Posterior National Institutes of Health Stroke Scale Improves Prognostic Accuracy in Posterior Circulation Stroke

Background and Purpose: The National Institutes of Health Stroke Scale (NIHSS) underestimates clinical severity in posterior circulation stroke and patients presenting with low NIHSS may be considered ineligible for reperfusion therapies. This study aimed to develop a modified version of the NIHSS, the Posterior NIHSS (POST-NIHSS), to improve NIHSS prognostic accuracy for posterior circulation stroke patients with mild-moderate symptoms. Methods: Clinical data of consecutive posterior circulation stroke patients with mild-moderate symptoms (NIHSS <10), who were conservatively managed, were retrospectively analyzed from the Basilar Artery Treatment and Management registry. Clinical features were assessed within 24 hours of symptom onset; dysphagia was assessed by a speech therapist within 48 hours of symptom onset. Random forest classification algorithm and constrained optimization were used to develop the POST-NIHSS in the derivation cohort. The POST-NIHSS was then validated in a prospective cohort. Poor outcome was defined as modified Rankin Scale score ≥3 at 3 months. Results: We included 202 patients (mean [SD] age 63 [14] years, median NIHSS 3 [interquartile range, 1–5]) in the derivation cohort and 65 patients (mean [SD] age 63 [16] years, median NIHSS 2 [interquartile range, 1–4]) in the validation cohort. In the derivation cohort, age, NIHSS, abnormal cough, dysphagia and gait/truncal ataxia were ranked as the most important predictors of functional outcome. POST-NIHSS was calculated by adding 5 points for abnormal cough, 4 points for dysphagia, and 3 points for gait/truncal ataxia to the baseline NIHSS. In receiver operating characteristic analysis adjusted for age, POST-NIHSS area under receiver operating characteristic curve was 0.80 (95% CI, 0.73–0.87) versus NIHSS area under receiver operating characteristic curve, 0.73 (95% CI, 0.64–0.83), P =0.03. In the validation cohort, POST-NIHSS area under receiver operating characteristic curve was 0.82 (95% CI, 0.69–0.94) versus NIHSS area under receiver operating characteristic curve 0.73 (95% CI, 0.58–0.87), P =0.04. Conclusions: POST-NIHSS showed higher prognostic accuracy than NIHSS and may be useful to identify posterior circulation stroke patients with NIHSS <10 at higher risk of poor outcome.

Abstract 1122‐000120: Clinical and Neuroperfusion Predictors of Functional Outcome and Final Infarct Volume in Posterior Circulation Stroke

Introduction : Computed tomography perfusion (CTP) is considered standard of care in patient selection for mechanical thrombectomy (MT) in anterior circulation large vessel occlusion (LVO) ischemic strokes presenting after 6 hours from symptom onset. Its role in triaging patients is uncertain in posterior circulation stroke. The aim of this study is to assess the value of the admission CTP sequences in predicting clinical and radiological outcomes in posterior circulation LVO. Methods : We performed a retrospective cohort study of a prospectively maintained stroke database of patients who were diagnosed with a posterior circulation LVO and underwent MT. We included patients with a CTP on arrival and follow‐up imaging (brain MRI or CT) after MT. Baseline clinical as well as CTP parameters (cerebral blood flow [CBF]; cerebellar blood volume [CBV]; time at maximum intensity [Tmax]) at different thresholds were estimated using post‐processing RAPID software. Final stroke volume was quantified on follow‐up imaging using the DWI sequence or plain CT. Good functional outcome was defined as using the mRS of 0–2 at 90 days. Results : Out of 81 patients with posterior circulation LVO who underwent MT, 23 had CTP on arrival along with follow‐up brain imaging (16 had MRI, and 7 had CT) and were included in the final analysis. Lower age, BMI, NIHSS on arrival, and faster time to reperfusion were significantly associated with better mRS at 90 days (p<0.05). Tmax>6 (p = 0.08) and Tmax>8 (0.057) seconds trended towards predicting good mRS at 90 days. None of the CTP parameters showed a predictive value for final stroke volume on follow‐up imaging. Conclusions : Age, NIHSS on arrival, and time to reperfusion were superior to neuroperfusion parameters in predicting good mRS at 90 days in patients who underwent MT in posterior circulation LVO. Since CTP might have limitations in the posterior fossa for accurate estimation of ischemic volumes, plain CT or acute MRI brain may represent a diagnostic tool for patient selection in posterior circulation strokes at this moment.

