The role of noninvasive and invasive diagnostic imaging techniques for detection of extra-cranial venous system anomalies and developmental variants

A novel score to estimate thrombus burden and predict intracranial hypertension in cerebral venous sinus thrombosis

BACKGROUND

Current methods to evaluate the severity of cerebral venous sinus thrombosis (CVST) lack patient-specific indexes. Herein, a novel scoring method was investigated to estimate the thrombus burden and the intracranial pressure (ICP) of CVST.

METHODS

In this retrospective study from January 2019 through December 2021, we consecutively enrolled patients with a first-time confirmed diagnosis of CVST by contrast-enhanced magnetic resonance venography (CE-MRV) or computed tomography venography (CTV). In these patients, a comprehensive CVST-Score was established using magnetic resonance black-blood thrombus imaging (MRBTI) to estimate the thrombus burden semi-quantitatively. The relationship between CVST-Score and ICP was explored to assess the potential of using the CVST-score to evaluate ICP noninvasively and dynamically.

RESULTS

A total of 87 patients were included in the final analysis. The CVST-Scores in different ICP subgroups were as follows: 4.29±2.87 in ICP<250mmH2O subgroup, 11.36±3.86 in ICP =250-330mmH2O subgroup and 14.99±3.15 in ICP>330mmH2O subgroup, respectively (p<0.001). For patients with ICP ≤330mmH2O, the CVST-Score was linearly and positively correlated with ICP (R2=0.53). The receiver operating characteristic (ROC) curves showed the optimal CVST-Score cut-off values to predict ICP ≥250mmH2O and >330mmH2O were 7.15 and 11.62, respectively (P<0.001). Multivariate analysis indicated CVST-Score as an independent predictor of ICP ≥250mmH2O (odds ratio, 2.15; 95% confidence interval, 1.49-3.10; p<0.001).

CONCLUSIONS

A simple and noninvasive CVST-Score can rapidly estimate the thrombus burden and predict the severity of intracranial hypertension in patients with CVST. The CVST-Score can aid in evaluating therapeutic responses and avoiding unnecessary invasive procedures at long-term follow-up.

The Negative Prognostic Role of Inflammatory Biomarkers in Patients With Chronic Cerebrospinal Venous Insufficiency

BACKGROUND

The pathologic consequences of inflammatory responses in chronic cerebrospinal venous insufficiency (CCSVI) remains poorly understood. Hence, this study was aimed to evaluate the peripheral inflammatory biomarkers in patients with intracranial and extracranial CCSVI pathology. In addition, the relationship between inflammatory cytokine profile and CCSVI prognosis was also evaluated.

METHODS

Patients diagnosed with CCSVI between July 2017 and July 2019 were included and subsequently divided into 3 groups based on the location of stenosis. The inflammatory biomarker assay included neutrophil-to-lymphocyte ratios (NLRs), platelet-to-lymphocyte ratios (PLRs), red blood cell distribution widths (RDW), C-reactive protein (CRP) levels, interleukin-6 (IL-6) levels, and neuron-specific enolase levels. Clinical outcomes were assessed using the modified Rankin Scale and Patient Global Impression of Change score. Univariate and multivariate regression analyses were performed to identify significant prognostic factors for poorer outcomes. Finally, we established a nomogram based on the multivariate regression analysis.

RESULTS

We enrolled 248 patients in total, including 102 males and 146 females, with an average age of 57.85±12.28 years. Compared with patients with internal jugular vein stenosis, cerebral venous sinus stenosis (CVSS) patients were mostly younger and had been suffering from headaches and severe papilledema. Higher levels of NLR, RDW, and CRP were also observed in the CVSS group. Multivariate analysis indicated that NLR, PLR, and IL-6 were the independent prognostic factors for poor CCSVI outcomes.

CONCLUSIONS

The clinical presentations and increases in NLR, PLR, IL-6, and CRP levels could be distinctly marked in patients with CVSS-related CCSVI than that in internal jugular vein stenosis-related CCSVI, indicating poor prognostic outcomes in these patients. A proinflammatory state might be associated with CCSVI pathology.

