Migraine-Associated Common Genetic Variants Confer Greater Risk of Posterior vs. Anterior Circulation Ischemic Stroke☆

OBJECTIVE

To examine potential genetic relationships between migraine and the two distinct phenotypes posterior circulation ischemic stroke (PCiS) and anterior circulation ischemic stroke (ACiS), we generated migraine polygenic risk scores (PRSs) and compared these between PCiS and ACiS, and separately vs. non-stroke control subjects.

METHODS

Acute ischemic stroke cases were classified as PCiS or ACiS based on lesion location on diffusion-weighted MRI. Exclusion criteria were lesions in both vascular territories or uncertain territory; supratentorial PCiS with ipsilateral fetal posterior cerebral artery; and cases with atrial fibrillation. We generated migraine PRS for three migraine phenotypes (any migraine; migraine without aura; migraine with aura) using publicly available GWAS data and compared mean PRSs separately for PCiS and ACiS vs. non-stroke control subjects, and between each stroke phenotype.

RESULTS

Our primary analyses included 464 PCiS and 1079 ACiS patients with genetic European ancestry. Compared to non-stroke control subjects (n=15396), PRSs of any migraine were associated with increased risk of PCiS (p=0.01-0.03) and decreased risk of ACiS (p=0.010-0.039). Migraine without aura PRSs were significantly associated with PCiS (p=0.008-0.028), but not with ACiS. When comparing PCiS vs. ACiS directly, migraine PRSs were higher in PCiS vs. ACiS for any migraine (p=0.001-0.010) and migraine without aura (p=0.032-0.048). Migraine with aura PRS did not show a differential association in our analyses.

CONCLUSIONS

Our results suggest a stronger genetic overlap between unspecified migraine and migraine without aura with PCiS compared to ACiS. Possible shared mechanisms include dysregulation of cerebral vessel endothelial function.

The Clinical Research Progress of Vertebral Artery Dominance and Posterior Circulation Ischemic Stroke

BACKGROUND

The diameters of the vertebral arteries on both sides are usually asymmetrical. Vertebral artery dominance (VAD) and congenital vertebral artery dysplasia are derived from the asymmetry of the vertebral artery diameters on both sides. They are usually regarded as normal congenital vascular variations and have no practical clinical significance.

SUMMARY

Recently, several clinical studies have found that VAD is a risk factor for posterior circulation ischemic stroke (PCIS). The existence of VAD is clinically significant for the occurrence of PCIS, and it is recognized by an increasing number of clinicians. Key Messages: This article reviews the frequency and evaluation methods of VAD, its correlation with PCIS, and its mechanism.

Risk of posterior circulation stroke in patients with cervical spondylosis: A nationwide, population-based study

BACKGROUND AND AIMS

Cervical spondylosis (CS) is reported to be associated with vertebrobasilar insufficiency. However, few cohort studies have investigated the association between CS and posterior circulation ischemic stroke.

METHODS

The study cohort comprised 27,990 patients aged ≥18 years with a first diagnosis of CS. The controls consisted of patients with propensity score matched for age, sex, and comorbidities at a ratio of 1:1. We investigated the relationships of CS with ischemic stroke and all-cause mortality. Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). The average follow-up duration was 6.13 (SD = 3.18) and 6.07 (SD = 3.19) years in the CS and non-CS cohorts, respectively.

RESULTS

The mean age of CS patients and non-CS patients was 54.9 ± 13.4 and 55.1 ± 14.9 years. Fifty-eight point five percent of CS patients and 59.2% of non-CS patients were women. CS patients were 1.46 folds more likely to develop a posterior circulation ischemic stroke (95% CI, 1.23-1.72) than non-CS patients. CS patients with myelopathy exhibited a 1.50-fold risk (95% CI, 1.21-1.86) of posterior circulation ischemic stroke compared with non-CS patients; CS patients without myelopathy were at a 1.43-fold risk (95% CI, 1.18-1.73) of posterior ischemic stroke compared with non-CS patients. The risk of posterior ischemic stroke was non-significant between non-CS patients and CS patients who had received spinal anterior decompression (adjusted HR, 1.66; 95% CI, 0.78-3.52), while receiving posterior decompression was associated with a 4.23-fold risk of posterior ischemic stroke (95% CI, 1.05-17.0).

CONCLUSIONS

This population-based study showed that CS is associated with an increased risk of posterior circulation ischemic stroke. Surgical posterior decompression was associated with the highest risk of posterior ischemic stroke.

Greater periventricular white matter hyperintensity severity in basilar artery branch atheromatous disease

Background

Basilar artery branch atheromatous disease (BABAD), in which basilar artery atheroma occludes penetrating arteries at their origin, is a common etiology of posterior circulation stroke (PCS). It is currently unknown whether white matter hyperintensity(WMH), a marker of small vessel disease(SVD), is associated with BABAD.

Methods

The present study analyzed data from patients with PCS who were enrolled in the Taipei Veterans General Hospital Stroke Registry between January 1, 2010 and February 28, 2014. WMH severity was rated using the Scheltens scale. We used multivariate analyses to: (1) compare the severity of WMH between patients with BABAD, patients with large-artery > 50% atherosclerotic stenosis-related PCS(LAA), and non-stroke subjects(NS); and (2) evaluate the relationship between WMH severity and the 3-month prognosis of patients with BABAD.

Results

The study pool included 151 BABAD, 97 LAA, and 78 non-stroke patients. Multivariate analyses adjusting for age, sex, and vascular risk factors showed that compared to patients with LAA [Odds ratio(OR) = 0.51, p = 0.037] and NS (OR = 0.40, p = 0.004), patients with BABAD (OR = 1) had greater WMH severity (score ≥ 50th percentile) in periventricular, but not subcortical, regions. Moreover, greater periventricular WMH severity predicted poor 3-month functional outcomes (modified Rankin Scale > 3) with an OR of 3.21 (p = 0.028) in BABAD patients.

Conclusions

We are the first to show a significant association between WMH and BABAD that is independent of vascular risk factors and atherosclerotic large-artery disease. Our results suggest that small vessel abnormalities other than lipohyalinosis may be involved in BABAD pathophysiology. A future management strategy should include both large and small vessel protection.