Aspiration Versus Stent Retriever Thrombectomy for Posterior Circulation Stroke

Background and Purpose: Whereas a clear benefit of endovascular treatment for anterior circulation stroke has been established, randomized trials assessing the posterior circulation have failed to show efficacy. Previous studies in anterior circulation stroke suggest that advanced thrombectomy devices were of great importance in achieving clinical benefit. Little is known about the effect of thrombectomy techniques on outcomes in posterior circulation stroke. In this study, we compare first-line strategy of direct aspiration to stent retriever thrombectomy for posterior circulation stroke. Methods: We analyzed data of patients with a posterior circulation stroke who were included in the Multicentre Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands Registry between March 2014 and December 2018, a prospective, nationwide study, in which data were collected from consecutive patients who underwent endovascular treatment for ischemic stroke in the Netherlands. We compared patients who underwent first-line aspiration versus stent retriever thrombectomy. Primary outcome was functional outcome according to the modified Rankin Scale. Secondary outcomes were reperfusion grade, complication rate, and procedure duration. Associations between thrombectomy technique and outcome measures were estimated with multivariable ordinal logistic regression analyses. Results: Overall, 71 of 205 patients (35%) were treated with aspiration, and 134 (65%) with stent retriever thrombectomy. Patients in the aspiration group had a lower pc-ASPECTS on baseline computed tomography, and general anesthesia was more often applied in this group. First-line aspiration was associated with better functional outcome compared with stent retriever thrombectomy (adjusted common odds ratio for a 1-point improvement on the modified Rankin Scale 1.94 [95% CI, 1.03–3.65]). Successful reperfusion (extended Thrombolysis in Cerebral Infarction ≥2B) was achieved more often with aspiration (87% versus 73%, P =0.03). Symptomatic hemorrhage rates were comparable (3% versus 4%). Procedure times were shorter in the aspiration group (49 versus 69 minutes P <0.001). Conclusions: In this retrospective nonrandomized cohort study, our findings suggest that first-line aspiration is associated with a shorter procedure time, better reperfusion, and better clinical outcome than stent retriever thrombectomy in patients with ischemic stroke based on large vessel occlusion in the posterior circulation.

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

Background and purpose Little is known about the distribution of the arteries responsible for noncardiogenic posterior circulation stroke due to vertebral artery disease in the Chinese population. Furthermore, few studies have compared the risk factors, imaging manifestations, and outcomes across different types of vertebral artery disease. Therefore, our aim was to compare the differences in the risk factors, imaging manifestations, and outcome across various types of vertebral artery disease. Methods We prospectively enrolled 228 patients from 22 Chinese centers with noncardiogenic posterior circulation stroke due to vertebral artery disease. Vertebral artery disease was classified by the involved segments of the responsible vertebral artery, and basilar artery (BA) involvement or not. Risk factors, clinical-radiologic patterns, and outcomes were compared across different types of vertebral artery disease. Results The intracranial vertebral artery (ICVA) was more frequently involved than was the extracranial vertebral artery (ECVA). The ICVA/ICVA + ECVA group more often presented with hypertension and higher systolic blood pressure than did the ECVA group. Compared with the single-segment-of-vertebral-artery group (SSVA), the group with multiple-segments-of-vertebral-artery (MSVA) involvement or SSVA with BA involvement had more serious clinical-radiologic patterns and worse outcomes. Multivariable Cox regression identified MSVA/SSVA + BA involvement as an independent predictor of recurrent ischemic cerebrovascular events. Conclusions The risk factors for ICVA/ICVA + ECVA were different from those of ECVA, and the MSVA/SSVA + BA group had more serious clinical-radiologic patterns and worse outcomes.

Classification of posterior circulation stroke: a narrative review of terminology and history

Background. Little is known about the history of classification of posterior circulation stroke. However, it helps in developing secondary prevention and treatment strategies. We purposed to provide a narrative review of terminology and history of classification of posterior circulation stroke. Materials and methods. A comprehensive electronic literature search was performed on Scopus, Web of Science, MEDLINE, ScieLo, PubMed, the Cochrane Library, EMBASE, Global Health, CyberLeninka, RINC databases, and databases of government scientific libraries of Ukraine, European Union, United Kingdom, and the USA for 1900–2021 to identify the articles and books that discussed the classification of posterior circulation stroke and its history. Results. A narrative review of terminology and two approaches to the classification of posterior circulation stroke are presented and discussed. Conclusions. We provided a comprehensive narrative review of terminology and history of classification of posterior circulation stroke.

Video-Oculography-Assisted Head Impulse Test and Caloric Testing for Detecting Stroke in Acute Vertigo Patients via Modified HINTS Plus

Background: We assessed whether detection of stroke underlying acute vertigo using HINTS plus (head-impulse test, nystagmus type, test of skew, hearing loss) can be improved by video-oculography for automated head-impulse test (V-HIT) analysis. Methods: We evaluated patients with acute vestibular syndrome (AVS) presenting to the emergency room using HINTS plus and V-HIT-assisted HINTS plus in a randomized sequence followed by cranial MRI and caloric testing. Image-confirmed posterior circulation stroke or vertebrobasilar TIA were the reference standards to calculate diagnostic accuracy. We repeated statistical analysis for a third protocol that was composed post hoc by replacing the head-impulse test with caloric testing in the HINTS plus protocol. Results: We included 30 AVS patients (ages 55.4 ± 17.2 years, 14 females). Of these, 11 (36.7%) had posterior circulation stroke (n = 4) or TIA (n = 7). Acute V-HIT-assisted HINTS plus was feasible and displayed tendentially higher accuracy than conventional HINTS plus (sensitivity: 81.8%, 95% CI 48.2–97.7%; specificity 31.6%, 95% CI 12.6–56.6% vs. sensitivity 72.7%, 95% CI 39.0–94.0%; specificity 36.8%, 95% CI 16.3–61.6%). The new caloric-supported algorithm showed high accuracy (sensitivity 100%, 95% CI 66.4–100%; specificity 66.7%, 95% CI 41–86.7%). Conclusions: Our study provides pilot data on V-HIT-assisted HINTS plus for acute AVS assessment and indicates the diagnostic value of integrated acute caloric testing.