Relationship between subclavian artery stenosis lesions and posterior circulation infarction: A preliminary study.

OBJECTIVE: To investigate the correlation between subclavian steal syndrome and posterior circulation infarction using magnetic resonance imaging. METHODS: A total of 294 patients diagnosed with subclavian steal syndrome using carotid Doppler ultrasonography were retrospectively included. According to the magnetic resonance imaging results, they were divided into posterior circulation infarction group and non- posterior circulation infarction group. Clinical indicators and carotid Doppler ultrasound parameters of patients were collected, and they were screened to establish a multiple logistic regression model. Receiver operating characteristic curve analysis of the established multiple logistic regression model was performed, and the area under the curve was calculated to evaluate the predictive efficiency of the model. RESULTS: After statistical analysis of all parameters of the two groups of patients, a total of 10 parameters were included in multiple logistic regression to establish a model. The results showed a correlation between posterior circulation infarction and subclavian artery occlusion, grade III subclavian steal syndrome, gender, vulnerable plaques, National Institutes of Health Stroke Scale score, and age. After the receiver operating characteristic curve analysis of the model, the area under the curve for the multiple logistic regression model was 0.773. CONCLUSION: The multiparameter composite model based on clinical baseline data and carotid Doppler ultrasonography parameters can effectively predict posterior circulation infarction and offer novel insight for clinical diagnosis.

Hidden Bow Hunter's Syndrome Diagnosed Using Dynamic Cerebral Angiography and Successfully Treated with Spinal Surgery: A Case Report and Review of the Literature.

Hidden bow hunter's syndrome (HBHS) is a rare disease in which the vertebral artery (VA) occludes in a neutral position but recanalizes in a particular neck position. We herein report an HBHS case and assess its characteristics through a literature review. A 69-year-old man had repeated posterior-circulation infarcts with right VA occlusion. Cerebral angiography showed that the right VA was recanalized only with neck tilt. Decompression of the VA successfully prevented stroke recurrence. HBHS should be considered in patients with posterior circulation infarction with an occluded VA at its lower vertebral level. Diagnosing this syndrome correctly is important for preventing stroke recurrence.

Frequency, characteristics, and predictors of headache attributed to acute ischemic stroke.

OBJECTIVES: Although headache is a common symptom in acute ischemic stroke, the clinical and radiological factors associated with its occurrence are controversial. This work aimed to determine the frequency, characteristics, and predictors of headache occurrence among patients with acute ischemic stroke. METHODS: This cross-sectional study was conducted on 303 patients with acute ischemic stroke. The patients were submitted to detailed history taking, clinical and radiological assessment. A detailed analysis of headache was performed for the patients who experienced headache temporally related to stroke onset. RESULTS: Diagnosis of headache attributed to the ischemic stroke was established in 129 (42.6%) patients; sentinel headache in 17.2% of patients, and headache at stroke onset in 25.4% of patients. The headache group had a significantly younger age (P=0.017), lower NIHSS score (P=0.042), higher frequency of pre-existing headache disorders (P=0.001), substance use disorder (P=0.021), and fever (P=0.036), and lower frequency of chronic hypertension (P=0.013) and small vessel disease (P=0.004) than non-headache group. Infarction involving posterior circulation was more frequent in headache than in non-headache groups (P=0.003). The presence of migraine, tension-type headache, other types of headache, fever and posterior circulation stroke increased the odds of headache by 27.4 (95%CI=8.0-94.4), 7.6 (95%CI=3.93-14.6), 26.2 (95%CI=8.0-85.8), 3.75 (95%CI=1.22-11.6) and 3.15 (95%CI=1.65-6.0) times, respectively, whereas, the presence of small vessel disease decreased the odds of headache by 0.51 (95%CI=0.279-0.95) times. CONCLUSION: Pre-existing headache disorder, fever, and posterior circulation stroke were associated with headache occurrence in acute ischemic stroke patients.

Optimal CT perfusion thresholds for core and penumbra in acute posterior circulation infarction.

