathology significantly contributes to worse clinical and MRI-derived disease outcomes in MS. Global and regional cerebral hypoperfusion may be associated with poorer physical and cognitive performance. Prevention, improved detection, and treatment of the cardiovascular-based pathology may improve the overall long-term health of MS patients.

Susceptibility mapping of the dural sinuses and other superficial veins in the brain

Quantitative susceptibility mapping (QSM) is a means to obtain direct measurements of local tissue susceptibility distribution. Usually the focus is on imaging tissues in the brain, and the region of the brain studied is dictated by an eroded skull stripped mask. Producing the pristine local phase behavior for regions at the edge of the brain has been difficult in the past. For structures such as the superior sagittal sinus (SSS) that run alongside the surface of the brain and under the skull bones, a considerable part of the external phase from the dipole effect is lost due to the short T2* of the bones. In this paper, we propose a method that seeks to reconstruct the susceptibility distribution inside the dural sinuses by ensuring that the entire geometry of the dural sinuses is preserved with the help of an MR angiogram and venogram (MRAV). Having a geometrical model of the vessels makes it possible to estimate the missing phase outside the brain as well, by using the forward phase model and, hence, allowing a complete phase map to be reconstructed. Fifteen healthy volunteers were scanned using a susceptibility weighted imaging (SWI) sequence with interleaved rephased-dephased echoes. QSM results were compared between the conventional techniques and the proposed method of phase preservation outside the brain and inside the dural sinuses. This method demonstrates the reconstruction of the SSS, whereas conventional methods are either unable to preserve this structure or unable to provide complete phase information. The mean and standard deviation inside the SSS for all volunteers was 435 ± 5 ppb (this is the inter-subject error). To validate the proposed approach, the mean susceptibility inside the straight sinus showed good agreement between conventional approach and the proposed method. The results presented in this study indicate the potential of generating the susceptibility map for the whole brain, including the SSS (as well as potentially all the cortical veins).

Safety and efficacy of venoplasty in MS: A randomized, double-blind, sham-controlled phase II trial

Objective

To determine the safety and efficacy of balloon vs sham venoplasty of narrowing of the extracranial jugular and azygos veins in multiple sclerosis (MS).

Methods

Patients with relapsing or progressive MS were screened using clinical and ultrasound criteria. After confirmation of >50% narrowing by venography, participants were randomized 1:1 to receive balloon or sham venoplasty of all stenoses and were followed for 48 weeks. Participants and research staff were blinded to intervention allocation. The primary safety outcome was the number of adverse events (AEs) during 48 weeks. The primary efficacy outcome was the change from baseline to week 48 in the patient-reported outcome MS Quality of Life–54 (MSQOL-54) questionnaire. Standardized clinical and MRI outcomes were also evaluated.

Results

One hundred four participants were randomized (55 sham; 49 venoplasty) and 103 completed 48 weeks of follow-up. Twenty-three sham and 21 venoplasty participants reported at least 1 AE; one sham (2%) and 5 (10%) venoplasty participants had a serious AE. The mean improvement in MSQOL-54 physical score was +1.3 (sham) and +1.4 (venoplasty) (p = 0.95); MSQOL-54 mental score was +1.2 (sham) and −0.8 (venoplasty) (p = 0.55).

Conclusions

Our data do not support the continued use of venoplasty of extracranial jugular and/or azygous venous narrowing to improve patient-reported outcomes, chronic MS symptoms, or the disease course of MS.

ClinicalTrials.gov identifier

NCT01864941.

Classification of evidence

This study provides Class I evidence that for patients with MS, balloon venoplasty of extracranial jugular and azygous veins is not beneficial in improving patient-reported, standardized clinical, or MRI outcomes.

Jugular Venous Flow Quantification Using Doppler Sonography

A consensus on venous flow quantification using echo spectral Doppler sonography is lacking. Doppler sonography data from 83 healthy individuals were examined using manually traced transverse cross-sectional area and diameter-derived cross-sectional area obtained in longitudinal view measurements of the internal jugular vein. Time-averaged velocity over a 4-s interval was obtained in the longitudinal plane using manual tracing of the waveform. Manual and computer-generated blood flow volume calculations were also obtained for the common carotid artery, for accuracy purposes. No differences were detected between semi-automated and manual blood flow volume calculations for the common carotid artery. The manual calculation method resulted in almost twofold larger venous internal jugular vein flow measurements compared with the semi-automated method. Doppler sonography equipment does not provide accurate automated calculation of venous size and blood flow. Until further technological development occurs, manual calculation of venous blood flow is warranted.

