New England Medical Center Posterior Circulation Stroke Registry II. Vascular Lesions

Safety and efficacy of enterprise stenting for symptomatic atherosclerotic severe posterior circulation stenosis

PURPOSE

To investigate the safety and efficacy of Enterprise stent angioplasty and risk factors for the prognoses in treating symptomatic severe posterior circulation atherosclerotic stenosis (SSPCAS).

MATERIALS AND METHODS

Patients with SSPCAS who were treated with the Enterprise stent angioplasty were retrospectively enrolled. The clinical data, peri-procedural complications, postoperative residual stenosis, in-stent restenosis and recurrent stroke at follow-up were analyzed.

RESULTS

262 patients with 275 stenotic lesions treated with the Enterprise stent angioplasty were enrolled. The stenosis degree was reduced from 86.3 ± 6.2% before to 19.3 ± 5.4% after stenting. Complications occurred in 14 (5.3%) patients. Clinical follow-up was performed in 245 (93.51%) patients for 16.5 ± 7.3 months. During 1 year follow-up, 7 patients (2.9%) had recurrent symptoms, including 4 patients with stenting in the intracranial vertebral artery and 3 in the basilar artery. Imaging follow-up was conducted in 223 (85.11%) patients. In-stent restenosis was present in 35 patients (15.7%), with the restenosis rate of 26.4% (n = 23) in the intracranial vertebral artery, which was significantly (P < 0.001) greater than in the basilar artery (8.8%). Six patients (17.1%) with in-stent restenosis were symptomatic. The stenotic length was the only significant (P = 0.026 and 0.024, respectively) independent risk factor for 1 year stroke or death events and in-stent restenosis.

CONCLUSION

The Enterprise stent can be safely and efficaciously applied in the treatment of symptomatic severe posterior circulation atherosclerotic stenosis, with a relatively low rate of in-stent restenosis and recurrent stroke within 1 year. The stenotic length was the only significant independent risk factor for 1 year stroke or death events and in-stent restenosis.

Acute stroke in familial Mediterranean fever: An analysis of 23 new cases and systematic review of the literature

OBJECTIVE

The nature of neurovascular involvement in cases of familial Mediterranean fever (FMF) has not been adequately clarified.

METHODS AND PATIENTS

Clinical features, infarct topography, vascular status, and stroke etiology were prospectively determined in 35 acute neurovascular events that occurred in 23 FMF patients. Clinicoradiological features were compared with an age- and gender-matched control group of 115 acute stroke patients. Characteristics of additional FMF and acute stroke cases (6 episodes in 6 patients) identified from a systematic literature review (PROSPERO registration no: CRD420212264820) were also analyzed.

RESULTS

There were 27 acute ischemic stroke episodes in 19 patients, 7 transient ischemic attack episodes in 3 patients, and 1 patient with a single episode of parietal hematoma in our cohort. Twenty (74%) ischemic stroke episodes in 12 patients were cryptogenic. Ten of these 12 cases had a previous FMF diagnosis and were taking colchicine. There was no significant difference in the FMF group in terms of the presence of vascular risk factors and angiography-documented disease in comparison to controls. Cerebral distal artery involvement was significantly prevalent in FMF (78% vs 45%, P = .002). Especially, midbrain central deep perforating territory involvement was higher (30% vs 1%, P < .001). The long-term prognosis (median 8.5 years) under antiplatelet agents and colchicine is favorable.

DISCUSSION

The acute stroke phenotype in FMF cases is herein described for the first time. Several clinicoradiological features such as thrombotic lacunar infarcts located in the central mesencephalon seem so typical that we recommend searching for FMF mutations in geographic regions where FMF is common.

Posterior fossa ischemic infarction: single-center retrospective review of non-surgical and surgical cases

Cerebellar ischemic stroke (CIS) is a morbid neurological event, with potentially fatal consequences. There is currently no objective standard of care regarding when surgical procedures are required for this entity. We retrospectively reviewed 763 patients with CIS, 247 patients of which had a stroke larger than 1 cm in greatest dimension on cranial imaging. In this subgroup, 11% of patients received ventriculostomy, 12% suboccipital craniectomy, and 9% mechanical endovascular thrombectomy. Various clinical and radiographic variables were examined for relationship to surgical procedures, 30-day mortality rate, and modified Rankin scores. The smallest volume of stroke requiring a surgical procedure was 15.5 mL3 (BrainLab Software). Patients receiving surgical procedures had a higher incidence of multi-territory infarctions, hydrocephalus, cistern compression, 4th ventricular compression, as well as younger age, lower admission GCS, higher admission NIHSS, and higher 30-day mortality/disability. Patients deemed to require surgical procedures for CIS have a higher expected morbidity and mortality than those not requiring surgery. Various clinical and radiographic variables, including stroke volume, can be used to guide selection of patients requiring surgery.

Acute Distal Vertebral Artery Occlusion in Patients with Asymmetrical Vertebral Artery Geometry: Role of Black-Blood-Enhanced MR Imaging

Background: The purpose of this study was to evaluate the diagnostic value of contrast enhancement in a unilateral distal vertebral artery (VA) using black blood (BB)-enhanced magnetic resonance (MR) imaging in patients with acute neurological symptoms and asymmetrical VA geometry. Methods: From January 2020 to August 2021, we retrospectively analyzed BB-contrast-enhanced MR imaging and MR angiography (MRA) findings in stroke patients visiting the emergency room for an evaluation of acute neurological symptoms. We classified four patterns according to asymmetrical VA geometry using MRA and contrast enhancement using BB-enhanced MR imaging: type 1 = enhanced VA + no visualization of VA, type 2 = enhanced VA + hypoplastic VA, type 3 = non-enhanced VA + hypoplastic VA, or type 4 = non-enhanced VA + no visualization of VA. Results: In total, 288 patients (type 1 = 65, type 2 = 17, type 3 = 130, type 4 = 76) were enrolled in this study. Of these patients, 82 (28.5%) showed contrast enhancement of a unilateral distal VA on BB-enhanced MR imaging, and 51 (17.8%) had positive findings on diffusion-weighted imaging (DWI) in the ipsilateral medulla, pons, or posterior inferior cerebellar artery (PICA) territory. The contrast enhancement of a unilateral distal VA using BB-enhanced MR imaging demonstrated a significantly higher prevalence in patients with acute infarction on DWI (50.0% vs. 4.9%, p < 0.001). Conclusions: The contrast enhancement of a unilateral distal VA on BB-enhanced MR imaging is associated with acute infarction of the medulla, pons, or PICA territory and suggests acute occlusion of a distal VA.