Background: At least 20% of strokes involve the posterior circulation (PC). Compared to the anterior circulation, posterior circulation infarction (POCI) are frequently misdiagnosed. CT perfusion (CTP) has advanced stroke care by improving diagnostic accuracy and expanding eligibility for acute therapies. Clinical decisions are predicated upon precise estimates of the ischaemic penumbra and infarct core. Current thresholds for defining core and penumbra are based upon studies of anterior circulation stroke. We aimed to define the optimal CTP thresholds for core and penumbra in POCI. Methods: Data were analyzed from 331-patients diagnosed with acute POCI enrolled in the International-stroke-perfusion-registry (INSPIRE). Thirty-nine patients with baseline multimodal-CT with occlusion of a large PC-artery and follow up diffusion weighted MRI at 24-48 h were included. Patients were divided into two-groups based on artery-recanalization on follow-up imaging. Patients with no or complete recanalisation were used for penumbral and infarct-core analysis, respectively. A Receiver operating curve (ROC) analysis was used for voxel-based analysis. Optimality was defined as the CTP parameter and threshold which maximized the area-under-the-curve. Linear regression was used for volume based analysis determining the CTP threshold which resulted in the smallest mean volume difference between the acute perfusion lesion and follow up MRI. Subanalysis of PC-regions was performed. Results: Mean transit time (MTT) and delay time (DT) were the best CTP parameters to characterize ischaemic penumbra (AUC = 0.73). Optimal thresholds for penumbra were a DT >1 s and MTT>145%. Delay time (DT) best estimated the infarct core (AUC = 0.74). The optimal core threshold was a DT >1.5 s. The voxel-based analyses indicated CTP was most accurate in the calcarine (Penumbra-AUC = 0.75, Core-AUC = 0.79) and cerebellar regions (Penumbra-AUC = 0.65, Core-AUC = 0.79). For the volume-based analyses, MTT >160% demonstrated best correlation and smallest mean-volume difference between the penumbral estimate and follow-up MRI (R 2 = 0.71). MTT >170% resulted in the smallest mean-volume difference between the core estimate and follow-up MRI, but with poor correlation (R 2 = 0.11). Conclusion: CTP has promising diagnostic utility in POCI. Accuracy of CTP varies by brain region. Optimal thresholds to define penumbra were DT >1 s and MTT >145%. The optimal threshold for core was a DT >1.5 s. However, CTP core volume estimates should be interpreted with caution.

Basilar artery curvature increases the risk of posterior circulation infarction occurrence in patients without vertebrobasilar stenosis.

INTRODUCTION: Limited cross-sectional or case-control studies have identified the relationship between basilar artery (BA) curvature and posterior circulation infarction (PCI). This study aimed to identify the influence of BA curvature severity on the risk of PCI occurrence in patients without vertebrobasilar stenosis through a prospective cohort study. METHODS: In this study, we enrolled 171 patients with BA dolichosis but without vertebrobasilar stenosis. The BA geometric parameters were evaluated on MRA. The primary outcome was the occurrence of PCI, mainly referring to cerebellar and/or brainstem infarction. Cox proportional hazard models were used to detect possible predictors of PCI. RESULTS: Among them, 134 (78.4%) patients were diagnosed with BA curvature, including 124 with moderate curvature and 10 with prominent curvature. The defined PCI occurrence was observed in 32 (18.7%) patients with a median follow-up time of 45.6 months. Cox proportional hazard analysis showed that BA prominent curvature (HR = 6.09; 95% CI: 1.36-27.28; P = 0.018) significantly increased the risk of PCI occurrence, and bending length (BL) was also significantly associated with PCI occurrence, with the adjusted HR per 1-mm increase of BL of 1.09 (95% CI: 1.01-1.18; P = 0.040). In the subgroup analysis stratified by age, BA prominent curvature was highly associated with PCI occurrence in patients aged > 61 years (HR = 11.76; 95% CI: 1.21-113.90; P = 0.033). Additionally, good antiplatelet therapy adherence could significantly reduce the risk of PCI occurrence. CONCLUSION: BA curvature may increase the risk of PCI occurrence, especially in elderly patients with prominent curvature. Improving adherence to antiplatelet therapy can help reduce the risk of PCI occurrence.

Effect of vertebrobasilar dolichoectasia on endovascular therapy in acute posterior circulation infarction.