Fixing the jugular flow reduces ventricle volume and improves brain perfusion

OBJECTIVE

Increased ventricle volume and brain hypoperfusion are linked to neurodegeneration. We hypothesized that in patients with restricted jugular flow, surgical restoration may reduce brain ventricle volume, because it should improve the pressure gradient, hence promoting cerebrospinal fluid reabsorption into the venous system.

METHODS

The effects of restoring the jugular flow were assessed by means of a validated echocardiography with color Doppler (ECD) protocol of flow quantification, magnetic resonance venography, and single-photon emission computed tomography combined with computed tomography (SPECT-CT). The main outcome measurement was the cerebral ventricle volume blindly assessed at SPECT-CT. Secondary outcomes were brain perfusion in the whole brain and in another 12 cerebral regions. The mean follow-up of the SPECT-CT and ECD parameters was 30 days. Patency rate was subsequently monitored by means of the same ECD protocol every 3 months.

RESULTS

Among 56 patients (28 male and 28 female; mean age, 44 ± 10 years) with ECD screening positive for chronic cerebrospinal venous insufficiency due to nonmobile jugular leaflets, 15 patients were excluded from the initial cohort because they did not meet the inclusion and exclusion criteria. Of the remaining 41 patients, 27 patients (14 male, 13 female; mean age, 48 ± 7 years) underwent endophlebectomy and autologous vein patch angioplasty. Omohyoid muscle section was performed when appropriate. The control group comprised 14 patients matched by age and gender (8 male, 6 female; mean age, 44 ± 11 years) who were not treated. Comorbidity was multiple sclerosis without significant differences in relapsing remitting (RR) and secondary progressive (SP) clinical course among groups. In the control group, neither ECD nor SPECT-CT showed any significant changes at follow-up. On the contrary, in the group operated on, the collateral flow index went from 70% to 30% (P < .0003) thanks to improved flow through the internal jugular vein. Correspondingly, ventricle volume dramatically decreased in the treated group (from 34 ± 14 cm(3) to 31 ± 13 cm(3); P < .01). The effect was much more evident in the RR subgroup (P = .009), whereas in the SP subgroup, it was not significant. Perfusion was found to be improved in the surgical group with respect to controls, particularly in the occipital and parietal regions of the RR subgroup (P < .0001 and P = .017, respectively), but not in the SP subgroup. The probability of reducing ventricle size is increased by 13-fold (P < .03) when restoration of the jugular flow achieves a postoperative collateral flow index ≤20%. Finally, the 18-month patency rate was 74%.

CONCLUSIONS

Fixing the flow in the jugulars in patients with chronic cerebrospinal venous insufficiency might significantly reduce brain ventricle volume and improve cerebral perfusion. These changes are more evident in patients in the earlier stages of neurodegenerative disease.

Understanding jugular venous outflow disturbance

Extracranial venous abnormalities, especially jugular venous outflow disturbance, were originally viewed as nonpathological phenomena due to a lack of realization and exploration of their feature and clinical significance. The etiology and pathogenesis are still unclear, whereas a couple of causal factors have been conjectured. The clinical presentation of this condition is highly variable, ranging from insidious to symptomatic, such as headaches, dizziness, pulsatile tinnitus, visual impairment, sleep disturbance, and neck discomfort or pain. Standard diagnostic criteria are not available, and current diagnosis largely depends on a combinatory use of imaging modalities. Although few researches have been conducted to gain evidence-based therapeutic approach, several recent advances indicate that intravenous angioplasty in combination with stenting implantation may be a safe and efficient way to restore normal blood circulation, alleviate the discomfort symptoms, and enhance patients' quality of life. In addition, surgical removal of structures that constrain the internal jugular vein may serve as an alternative or adjunctive management when endovascular intervention is not feasible. Notably, discussion on every aspect of this newly recognized disease entity is in the infant stage and efforts with more rigorous designed, randomized controlled studies in attempt to identify the pathophysiology, diagnostic criteria, and effective approaches to its treatment will provide a profound insight into this issue.