The role of trans-thoracic echocardiography in the assessment of aortic annular diameter

We aimed to compare two-dimension transthoracic echocardiogram (2D-TTE) and three-dimension transthoracic echocardiogram (3D-TTE) measurements of the aortic annular diameter using multi-detector CT (MDCT) as a gold standard.This prospective observational study included 50 consecutive patients who came to the cardiology department, Al-Azhar University Hospital, New Damietta, for MDCT coronary angiography. The study was carried out in the period from July 2016 until February 2017. All patients were subjected to informed consent, clinical history, physical examination, transthoracic echocardiography 2D and 3D, and MDCT.The aortic annular areas measured by MDCT and 3D-TTE were significantly larger than areas by 2D-TTE. A good correlation (r = 0.82) was observed between the areas obtained by 3D-TTE and MDCT; however, the correlation between the values by 2D-TTE and MDCT was rough (r = 0.30). Eccentricity Index (EI) values in 28% of the patients were greater than 0.1, that is, the aortic annulus was elliptical.Accuracy of aortic annular diameter measurement by 3D-TTE was superior to that by 2D-TTE. Three-D TTE and MDCT revealed that the shape of the aortic annulus was elliptical in 28% to 30% respectively of study subjects. There is a strong concordance between the minimum and the maximum diameter determine by 3D-TTE and MDCT.

Normobaric Oxygen May Ameliorate Cerebral Venous Outflow Disturbance-Related Neurological Symptoms

Cerebral venous outflow disturbance (CVOD) has begun to garner the attention of researches owing to a series of clinical symptoms that impose a significant impact on people's quality of life. Herein, we aimed to investigate whether normobaric oxygen (NBO) can ameliorate CVOD-induced neurological symptoms. This was one part of the prospective trial registered in ClinicalTrials.gov (NCT03373292). A total of 37 CVOD patients were divided into the NBO group (5–8 L/min of oxygen inhalation, 1 h per time, 3 times daily, n = 19) and the control group (without oxygen inhalation, n = 18) randomly. The assessments were performed at admission, 1-week hospitalization, and 6-month follow-up. Quantitative electroencephalogram (qEEG) data were recorded prior to and post 1 h of NBO in some patients. R software was used for data analysis. No NBO-related adverse events were observed during the whole NBO intervention process. The 1-week Patient Global Impression of Change (PGIC) scale showed that the symptom improvement occurred in nine patients in the NBO group (47.4%) while none in the control group (p = 0.001). NBO could improve headache evaluated with visual analog scale (pre-NBO vs. post-NBO: 4.70 ± 2.16 vs. 2.90 ± 2.03, p = 0.024) and Headache Impact Test-6 (53.40 ± 12.15 vs. 50.30 ± 13.04, p = 0.041). As for 6-month PGIC follow-up, eight out of 14 cases (57.1%) in the NBO group reported improvement, while only one out of 12 patients in the control group replied mild improvement (p = 0.014). The qEEG revealed that NBO reduced the ratio of theta to alpha power (0.65 ± 0.38 vs. 0.56 ± 0.35, p = 0.030) over the fronto-central electrodes. To sum up, NBO may be a safe and effective approach to attenuate CVOD-related symptoms (especially for headache) by brain functional improvement resulting from increasing oxygen supply to the brain tissues.

SCMR Position Paper (2020) on clinical indications for cardiovascular magnetic resonance

The Society for Cardiovascular Magnetic Resonance (SCMR) last published its comprehensive expert panel report of clinical indications for CMR in 2004. This new Consensus Panel report brings those indications up to date for 2020 and includes the very substantial increase in scanning techniques, clinical applicability and adoption of CMR worldwide. We have used a nearly identical grading system for indications as in 2004 to ensure comparability with the previous report but have added the presence of randomized controlled trials as evidence for level 1 indications. In addition to the text, tables of the consensus indication levels are included for rapid assimilation and illustrative figures of some key techniques are provided.

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.

