Cerebral venous outflow resistance and interpretation of cervical plethysmography data with respect to the diagnosis of chronic cerebrospinal venous insufficiency

The investigation of the cerebral venous system in multiple sclerosis

Bateman et al. (2021) shows that multiple sclerosis (MS) is strongly associated with raised pressure in the superior sagittal sinus (SSS) and increased jugular bulb height above the sigmoid sinus. These findings are consistent with an increased aqueductal CSF pulse, as previously described in MS. They reinforce the hypothesis that intracranial compliance is reduced in MS and that internal jugular vein abnormalities contribute to SSS hypertension. However, the contribution of this to the pathophysiology of MS has not been established. Further investigation is therefore needed to determine what role, if any, these changes play in the complex puzzle of MS.

The clinical characteristic, diagnosis, treatment, and prognosis of cerebral cortical vein thrombosis: a systematic review of 325 cases

Cerebral cortical vein thrombosis (CCVT) is a rare type of cerebral venous thrombosis, which is frequently combined with cerebral venous sinus thrombosis (CVST). We aimed to compare the difference of clinical features between the isolated and the combined subtypes of CCVT. A literature search was conducted utilizing the PubMed Central and EMBASE databases to identify studies up to Dec 2019. Clinical manifestations, presumable risk factors, imaging modalities, radiological findings, treatment, and prognosis in patients with CCVT were recorded. 335 publications were identified (n = 325, 141 males and 184 females, mean age 40.24 ± 16.26 years). Headaches (46.8%), motor/sensory disorders (43.3%), and seizures (42.5%) were commonly seen. Pregnancy/postpartum (n = 29), oral contraception use (n = 15), fertility drug use (n = 4) ranked the top three comorbidities of CCVT in female patients, while for general populations, thrombophilia, invasive interventions in the cerebrospinal system, as well as malignancy, would be the common risk factors. MRV and DSA were more likely to confirm diagnosis. More than 30% of CCVT presented brain lesions, including infarction (6.5%) and hemorrhage (24.0%). Isolated CCVT was prone to develop hemorrhagic infarction while combined CCVT was more likely to have ischemic lesions. More than 90% of the patients acquired good outcomes at discharge or short-term follow-up (within one year). There is a difference between Isolated CCVT and CCVT combined CVST on the sites and types of brain lesions. MRV and DSA may contribute to the final diagnosis. Most patients acquired complete or partial recovery of clinical symptoms or imaging presentations after long-term anticoagulation (3-6 months).

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.

Mid-term sustained relief from headaches after balloon angioplasty of the internal jugular veins in patients with multiple sclerosis

OBJECTIVES

Multiple sclerosis (MS) patients frequently suffer from headaches and fatigue, and many reports have linked headaches with intracranial and/or extracranial venous obstruction. We therefore designed a study involving MS patients diagnosed with obstructive disease of internal jugular veins (IJVs), with the aim of evaluating the impact of percutaneous transluminal angioplasty (PTA) on headache and fatigue indicators.

METHODS

286 MS patients (175 relapsing remitting (RR), 75 secondary progressive (SP), and 36 primary progressive (PP)), diagnosed with obstructive disease of IJVs, underwent PTA of IJVs during the period 2011-2015. This included 113 headache positive patients (82 RR, 22 SP, and 9 PP) and 277 fatigue positive patients (167 RR, 74 SP, and 36 PP). Migraine Disability Assessment (MIDAS), and the Fatigue Severity Scale (FSS) were evaluated: before PTA; 3-months after PTA; and at final follow-up in 2017. Patients were evaluated with Doppler sonography of the IJVs at 1, 6 and 12 months after PTA and yearly thereafter. Non-parametric statistical analysis was performed using a combination of the Friedman test and Spearman correlation analysis.

RESULTS

With the exception of the PP patients there were significant reductions (all p < 0.001) in the MIDAS and FSS scores in the 3-month following PTA. The improvement in MIDAS score following PTA was maintained throughout the follow-up period in both the RR (p < 0.001; mean of 3.55 years) and SP (p = 0.002; mean of 3.52 years) MS cohorts. With FSS, significant improvement was only observed at 2017 follow-up in the RR patients (p < 0.001; mean of 3.37 years). In the headache-positive patients, post-PTA MIDAS score was significantly negatively correlated with the change in the blood flow score in the left (r = -0.238, p = 0.031) and right (r = -0.250, p = 0.023) IJVs in the RR patients and left IJV (r = -0.727, p = 0.026) in the PP patients. In the fatigue-positive cohort, post-PTA FSS score was also significantly negatively correlated with the change in blood flow in the right IJV in the PP patients (r = -0.423, p = 0.010). In addition, the pre and post-PTA FSS scores were significantly positively correlated in the fatigue-positive RR (r = 0.249, p = 0.001) and SP patients (r = 0.272, p = 0.019).