Posterior circulation stroke due to intracranial artery disease in the Chinese population

BACKGROUND

Little is known about the distribution of the intracranial arteries that are responsible for noncardiogenic posterior circulation stroke (PCS) in the Chinese population. Furthermore, few studies have compared the imaging manifestations and outcomes across PCS due to the disease of different intracranial arteries. Therefore, our aim was to demonstrate the distribution of the intracranial arteries that were responsible for noncardiogenic PCS and to compare the imaging manifestations and outcome across PCS due to the disease of different intracranial arteries.

METHODS

We prospectively enrolled 690 patients from 22 Chinese centers with noncardiogenic PCS due to intracranial artery disease. Intracranial artery disease was classified as intracranial vertebral artery disease (IVAD) and intracranial nonvertebral artery disease (INVAD). Clinical-radiologic patterns and outcomes were compared between IVAD and INVAD.

RESULTS

INVAD was more frequent than IVAD. Compared to the INVAD group, the IVAD group more frequently had hypertension, coronary heart disease, multiple infarcts, border zone infarcts, territorial infarcts, small cortical infarcts, multilevel infarcts, multisector infarcts, and more often had severe stenosis of the responsible artery, more often presented with decreased alertness, gaze palsy, bilateral limb weakness, ataxia, dysphagia, diplopia, vertigo, and headache. In addition, the IVAD group had a higher National Institutes of Health stroke scale score and modified Rankin Scale score at discharge and more deaths and recurrent ischemic cerebrovascular disease within 1 year of onset. Multivariable Cox regression identified IVAD as an independent predictor of recurrent ischemic cerebrovascular disease.

CONCLUSIONS

PCS due to INVAD was more common in the Chinese population. However, PCS due to IVAD had more serious clinical-radiologic patterns and worse outcomes.

Diffusion-weighted imaging as predictor of acute ischemic stroke etiology

BACKGROUND

Topographic patterns may correlate with causes of ischemic stroke.

OBJECTIVE

To investigate the association between diffusion-weighted imaging (DWI) and Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification.

METHODS

We included 1019 ischemic stroke patients. DWI were classified as: i) negative; ii) DWI single lesion (cortico-subcortical, cortical, subcortical ≥20 mm, or subcortical <20 mm); iii) scattered lesions in one territory (small scattered lesions or confluent with additional lesions); and iv) multiple lesions (multiple unilateral anterior circulation [MAC], multiple posterior circulation [MPC], multiple bilateral anterior circulation [MBAC], and multiple anterior and posterior circulations [MAP]).

RESULTS

There was a relationship between DWI patterns and TOAST classification (p<0.001). Large artery atherosclerosis was associated with small, scattered lesions in one vascular territory (Odds Ratio [OR] 4.22, 95% confidence interval [95%CI] 2.61-6.8), MPC (OR 3.52; 95%CI 1.54-8.03), and subcortical lesions <20 mm (OR 3.47; 95%CI 1.76-6.85). Cardioembolic strokes correlated with MAP (OR 4.3; 95%CI 1.64-11.2), cortico-subcortical lesions (OR 3.24; 95%CI 1.9-5.5) and negative DWI (OR 2.46; 95%CI 1.1-5.49). Cryptogenic strokes correlated with negative DWI (OR 4.1; 95%CI 1,84-8.69), cortical strokes (OR 3.3; 95%CI 1.25-8.8), MAP (OR 3.33; 95%CI 1.25-8.81) and subcortical lesion ≥20 mm (OR 2.44; 95%CI 1,04-5.73). Lacunar strokes correlated with subcortical lesions diameter <20 mm (OR 42.9; 95%CI 22.7-81.1) and negative DWI (OR 8.87; 95%CI 4.03-19.5). Finally, MBAC (OR 9.25; 95%CI 1.12-76.2), MAP (OR 5.54; 95%CI 1.94-15.1), and MPC (OR 3.61; 95%CI 1.5-8.7) correlated with stroke of other etiologies.

CONCLUSIONS

A relationship exists between DWI and stroke subtype.

Iron Deposition in Gray Matter Nuclei of Patients With Intracranial Artery Stenosis: A Quantitative Susceptibility Mapping Study

Purpose: This study aimed to use quantitative susceptibility mapping (QSM) to systematically investigate the changes of iron content in gray matter (GM) nuclei in patients with long-term anterior circulation artery stenosis (ACAS) and posterior circulation artery stenosis (PCAS).

Methods: Twenty-five ACAS patients, 25 PCAS patients, and 25 age- and sex-matched healthy controls underwent QSM examination. Patients were scored using the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) to assess the degree of neural function deficiency. On QSM images, iron related susceptibility of GM nuclei, including bilateral caudate nucleus, putamen (PU), globus pallidus (GP), thalamus (TH), substantia nigra (SN), red nucleus, and dentate nucleus (DN), were assessed. Susceptibility was compared between bilateral GM nuclei in healthy controls, ACAS patients, and PCAS patients. Partial correlation analysis, with age as a covariate, was separately performed to assess the relationships of susceptibility with NIHSS and mRS scores.

Results: There were no significant differences between the susceptibilities for left and right hemispheres in all seven GM nucleus subregions for healthy controls, ACAS patients, and PCAS patients. Compared with healthy controls, mean susceptibility of bilateral PU, GP, and SN in ACAS patients and of bilateral PU, GP, SN, and DN in PCAS patients were significantly increased (all P < 0.05). In addition, mean susceptibility of bilateral TH and SN in PCAS patients was significantly higher than in ACAS patients (both P < 0.05). With partial correlation analysis, mean susceptibility at bilateral PU of ACAS patients was significantly correlated with mRS score (r = 0.415, P < 0.05), and at bilateral PU in PCAS patients was correlated with NIHSS score (r = 0.424, P < 0.05).

Conclusion: Our findings indicated that abnormal iron metabolism may present in different subregions of GM nuclei after long-term ACAS and PCAS. In addition, iron content of PU in patients with ACAS and PCAS was correlated with neurological deficit scores. Therefore, iron quantification measured by QSM susceptibility may provide a new insight to understand the pathological mechanism of ischemic stroke caused by ACAS and PCAS.

Prevalence and characteristics of atherosclerotic plaque: Left compared with right arteries and anterior compared with posterior circulation stroke

PURPOSE

To evaluate atherosclerotic plaque prevalence and characteristics between left and right cervicocephalic arteries and between anterior and posterior circulation stroke (ACS and PCS).

METHODS

This retrospective study included 284 patients with acute ischemic stroke (199 ACS and 85 PCS) involving large-artery atherosclerosis or small-artery occlusion. We assessed atherosclerotic plaque prevalence and characteristics (plaque type, plaque surface morphology, plaque distribution, location of calcified nodules and plaque thickness) in each segment and their comparisons between left and right arteries and between ACS and PCS.

