Obstruction of Venous Drainage Linked to Transient Global Amnesia

Differential Assessment of Internal Jugular Vein Stenosis in Patients Undergoing CT and MRI with Contrast

OBJECTIVE

Internal Jugular Vein Stenosis (IJVS) is hypothesized to play a role in the pathogenesis of diverse neurological diseases. We sought to evaluate differences in IJVS assessment between CT and MRI in a retrospective patient cohort.

METHODS

We included consecutive patients who had both MRI of the brain and CT of the head and neck with contrast from 1 June 2021 to 30 June 2022 within the same admission. The degree of IJVS was categorized into five grades (0-IV).

RESULTS

A total of 35 patients with a total of 70 internal jugular (IJ) veins were included in our analysis. There was fair intermodality agreement in stenosis grades (κ = 0.220, 95% C.I. = [0.029, 0.410]), though categorical stenosis grades were significantly discordant between imaging modalities, with higher grades more frequent in MRI (χ2 = 27.378, p = 0.002). On CT-based imaging, Grade III or IV stenoses were noted in 17/70 (24.2%) IJs, whereas on MRI-based imaging, Grade III or IV stenoses were found in 40/70 (57.1%) IJs. Among veins with Grade I-IV IJVS, MRI stenosis estimates were significantly higher than CT stenosis estimates (77.0%, 95% C.I. [35.9-55.2%] vs. 45.6%, 95% C.I. [35.9-55.2%], p < 0.001).

CONCLUSION

MRI with contrast overestimates the degree of IJVS compared to CT with contrast. Consideration of this discrepancy should be considered in diagnosis and treatment planning in patients with potential IJVS-related symptoms.

A Perplexing case of isolated abducens nerve palsy in a primigravida woman: A case report

Isolated abducens nerve palsy is a rare presentation in women during pregnancy. When an abducens nerve palsy is elicited in a pregnant woman, work-up should start with labs and neuroimaging to rule out mechanical and organic causes such as tumors, preeclampsia, and multiple sclerosis. This case report highlights a 35-year-old woman, gravida 1, para 0, who was sent to the local medical center by her ophthalmologist at 37 weeks of gestation due to a left-sided headache and blurry vision. Upon admission, work-up was negative for preeclampsia. Tick-borne disease panel and lumbar puncture were unrevealing. No other mechanical or lab abnormalities were elicited. Magnetic resonance venography revealed a diminutive left transverse sinus, left sigmoid sinus, and left internal jugular vein in comparison with the right, indicating a possible congenital variant. Labor was induced to see if this would alleviate the patient's abducens nerve palsy. After induction of labor and initiation of dexamethasone, the patient's sixth cranial nerve palsy began to improve.

Stylohyoid Eagle syndrome and EXTracranial INternal Carotid arTery pseudoaneurysms (EXTINCT) with internal jugular vein nutcracker syndrome: a challenging clinical scenario

We report a 4-year delay in diagnosing a combined carotid arterial and jugular venous styloid compression. The symptoms, which included dull neck pain, dizziness, intermittent diplopia, tinnitus, severe incapacitating right side headache and eye bloating, were challenging and wrongly attributed initially to various facial neuralgias. The patient presented during COVID-19 pandemic and was labelled as ‘carotidynia’ first and later as a transient perivascular inflammation of carotid artery syndrome. Combined targeted duplex ultrasonography and CT angiography with 3D reconstruction revealed a long styloid process and its tendinous-ligamentous attachments, injuring the internal carotid artery. Moreover, there was substantial internal jugular vein compression on a long C1 transverse process with a nutcracker syndrome. Release of the tendinous portion of the long styloid process and repair of the carotid artery pseudoaneurysm ended the patient’s complaints and allowed him to have a better quality of life.

Resolved Cerebral Venous Hypertension after Angioplasty of Central Venous Stenosis in a Hemodialysis Patient: A Case Report

Stenosis of the central veins is a common complication in hemodialysis patients. However, cerebral venous hypertension and neurological symptoms caused by central vein stenosis are relatively rare. We present a rare case of cerebral venous hypertension in a 63-year-old male who showed venous reflux into the dural sinuses due to central venous stenosis on time-of-flight MR angiography. After management for central venous stenosis, the venous reflux disappeared.