Ultrasound diagnosis of transverse sinus hypoplasia using flow profiles of the internal jugular vein

Accurate diagnosis of subtypes of transverse sinus (TS) hypoplasia requires more expensive methods like magnetic resonance (MR) imaging. We hypothesized ultrasound findings of the internal jugular vein (IJV) can be surrogate indicators for diagnosis of TS hypoplasia. MR images were reviewed in 131 subjects to evaluate TS diameter and the location and degree of venous flow stenosis and obstruction. Ultrasound parameters including the cross-sectional lumen area (CSA), time-average-mean velocity (TAMV), and flow volume (FV) at each IJV segment were also evaluated. Sixty-nine subjects had TS hypoplasia based on MRV criteria, of which 39 TS hypoplasia were considered a subtype of TS hypoplasia, which is secondary to the downstream venous compression/stenosis or left brachiocephalic vein. In the ultrasound study, the CSA of the IJV ipsilateral to TS hypoplasia was significantly smaller. Further, a contralateral/ipsilateral IJV CSA ratio >1.55 provided good sensitivity, specificity, and positive predictive value for discriminating TS hypoplasia.

Aging of cerebral white matter

White matter (WM) occupies a large volume of the human cerebrum and is mainly composed of myelinated axons and myelin-producing glial cells. The myelinated axons within WM are the structural foundation for efficient neurotransmission between cortical and subcortical areas. Similar to neuron-enriched gray matter areas, WM undergoes a series of changes during the process of aging. WM malfunction can induce serious neurobehavioral and cognitive impairments. Thus, age-related changes in WM may contribute to the functional decline observed in the elderly. In addition, aged WM becomes more susceptible to neurological disorders, such as stroke, traumatic brain injury (TBI), and neurodegeneration. In this review, we summarize the structural and functional alterations of WM in natural aging and speculate on the underlying mechanisms. We also discuss how age-related WM changes influence the progression of various brain disorders, including ischemic and hemorrhagic stroke, TBI, Alzheimer's disease, and Parkinson's disease. Although the physiology of WM is still poorly understood relative to gray matter, WM is a rational therapeutic target for a number of neurological and psychiatric conditions.

Clinical Applicability of Assessment of Jugular Flow over the Individual Cardiac Cycle Compared with Current Ultrasound Methodology

There is growing interest in measuring cerebral venous outflow with ultrasound (US). However, results obtained with the current US Doppler methodology, which uses just a single value of cross-sectional area (CSA) of the vessel, are highly variable and inconclusive. The product of CSA and time-averaged velocity in the case of pulsatile vessels may be a possible source of error, particularly for a pulsatile vein like the internal jugular vein (IJV), where the cardiac pump transmits a sequence of well-established waves along the conduit. We herein propose a novel technique for US IJV flow assessment that accurately accounts for IJV CSA variations during the cardiac cycle. Five subjects were investigated with a high-resolution real-time B-mode video, synchronized with an electrocardiography trace. In this approach, CSA variations representing the pulsatility of the IJV are overlapped with the velocity curve obtained by the usual spectral Doppler trace. The overlap is then phased point by point using the electrocardiography pacemaker. This allows us to experimentally measure the velocity variation in relation to the change in CSA precisely, ultimately enabling calculation of IJV flow. (i) The sequence of CSA variation with respect to the electrocardiography waves corresponds exactly to the jugular venous pulse as measured in physiology. (ii) The methodology permits us to phase the velocity and CSA, which is ultimately what is currently lacking to precisely calculate the flow in the IJV with US. (iii) The time-averaged flow, calculated with the described technique, is very close to that calculated assuming a constant IJV CSA, whereas the time-dependent flow shows differs as much as 40%. (iv) Finally, we tested the accuracy of the technique with a methodology that may allow for universal assessment of the accuracy of each personal US-based evaluation of flow rate.

Internal Jugular Vein Cross-Sectional Area and Cerebrospinal Fluid Pulsatility in the Aqueduct of Sylvius: A Comparative Study between Healthy Subjects and Multiple Sclerosis Patients

Objectives

Constricted cerebral venous outflow has been linked with increased cerebrospinal fluid (CSF) pulsatility in the aqueduct of Sylvius in multiple sclerosis (MS) patients and healthy individuals. This study investigates the relationship between CSF pulsatility and internal jugular vein (IJV) cross-sectional area (CSA) in these two groups, something previously unknown.