RESULTS

The left subclavian artery (L-SA), common carotid artery (L-CCA) and intracranial vertebral artery (L-IVA) had significantly higher prevalence of atherosclerotic plaque than the right (R) corresponding arteries (70.1% versus 59.5%, P = 0.008), (48.1% versus 28.9%, P < 0.001), (23.9% versus 16%, P = 0.018), respectively. L-SA had a higher prevalence of mixed plaque (non-calcified > calcified) (19.6% versus 16.4%) and noncalcified plaque (51.9% versus 31.7%), and a lower prevalence of calcified plaque (8.9% versus 23.3%) and mixed plaque (calcified > non-calcified) (19.6% versus 28.6%) than R-SA, P < 0.001. The distribution of plaque type in the SA and extracranial vertebral artery (EVA) were significantly different between ACS and PCS. The soft plaque thickness of SA in PCS was significantly greater than that in ACS (3.85 ± 1.27 versus 3.51 ± 1.04, P = 0.032).

CONCLUSIONS

Atherosclerotic plaque prevalence and characteristics vary in different segments, sides and between ACS and PCS. These differences should be noted during plaque diagnosis.

Transradial approach using a distal access catheter without guiding support for symptomatic intracranial vertebral artery and basilar artery stenosis: a multicenter experience and technical procedure

BACKGROUND

There is little consensus on endovascular treatment for symptomatic intracranial posterior circulation stenosis via the transradial approach (TRA). We report our multicenter experience and technical procedures that directly used a distal access catheter (DAC) via TRA for the treatment of symptomatic intracranial vertebral (VA) and basilar (BA) artery stenosis.

METHODS

From January 2019 to December 2020, 92 consecutive patients with severe symptomatic intracranial VA or BA stenosis were retrospectively collected and divided into two groups (TRA group and transfemoral approach (TFA) group) for neurointerventional treatment. The percentages of catheters reaching the V3/V4 segment of the VA and technical success, postoperative care conditions, preoperative outcomes and complications, long term clinical outcomes, and imaging follow-ups were observed.

RESULTS

The catheter, CAT 5, reached the V4 segment of the VA in 37 TRA patients (88.1%). The duration of the procedure was significantly shorter in the TRA group than in the TFA group (median 48.0 min vs 55.5 min, p=0.037). More patients in the TRA group could walk within 2 hours after the procedure (85.7% vs 10.0%, p=0.000), and the duration of retaining catheterization in the TRA group was shorter (3.0±1.2 hours vs 11.7±5.6 hours, p=0.000).

CONCLUSION

This study demonstrates the potential feasibility and safety of using a DAC via the TRA without guiding support for the treatment of symptomatic intracranial VA and BA stenosis. The TRA demonstrated some advantages over the standard TFA in terms of patient comfort. Further randomized controlled trials comparing the TRA and TFA for posterior circulation stenosis are needed.

Intracranial arteries of New Zealand rabbits; identification, three-dimensional modelling, and morphometry by computed tomography angiography

The aim of the study was to determine identification, three-dimensional modelling, and morphometry of intracranial arteries in New Zealand Rabbit by using computed tomography angiography. A total of 20 adult New Zealand Rabbits from both sexes were used in the study. General anaesthesia procedure was followed before computed tomography angiography imaging. Rabbits were placed in a prone position for imaging. Computed tomography angiography imaging was performed by injecting contrast agent into vena auricularis marginalis of rabbits. Morphometric measurements of the specified points were taken by MIMICS program using the computed tomography angiography images acquired. Three-dimensional intracranial artery model was prepared from the two-dimensional images on the same program. Measurements were statistically compared in terms of sex and side. It was observed in the study that arteria basilaris was generated by bilateral arteria vertebralis at the basal level of medulla oblongata. In the study, a statistically significant difference was determined only in diameter values of arteria cerebri caudalis dextra et sinistra in both female and male rabbits. On the other hand, no statistically significant difference was determined with respect to the side. Consequently, we think that the data of the present study will contribute to further studies on cerebrovascular pathology, clinicians or researchers.

Bilateral Vertebral Artery Hypoplasia and Fetal-Type Variants of the Posterior Cerebral Artery in Acute Ischemic Stroke

Aim: Unilateral vertebral artery hypoplasia is considered a risk factor for posterior circulation infarction. Despite the increasing attention on unilateral vertebral artery hypoplasia, few studies have discussed bilateral vertebral artery hypoplasia, its influence on stroke, or its collateral supply from the circle of Willis. We aimed to identify its characteristics, stroke pattern, and unique ultrasonographic and brain imaging findings.

Materials and Methods: Of the 1,301 consecutive in-patients diagnosed with acute ischemic stroke from January 2013 to December 2015, medical and laboratory data and stroke or transient ischemic attack history were recorded. We enrolled patients who underwent both brain magnetic resonance imaging and sonography examinations. Vertebral artery and posterior cerebral artery analyses were conducted in accordance with clinical criteria.

Results: Adequate imaging data were available for 467 patients. Of these, eight patients met the criteria for bilateral vertebral artery hypoplasia. The mean age was 62.9 ± 12.1 years. There were six male (75.0%) and two female patients (25.0%). A high prevalence of hypertension (7/8, 87.5%) was noted.

Sonograms displayed a very low net flow volume in the vertebral arteries, with the average net flow volume being 28.9 ± 9.7 mL/min. A high frequency (6/8; 75.0%) of the fetal variant posterior cerebral artery from the carotids was found. The infarction patterns in these patients were all bilateral, scattered, and in multiple vascular territories.

Conclusion: Patients with bilateral vertebral hypoplasia displayed a unique collateral supply, special stroke pattern, and younger stroke onset. Early recognition and stroke prevention should be considered critical in clinical practice.

Endovascular revascularization of chronically occluded vertebral artery: single-center experience

Introduction

Chronic vertebral basilar artery occlusion is one of the most common causes of ischemic stroke, which accounts for roughly 20% of all cases. However, the evidence for the precise clinical effect in treatment of the initial segment of chronic vertebral basilar artery occlusion is not sufficient.

Aim

To evaluate the feasibility and efficacy of endovascular therapy in the initial segment of chronic vertebral basilar artery occlusion.

Material and methods

This is a retrospective study based on data obtained from Lishui Hospital of Zhejiang University. We identified patients who underwent treatment for initial segment occlusion of the vertebral basilar artery from September 2014 to September 2018.

Results

Among a total of twenty-two subjects, 77.27% of them were men and the median age was 61 years old. The primary medical history of these patients included hypertension (15, 68.18%), hyperlipidemia (13, 59.09%), diabetes mellitus (11, 50.00%), and coronary artery disease (6, 27.27%). About 54.54% of the patients were current smokers. Successful recanalization was achieved in 86.36% of patients. Five cases of balloon dilatation were recanalized and fourteen cases were treated by balloon dilation combined with stent implantation. During the follow-up period, there were no recurrent cerebral ischemic events, including transient ischemic attack or stroke. Six (27.27%) arteries were found to exhibit angiographic re-stenosis.

