Intrinsic stenosing and occlusive pathologies of the vertebral artery: A narrative review

Intrinsic pathologies of the vertebral arteries, such as atherosclerosis, dissection, fibromuscular dysplasia, radionecrosis and vasculitis, are important causes of vertebrobasilar insufficiency and cerebrovascular events. This review focuses on non-aneurysmal intrinsic stenosing and occlusive pathologies, covering their epidemiology, diagnosis, and treatment options. It also provides a detailed summary of key clinical presentations and syndromes, including an in-depth examination of lateral medullary syndrome, historically known as Wallenberg's syndrome, which is arguably the most emblematic condition resulting from vertebral artery involvement and is depicted in an illustrative cartoon.

Preconditioning by Preceding Ischemic Cerebrovascular Events

Background Emerging yet contrasting evidence from animal and human studies associates ischemic preconditioning with improvement of subsequent stroke severity, although long-term outcome remains unclear. The purpose of this study was to analyze how preceding cerebral ischemic events influence subsequent stroke severity and outcome. Methods and Results Data for this retrospective cohort study were extracted from ASTRAL (Acute Stroke Registry and Analysis of Lausanne). This registry includes a sample of all consecutive patients with acute ischemic strokes admitted to the stroke unit and/or intensive care unit of the Lausanne University Hospital, Switzerland. We investigated associations between preceding ischemic events (transient ischemic attacks or ischemic strokes) and the impact on subsequent stroke severity and clinical improvement within 24 hours, measured through National Institute of Health Stroke Scale, as well as 3-month outcome, determined through a shift in the modified Rankin Scale. Of 3530 consecutive patients with ischemic stroke (43% women, median age 73 years), 1001 (28%) had ≥1 preceding cerebral ischemic events (45% transient ischemic attack, 55% ischemic stroke; 31% multiple events). After adjusting for multiple prehospital, clinical, and laboratory confounders, admission stroke severity was significantly lower in patients preconditioned through a preceding ischemic event, but 24-hour improvement was not significant and 3-month outcome was unfavorable. Conclusions Preceding ischemic events were independently associated with a significant reduction in subsequent stroke severity but worsened long-term clinical outcome. These results, if confirmed by future randomized studies, may help design neuroprotective strategies. The unfavorable effect on stroke outcome is probably a consequence of the cumulative disability burden after multiple ischemic events.

Abstract TP421: Ischemic Preconditioning From Preceding Cerebrovascular Events in Stroke Patients

Introduction: Preconditioning improves acute ischemic stroke (AIS) outcomes in animals and possibly in humans. The influence of a preceding ischemic event (PIE), such as a TIA or AIS occurring at different intervals, sites and for different durations, needs to be studied in humans.

Hypothesis: We aimed to identify whether a PIE can have a preconditioning effect on a subsequent AIS.

Methods: Using consecutive AIS from the ASTRAL registry we determined demographics, risk factors, past medical history,stroke mechanism,PIE and other features that were associated with initial stroke severity measured by NIHSS. We used a multivariate linear regression model with NIHSS as the dependent variable to compare groups with and without PIE.

Results: Of 3501 consecutive AIS patients (43% females, median age 73 y), 996 (28.4%) had preceding PIEs (15.7% TIA, 12.9% ischemic stroke, 2.4% retinal ischemia, 8.8% multiple events). There were 162 acute PIE in the preceding 24 h, and 94 subacute PIE up to 7 d before the stroke, respectively with a median delay between the PIE and the subsequent stroke of 180 days.Results of the adjusted multivariate regression analysis are shown as forest plots below.

Conclusions: In patients with AIS, we found an independent association between lesser stroke severity and PIE, suggesting a possible beneficial role of ischemic preconditioning in stroke in humans. The effect of timing, severity,location of PIE and long-term outcome of such patients needs to be analyzed in further studies.

Beauty parlor stroke revisited: An 11-year single-center consecutive series

BACKGROUND

Hairdresser-related ischemic cerebrovascular events (HICE) are attributed to compression of vertebral arteries or cervical artery dissections. We determined their frequency, mechanisms, localization and outcome in a pre-specified study.

METHODS

We prospectively collected ischemic strokes and transient ischemic attacks occurring in relation to a hairdresser visit from 2002 to 2013, using consecutive data from an ischemic stroke registry (ASTRAL). HICE were compared to all other acute ischemic strokes in ASTRAL.

RESULTS

We identified 10 HICE (9 strokes and 1 transient ischemic attack). Age and anterior-posterior distribution were similar with a significantly higher rate of females (90% vs. 43%, p = 0.02) in the HICE group compared to ASTRAL. Patients with HICE had significantly lower incidence of hyperlipidemia (30% vs. 73%) and diabetes (0% vs. 19%). The mechanisms of HICE were diverse: carotid artery dissection (n = 2), cardiac (n = 2), lacunar (n = 2), other determined (n = 2) and unknown etiology (n = 2). Two HICE with atherosclerotic intracranial disease were possibly caused by acute hemodynamic changes related to systemic hypotension during hot air hair drying. Unadjusted favorable outcome at three months seemed to be better in HICE (90% vs. 57%), and 12-month mortality and recurrences were similar.

CONCLUSIONS

HICE may occur frequently in females without a predilection for the posterior circulation. Although some HICE may occur by chance (pseudo-HICE), hairdresser visits may have a causal role in some cases, including cervical artery dissection or hemodynamic compromise related to pre-existing arterial disease (true HICE). Available data are insufficient for specific preventive recommendations.

Acute salivary gland hypofunction in the duct ligation model in the absence of inflammation

Objective

The commonly associated aetiology of salivary gland inflammation and salivary hypofunction has led to the widely held belief that inflammation causes salivary gland hypofunction. Indeed, our own recent study seemed to support this contention. Here, we tested the hypothesis that, in an acute duct ligation model, eliminating inflammation the submandibular gland would recover normal function.

Materials and methods

Ligation of the rat submandibular gland excretory duct for 24 h was used to induce inflammation and salivary gland hypofunction. A group of duct ligated rats was compared with a second group given dexamethasone, on the day of duct ligation. Twenty-four hours later salivary gland function was assessed and salivary glands were collected.

Results

Histology and myeloperoxidase activity assay revealed a profound decrease in inflammatory cell infiltration of ligated glands from rats given dexamethasone, compared with ligated glands in the absence of dexamethasone. Salivary flow rate evoked by methacholine was decreased (P < 0.01) by approximately 56% (ligated vs control, 79 ± 9 μl min⁻¹ g⁻¹vs 177 ± 11 μl min⁻¹ g⁻¹) and salivary flow from ligated dexamethasone-treated and ligated glands was similar.

Conclusion

Despite eliminating the inflammatory reaction in the ligated gland, salivary hypofunction was not reversed, suggesting that other mechanisms must be at work in the ligation-induced salivary hypofunction.