Methods

65 relapsing-remitting MS patients (50.8% female; mean age = 43.8 years) and 74 healthy controls (HCs) (54.1% female; mean age = 43.9 years) were investigated. CSF flow quantification was performed on cine phase-contrast MRI, while IJV-CSA was calculated using magnetic resonance venography. Statistical analysis involved correlation, and partial least squares correlation analysis (PLSCA).

Results

PLSCA revealed a significant difference (p<0.001; effect size = 1.072) between MS patients and HCs in the positive relationship between CSF pulsatility and IJV-CSA at C5-T1, something not detected at C2-C4. Controlling for age and cardiovascular risk factors, statistical trends were identified in HCs between: increased net positive CSF flow (NPF) and increased IJV-CSA at C5-C6 (left: r = 0.374, p = 0.016; right: r = 0.364, p = 0.019) and C4 (left: r = 0.361, p = 0.020); and increased net negative CSF flow and increased left IJV-CSA at C5-C6 (r = -0.348, p = 0.026) and C4 (r = -0.324, p = 0.039), whereas in MS patients a trend was only identified between increased NPF and increased left IJV-CSA at C5-C6 (r = 0.351, p = 0.021). Overall, correlations were weaker in MS patients (p = 0.015).

Conclusions

In healthy adults, increased CSF pulsatility is associated with increased IJV-CSA in the lower cervix (independent of age and cardiovascular risk factors), suggesting a biomechanical link between the two. This relationship is altered in MS patients.

Diagnosis of Transverse Sinus Hypoplasia in Magnetic Resonance Venography: New Insights Based on Magnetic Resonance Imaging in Combined Dataset of Venous Outflow Impairment Case-Control Studies: Post Hoc Case-Control Study

In previous studies of transverse sinus (TS) hypoplasia, discrepancies between TS diameter measured by magnetic resonance venography (MRV) and contrast T1-weighted magnetic resonance (contrast T1) were observed. To investigate these discrepancies, and considering that TS hypoplasia is associated with neurological disorders, we performed a post hoc analysis of prospectively collected data from 3 case-control studies on transient global amnesia (TGA), transient monocular blindness (TMB), and panic disorders while retaining the original inclusion and exclusion criteria. Magnetic resonance (MR) imaging of 131 subjects was reviewed to evaluate TS diameter and the location and degree of venous flow stenosis and obstruction.MRV without contrast revealed that TS hypoplasia was observed in 69 subjects, whom we classified into 2 subgroups according to the concordance with contrast T1 observations: concordance indicated anatomically small TS (30 subjects), and discrepancy indicated that the MRV diagnosis is in fact flow-related and that TS is not anatomically small (39 subjects). The latter subgroup was associated with at least 1 site of venous compression/stenosis in the internal jugular vein (IJV) or the left brachiocephalic vein (BCV) (P < 0.001), which was significantly larger in patients than controls. Compensatory dilatation of contralateral TS diameter was only observed with MRV, not with contrast T1 imaging.The clinical implication of these results is that using MRV only, IJV/BCV compression/stenosis may be misdiagnosed as TS hypoplasia. And contralateral TS have no compensatory dilatation in its diameter in contrast T1 imaging, just compensatory increased flow volume.

Why Current Doppler Ultrasound Methodology Is Inaccurate in Assessing Cerebral Venous Return: The Alternative of the Ultrasonic Jugular Venous Pulse

Assessment of cerebral venous return is growing interest for potential application in clinical practice. Doppler ultrasound (DUS) was used as a screening tool. However, three meta-analyses of qualitative DUS protocol demonstrate a big heterogeneity among studies. In an attempt to improve accuracy, several authors alternatively measured the flow rate, based on the product of the time average velocity with the cross-sectional area (CSA). However, also the quantification protocols lacked of the necessary accuracy. The reasons are as follows: (a) automatic measurement of the CSA assimilates the jugular to a circle, while it is elliptical; (b) the use of just a single CSA value in a pulsatile vessel is inaccurate; (c) time average velocity assessment can be applied only in laminar flow. Finally, the tutorial describes alternative ultrasound calculation of flow based on the Womersley method, which takes into account the variation of the jugular CSA overtime. In the near future, it will be possible to synchronize the electrocardiogram with the brain inflow (carotid distension wave) and with the outflow (jugular venous pulse) in order to nicely have a noninvasive ultrasound picture of the brain-heart axis. US jugular venous pulse may have potential use in neurovascular, neurocognitive, neurosensorial, and neurodegenerative disorders.