CONCLUSIONS

The intervention of PTA was associated with a large and sustained (>3 years) reduction in MIDAS score in both RR and SP MS patients. While a similar initial post-PTA reduction in FSS score was also observed, this was not maintained in the SP and PP patients, although it remained significant at follow-up (>3 years) in the RR MS patients. This suggests that venoplasty might be a useful intervention for treating patients with persistent headaches and selected concomitant obstructive disease of the IJVs.

A comparison between the pathophysiology of multiple sclerosis and normal pressure hydrocephalus: is pulse wave encephalopathy a component of MS?

BACKGROUND

It has been suggested there is a chronic neurodegenerative disorder, underlying the pathophysiology of multiple sclerosis (MS), which is distinct from the more obvious immune-mediated attack on the white matter. Limited data exists indicating there is an alteration in pulse wave propagation within the craniospinal cavity in MS, similar to the findings in normal pressure hydrocephalus (NPH). It is hypothesized MS may harbor pulse wave encephalopathy. The purpose of this study is to compare blood flow and pulse wave measurements in MS patients with a cohort of NPH patients and control subjects, to test this hypothesis.

METHODS

Twenty patients with MS underwent magnetic resonance (MR) flow quantification techniques. Mean blood flow and stroke volume were measured in the arterial inflow and venous out flow from the sagittal (SSS) and straight sinus (ST). The arteriovenous delay (AVD) was defined. The results were compared with both age-matched controls and NPH patients.

RESULTS

In MS there was a 35 % reduction in arteriovenous delay and a 5 % reduction in the percentage of the arterial inflow returning via the sagittal sinus compared to age matched controls. There was an alteration in pulse wave propagation, with a 26 % increase in arterial stroke volume but 30 % reduction in SSS and ST stroke volume. The AVD and blood flow changes were in the same direction to those of NPH patients.

CONCLUSIONS

There are blood flow and pulsation propagation changes in MS patients which are similar to those of NPH patients. The findings would be consistent with an underlying pulse wave encephalopathy component in MS.

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.

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.

Transvascular autonomic modulation: a modified balloon angioplasty technique for the treatment of autonomic dysfunction in multiple sclerosis patients

PURPOSE

To describe the use of transvascular autonomic modulation (TVAM) to improve cardiovascular autonomic nervous system (ANS) dysfunction in multiple sclerosis (MS) patients, comparing the safety and efficacy of this modified technique with traditional balloon angioplasty.

METHODS

Twenty-one MS patients (11 men; mean age 48.7±13.0 years) who presented with symptoms of cardiovascular ANS dysfunction underwent TVAM. These patients were compared with age/sex-matched MS patients (10 men; 49.3±11.1 years) in the same stages of the disease who presented with chronic cerebrospinal venous insufficiency (CCSVI) and who underwent venous balloon angioplasty. TVAM involved the coupling of balloon angioplasty of the internal jugular veins with the application of external manual compression and dilation of the azygos and renal veins; unlike traditional angioplasty for CCSVI, which treats only abnormal veins (≥50% stenosis or static valve), all targeted vessels were treated with TVAM regardless of the presence of an abnormality. The effect of TVAM on ANS function was indicated by determining heart rate variability based on the electrocardiographic R-R interval lengths using vector analysis to derive the mean circular resultant (MCR) and the expiration/inspiration (E/I) ratio, the Valsalva ratio, and the 30:15 postural ratio at 24 hours after intervention.

RESULTS

Left renal vein compression was common among the TVAM patients and resulted in ≥50% luminal compromise in 10 of 21 patients. Azygos vein abnormalities (a static valve) were identified in 5 patients. Overall, 18 patients met the diagnostic criteria for CCSVI with at least one lesion >50%, but only 10 lesions were considered treatable by traditional balloon angioplasty. After intervention, the R-R interval values, including the 30:15 postural ratio (p=0.01), the MCR (p=0.1), and E/I ratio (p=0.1), were higher for the TVAM patients compared to the control group. The safety profile of the TVAM procedure was similar to that of traditional balloon angioplasty.

CONCLUSION

The combination of balloon angioplasty of anatomically normal veins coupled with external compression during dilation of these veins can improve indicators of ANS dysfunction. The safety and efficacy of TVAM in MS patients observed in this pilot study is encouraging, paving the way for the treatment of dysautonomia in pathological states other than MS. Further studies should investigate TVAM in a larger MS cohort.