Conclusions

The clinical effect of balloon dilatation or balloon dilatation combined with stenting in the treatment of chronic vertebral basilar artery occlusion in the beginning segment was feasible and safe.

Brachiocephalic atherosclerosis in patients with posterior circulation ischemic stroke

Aim. To study echographic and acoustic characteristics of atherosclerotic plaques (ASP) in brachiocephalic arteries (BCA) in patients with acute posterior circulation ischemic stroke (PCIS).

Material and methods. In this study we included data of duplex ultrasound from 235 patients (men, 129; women, 106; age, 59±12 and 63±10 years, respectively) with PCIS. Pathogenesis of PCIS was established only in 23 cases: in 17 (74%) — atherothrombosis, in 3 (13%) — cardioembolism, in 3 (13%) — lacunar stroke. Atrial fibrillation was established in 18,5% of patients. A total of 903 asymptomatic individuals were included in the control group, comparable with studied patients by sex and age.

Results. The prevalence of ASP in vertebral arteries (VA) was equal in both groups. Also, no significant differences in the degree of VA stenosis were observed. Atherosclerotic lesions of common (CCA) and internal carotid arteries (ICA) on both sides were more often observed in control group, but the degree of their stenosis was higher in PSIS group (р<0,003). In ischemic stroke, stenosis of the right ICA was 47±17%, left ICA — 46±18%, while in asymptomatic individuals, right ICA stenosis was 40±14%, left ICA — 39±15%. In patients with PCIS, ASPs were significantly more often regarded as concentric (22,0% vs 10,4% in PCIS and asymptomatic individuals, respectively), prolonged (24,2% vs 7,5%), homogeneous (41,0% vs 21,1%), as well as were more likely to have an uneven contour (27,7% vs 2,8%).

Conclusion. In patients with acute PCIS, the peculiarities of BCA atherosclerosis were recorded, distinguishing it from that in the asymptomatic population.

Endovascular Treatment of Symptomatic Intracranial Vertebrobasilar Stenosis: A 10-Year Single Centre Experience Using Balloon-Expandable Coronary Artery Stents

BACKGROUND

Symptomatic intracranial vertebro-basilar stenoses (SIVBS) are associated with high risk of recurrent ischemic stroke, even in patients receiving the best medical treatment. Although medical treatment is still the standard of care, non-responding patients may require endovascular treatment; balloon-mounted coronary stents (BMCS) could be successfully employed. This study aims to retrospectively analyze our high volume Interventional Neurovascular center ten-year experience in the off-label use of BMCS for the treatment of SIVBS, in order to assess its feasibility and safety.

METHODS

We retrospectively analyzed all consecutive patients with SIVBS treated with BMCS in the last ten years in our center. Data collected included patient demographics, stenosis location and characteristics, early (<30 days) and late (>30 days) stroke and death rates, pre-symptomatic and post-treatment modified Rankin Scale (mRS) scores.

RESULTS

42 patients (35 males, average age 65,7 ± 10,7, range 37-85) with SIVBS were treated with BMCS. Thirty-four (80,9%) patients were symptomatic despite ongoing best medical therapy; eight (19,1%) patients were treated in emergency for large vessel occlusion, due to an underlying stenosis. BMCSs were successfully deployed in all cases. The incidence of stroke and death at one month was 7,1% (3/42). The incidence of TIA, stroke and death at long-term follow-up (average time of 3 years) was 14,3% (4,7 per 100 person-years). At long-term follow-up, mRS improved in 82% of patients who underwent elective treatment.

CONCLUSIONS

In our experience, the off-label use of BMCS in the endovascular treatment of SIVBS resistant to medical treatment is feasible and safe.

Vertebral Artery Stenoses Contribute to the Development of Diffuse Plaques in the Basilar Artery

Vertebral artery (VA) stenosis is relevant to a high early risk of recurrent stroke and basilar artery (BA) is the most common intracranial site of atherosclerotic lesions. It is important to show predictive risk factors for transient ischemic attack (TIA) or posterior infarctions. The aim of the study is to investigate morphometry and hemodynamics in intracranial vertebral and basilar arteries of health and diseased patients to enhance the risk assessment. Based on the geometrical model reconstructed from CTA images in 343 patients, a transient three-dimensional computational model was used to determine the hemodynamics. Patients were classified in symmetric, asymmetric, hypoplastic, and stenotic groups while patients in the stenotic group were divided into unilateral, bilateral, bifurcation, and tandem stenotic sub-groups. Patients in bilateral, bifurcation, and tandem stenotic sub-groups had significantly lower basilar artery diameters than other groups. Patients in the stenotic group had significantly higher surface area ratio (SAR) of high time-averaged wall shear stress gradient (TAWSSG) and higher incidence of TIAs or posterior infarctions than other groups while patients in the tandem stenotic sub-group had the highest values (SAR-TAWSSG of 57 ± 22% and TIAs or posterior infarction incidence of 54%). The high SAR-TAWSSG is predisposed to induce TIAs or posterior infarction.

Do thrombolysis outcomes differ between anterior circulation stroke and posterior circulation stroke? A systematic review and meta-analysis

BACKGROUND

It remains unclear whether thrombolysis outcomes can be influenced by the affected vascular territory (i.e. anterior circulation stroke vs. posterior circulation stroke) in stroke patients owing to the lack of randomized controlled trials.

AIMS

Using multiple comprehensive databases, we searched for observational studies of the safety and efficacy of intravenous thrombolytics and intra-arterial treatment with or without intravenous thrombolytics in accordance with the affected vascular territory. We performed a systematic review and meta-analysis. We evaluated symptomatic intracerebral hemorrhage, all-type intracerebral hemorrhage, mortality, and functional outcomes at three months. The recanalization rate was assessed in the intra-arterial treatment group.

SUMMARY OF REVIEW

Twenty-one studies including a report from our own stroke registry were included through quantitative synthesis. Compared with the anterior circulation stroke group, the posterior circulation stroke group had a lower risk of ICH, including symptomatic intracerebral hemorrhage and all-type intracerebral hemorrhage, after intravenous thrombolytics and tended to have favorable functional outcomes at three months. Mortality was similar between the two groups. Regarding intra-arterial treatment, the symptomatic intracerebral hemorrhage and post-procedural recanalization rates were comparable between the two groups, although the posterior circulation stroke group had a higher mortality risk and lower tendency for a favorable functional outcome.

CONCLUSIONS

Safety and efficacy of thrombolysis in posterior circulation stroke depends on involvement of large vessel occlusion and reperfusion modality such that intravenous thrombolytics is more effective and safer than in anterior circulation stroke; the safety and efficacy of intra-arterial treatment is comparable or lower than anterior circulation stroke. Considering the limitations of our meta-analysis, further studies are needed to provide high level evidence of a beneficial effect of intra-arterial treatment, and to identify patients' profiles associated with benefit of treatment.