Background and purpose: This study aimed to analyze the feasibility and safety of endovascular therapy (EVT) in patients with acute posterior circulation stroke and vertebrobasilar dolichoectasia (VBD). Materials and methods: BASILAR was a national prospective registry of consecutive patients with symptomatic and imaging-confirmed acute stroke in the posterior circulation within 24 h of symptom onset. We evaluated EVT feasibility and safety in patients with VBD. Primary outcomes included improvement in modified Rankin Scale scores (mRS) at 90 days and mortality within 90 days. The secondary outcome was the rate of favorable functional outcome, defined as mRS ≤ 3 (indicating independent ambulation) at 90 days. Safety outcomes included surgery-related complications and other serious adverse events. Results: A total of 534 cases were included: 159 with VBD and 375 controls. No significant difference in mRS at 90 days was found between groups, but patients with VBD had a higher baseline National Institutes of Health Stroke Scale (NIHSS) score [30 (19-33) vs. 25 (15-32)] and were older [65 (59-74) vs. 63 (55-72) year]. After propensity score matching, there were no significant differences in baseline NIHSS score between the two groups, and the efficacy and safety of EVT were similar between patients with or without VBD. Furthermore, the prognostic effect of puncture-to-recanalization time on the probability of mortality within 90 days in EVT-treated patients with VBD was significant {adjusted odds ratio, 1.008 [95% confidence interval (1.001-1.015)]}. Conclusion: Endovascular therapy is safe and feasible in patients with acute posterior circulation stroke and VBD. The puncture-to-recanalization time is important for predicting the prognosis of EVT-treated patients with VBD.

Incidence and clinical features of acute multiple small cerebellar infarction.

OBJECTIVE: To investigate the clinical and imaging features and to identify possible etiology of acute multiple small cerebellar infarction (MSCI). METHODS: We retrospectively enrolled 220 patients with acute cerebellar infarction, divided them into MSCI and large cerebellar infarction (LCI) groups, according to the quantity and size of lesions confirmed by MRI analysis. Clinical and imaging features were compared between the two groups to explore the possible etiology and pathogenesis. RESULTS: Among 220 patients, 90 patients presented MSCI symptoms. The proportions of extracerebellar lesions (P = 0.001) and bilateral infarction (P = 0.001) in the MSCI group were higher than those in the LCI group. No significant differences were found in terms of age, gender, and common vascular risk factors between the two groups. The proportions of vertigo and headache in the MSCI group were significantly lower than those in the LCI group (P < 0.000 and 0.034, respectively), and limb weakness was significantly higher (P = 0.039) in the MSCI patients. Moreover, the proportions of nystagmus and ataxia in the MSCI group were significantly lower than those in the LCI group (P < 0.043 and 0.003, respectively). The MSCI group had higher proportions of ACA and MCA stenosis, while the proportion of posterior circulation stenosis was similar between the two groups. Infarctions involving the posterior inferior cerebellar (PICA) region and mixed territories were far more frequent than those involving the anterior inferior cerebellar artery (AICA) region and superior cerebellar artery (SCA) territory (P < 0.05). Large-artery atherosclerosis and multiple plus undetermined etiology were the main etiological factors of MSCI. CONCLUSION: In patients with acute cerebellar infarction, 30% of patients presented with MSCI. MSCI and LCI showed similar vascular risk factors and vascular stenosis in the posterior circulation system. Patients with MSCI should pay more attention to evaluating anterior circulation vessels' anatomy. Large-artery atherosclerosis was the main pathogenesis of acute MSCI. Assessment of cerebral vessels might be critically required in patients with MSCI complicated atrial fibrillation.

Association of Vertebral Artery Hypoplasia and Vertebrobasilar Cerebrovascular Accident.

Background and Objectives: Vertebral artery hypoplasia (VAH) is a controversial risk factor for cerebral infarction. The aim of this study was to analyze the prevalence of vertebral artery hypoplasia and to evaluate its association with vertebrobasilar cerebrovascular accidents. Materials and Methods: The study was conducted in the Neurology Departments of the Republican Vilnius University Hospital from 2015 to 2020. Data of 742 subjects (133 patients with posterior circulation infarction or vertebral artery syndrome (PCI/VAS), 80 patients with anterior circulation infarction (ACI) and 529 control subjects with no symptoms of cerebrovascular accident) were analyzed. Ultrasound examination of the extracranial internal carotid and vertebral arteries (VA) was performed, risk factors were recorded. Results: The mean age of the subjects was 64.51 ± 13.02 years. In subjects with PCI/VAS the diameter of VA was smaller, and the prevalence of VAH was higher compared to those in subjects with ACI and in the control group. A higher degree of VAH in subjects younger than 65 years of age increased the risk of PCI/VAS. Subjects with non-dominant VA diameter of 2.7-2.9 mm had 2.21 times higher risk of PCI/VAS, subjects with non-dominant VA diameter of 2.5-2.6 mm had 2.36 times higher risk of PCI/VAS, and subjects with non-dominant VA diameter of 2.2-2.4 mm had 4.12 times higher risk of PCI/VAS compared with subjects with non-dominant VA diameter of ≥3 mm. Among patients with PCI/VAS those with VAH had lower rates of ischemic heart disease compared with patients with normal VA diameter. There was no difference in the rates of other risk factors between PCI/VAS patients with and without VAH. Conclusions: Vertebral artery hypoplasia is not a rare finding in individuals without symptoms of cerebrovascular accident, but more frequent in patients with vertebrobasilar cerebral infarction or vertebrobasilar artery syndrome. Vertebral artery hypoplasia can be considered a risk factor for posterior circulation infarction in subjects under 65 years of age.