Clinical and neuroimaging correlates among cohorts of cerebral arteriostenosis, venostenosis and arterio-venous stenosis

The purpose of this study was to discriminate the clinical and imaging correlates of cerebral arterial stenosis (CAS), venous stenosis (CVS) and arterio-venous stenosis (CAVS) in the clinical setting. Patients were classified into three groups: CAS (n = 75), CVS (n=74) and CAVS (n=67). Focal neurological deficits were the prominent presenting symptoms in CAS group, while venous turbulence related symptoms were common in both CVS and CAVS group. Risk factor analysis showed the OR (95%CI) for diabetes, male gender and age in CAS vs. CVS group were 13.67(2.71, 68.85), 6.69(2.39, 18.67) and 1.07(1.03, 1.12) respectively. Male gender, diabetes and age in CAVS vs. CAS groups were 0.27(0.11, 0.63), 0.26(0.10, 0.67) and 1.09(1.04, 1.14) respectively, while age in CAVS vs. CVS group was 1.11(1.07, 1.15). The white matter lesions (WMLs) in CAS group varied in size, with clear boundaries asymmetrically distributed in bilateral hemispheres. CVS-induced WMLs revealed a bilaterally symmetric, cloudy-like appearance. The cerebral perfusion was asymmetrically reduced in CAS but symmetrically reduced in CVS group. The clinical characteristics and neuroimaging presentations were different among patients with CAS, CVS and CAVS. We recommended for aged patients, both arterial and venous imaging should be considered in diagnosis of cerebral stenotic vascular disorders.

Percutaneous Venous Angioplasty in Patients with Multiple Sclerosis and Chronic Cerebrospinal Venous Insufficiency: A Randomized Wait List Control Study

BACKGROUND

Venous percutaneous transluminal angioplasty (vPTA) in patients with multiple sclerosis (MS) and chronic cerebrospinal venous insufficiency (CCSVI) have shown contradictory results. The aim of the study is to evaluate the efficacy of the procedure in a randomized wait list control study.

METHODS

66 adults with neurologist-confirmed diagnosis of MS and sonographic diagnosis of CCSVI were allocated into vPTA-yes group (n = 31) or vPTA-not group (n = 35, control group). vPTA was performed immediately 15 days after randomization in the PTA-yes group and 6 months later in the control group. Evoked potentials (EPs), clinical-functional measures (CFMs), and upper limb kinematic measures (ULKMs) were measured at baseline (T0) and six months after in both groups, just before the venous angioplasty in the vPTA-not group (T1).

RESULTS

Comparing the vPTA-yes and vPTA-not group, the CFM-derived composite functional outcome showed 11 (37%) versus 7 (20%) improved, 1 (3%) versus 3 (8%) stable, 0 versus 7 (20%) worsened, and 19 (61%) versus 18 (51%) mixed patients (χ² = 8.71, df = 3, P = 0.03). Unadjusted and adjusted (for baseline confounding variables) odds ratio at 95% confidence interval were, respectively, 1.93 (1.3-2.8), P value 0.0007, and 1.85 (1.2-1.7), P value 0.002. EP- and ULKM-derived composite functional outcome showed no significant difference between the two groups.

CONCLUSIONS

Venous angioplasty can positively impact a few CFMs especially for the quality of life but achieving disability improvement is unlikely.

No association between variations in extracranial venous anatomy and clinical outcomes in multiple sclerosis patients over 5 years

Background

No longitudinal, long-term, follow-up studies have explored the association between presence and severity of variations in extracranial venous anatomy, and clinical outcomes in patients with multiple sclerosis (MS).

Objective

This prospective 5-year follow-up study assessed the relationship of variations in extracranial venous anatomy, indicative of chronic cerebrospinal venous insufficiency (CCSVI) on Doppler sonography, according to the International Society for Neurovascular Disease (ISNVD) proposed consensus criteria, with clinical outcomes and disease progression in MS patients.

Methods

90 MS patients (52 relapsing-remitting, RRMS and 38 secondary-progressive, SPMS) and 38 age- and sex-matched HIs were prospectively followed for 5.5 years. Extracranial and transcranial Doppler-based venous hemodynamic assessment was conducted at baseline and follow-up to determine the extent of variations in extracranial venous anatomy. Change in Expanded Disability Status Scale (∆EDSS), development of disability progression (DP) and annualized relapse rate (ARR) were assessed.

Results

No significant differences were observed in MS patients, based on their presence of variations in extracranial venous anatomy at baseline or at the follow-up, in ∆EDSS, development of DP or ARR. While more MS patients had ISNVD CCSVI criteria fulfilled at baseline compared to HIs (58% vs. 37%, p = 0.03), no differences were found at the 5-year follow-up (61% vs. 56%, p = 0.486).