Endovascular Recanalization for Chronic Total Occlusion of Intracranial Vertebral Artery: A Mini Review

Intracranial vertebral artery (ICVA) refers to the intracranial segment of the vertebral artery which is usually involved with atherosclerosis and dissection. Considering the high incidence and severe consequence of occlusive artery disease in this location, little attention has been paid to the chronic total occlusion (CTO) of ICVA and the corresponding endovascular treatment (EVT). In this mini review, ICVA CTO is discussed based on the definition, incidence, clinical manifestation, endovascular recanalization treatment, complications, and outcomes.

Posterior circulation ischaemic stroke-a review part I: anatomy, aetiology and clinical presentations

Posterior circulation ischaemia is a clinicopathological condition with complex symptomatology associated with an infarction within the vertebrobasilar arterial system. Posterior circulation strokes account for about 20-25% of all ischemic strokes and remain a significant cause of patient disability and mortality. Diagnosis can be challenging because presenting symptoms are often non-focal and because there is a substantial overlap in symptoms and signs of ischaemia in the anterior circulation. Despite better imaging techniques, diagnosis and treatment of life-threatening conditions, such as basilar artery occlusions, are often delayed. Therefore, early detection of symptoms and causes of posterior circulation ischaemia is essential for choosing the most appropriate therapy. In this review, we summarise the anatomy, aetiology, typical presentations and characteristic findings of common strokes resulting from disease in the vertebrobasilar arterial system.

Association between Leukoaraiosis and Symptomatic Intracranial Large Artery Stenoses and Occlusions: the Chinese Intracranial Atherosclerosis (CICAS) Study

Leukoaraiosis (LA) is frequently found in ischemic stroke patients, especially when those patients have intracranial atherosclerosis (ICAS). However, previous studies regarding an association of LA with cerebral large artery atherosclerosis showed conflicting results, and the relationship of LA with ICAS is uncertain. This study aimed to explore the association between LA and cerebral large artery atherosclerosis in Chinese patients with cerebral ischemia. Data were derived from the Chinese Intracranial Atherosclerosis (CICAS) study. Patients diagnosed with an ischemic stroke or transient ischemic attack (TIA) within 7 days of symptom onset were included. The analysis of magnetic resonance imaging (MRI) focused on severity of LA in periventricular and deep white matter; type of cerebral large artery stenosis; and the number, severity, and distribution of ICAS lesions. ICAS was defined as an occlusion or more than 50% stenosis of intracranial vessels on magnetic resonance angiography. Among 2420 patients included, distinct LA was observed in 898 (37.11%) patients, and the rate of LA increased significantly with an increased number of risk factors. Multivariate analysis revealed that LA was independently associated with ICAS (odds ratio [OR], 1.388; 95% confidence interval [CI], 1.132-1.702; P=0.0016). In the subgroup analysis of ICAS, LA was more frequently observed in multiple lesions (OR, 1.342; 95% CI, 1.060-1.699; P=0.0146), occlusive lesions (OR, 1.554; 95% CI, 1.214-1.998; P=0.0005), and lesions in the posterior circulation (OR, 1.360; 95% CI, 1.003-1.846; P=0.0481). In this nationwide prospective study, LA was associated with symptomatic ICAS, patients with multiple ICAS lesions, occlusive lesions, and atherosclerotic lesions in the posterior circulation were more likely to coexist with LA.

Differences in Ischemic Anterior and Posterior Circulation Strokes: A Clinico-Radiological and Outcome Analysis

BACKGROUND

There are limited data comparing posterior (PC) and anterior (AC) circulation acute ischemic strokes (AIS). We aimed to identify specific features of PC and AC strokes regarding clinical, etiological, radiological, and outcome factors.

METHODS

Patients from the Acute STroke Registry and Analysis of Lausanne, a prospective cohort of consecutive AIS, from years 2003 to 2008 were included. The stroke territory was determined by a combination of neuroimaging and clinical symptoms. Patients with uncertain localization or with simultaneous AC and PC strokes were excluded. Multivariate associations between territory and multiple variables were investigated.

RESULTS

A total of 1449 patients were included, 466 (32.2%) had a PC territory stroke and 983 (67.8%) an AC. On multivariate analysis, those with PC AIS had lower National Institutes of Health Stroke Scale at admission, more often showed decreased consciousness, visual field defects, and vestibulo-cerebellar signs, but less hemisyndromes, dysarthria, and cognitive symptoms compared to AC AIS patients. Male sex, arterial dissection, lacunar mechanisms, and endovascular recanalization were more frequent in PC strokes, whereas cardioembolic strokes and IV-thrombolysis rates were lower. Less early ischemic signs on admission CT, overall arterial pathology, and 24-hour recanalization were present in PC strokes but intracranial arterial pathology was more prevalent than in AC. The adjusted clinical outcome at 3 months was similar in both groups.

CONCLUSIONS

In this large retrospective consecutive AIS series, there were specific differences in clinical presentation, etiology, and arterial pathology between PC and AC strokes which did not influence clinical outcome. These findings could lead to a tailored diagnostic work-up, acute treatment strategies, and secondary prevention.

Morphometric Study of Basilar Artery in the Eastern Indian Population

Introduction

The basilar artery (BA) is formed by the fusion of right and left vertebral arteries and divides to form right and left posterior cerebral arteries. This study was done to provide a baseline database regarding length, mid-length diameter, level of origin, and level of termination of BA.

Materials and Methods

Thirty-eight formalin-fixed brains were obtained from cadavers dissected for undergraduate studies. The external length and the average external diameter of BA were measured by a digital Vernier caliper. Variation in origin and termination of BA was noted using magnifying glass.

Results

The length and diameter of the BA were 25.58 ± 3.57 mm and 3.05 ± 0.41 mm, respectively. The origin and termination of BA was normal in most cases. In two cases, the origin was above the pontomedullary junction, and in one case, it was below. In two cases, the termination was above the pontomesencephalic junction, and in one case, it was below.

Conclusion

There was no gender predisposition in length and diameter of the basilar artery. The baseline data established in this study regarding length, diameter, level of origin and level of termination of basilar artery will help neurosurgeons and interventional radiologists to diagnose as well as plan and execute various vascular procedures such as shunting for the treatment of aneurysms and stenosis in the blood vessels of the posterior cranial fossa.