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.

Evaluation of hemodynamic characteristics in posterior circulation infarction patients with vertebral artery dominance by color doppler flow imaging and transcranial doppler sonography.

PURPOSE: The aim of this study was to investigate the hemodynamic characteristics of posterior circulation infarction (PCI) patients with the vertebral artery dominance (VAD) using Color Doppler flow imaging (CDFI) and Transcranial Doppler sonography (TCD) and to explore the pathogenesis of PCI caused by VAD. MATERIALS AND METHODS: A total of 186 consecutive PCI patients were enrolled. All the patients underwent magnetic resonance (MR) examination and the clinical data were collected. According to the brain magnetic resonance angiography (MRA), the patients were divided into VAD and non-VAD groups. CDFI and TCD were performed to identify the hemodynamic parameters of the vertebral artery (VA) and basilar artery (BA). RESULTS: The male population was significantly more frequent in the VAD group (71.3%) as compared to the non-VAD group (53.1%). The significant difference in hemodynamic parameters was observed between VAD and non-VAD groups. Resistance index (RI) of extracranial and intracranial VA was different as well. There were also differences in the VA side-to-side diameter difference-value, peak velocity (Vp), mean velocity (Vm) and pulsatility index (PI) with varying degrees of BA curvature. CONCLUSIONS: VA and BA hemodynamic changes caused by VAD may be an important risk factor in the process of occurrence of PCI. The combination of CDFI and TCD can help to detect the hemodynamic changes in the intracranial and extracranial segments of VA and BA. This can have important clinical value in understanding the pathogenesis of PCI.

Influencing factors for early clinical deterioration in patients with mild posterior circulation infarction / 中华行为医学与脑科学杂志

Objective:To study the incidence and influencing factors for clinical deterioration at an early stage in patients with mild posterior circulation infarction (PCI).Methods:Totally 291 patients with mild PCI from January 1, 2016 to January 1, 2020 were retrospectively included. Clinical deterioration within 24 h (CD 24h) and clinical deterioration between 2 d and 14 d (CD 14d) were the endpoint events. IBM SPSS Statistics 19.0 software was used for statistical analysis. Pearson chi-square test or Mann-Whitney U test were used to compare the group differences of corresponding variables. Multivariate logistic regression model was used to analyze the influencing factors of the primary endpoint events. Results:The incidences of CD 24h and CD 14d were 21.6% (63/291) and 30.6% (89/291) respectively, with the reperfusion therapy rate of 13.4% (39/291). The results of multivariate logistic regression analysis with CD 24h as the endpoint event showed that the baseline NIHSS was a positive independent factor increasing the risk of CD 24h ( OR=1.184, 95% CI=1.078-1.300, P<0.01). Cerebellar infarction (compared with brainstem infarction) ( OR=0.250, 95% CI=0.082-0.757, P=0.014)and non-macroatherosclerosis (compared with major atherosclerosis) ( OR=0.026, 95% CI=0.002-0.325, P=0.005) had negative predictive effects on CD 24h. The results of multivariate logistic regression analysis with CD 14d as the endpoint event showed that pulmonary infection complications after stroke ( OR=28.085, 95% CI=6.863-114.927, P<0.01) and baseline NIHSS ( OR=1.114, 95% CI=1.001-1.240, P=0.048) were independent factors of CD 14d. Reperfusion therapy ( OR=0.089, 95% CI=0.013-0.613, P=0.014) could reduce the risk of CD 14d.Top of basilar syndrome(compared with single brainstem infarction) ( OR=7.526, 95% CI=1.565-36.188, P=0.012) increased the risk of CD 14d, while the non-macroatherosclerotic (compared with the macroatherosclerotic subtype) ( OR=0.076, 95% CI=0.009-0.683, P=0.021) negatively predicted the risk of CD 14d. Baseline NIHSS ( OR=0.834, 95% CI=0.758-0.918, P<0.01), CD 14d ( OR=0.048, 95% CI=0.018-0.130, P<0.01) and pulmonary infection complications ( OR=0.045, 95% CI=0.012-0.167, P<0.01) were negatively predicted the good clinical prognosis (modified Rankin score 14 days after onset ≤2). Conclusion:Early clinical deterioration has a negative predictive effect on clinical prognosis improvement of patients with mild PCI. Large artery atherosclerotic stenosis subtype and basilar apex syndrome are the risk factors of CD 24h and CD 14d of patients with mild PCI, and pulmonary infection is the risk factor of CD 14d. Reperfusion therapy in acute phase is helpful to reduce the risk of early clinical deterioration and improve clinical prognosis in patients with mild PCI.