Discussion

This is the longest follow-up study assessing the longitudinal relationship between the presence of variations in extracranial venous anatomy and clinical outcomes in MS patients. Conclusion: The presence of variations in extracranial venous anatomy does not influence clinical outcomes over the 5-year follow-up in MS patients.

Electronic supplementary material

The online version of this article (10.1186/s12883-019-1350-2) contains supplementary material, which is available to authorized users.

Cervical spondylotic internal jugular venous compression syndrome

Aims

This study aimed to identify the clinical profiles of cervical spondylosis‐related internal jugular vein stenosis (IJVS) comprehensively.

Methods

A total of 46 patients, who were diagnosed as IJVS induced by cervical spondylotic compression were recruited. The clinical manifestations and imaging features of IJVS were presented particularly in this study.

Results

Vascular stenosis was present in 69 out of the 92 internal jugular veins, in which, 50.7% (35/69) of the stenotic vessels were compressed by the transverse process of C1, and 44.9% (31/69) by the transverse process of C1 combined with the styloid process. The transverse process of C1 compression was more common in unilateral IJVS (69.6% vs 41.3%, P = 0.027) while the transverse process of C1 combined with the styloid process compression had a higher propensity to occur in bilateral IJVS (52.2% vs 30.4%, P = 0.087). A representative case underwent the resection of the elongated left lateral mass of C1 and styloid process. His symptoms were ameliorated obviously at 6‐month follow‐up.

Conclusions

This study proposes cervical spondylotic internal jugular venous compression syndrome as a brand‐new cervical spondylotic subtype. A better understanding of this disease entity can be of great relevance to clinicians in making a proper diagnosis.

Assessment of Hemodynamic Alterations in Cerebral Veins in Patients With Intracerebral Hemorrhage Using Duplex Color-Coded Sonography

OBJECTIVES

To investigate the contributions of hemodynamic alterations in cerebral veins to the prognosis of patients with primary intracerebral hemorrhage (ICH).

METHODS

Duplex color-coded sonography was performed on 87 ICH patients between July 2016 and October 2017. The time-averaged peak velocity, the time-averaged mean velocity (TAMV), the blood flow volume (BFV) of bilateral internal jugular veins (IJVs) and vertebral veins (VVs), and the mean velocities of bilateral basal veins of Rosenthal, straight sinus, and bilateral transverse sinuses were calculated to understand the relationship of hemodynamic data with prognosis in patients with ICH.

RESULTS

The study revealed that the time-averaged peak velocities, TAMVs and BFVs of both right IJV and VV in ICH patients with good clinical outcomes were higher than those of the left IJV and VV, whereas statistically significant differences were not found in the mean velocity of bilateral veins of Rosenthal. The perihematomal edema volume, time-averaged peak velocities, TAMVs, and BFVs of the bilateral IJVs and right VV and the TAMV of the left VV were associated with the prognosis of ICH patients in the univariate analysis. However, the TAMV of the right IJV and BFV of the left IJV were the independent factors that predicted prognosis in multivariate analysis. Partial correlation showed that there was a linear dependence between the differences in TAMV and BFV between bilateral IJVs.

CONCLUSIONS

The presence of hemodynamic changes in cerebral veins in patients with ICH has an impact on prognosis.

Intra- and Extracranial MR Venography: Technical Notes, Clinical Application, and Imaging Development

Scientific debate over chronic cerebrospinal venous insufficiency (CCSVI) has drawn attention to venous system involvement in a series of pathologic brain conditions. In the last few decades, the MRI venography (MRV) field has developed a number of valuable sequences to better investigate structural anatomy, vessel patency, and flow characteristics of venous drainage in the intra- and extracranial systems. A brief two-tier protocol is proposed to encompass the study of intra- and extracranial venous drainage with and without contrast administration, respectively. Contrast-enhanced protocol is based on time-resolved contrast-enhanced MRV of the whole region plus extracranial flow quantification through 2D Cine phase contrast (PC); non-contrast-enhanced protocol includes intracranial 3D PC, extracranial 2D time of flight (TOF), and 2D Cine PC flow quantification. Total scanning time is reasonable for clinical applications: approximately seven minutes is allocated for the contrast protocol (most of which is due to 2D Cine PC), while the noncontrast protocol accounts for around twenty minutes. We believe that a short though exhaustive MRI scan of the whole intra- and extracranial venous drainage system can be valuable for a variety of pathologic conditions, given the possible venous implication in several neurological conditions.