Internal Jugular Vein Cross-Sectional Area Enlargement Is Associated with Aging in Healthy Individuals

Background

Internal jugular vein (IJV) narrowing has been implicated in central nervous system pathologies, however normal physiological age- and gender-related IJV variance in healthy individuals (HIs) has not been adequately assessed.

Objectives

We assessed the relationship between IJV cross-sectional area (CSA) and aging.

Materials and Methods

This study involved 193 HIs (63 males and 130 females) who received 2-dimensional magnetic resonance venography at 3T. The minimum CSA of the IJVs at cervical levels C2/C3, C4, C5/C6, and C7/T1 was obtained using a semi-automated contouring-thresholding technique. Subjects were grouped by decade. Pearson and partial correlation (controlled for cardiovascular risk factors, including hypertension, heart disease, smoking and body mass index) and analysis of variance analyses were used, with paired t-tests comparing side differences.

Results

Mean right IJV CSA ranges were: in males, 41.6 mm² (C2/C3) to 82.0 mm² (C7/T1); in females, 38.0 mm² (C2/C3) to 62.3 mm² (C7/T1), while the equivalent left side ranges were: in males, 28.0 mm² (C2/C3) to 52.2 mm² (C7/T1); in females, 27.2 mm² (C2/C3) to 47.8 mm² (C7/T1). The CSA of the right IJVs was significantly larger (p<0.001) than the left at all cervical levels. Controlling for cardiovascular risk factors, the correlation between age and IJV CSA was more robust in males than in the females for all cervical levels.

Conclusions

In HIs age, gender, hand side and cervical location all affect IJV CSA. These findings suggest that any definition of IJV stenosis needs to account for these factors.

The Oscillating Component of the Internal Jugular Vein Flow: The Overlooked Element of Cerebral Circulation

The jugular venous pulse (JVP) provides valuable information about cardiac haemodynamics and filling pressures and is an indirect estimate of the central venous pressure (CVP). Recently it has been proven that JVP can be obtained by measuring the cross-sectional area (CSA) of the IJV on each sonogram of an ultrasound B-mode sonogram sequence. It has also been proven that during its pulsation the IJV is distended and hence that the pressure gradient drives the IJV haemodynamics. If this is true, then it will imply the following: (i) the blood velocity in the IJV is a periodic function of the time with period equal to the cardiac period and (ii) the instantaneous blood velocity is given by a time function that can be derived from a flow-dynamics theory that uses the instantaneous pressure gradient as a parameter. The aim of the present study is to confirm the hypothesis that JVP regulates the IJV blood flow and that pressure waves are transmitted from the heart toward the brain through the IJV wall.

Obstruction of Venous Drainage Linked to Transient Global Amnesia

Abnormal extracranial venous drainage modality has been considered an etiology of transient global amnesia (TGA). Evidence suggests that the transmission of the intrathoracic/intraabdominal pressure during a Valsalva maneuver (VM) is mainly through the vertebral venous system, and patency of internal jugular vein (IJV) is essential for venous drainage and pressure releasing. We hypothesize that obstruction of IJV venous drainage is a contributing factor in TGA pathogenesis. A magnetic resonance (MR) imaging protocol was used in 45 TGA patients and 45 age- and sex-matched controls to assess the morphologies of IJV, brachiocephalic vein (BCV) and asymmetry of transverse sinus (TS). The IJV was divided into the upper- and middle-IJV segments. Compared to the controls, TGA patients had significantly higher rates of moderate and severe compression/stenosis at the bilateral upper-IJV segment (left: 37.8% vs. 17.8%, P = 0.0393; right: 57.8% vs.15.6%, P<0.0012), in left BCV (60% vs. 8.9%, P<0.0004), and in TS hypoplasia (53.3%% vs. 31.1%, P = 0.0405). The prevalence of at least one site of venous compression/stenosis in IJV or BCV was significantly higher in patients than in controls (91.1% vs. 33.3%, P<0.0004). The diameter of the left TS in MRV, but not in T1 contrast imaging, was significantly smaller in TGA patients than in controls (0.31±0.21 vs. 0.41±0.19, P = 0.0290), which was compatible with downstream venous stenosis/obstruction. TGA patients have a higher prevalence of compression/stenosis of the bilateral IJV and the left BCV and TS hypoplasia, which is new evidence that supports the role of extracranial veins in TGA pathogenesis.