Rotational vertebral artery syndrome treated via an anterior approach and selective decompression only.

We present the case of a 38-year-old male who complained of repeated dizziness and syncope. Rotational vertebral artery syndrome (RVAS) was diagnosed via videonystagmoraphy (VNG), computed tomography angiography (CTA) and three-position digital subtraction angiography (DSA). In the neutral position, CTA and DSA revealed left vertebral artery (VA) stenosis at the C2 transverse foramen and right VA hypoplasia. When the head was turned to the right, the blood flow stopped at the C2 level. The bony structure around the VA at the C2 transverse foramen was decompressed via an anterior surgical approach, and the symptoms resolved. This case present the precise stenotic point evaluation by three-position DSA is crucial for the planning of surgical treatment.

Basilar Artery Occlusion: Diagnosis and Acute Treatment.

PURPOSE OF REVIEW: To provide the latest updates in the diagnosis, management, and prognosis in patients with basilar artery occlusion (BAO). RECENT FINDINGS: The diagnosis of BAO requires a high index of suspicion among patients with sudden onset depressed level of consciousness, quadraparesis (or hemiparesis), and cranial nerve dysfunction. Computed topography with angiography is currently the diagnostic modality of choice for the diagnosis of BAO. Given the often catastrophic nature of BAO, intravenous thrombolysis combined with mechanical thrombectomy should be offered in eligible patients. Despite a lack of data from randomized clinical trials, good outcomes are possible, especially in patients without early evidence of infarction. Aggressive treatment with intravenous thrombolysis and mechanical thrombectomy should be considered in eligible patients with BAO, but there remains a dearth of information from randomized clinical trials.

Diagnostic value of eye movement and vestibular function tests in patients with posterior circulation infarction.

OBJECTIVE: To evaluate the diagnostic value of eye movements and vestibular function tests in PCI patients. METHODS: Thirty-eight PCI patients and 31 patients with unilateral vestibular neuritis (UVN) were enrolled and underwent eye movement tests and vestibular function tests (spontaneous nystagmus [SN], head-shaking nystagmus [HSN]). RESULTS: The rates of eye movement abnormality were 78.9% and 41.9% in PCI and UVN patients, respectively. The positive rate of SN and HSN were, respectively, 41.2% and 43.8% in cerebellar infarction patients, 33.3% and 66.7% in medullary infarction patients, and 100.0% and 86.2% in UVN patients. The horizontal direction of SN and HSN coincided with the affected side in cerebellar infarction patients, and the healthy side in UVN patients, which coincided with the healthy side and the affected side, respectively in medullary infarction patients. The horizontal direction of HSN was bidirectional nystagmus in 16.0% (4/25) of UVN patients. CONCLUSIONS AND SIGNIFICANCE: Eye movement and vestibular function tests contribute to the early diagnosis of PCI. The horizontal direction of SN and HSN are consistently toward the affected side in cerebellar infarction patients and the healthy side in UVN patients, in contrast to medullary infarction patients, and deserve further investigations.

Rotational vertebral artery syndrome treated via an anterior approach and selective decompression only

We present the case of a 38-year-old male who complained of repeated dizziness and syncope. Rotational vertebral artery syndrome (RVAS) was diagnosed via videonystagmoraphy (VNG), computed tomography angiography (CTA) and three-position digital subtraction angiography (DSA). In the neutral position, CTA and DSA revealed left vertebral artery (VA) stenosis at the C2 transverse foramen and right VA hypoplasia. When the head was turned to the right, the blood flow stopped at the C2 level. The bony structure around the VA at the C2 transverse foramen was decompressed via an anterior surgical approach, and the symptoms resolved. This case present the precise stenotic point evaluation by three-position DSA is crucial for the planning of surgical treatment.