Subtraction MR Venography Acquired from Time-Resolved Contrast-Enhanced MR Angiography: Comparison with Phase-Contrast MR Venography and Single-Phase Contrast-Enhanced MR Venography

OBJECTIVE

To evaluate the image characteristics of subtraction magnetic resonance venography (SMRV) from time-resolved contrast-enhanced MR angiography (TRMRA) compared with phase-contrast MR venography (PCMRV) and single-phase contrast-enhanced MR venography (CEMRV).

MATERIALS AND METHODS

Twenty-one patients who underwent brain MR venography (MRV) using standard protocols (PCMRV, CEMRV, and TRMRA) were included. SMRV was made by subtracting the arterial phase data from the venous phase data in TRMRA. Co-registration and subtraction of the two volume data was done using commercially available software. Image quality and the degree of arterial contamination of the three MRVs were compared. In the three MRVs, 19 pre-defined venous structures (14 dural sinuses and 5 cerebral veins) were evaluated. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the three MRVs were also compared.

RESULTS

Single-phase contrast-enhanced MR venography showed better image quality (median score 4 in both reviewers) than did the other two MRVs (p < 0.001), whereas SMRV (median score 3 in both reviewers) and PCMRV (median score 3 in both reviewers) had similar image quality (p ≥ 0.951). SMRV (median score 0 in both reviewers) suppressed arterial signal better than did the other MRVs (median score 1 in CEMRV, median score 2 in PCMRV, both reviewers) (p < 0.001). The dural sinus score of SMRV (median and interquartile range [IQR] 48, 43-50 for reviewer 1, 47, 43-49 for reviewer 2) was significantly higher than for PCMRV (median and IQR 31, 25-34 for reviewer 1, 30, 23-32 for reviewer 2) (p < 0.01) and did not differ from that of CEMRV (median and IQR 50, 47-52 for reviewer 1, 49, 45-51 for reviewer 2) (p = 0.146 in reviewer 1 and 0.123 in reviewer 2). The SNR and CNR of SMRV (median and IQR 104.5, 83.1-121.2 and 104.1, 74.9-120.5, respectively) were between those of CEMRV (median and IQR 150.3, 111-182.6 and 148.4, 108-178.2) and PCMRV (median and IQR 59.4, 49.2-74.9 and 53.6, 43.8-69.2).

CONCLUSION

Subtraction magnetic resonance venography is a promising MRV method, with acceptable image quality and good arterial suppression.

An anatomy-based lumped parameter model of cerebrospinal venous circulation: can an extracranial anatomical change impact intracranial hemodynamics?

BACKGROUND

The relationship between extracranial venous system abnormalities and central nervous system disorders has been recently theorized. In this paper we delve into this hypothesis by modeling the venous drainage in brain and spinal column areas and simulating the intracranial flow changes due to extracranial morphological stenoses.

METHODS

A lumped parameter model of the cerebro-spinal venous drainage was created based on anatomical knowledge and vessels diameters and lengths taken from literature. Each vein was modeled as a hydraulic resistance, calculated through Poiseuille's law. The inputs of the model were arterial flow rates of the intracranial, vertebral and lumbar districts. The effects of the obstruction of the main venous outflows were simulated. A database comprising 112 Multiple Sclerosis patients (Male/Female = 42/70; median age ± standard deviation = 43.7 ± 10.5 years) was retrospectively analyzed.

RESULTS

The flow rate of the main veins estimated with the model was similar to the measures of 21 healthy controls (Male/Female = 10/11; mean age ± standard deviation = 31 ± 11 years), obtained with a 1.5 T Magnetic Resonance scanner. The intracranial reflux topography predicted with the model in cases of internal jugular vein diameter reduction was similar to those observed in the patients with internal jugular vein obstacles.

CONCLUSIONS

The proposed model can predict physiological and pathological behaviors with good fidelity. Despite the simplifications introduced in cerebrospinal venous circulation modeling, the key anatomical feature of the lumped parameter model allowed for a detailed analysis of the consequences of extracranial venous impairments on intracranial pressure and hemodynamics.