A review of the diagnosis and management of vertebral basilar (posterior) circulation disease

We have reviewed the English literature published in the last 70 years on Diseases of the Vertebral Basilar Circulation, or Posterior Circulation Disease (PCD). We have found that errors have been made in the conduct and interpretation of these studies that have led to incorrect approaches to the management of PCD. Because of the difficulty in evaluating the PC, the management of PCD has been incorrectly applied from anterior circulation disease (ACD) experience to PCD. PCD is a common form of stroke affecting 20-40% patients with stroke. Yet, the evidence is strong that the Anterior Circulation (AC) and Posterior Circulations (PC) differ in their pathology, in their clinical presentations, in the rapidity of development of symptoms, in optimal imaging methods, and in available treatments. There appears to be two categories of patients who present with PCD. The first, acute basilar artery occlusion has a more rapid onset. The diagnosis must be made quickly and if imaging proves a diagnosis of Basilar Artery Occlusion (BAO), the treatment of choice is Interventional removal of the basilar artery thrombosis or embolus. The second category of PCD and the most commonly seen PCD disease process presents with non-specific symptoms and early warnings of PCD that now can be related to ischemic events in the entire PC vessels. These warning symptoms and signs occur much earlier than those in the AC. IA angiography is still the gold standard of diagnosis and is superior in definition to MR and CT angiography which are commonly used as a convenient screening imaging tool to evaluate PCD but are both inferior to IA angiography in definition for lesions below 3-4 mm. In at least two reported studies 7T MR angiography appears superior to other imaging modalities and will become the gold standard of imaging of PCD in the future. Medical treatments applied to the ACD have not been proven of value in specific forms of PCD. Interventional therapy was promising but of unproven value in Randomized Controlled Trials (RCT) except for the treatment of Basilar Artery Occlusion (BAO). Surgical revascularization has been proved to be highly successful in patients, who are refractory to medical therapy. These studies have been ignored by the scientific community basically because of an incorrect interpretation of the flawed EC-IC Bypass Trial in 1985 as applying to all stroke patients. Moreover, the EC-IC Bypass Study did not include PCD patients in their study population, but the study results were extrapolated to patients with PCD without any scientific basis. This experience led clinicians to an incorrect bias that surgical treatments are of no value in PCD. Thus, incorrectly, surgical treatments of PCD have not been considered among the therapeutic possibilities for PCD. QMRA is a new quantitative MR technique that measures specific blood flow in extra and intracranial vessels. QMRA has been used to select those patients who may benefit from medical, or interventional, or surgical treatment for PCD based on flow determinations with a high success rate. QMRA accurately predicts the flows in many large and small vessels in the PC and AC and clearly indicates that both circulations are intimately related. From medical and surgical studies, the longer one waits for surgical treatment the higher the risk of a poor outcome results. This observation becomes obvious when the rapidity of development of PCD is compared with ACD. Recent advances in endovascular therapy in the treatment of acute basilar thrombosis is a clear sign that early diagnosis and treatment of PCD will reduce the morbidity and mortality of these diseases. In this review it is evident that there are multiple medical and surgical treatments for PCD depending upon the location of the lesion(s) and the collateral circulation demonstrated. It is clear that the AC and PC have significant differences. With the exception of the large population studies from Oxford England, the reported studies on the management of PCD in the literature represent small selected subsets of the universe of PC diseases, the information from which is not generalizable to the universe of PCD patients. At this point in the history of PCD, there are not large enough databases of similar patients to provide a basis for valid randomized studies, with the exception of the surgical studies. Thus, a high index of suspicion of the early warning symptoms of PCD should lead to a rapid individual clinical assessment of patients selecting those with PCD. Medical, interventional, and/or surgical treatments should be chosen based on knowledge presented in this review. Recording the results in a national Registry on a continuing basis will provide the data that may help advance the management of PCD based on larger data bases of well documented patient information to guide the selection of future therapies for PCD treatments. It is also clear that the management of patients within the complex of diseases that comprise PCD should be performed in centers with expertise in the imaging, medical, interventional and surgical approaches to diseases of the PCD.

[Cerebral infarctions in vertebrobasilar artery atherosclerosis]

AIM

to obtain more specific information on the morphology and pathogenesis of cerebral infarctions occurring in vertebrobasilar artery (VBA) atherosclerosis.

MATERIAL AND METHODS

Macro- and microscopic investigations of the brain, its arterial system, and heart were conducted in 69 autopsy cases with infarctions located in the vertebrobasilar system (VBS) in atherosclerosis.

RESULTS

69 cases were found to have 206 VBA infarctions of various extent and locations. The detected infarctions were single and multiple in 27 and 42 cases, respectively. The detected infarctions included extensive (n=7), large (n=9), medium (n=63), small deep (lacunar) (n=97), and small superficial (n=30). The brain stem showed lacunar infarctions most frequently (76% of the infarctions at this site). Medium and small infarctions were identified at the same frequency in the cerebral hemispheres and cerebellum. The occurrence of 94% of the extensive and large infarctions was ascertained to be pathogenetically associated with atherothrombotic occlusion of the intracranial arteries in the VBS. 76% of the small infarctions occurred through the mechanism of cerebral vascular insufficiency in tandem atherostenosis of VBAs in conjunction with an additional decrease in cerebral blood flow under the influence of an extracerebral factor (coronary heart disease). Medium infarctions were approximately equifrequently due to the two aforementioned causes and, in some cases, to cardiogenic thromboembolism of VBAs. Infarctions were multiple in most cases; while recent large atherothrombotic infarctions were frequently concurrent with small organized infarctions resulting from tandem atherostenosis of VBAs.

CONCLUSION

This investigation could establish the relationship between the site, extent, and pathogenetic factors of infarctions in the VBA bed in atherosclerosis, as well as the prognostic value of small infarctions as predictors for severe ischemic stroke.

Are the anomalous vertebral arteries more hypoplastic?: retrospective linear mixed model approach

Background

Small or hypoplastic vertebral artery (VA) is one of the risk factor for posterior circulation stroke. We assess whether various types of VA anomaly contribute to its diameter.

Methods

We screened 238 patients who underwent neck CT and MR angiography within 1 month. A V1 anomaly was defined as the abnormal origin of the VA on a three-dimensional MR angiography and a V2 anomaly was defined as the VA not passing through the 6th cervical transverse foramen (TF) on an axial CT image. A linear mixed model was used to evaluate the determinants of VA size.

Results

Among participants, 24 (10.1%) subjects exhibited an anomalous VA and, of the 476 VAs examined, 11 (2.3%) had an aortic origin and 27 (5.7%) had an abnormal entrance into the C6 TF. Presence of the V1 anomaly was positively associated with the V2 anomaly (P for chi-square < 0.001) and a linear mixed model revealed that being male (0.2 mm larger, P = 0.015), having a right VA anomaly (0.3 mm smaller, P < 0.001), having a V1 anomaly (0.9 mm smaller, P < 0.001), and having a V2 anomaly (0.7 mm smaller, P < 0.001) were significant predictor of VA diameter.

Conclusion

The diameters of VAs with an anomalous aortic origin or an abnormal entrance of the TF were significantly smaller than those of normal VAs. These findings suggest that anomalies of the VA detected in 3-dimensional CTA or MRA may be clues for vertebral artery hypoplasia.

Electronic supplementary material

The online version of this article (10.1186/s12883-017-0951-x) contains supplementary material, which is available to authorized users.