Changes and significance of the posterior circulation blood flow and wall shear stress in patients with vertebral artery hypoplasia / 中国脑血管病杂志

Objectives To evaluate the parameter changes of posterior circulation blood flow and wall shear stress in patients with vertebral artery hypoplasia (VAH) and to understand the possible mechanisms of VAH-induced posterior circulation infarction (PCI). Methods A total of 261 consecutive patients with suspected vascular vertigo admitted to the Department of Neurology, People's Hospital of Zhengzhou from October 2014 to January 2016 were enrolled. The vertigo symptom scale (VSS) was used to evaluate the severity of vertigo. All patients completed TCD and high field strength MR examination within 3 d of admission (Tl ,T2 weighted imaging,fluid attenuation inversion recovery [FLAIR] ,diffusion-weighted imaging [DWI],MR angiography [MRA], contrast-enhanced MRA [CEMRA]),and according to the diameter of the vertebral artery combined with the diagnostic criteria of VAH, they were divided into VAH group and non-VAH group, Posterior circulation blood flow velocity (systolic velocity [V,], diastolic velocity [Vd] , mean velocity [V]) , pulsatility index (PI) , resistance index (RI) , mean flow velocity (MFV) ,and wall shear stress (WSS) between the two group were analyzed. The paired or independent sample t test, Mann-Whitney U test and the 2 test were conducted with SPSS19.0 for intra-group or inter-group comparisons. Results Of 261 patients,78 (29.9%) had VAH,26 were complicated with basilar artery hypoplasia,37 were complicated with fetal type posterior circle of Willis,and posterior circulation infarction occurred in 48 (18. 4%). Compared with the non-VAH group, the degree of vertigo of patients was more severe in the VAH group(3[2,4] vs. 3[1,3] ,Z = 2. 29) ,and the incidence of posterior circulation infarction was significantly increased (25. 6% [20/78] vs. 13. 5% (28/183) ,x =5- 34)- The differences were statistically significant (all P 0. 05). Conclusions The incidence of VAH was higher in patients with vertigo and vascular risk factors. VAH affected the posterior circulation hemodynamics, which might be associated with the occurrence of PCI.

A case report of recurrent posterior circulation infarction caused by bow hunter syndrome / 中国脑血管病杂志

Rotational vertebral artery occlusion syndrome, also known as Bow Hunter Syndrome (BHS), is a rare clinical syndrome that causes mechanical occlusion or stenosis of the vertebral artery during head and neck rotation or extension. Ischemia symptoms of the vertebral-basilar artery system often occur during head rotation and could rapidly improve with neutral position. In a few cases, BHS may result in arterio-arterial embolic infarction due to secondary thrombosis from intimai injury caused by repeated compression of the vertebral artery. The author reported a case of a young female patient with repeated posterior circulatory infarction caused by BHS. The patient suffered from sudden unresponsiveness,memory decline,and right limb inflexibility. There were no vascular risk factors in her past history,and no correlation between clinical symptoms and neck rotation. Neck rotation test by carotid ultrasound showed the blood flow of left vertebral artery was decreased and reversed when the neck rotated to the right. Head and neck CT angiography (CTA) and DSA examination showed left vertebral artery local protrusion at the junction of V3 and V4,which was considered as dissection or pseudoaneurysm. Left vertebral artery segment after axial transverse foramen was not visible on CTA during right head rotation. High resolution MR showed a membranous structure protruding into the lumen at the V3-V4 junction of the left vertebral artery. It is suggested that the clinical symptoms of BHS may be unrelated to neck rotation, but could only present as posterior circulation area infarction combined with ipsilateral vertebral artery imaging characteristics of limited range of dissection or pseudoaneurysm. Missed diagnosis and misdiagnosis may occur if the clinicians lack the corresponding understandings and knowledge. Therefore, in young patients with posterior circulation cryptogenic stroke,morphological changes of posterior circulation vessels should be carefully analyzed. If necessary,carotid ultrasound neck rotation test or dynamic DAS should be conducted to clarify whether BHS is involved.

Dyslipidaemia was correlated to the posterior circulation infarction in non-diabetic populations.

