Intravenous thrombolysis in posterior cerebral artery infarctions

Thrombectomy vs Medical Management for Posterior Cerebral Artery Stroke: Systematic Review, Meta-Analysis, and Real-World Data

BACKGROUND AND OBJECTIVES

There is a paucity of high-level evidence for endovascular thrombectomy (EVT) in posterior cerebral artery (PCA) strokes.

METHODS

The MEDLINE, Embase, and Web of Science databases were queried for well-conducted cohort studies comparing EVT vs medical management (MM) for PCA strokes. Outcomes of interest included 90-day functional outcomes, symptomatic intracranial hemorrhage (sICH), and death. The level of evidence was determined per the Oxford Centre for Evidence-Based Medicine criteria. We also conducted a propensity score matched (PSM) analysis of the 2016-2020 National Inpatient Sample (NIS) to provide support for our findings with real-world data.

RESULTS

A total of 2,095 patients (685 EVT and 1,410 MM) were identified across 5 well-conducted cohort studies. EVT was significantly associated with higher odds of no disability at 90 days (odds ratio [OR] 1.25, 95% CI 1.04-1.50, p = 0.015) but not functional independence (OR 0.87, 95% CI 0.72-1.07, p = 0.18). EVT was also associated with higher odds of sICH (OR 2.48, 95% CI 1.55-3.97, p < 0.001) and numerically higher odds of death (OR 1.32, 95% CI 0.73-2.38; p = 0.35). PSM analysis of 95,585 PCA stroke patients in the NIS showed that EVT (n = 1,540) was associated with lower rates of good discharge outcomes (24.4% vs 30.7%, p = 0.037), higher rates of in-hospital mortality (8.8% vs 4.9%, p = 0.021), higher rates of ICH (18.2% and 11.7%, p = 0.008), and higher rates of subarachnoid hemorrhage (3.9% vs 0.6%, p < 0.001). Among patients with moderate to severe strokes (NIH Stroke Scale 5 or greater), EVT was associated with significantly higher rates of good outcomes (21.7% vs 13.8%, p = 0.023) with similar rates of mortality (7.6% vs 6.6%, p = 0.67) and ICH (17.8% vs, 13.1%, p = 0.18).

DISCUSSION

Our meta-analysis revealed that while EVT may be effective in alleviating disabling deficits due to PCA strokes, it is not associated with different odds of functional independence and may be associated with higher odds of sICH. These findings were corroborated by our large propensity score matched analysis of real-world data in the United States. Thus, the decision to pursue PCA thrombectomies should be carefully individualized for each patient. Future randomized trials are needed to further explore the efficacy and safety of EVT for the treatment of PCA strokes.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that in patients with acute PCA ischemic stroke, treatment with EVT compared with MM alone was associated with higher odds of no disabling deficit at 90 days and higher odds of sICH.

Intravenous thrombolysis for ischemic stroke in the posterior circulation: A systematic review and meta-analysis

OBJECTIVES

Intravenous thrombolysis (IVT) is recommended in patients with ischemic stroke in the anterior and posterior circulation. Neurological outcomes due to posterior circulation strokes (PCS) without treatment remain poor. Our aim was to overview the literature on outcomes of IVT and conservative treatment in PCS, based on a systematic review and meta-analysis.

METHODS

A systematic literature search was performed on February 27th 2023. Outcome measures included favorable functional outcome at 90 days (modified Rankin Scale [mRS] 0-2), mortality at 90 days, and symptomatic intracranial hemorrhages (sICH). Weighted averages with DerSimonian-Laird approach was used to analyze the data. Subgroup analyses by time window were performed: standard time window (<4.5 hours after symptom onset) and extended time window (>4.5 hours). Analyses were performed using R.

RESULTS

Eight prospective and four retrospective cohort studies were included (n = 1589 patients); no studies with conservative treatment were eligible. The pooled weighted probability regarding favorable functional outcome after IVT was 63 % (95 %CI:0.45-0.78), for mortality 19 % (95 %CI:0.11-0.30), and for sICH 4 % (95 %CI:0.02-0.07). Subgroup analyses showed higher probabilities on achieving favorable functional outcomes for patients treated in the standard (77 %; 95 %CI:0.62-0.88) compared to the extended time window (38 %; 95 %CI:0.29-0.48) with RR = 1.93 (95 %CI:1.66-2.24). Lower probabilities regarding mortality at 90 days and sICH were seen in patients treated in standard compared to extended time window (RR = 0.42, 95 %CI:0.34-0.51 and RR = 0.27, 95 %CI:0.16-0.45, respectively).

CONCLUSIONS

IVT in patients with PCS seems to be safe and effective in standard and extended time window. The effect of IVT is higher in the standard time window.