Delayed Endovascular Stenting for Severe Vertebral Artery Stenosis with Precarious Thrombosis

A significant but less recognized cause of ischemic stroke and transient ischemic attack (TIA) is atherosclerosis of the vertebrobasilar system, which accounts for 20% of ischemic strokes. Pathology of the vertebrobasilar system can present significant challenges in determining the course of treatment. Due to the complexity of the vertebrobasilar system, there is slight disagreement about how to approach patients with atherosclerotic pathology of the posterior circulation. Two such approaches are either stenting of the vertebral or basilar artery or aggressive medical management. Here, we present the case of a 63-year-old male who presented with lightheadedness, diaphoresis, two episodes of loss of consciousness, and the abrupt onset of unilateral right-sided paresis. A computed tomography angiogram (CTA) of the head and neck demonstrated complex posterior circulation vertebrobasilar vascular stenosis and occlusions. There was an unstable clot located at the junction of the vertebral and basilar arteries requiring a carefully nuanced approach. The patient was started on dual antiplatelet therapy and heparin in an effort to resolve the clot. Repeat CTA after five days revealed resolution of the unstable clot; however, the distal intradural right vertebral artery remained occluded and the left vertebral artery remained stenosed. The patient was then treated with a balloon-mounted coronary stent to eliminate the stenosis, which ultimately restored normal posterior fossa flow dynamics. This case serves as a testament to the variability and complexity of vertebrobasilar arteriopathies as well as the benefit of experienced neurointerventionalists in the successful management of these cases. 

Clinical Features of Thalamic Stroke

OPINION STATEMENT

The thalamus plays an important role in different brain functions including memory, emotions, sleep-wake cycle, executive functions, mediating general cortical alerting responses, processing of sensory (including taste, somatosensory, visual, and auditory) information and relaying it to the cortex, and sensorimotor control. Thalamic stroke, both in isolation and in combination with infarcts involving other structures, are not rare. The functional complexity of the thalami nuclei and the not uncommon normal variations of arteries supply the thalamus induce wide variations in presentation of thalami infarcts. In patients with an unusual collection of deficits difficult to explain by a single lesion, in particular where there is impaired vigilance, thalamic disease should be considered which may mimic several different neurological conditions. By researching the literature, we found that the characteristic stroke syndrome of paramedian thalamic infarction is probably underdiagnosed. In addition to thalamic infarct, thalamic lesions can be caused by deep cerebral venous thrombosis with neuropsychological and radiological features that should be considered in the differential diagnosis of intracranial artery occlusion or bleeding, especially in young patients.

Infratentorial posterior circulation stroke in a Nigerian population: Clinical characteristics, risk factors, and predictors of outcome

Background:

Posterior circulation stroke (PCS), though less common, differs from stroke in anterior circulation in many aspects. Relatively, it portends a poorer prognosis. However, there is a paucity of data from African countries, in particular, where stroke is a menace.

Objective:

The study aimed to evaluate the etiology, clinical characteristics, outcome, and predictors of outcome in a cohort of patients with IPCS in Northwestern Nigeria.

Materials and Methods:

Out of 595 patients with stroke, we prospectively analyzed 57 patients with PCS in a Tertiary Care Center in Kano, Northwestern Nigeria. Patients were analyzed for demographic data, risk factors, clinical characteristics, stroke subtypes, mortality, and predictors of mortality.

Results:

Posterior circulation ischemic stroke accounted for 57 (9.6%) of 595 of all strokes seen in the study period. They comprised 44 males (mean age 47.8 ± 17.7) and 13 females (mean age 46.3 ± 13.7). Overall, their age ranged between 24 and 90 (mean age 47.4 ± 16.7). However, 52.7% of the patients were < 45 years of age. The most common site affected was the cerebellum seen in 33 (57.9%) patients. Hypertension was the most common risk factor (86%). Headache and vertigo were the most common features accounting for 83.6% and 86.3%, respectively. Thirty-eight (66.7%) patients had an ischemic stroke. Twenty-one (36.8%) of the patients died during the 1-month period of follow-up. Independent predictors of death in the study were hyperglycemia on admission and hemorrhagic stroke.

Conclusions:

IPCS occurred in a relatively younger age group. Headache and vertigo were the most common symptoms. The independent predictors of death in the study were hyperglycemia at presentation and hemorrhagic stroke.

Cerebellar infarct patterns: The SMART-Medea study

OBJECTIVE

Previous studies on cerebellar infarcts have been largely restricted to acute infarcts in patients with clinical symptoms, and cerebellar infarcts have been evaluated with the almost exclusive use of transversal MR images. We aimed to document the occurrence and 3D-imaging patterns of cerebellar infarcts presenting as an incidental finding on MRI.

METHODS

We analysed the 1.5 Tesla MRI, including 3D T1-weighted datasets, of 636 patients (mean age 62 ± 9 years, 81% male) from the SMART-Medea study. Cerebellar infarct analyses included an assessment of size, cavitation and gliosis, of grey and white matter involvement, and of infarct topography.

RESULTS

One or more cerebellar infarcts (mean 1.97; range 1-11) were detected in 70 out of 636 patients (11%), with a total amount of 138 infarcts identified, 135 of which showed evidence of cavitation. The average mean axial diameter was 7 mm (range 2-54 mm), and 131 infarcts (95%) were smaller than 20 mm. Hundred-thirty-four infarcts (97%) involved the cortex, of which 12 in combination with subcortical white matter. No infarcts were restricted to subcortical branches of white matter. Small cortical infarcts involved the apex of a deep (pattern 1) or shallow fissure (pattern 2), or occurred alongside one (pattern 3) or opposite sides (pattern 4) of a fissure. Most (87%) cerebellar infarcts were situated in the posterior lobe.

CONCLUSIONS

Small cerebellar infarcts proved to be much more common than larger infarcts, and preferentially involved the cortex. Small cortical infarcts predominantly involved the posterior lobes, showed sparing of subcortical white matter and occurred in characteristic topographic patterns.

Bilateral Intracranial Vertebral Artery Stenosis Presenting as Recurrent Prolonged Presyncopal Episodes

Amongst various mechanisms of presyncopal events, posterior circulation disease needs to be considered. This particular mechanism has been underrecognized. We describe a case of a 76-year-old patient with recurrent posterior circulation TIAs, presenting as recurrent prolonged presyncopal events.

Stent fracture and occlusion after treatment of symptomatic vertebral artery ostium stenosis with a self-expanding device. A case report

Endovascular stenting with a balloon expandable device is currently the preferred treatment modality for symptomatic proximal vertebral artery stenosis, but high rates of in-stent restenosis remain a major problem, for which stent fracture might be a contributing factor. Limited reports showed that placement of self-expanding stents in the proximal vertebral artery might reduce restenosis; no stent fracture has been reported to date. We describe here a new case of fracture and occlusion of a self-expanding stent after endovascular treatment of symptomatic vertebral artery ostium stenosis.