Chronic cerebrospinal venous insufficiency: pitfalls and perils of sonographic assessment

OBJECTIVES

Duplex sonography has been proposed as a diagnostic modality for detection of chronic cerebrovascular venous insufficiency, a recently proposed hypothesis of multiple sclerosis (MS) pathogenesis. We reviewed potential challenges of duplex sonography for diagnosis of chronic cerebrovascular venous insufficiency and used interim pooled data from a study aimed to apply cerebrovascular venous insufficiency criteria to a group of patients with MS and control patients without MS.

METHODS

Duplex sonography for chronic cerebrovascular venous insufficiency was performed in patients with MS and controls. Extracranial and deep cerebral veins were studied by using a published chronic cerebrovascular venous insufficiency protocol and criteria. Comparative imaging was performed to explore how physiologic factors and imaging techniques could affect key parameters. The effects of varying definitions on fulfilling chronic cerebrovascular venous insufficiency diagnostic criteria were also explored.

RESULTS

Forty-two patients were enrolled. Twenty-five (60%) had a reduction in internal jugular vein cross-sectional area by 50% or more, cross-sectional area of 0.3 cm(2) or less, and/or a B-mode abnormality. No patients had reflux longer than 0.88 seconds in both sitting and supine positions, the presence of duplex sonographic reflux on transcranial Doppler imaging, or a larger internal jugular vein cross-sectional area in the sitting versus supine position. Fourteen patients (33.3%) had either a flap or septum, and 1 had a web. Collateral veins to the vertebral veins were identified in 14 of 42 patients (33.3%). The use of transcranial Doppler imaging versus quality Doppler profiles resulted in fewer patients meeting criteria for chronic cerebrovascular venous insufficiency.

CONCLUSIONS

There are several important variables, including physiologic, technical, and criterion definitions, in the application of sonographic assessment of chronic cerebrovascular venous insufficiency that may affect diagnostic accuracy.

Is there a link between the extracranial venous system and central nervous system pathology?

The extracranial venous system is complex and variable between individuals. Until recently, these variations were acknowledged as developmental variants and were not considered pathological findings. However, in the last decade, the presence and severity of uni- or bi-lateral jugular venous reflux (JVR) was linked to several central nervous system (CNS) disorders such as transient global amnesia, transient monocular blindness, cough headache, primary exertional headache and, most recently, to Alzheimer's disease. The most recent introduction of a composite criteria-based vascular condition named chronic cerebrospinal venous insufficiency (CCSVI), which was originally linked to multiple sclerosis, increased the interest in better understanding the role of the extracranial venous system in the pathophysiology of CNS disorders. The ultimate cause-consequence relationship between these conditions and CNS disorders has not been firmly established and further research is needed. The purpose of this article collection in BMC Medicine and BMC Neurology is to synthesize current concepts and most recent findings concerning the evaluation, etiology, pathophysiology and clinical relevance of the potential involvement of the extracranial venous system in the pathology of multiple CNS disorders and in aging.

Potential involvement of the extracranial venous system in central nervous system disorders and aging

BACKGROUND

The role of the extracranial venous system in the pathology of central nervous system (CNS) disorders and aging is largely unknown. It is acknowledged that the development of the venous system is subject to many variations and that these variations do not necessarily represent pathological findings. The idea has been changing with regards to the extracranial venous system.

DISCUSSION

A range of extracranial venous abnormalities have recently been reported, which could be classified as structural/morphological, hemodynamic/functional and those determined only by the composite criteria and use of multimodal imaging. The presence of these abnormalities usually disrupts normal blood flow and is associated with the development of prominent collateral circulation. The etiology of these abnormalities may be related to embryologic developmental arrest, aging or other comorbidities. Several CNS disorders have been linked to the presence and severity of jugular venous reflux. Another composite criteria-based vascular condition named chronic cerebrospinal venous insufficiency (CCSVI) was recently introduced. CCSVI is characterized by abnormalities of the main extracranial cerebrospinal venous outflow routes that may interfere with normal venous outflow.

SUMMARY

Additional research is needed to better define the role of the extracranial venous system in relation to CNS disorders and aging. The use of endovascular treatment for the correction of these extracranial venous abnormalities should be discouraged, until potential benefit is demonstrated in properly-designed, blinded, randomized and controlled clinical trials.