BACKGROUND: Diabetes mellitus (DM) was prone to happening in posterior circulation infarction (POCI) and DM also has the impact on the lipids, our study was to investigate the correlation between lipid compositions and POCI. METHODS: Data was collected from the patients with acute ischemic stroke (AIS) hospitalization in Affiliated Drum Tower Hospital of Nanjing University Medical School from October 2008 to May 2012. Lipids and other risk factors in the different populations were investigated in relation to occurrence of POCI based on the infarction location. RESULTS: Six hundred ten patients with AIS were included in this study, which had 428 with anterior circulation infarction (ACI) and 182 with POCI. Elevated Triglyceride (TG) and decreased High density lipoprotein cholesterol (HDL-C) were seen in the POCI of total populations and AIS without DM compared to the ACI, but not in the populations of AIS with DM, so did the elevated TG/HDL-C ratios. Also, the percent of low HDL-C level and high TG level were higher in POCI group than that in ACI group. Furthermore, single factors logistic regression demonstrated that TG, HDL-C and TG/HDL-C ratio were correlated to the POCI whatever in the total populations or AIS without DM, but this kind of trend just maintained in the populations of AIS without DM after adjusting by relative interference factors. CONCLUSION: Dyslipidaemia was prone to happening in POCI compared to ACI in the non-diabetic populations, which was correlated to the pathogenesis of POCI.

Association Between Net Vertebral Artery Flow Volume and Non-AF Stroke: A Retrospective 2-Year Analysis.

Objectives: Association between net vertebral artery flow volume (NVAFV) and stroke types remains unclear. We hypothesize NVAFV is low in patients with posterior circulation infarction (PCI) and an ideal cut-off value for discriminating PCI from anterior circulation infarction (ACI) and controls may be present. Materials and Methods: As study candidates, we retrospectively enrolled hospitalized patients with first-time non-AF stroke within 2-years period. Consecutive non-AF, non-stroke subjects were enrolled as the control group. We compared NVAFV values among the PCI, ACI, and control groups. Results: Overall, 866 candidates-213, 418, and 235 candidates in the PCI, ACI, and control groups, respectively-were enrolled. NVAFV (mean ± SD) values were 134.8 ± 52.7, 152.3 ± 59.2, and 172.0 ± 54.7 mL/min in the PCI, ACI, and control groups, respectively. Statistics revealed significant difference (p < 0.001) among three groups. To use NVAFV as a diagnostic parameter, the AUC of any two groups should be between 0.58 and 0.69. Most (93.6%) of the controls had NVAFV above 100 mL/min. The odds ratio of any non-AF stroke is 3.48 if the NVAFV is below 100 mL/min. Conclusions: NVAFV is lowest in non-AF PCI group. Low NVAFV is associated with both non-AF ACI and PCI. No ideal cut-off value is available to discriminate PCI from other two conditions. We agree that an NVAFV of 100 mL/min is the lower limit of a normal value. Any value below 100 mL/min indicates high stroke risk and implies diffuse cerebral atherosclerosis and impaired cerebral perfusion.

The effect of vertebral artery hypoplasia in posterior circulation infarction in young patients.

Purpose Vertebral artery hypoplasia (VAH) is prevalent in the asymptomatic population and contributes to posterior circulation ischaemic events. The aims of this study were to determine whether VAH is an independent risk factor for posterior circulation infarction (PCI) stroke in young patients and to evaluate its impact on the clinical prognosis of PCI stroke in young patients. Materials and Methods The medical records of 235 young stroke patients were reviewed retrospectively. All patients underwent digital subtraction angiography (DSA). VAH was defined by a diameter of <2 mm or the absence of the lateral vertebral artery on DSA. Logistic regression analyses were performed to elucidate the independent factors associated with PCI stroke in young patients. Then, an independent two-sample t-test was performed to evaluate the clinical effect of VAH. Results Our study included 235 young patients who experienced acute ischaemic stroke, 64 of whom were diagnosed with PCI stroke and 38 of whom (16.2%) were found to have VAH. The multivariate logistic regression analysis indicated that gender and VAH were independent risk factors for PCI stroke in young patients. The independent two-sample t-test showed that among the young patients who experienced PCI stroke, the National Institute of Health Stroke Scale score was not significantly different between the patients with and without VAH. Conclusions Our study showed that VAH increases the risk of PCI stroke in young patients. However, the influence of VAH on clinical outcomes in young patients following PCI stroke is minor.