Vascular pathology in the extracranial vertebral arteries in patients with acute ischemic stroke

Introduction

Vascular pathology in the extracranial vertebral arteries remains among the possible causes in cryptogenic stroke. However, the diagnosis is challenged by the great variety in the anatomy of the vertebral arteries, clinical symptoms and difficulties in the radiological assessments. The aim of this study was to assess the prevalence of CT angiography (CTA)-detected pathological findings in the extracranial vertebral arteries in an acute stroke population and secondly to determine the frequency of posterior pathology as probable cause in patients with otherwise cryptogenic stroke.

Method

The analysis was based on 657 consecutive patients with symptoms of acute stroke and a final diagnosis of ischemic stroke or transient ischemic attack. On admission, a noncontrast CT cerebrum and CTA were performed. A senior consultant neuroradiologist, blinded to clinical data, reviewed all CTA scans systematically, assessing the four segments of the extracranial vertebral arteries. First, the frequency of pathological findings including stenosis, plaques, dissection, kinked artery and coiling was assessed. Subsequently, we explored the extent of the pathological findings that were the most plausible causes of stroke, namely either a possible dissection or a kinked artery.

Results

Findings in the extracranial vertebral arteries included significant stenosis (0.8%), atherosclerotic plaque types (3.8%), possible dissections (2.6%), kinked arteries (2.6%) and coiling (32.0%). Eighteen patients (2.8%) with pathological findings had an unknown cause of stroke, likely posterior symptoms and no clinical stroke symptoms from the anterior circuit. Of these, 3 cases were kinked arteries (0.5%) and 15 cases (2.3%) were possible dissections.

Conclusion

We found that in approximately 3% of the study population, the most plausible cause of the cryptogenic strokes was due to a pathological finding in the posterior extracranial vertebral arteries, being either a possible dissection or a kinked artery. In general, posterior vascular pathology is not uncommon, and CTA is a useful modality in the detection of changes based on characteristics and locations of findings in the extracranial vertebral arteries. Ultrasound examination can be a useful supplementary tool in deciding the consequence of vascular findings on CTA.

Effectiveness of mastoid process percussion for identification of the vertebral artery ostium on Doppler studies

OBJECTIVES

The pretransverse or first segment of the vertebral artery may be confused with adjacent branches of the proximal subclavian artery during Doppler assessment. This study investigated the effectiveness of mastoid process percussion, the "mastoid tap" maneuver, for identification of the vertebral artery ostium.

METHODS

Fifty patients presenting consecutively for carotid sonography were recruited. Doppler waveforms were collected at the vertebral artery ostia, thyrocervical trunks, and proximal subclavian arteries while the mastoid tap maneuver was performed. The outcome indicator was serrate distortion of the Doppler waveform. Two raters graded the waveforms according to a 3-grade system: grade 0, no distortion; grade 1, mild distortion; and grade 3, marked distortion. The difference between the proportions of the vertebral artery ostia and thyrocervical trunks showing waveform distortion was evaluated with the χ(2) test. The differences in the extents of waveform distortion in the ipsilateral vertebral artery ostia, thyrocervical trunks, and subclavian arteries were evaluated with Friedman and Wilcoxon signed rank tests.

RESULTS

Ninety-five vertebral artery ostia in 50 patients were successfully assessed. There was a significant difference between the proportions of vertebral artery ostia (95 of 95 [100%]) and thyrocervical trunks (9 of 95 [9.5%]) that showed waveform distortion (P < .001). There were significant differences in the extents of distortion between the ipsilateral vertebral artery ostia and thyrocervical trunks and between the ipsilateral vertebral artery ostia and subclavian arteries, with the vertebral artery ostia showing a higher degree of distortion in both cases (P < .001).

CONCLUSIONS

The mastoid tap maneuver is useful for distinguishing between the vertebral arteries and thyrocervical trunks on Doppler studies.

Ataxia in patients with brain infarcts and hemorrhages

Gait and limb incoordination and ataxia are most often found in patients with brainstem and cerebellar infarcts and hemorrhages. Lesions involving the thalamus and the deep portions of the cerebral hemispheres also may cause ataxia accompanied by weakness and sensory symptoms. Patients who have lesions in the lateral medulla and inferior cerebellum often topple, lean, or veer when attempting to sit, stand, or walk. They list to the side or abruptly veer when walking. The affected limbs are often hypotonic. In pontine lesions, ataxia is accompanied by weakness and pyramidal tract signs as part of an ataxic hemiparesis syndrome. In lesions affecting the superior cerebellum and the brachium conjunctivum, limb dysmetria and overshoot and dysarthria predominate and gait ataxia is absent or slight and transient. Infarcts affecting the thalamus can cause gait instability and astasia with ataxia. Lateral thalamic lesions are characterized by hemisensory symptoms, extrapyramidal limb postures and dysfunction, and gait ataxia. Lesions that affect the posterior limb of the internal capsule and its afferent and efferent projections may also cause an ataxic hemiparesis syndrome, often with accompanying hemisensory abnormalities.

Hypertension before and after posterior circulation infarction: analysis of data from the South London Stroke Register

BACKGROUND

Postmortem data have shown that blood pressure before death correlates more closely with a narrowing of the vertebral arteries than any other vessel studied. This study explores a possible association between hypertension, both before and after posterior circulation infarction (POCI) compared to anterior circulation infarction (ACI).

METHODS

Patients with a first-ever stroke enrolled in the South London Stroke Register between 2000 and 2006 were included. Chi-square tests and multivariable logistic regression were used to compare risk factors including hypertension, sex, smoking history, diabetes, and hypercholesterolemia in patients with POCI compared to ACI. Chi-square testing was used to compare the incidence of newly diagnosed hypertension after POCI and ACI. Absolute blood pressure readings recorded before stroke and 7 days after stroke were also compared between groups.

RESULTS

On multivariable analysis, POCI was significantly associated with male sex (odds ratio [OR] 2.24; 95% confidence interval [CI] 1.55-3.22; P < .001) and hypertension (OR 1.69; 95% CI 1.15-2.50; P = .008). After stroke, patients with POCI were more likely to be newly diagnosed with hypertension during a 1-year follow-up period (OR 2.15; 95% CI 1.20-3.86; P = .009) and as an inpatient (OR 3.27; 95% CI 1.49-7.13; P = .002). Systolic blood pressure was significantly higher in the POCI group before stroke (152 v 146 mm Hg; P = .027). Diastolic blood pressure was significantly higher 7 days poststroke (81 v 74 mm Hg; P = .01) in patients not previously diagnosed with hypertension.

CONCLUSIONS

This study has shown a significant association between hypertension before and after POCI compared to ACI. We believe further investigation with brainstem imaging and recordings of sympathetic nervous system activity after stroke is warranted.