Internal jugular vein blood flow in multiple sclerosis patients and matched controls

The aim of the study was to investigate the Internal Jugular Veins dynamics using contrast enhanced ultrasonography in Multiple Sclerosis patients, clinically isolated syndrome patients and healthy controls. Contrast enhanced ultrasonography imaging of the Internal Jugular Vein was performed in fifty-eight patients with Multiple Sclerosis, seven clinically isolated syndrome patients and in thirteen healthy controls. Time-intensity curves were quantified using a semi-automated method and compared with clinical disease outcomes. Wash-out parameters were calculated and six Time-intensity curves shapes were created. Significantly reduction of wash-out rate in Internal Jugular Veins was detected in Multiple Sclerosis patients compared to healthy controls [22.2% (2.7%–65.9%) vs. 33.4% (16.2%–76.8%); P<0.005]. Internal Jugular Vein enhancement was heterogeneous in patients with Multiple Sclerosis and consisted of slow wash-out Time-intensity curves shapes, compared with almost only one type of Time-intensity curves shape in control subjects that correspond to fast enhancement and fast wash-out. The vein wash-in parameters were similar in Multiple Sclerosis group compared with controls. A significant correlation was found between Internal Jugular Vein wash-out and level of disability (R = −0.402, p<0.05). Contrast enhanced ultrasonography of the Internal Jugular Vein with time intensity curve analysis revealed alterations of cerebral venous outflow in Multiple Sclerosis patients, however mechanisms that determine this condition remains unclear.

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.

An ultrasound model to calculate the brain blood outflow through collateral vessels: a pilot study

Background

The quantification of the flow returning from the head through the cervical veins and the collaterals of the internal jugular vein (IJV), is becoming of prominent interest in clinical practice. We developed a novel model to calculate the cerebral venous return, normalized to the arterial inflow, in the different segments of the IJV.

Methods

We assessed, by established Echo Colour Doppler (ECD) methodology, the head inflow (HBinF) defined as the sum of common carotids and vertebral arteries, as well as the cerebral flow (CBF) defined as the sum of internal carotid and vertebral arteries. We also assessed the head outflow (HBoutF) defined as the sum of the measurements at the junction of the IJV and the vertebral veins. In addition, we also calculated the collateral flow index (CFI) by estimating the flow which re-enters directly into the superior vena cava as the amount of blood extrapolated by the difference between the HBinF and the HBoutF. We preliminarily tested the model by comparing ten healthy controls (HC) with ten patients affected by chronic cerebral spinal venous insufficiency (CCSVI), a condition characterized by some blockages in the IJV which are bypassed by collateral circulation.

Results

In HC the HBinF was 956+-105ml/min, whereas the HBoutF was > 90% of the HBinF, leading to a final CFI value of 1%. The last result shows that a very small amount of blood is drained by the collaterals. In upright we confirmed a reduction of the outflow through the IJV which increased CFI to 9%. When we applied the model to CCSVI, the HBinF was not significantly different from controls. In supine, the flow of CCSVI patients in the IJV junction was significantly lower (p < 0.001) while the correspondent CFI value significantly increased (61%, p < 0.0002).

Conclusions

Our preliminary application of the novel model in the clinical setting suggests the pivotal role of the collateral network in draining the blood into the superior vena cava under CCSVI condition.

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

The extra-cranial venous system is complex and not well studied in comparison to the peripheral venous system. A newly proposed vascular condition, named chronic cerebrospinal venous insufficiency (CCSVI), described initially in patients with multiple sclerosis (MS) has triggered intense interest in better understanding of the role of extra-cranial venous anomalies and developmental variants. So far, there is no established diagnostic imaging modality, non-invasive or invasive, that can serve as the "gold standard" for detection of these venous anomalies. However, consensus guidelines and standardized imaging protocols are emerging. Most likely, a multimodal imaging approach will ultimately be the most comprehensive means for screening, diagnostic and monitoring purposes. Further research is needed to determine the spectrum of extra-cranial venous pathology and to compare the imaging findings with pathological examinations. The ability to define and reliably detect noninvasively these anomalies is an essential step toward establishing their incidence and prevalence. The role for these anomalies in causing significant hemodynamic consequences for the intra-cranial venous drainage in MS patients and other neurologic disorders, and in aging, remains unproven.

Venous hemodynamics in neurological disorders: an analytical review with hydrodynamic analysis

Venous abnormalities contribute to the pathophysiology of several neurological conditions. This paper reviews the literature regarding venous abnormalities in multiple sclerosis (MS), leukoaraiosis, and normal-pressure hydrocephalus (NPH). The review is supplemented with hydrodynamic analysis to assess the effects on cerebrospinal fluid (CSF) dynamics and cerebral blood flow (CBF) of venous hypertension in general, and chronic cerebrospinal venous insufficiency (CCSVI) in particular.CCSVI-like venous anomalies seem unlikely to account for reduced CBF in patients with MS, thus other mechanisms must be at work, which increase the hydraulic resistance of the cerebral vascular bed in MS. Similarly, hydrodynamic changes appear to be responsible for reduced CBF in leukoaraiosis. The hydrodynamic properties of the periventricular veins make these vessels particularly vulnerable to ischemia and plaque formation.Venous hypertension in the dural sinuses can alter intracranial compliance. Consequently, venous hypertension may change the CSF dynamics, affecting the intracranial windkessel mechanism. MS and NPH appear to share some similar characteristics, with both conditions exhibiting increased CSF pulsatility in the aqueduct of Sylvius.CCSVI appears to be a real phenomenon associated with MS, which causes venous hypertension in the dural sinuses. However, the role of CCSVI in the pathophysiology of MS remains unclear.