Conventional cardiovascular risk factors in Transient Global Amnesia: Systematic review and proposition of a novel hypothesis

Transient Global Amnesia (TGA) is an enigmatic amnestic syndrome. We conducted a systematic review to investigate the relationship between the conventional cardiovascular risk factors and TGA. MEDLINE, CENTRAL, EMBASE and PsycINFO were comprehensively searched and 23 controlled observational studies were retrieved. The prevalence of hypertension, diabetes mellitus, dyslipidemia and smoking was lower among patients with TGA compared to Transient Ischemic Attack. Regarding the comparison of TGA with healthy individuals, there was strong evidence suggesting a protective effect of diabetes mellitus on TGA and weaker evidence for a protective effect of smoking. Hypertension was associated with TGA only in more severe stages, while dyslipidemia was not related. In view of these findings, a novel pathophysiological hypothesis is proposed, in which the functional interactions of Angiotensin-II type-1 and N-methyl-D-aspartate receptors are of pivotal importance. The whole body of clinical evidence (nature of precipitating events, associations with migraine, gender-based association patterns) was integrated.

Styloidogenic jugular venous compression syndrome: a case report and review of the literature

BACKGROUND

Styloidogenic jugular venous compression syndrome (SJVCS) has been shown to present with a similar symptomatology to idiopathic intracranial hypertension (IIH) and is caused by compression of the internal jugular vein (IJV) between the lateral tubercle of C1 and the styloid process. Treatments including venous stenting and styloidectomy have been reported with good outcomes; however, treatment of a pediatric patient with SJVCS with styloidectomy has not previously been reported in the literature.

CASE REPORT

A 12-year-old male presented with refractory positional headaches, nausea, and vomiting, and after, workup including lumbar puncture (LP) and intracranial pressure (ICP) monitoring was found to have intracranial hypertension associated with contralateral neck turning. Computed tomography venogram (CTV) revealed severe bilateral compression of the IJV's between the styloid processes and C1 tubercle. The patient was successfully treated with unilateral right-sided styloidectomy with symptomatic relief.

CONCLUSIONS

This is the first reported pediatric case of SJVCS treated successfully with styloidectomy to our knowledge and adds to the limited literature that styloidectomy is a durable treatment option for SJVCS.

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.

Internal jugular vein stenosis induced by tortuous internal carotid artery compression: two case reports and literature review

Although internal jugular vein stenosis (IJVS) is not uncommon, a lack of clinical attention will lead to misdiagnosis and missed diagnosis. This study describes two 61-year-old women with bilateral IJVS induced by tortuous internal carotid artery compression and reviews current reports on this condition, including its clinical characteristics and treatment strategies, to provide a reference for clinicians.

Internal jugular vein stenosis associated with elongated styloid process: five case reports and literature review

Background

Internal jugular vein stenosis (IJVS), characterized by a series of clinical manifestations, such as head and neck symptoms, visual and ear symptoms, as well as sleep disorder, has been receiving attention in recent years. However, its’ etiologies are not fully understood.

Case presentation

We report a cases series of IJVS induced by styloid oppression. We define it as the stylo-jugular type of Eagle syndrome (ES).

Conclusions

Our study reveals that external oppression, especially by styloid process, is an important etiology of IJVS. The stylo-jugular ES diagnosis can be identified by Computed tomography venography. Whether stylo-jugular ES can be corrected by styloidectomy requires further investigation.

Transient Global Amnesia Linked to Impairment of Brain Venous Drainage: An Ultrasound Investigation

Background: Previous neuroimaging and ultrasound studies suggested that compression and stenosis of the internal jugular vein (IJV) in patients with transient global amnesia (TGA) may impair IJV drainage, while a patent IJV releases intracranial pressure caused by the Valsalva maneuver (VM).

Methods: Seventy-nine TGA patients with complete ultrasound examination data during admission were recruited prospectively to evaluate IJV drainage, which included the time-averaged mean velocity, and the cross-sectional lumen area of the IJV at the vein's middle (J2) and distal (J3) segments and the cross-sectional area during a 10-s VM to test for any retrograde or anti-grade flow. Forty-five TGA patients and 45 age- and sex-matched control subjects underwent complete contrast-enhanced magnetic resonance (MR) venous studies, which included time-resolved imaging of contrast kinetics, contrast-enhanced axial T1-weighted MR imaging, and phase-contrast-based non-contrast enhanced magnetic resonance venography (MRV).