Jugular Venous Flow Abnormalities in Multiple Sclerosis Patients Compared to Normal Controls

BACKGROUND

To determine if extracranial venous structural and flow abnormalities exist in patients with multiple sclerosis (MS).

METHODS

Magnetic resonance imaging was used to assess the anatomy and function of major veins in the neck in 138 MS patients and 67 healthy controls (HC). Time-of-flight MR angiography (MRA) was used to assess stenosis while 2-dimensional phase-contrast flow quantification was used to assess flow at the C2/C3 and C5/C6 levels. Venous flow was normalized to the total arterial flow. The MS patients were divided into stenotic (ST) and nonstenotic (NST) groups based on MRA assessment, and each group was compared to the HC group in anatomy and flow.

RESULTS

The MS group showed lower normalized internal jugular vein (IJV) blood flow (tIJV/tA) than the HC group (P < .001). In the MS group, 72 (52%) were classified as ST while 66 (48%) were NST. In the HC group, 11 (23%) were ST while 37 (77%) were NST. The ST-MS group had lower IJV flow than both HC and NST-MS groups.

CONCLUSION

After categorizing the MS population into two groups based upon anatomical stenosis, as determined from an absolute quantification of IJV cross section, clear differences in IJV flow between the ST-MS and HC samples became evident. Despite the unknown etiology of MS, abnormal venous flow was noted in a distinct group of MS patients compared to HC.

Database integration of protocol-specific neurological imaging datasets

For many years now, Magnetic Resonance Innovations (MR Innovations), a magnetic resonance imaging (MRI) software development, technology, and research company, has been aggregating a multitude of MRI data from different scanning sites through its collaborations and research contracts. The majority of the data has adhered to neuroimaging protocols developed by our group which has helped ensure its quality and consistency. The protocols involved include the study of: traumatic brain injury, extracranial venous imaging for multiple sclerosis and Parkinson's disease, and stroke. The database has proven invaluable in helping to establish disease biomarkers, validate findings across multiple data sets, develop and refine signal processing algorithms, and establish both public and private research collaborations. Myriad Masters and PhD dissertations have been possible thanks to the availability of this database. As an example of a project that cuts across diseases, we have used the data and specialized software to develop new guidelines for detecting cerebral microbleeds. Ultimately, the database has been vital in our ability to provide tools and information for researchers and radiologists in diagnosing their patients, and we encourage collaborations and welcome sharing of similar data in this database.

Calcium micro-depositions in jugular truncular venous malformations revealed by Synchrotron-based XRF imaging

It has been recently demonstrated that the internal jugular vein may exhibit abnormalities classified as truncular venous malformations (TVMs). The investigation of possible morphological and biochemical anomalies at jugular tissue level could help to better understand the link between brain venous drainage and neurodegenerative disorders, recently found associated with jugular TVMs. To this end we performed sequential X-ray Fluorescence (XRF) analyses on jugular tissue samples from two TVM patients and two control subjects, using complementary energies at three different synchrotrons. This investigation, coupled with conventional histological analyses, revealed anomalous micro-formations in the pathological tissues and allowed the determination of their elemental composition. Rapid XRF analyses on large tissue areas at 12.74 keV showed an increased Ca presence in the pathological samples, mainly localized in tunica adventitia microvessels. Investigations at lower energy demonstrated that the high Ca level corresponded to micro-calcifications, also containing P and Mg. We suggest that advanced synchrotron XRF micro-spectroscopy is an important analytical tool in revealing biochemical changes, which cannot be accessed by conventional investigations. Further research on a larger number of samples is needed to understand the pathogenic significance of Ca micro-depositions detected on the intramural vessels of vein walls affected by TVMs.