Results: In those subjects with complete MRV studies, the flow volumes exhibited at both the J2 and J3 segments of the left IJV and left vertebral vein (VV) were significantly lower in the TGA patients than in the control subjects. Although there was no significant difference in the flow volume of right IJV, the total of bilateral IJV, and VV flow volumes was still significantly lower in the TGA patients. As compared with the control subjects, the TGA patients exhibited significantly higher prevalence of completely blocked right IJV drainage at the J3 segment during the VM, but non-significantly higher for the left IJV at the J3 segment and for the right IJV at the J2 segment.

Conclusion: Our results confirmed that the total venous flow decreases in the IJVs and VVs of the patients with TGA. This is consistent with the findings of previous MR imaging studies that have reported about compression and stenosis of the draining veins. We also found that IJV drainage is relatively compromised during the VM in the patients with TGA.

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.

Cardiac, Respiratory and Postural Influences on Venous Return of Internal Jugular and Vertebral Veins

It is known from physiology that heartbeat and respiration influence venous return, but little is known regarding the extent to which these two factors affect flow. In this study, we estimated the prevalence of cardiac- and breathing-induced venous flow modulations in the internal jugular vein (IJV) and vertebral vein (VV) and the effects of posture. In 19 healthy patients, neck vein flow was examined with pulsed wave Doppler. Electrocardiogram and respiratory signals were simultaneously acquired. In supine position, heart contraction always influenced venous flow, whereas breathing influenced 68% of IJV and 34% of VV flow. In sitting position, heart contraction influenced 74% of IJV and 42% of VV flow; breathing influenced 68% of IJV and 61% of VV measures. Thus, cardiac influence is greatly present in supine position, whereas breathing influence prevails in the VV while sitting. This setup allowed us to observe that in some patients, expiration may cause an unexpected increase in venous flow.

Simultaneous transient global amnesia and right MCA stroke after Valsalva manoeuvre

A 61-year-old man suffered an episode of transient confusion and anterograde amnesia after a Valsalva-related manoeuvre. The MRI diffusion weighted imaging (DWI) sequences showed a left hippocampal and two right parietal lesions that were deemed as acute. The MR angiography disclosed a high-grade stenosis in the right middle cerebral artery as was described by a transcranial colour-coded ultrasound as well. Ultrasound investigation of the jugular veins showed a right jugular venous reflux after a Valsalva manoeuvre. The patient was diagnosed with transient global amnesia based on clinical grounds and the right parietal lesions were considered as silent strokes. The Valsalva manoeuvre could have played as a common trigger for both diseases.

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.

Longitudinal Cerebral Perfusion Change in Transient Global Amnesia Related to Left Posterior Medial Network Disruption

BACKGROUND

The pathophysiology of transient global amnesia (TGA) is not fully understood. Previous studies using single photon emission computed tomography (SPECT) have reported inconclusive results regarding cerebral perfusion. This study was conducted to identify the patterns of regional cerebral blood flow (rCBF) in TGA patients via longitudinal SPECT analysis. An association between the observed SPECT patterns and a pathophysiological mechanism was considered.

METHODS

Based on the TGA registry database of Seoul National University Bundang Hospital, 22 TGA patients were retrospectively identified. The subjects underwent initial Tc-99m-ethyl cysteinate dimer (ECD) SPECT within 4 days of an amnestic event and underwent follow-up scans approximately 6 months later. The difference in ECD uptake between the two scans was measured via voxel-based whole brain analysis, and the quantified ECD uptake was tested using a paired t-test.

RESULTS

The TGA patients had significantly decreased cerebral perfusion at the left precuneus (P<0.001, uncorrected) and at the left superior parietal and inferior temporal gyrus according to the voxel-based whole brain analysis (P<0.005, uncorrected). A difference in the quantified ECD uptake between the 2 scans was also found at the left precuneus among the 62 cortical volumes of interest (P = 0.018, Cohen's d = -0.25).

CONCLUSION

We identified left hemispheric lateralized hypoperfusion that may be related to posterior medial network disruption. These findings may be a contributing factor to the pathophysiology of TGA.