Endovascular therapy outcome in isolated posterior cerebral artery occlusion strokes: A multicenter analysis of the Swiss Stroke Registry

PURPOSE

There is little data on the safety and efficacy of endovascular treatment (EVT) in comparison with intravenous thrombolysis (IVT) in acute ischemic stroke due to isolated posterior cerebral artery occlusion (IPCAO). We aimed to investigate the functional and safety outcomes of stroke patients with acute IPCAO treated with EVT (with or without prior bridging IVT) compared to IVT alone.

METHODS

We did a multicenter retrospective analysis of data from the Swiss Stroke Registry. The primary endpoint was overall functional outcome at 3 months in patients undergoing EVT alone or as part of bridging, compared with IVT alone (shift analysis). Safety endpoints were mortality and symptomatic intracranial hemorrhage. EVT and IVT patients were matched 1:1 using propensity scores. Differences in outcomes were examined using ordinal and logistic regression models.

FINDINGS

Out of 17,968 patients, 268 met the inclusion criteria and 136 were matched by propensity scores. The overall functional outcome at 3 months was comparable between the two groups (EVT vs IVT as reference category: OR = 1.42 for higher mRS, 95% CI = 0.78-2.57, p = 0.254). The proportion of patients independent at 3 months was 63.2% in EVT and 72.1% in IVT (OR = 0.67, 95% CI = 0.32-1.37, p = 0.272). Symptomatic intracranial hemorrhages were overall rare and present only in the IVT group (IVT = 5.9% vs EVT = 0%). Mortality at 3 months was also similar between the two groups (IVT = 0% vs EVT = 1.5%).

CONCLUSION

In this multicenter nested analysis, EVT and IVT in patients with acute ischemic stroke due to IPCAO were associated with similar overall good functional outcome and safety. Randomized studies are warranted.

Endovascular Therapy versus No Endovascular Therapy in Patients receiving Best Medical Management for Acute Isolated Occlusion of the Posterior Cerebral Artery: Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Endovascular therapy (EVT) is increasingly reported for treatment of isolated posterior cerebral artery (PCA) occlusions although its clinical benefit remains uncertain. This study-level meta-analysis investigated functional outcome and safety of EVT and best medical management (BMM) compared to BMM for treatment of PCA occlusion stroke.

METHODS

We conducted a literature search in PubMed, Web of Science and Embase for articles reporting patients with isolated PCA occlusion stroke treated with EVT+BMM or BMM including intravenous thrombolysis. There were no randomized trials and all studies were retrospective. Primary outcome was a modified Rankin Scale score of 0-2 at 3 months; safety outcomes included mortality rate and incidence of symptomatic intracranial hemorrhage.

RESULTS

Twelve articles with a total of 679 patients were included in the meta-analysis consisting of 338 patients with EVT+BMM and 341 patients receiving BMM alone. Good functional outcome at 3 months was achieved in 58.0% [95% confidence interval (CI) 43.83-70.95] of patients with EVT+BMM and 48.1% [95% CI 40.35-55.92] of patients with BMM with respective mortality rates of 12.6% [7.30-20.93] and 12.3% [8.64-17.33]. Symptomatic intracranial hemorrhage occurred in 4.2% [95% CI 2.47-7.03] of patients with EVT+BMM and 3.2% [95% CI 1.75-5.92] of patients with BMM. Comparative analyses were performed of publications reporting both treatments and demonstrated no significant differences.

CONCLUSIONS

The results demonstrate that EVT represents a safe treatment for patients with isolated PCA occlusion stroke. There were no differences in clinical or safety outcomes between treatments, supporting randomization of future patients into distal vessel occlusion trials.

Rt-PA thrombolytic therapy in patients with acute posterior circulation stroke: A retrospective study

At present, recombinant tissue-type plasminogen activator (rt-PA) thrombolytic therapy is widely used in patients with acute ischemic stroke within 4.5 h following stroke onset. However, the efficacy of intravenous alteplase thrombolytic therapy for posterior circulation stroke (PCS) has been rarely described. The present study aimed to predict the outcome of patients with PCS following rt-PA thrombolytic therapy in a more efficient manner. Data were collected from patients who had suffered from posterior circulation ischemic stroke, who had been treated with rt-PA over a period of 4 years (2016-2020), and had been treated at a stroke center. All patients were treated with alteplase at a standard dose of 0.9 mg/kg. According to the onset to needle time (ONT), these patients were divided into the 0-3 and 3-4.5 h groups, and the National Institutes of Health Stroke Scale (NIHSS) score was compared before thrombolysis and at 24 h after thrombolysis. Subsequently, the patients with acute PCS whose ONT was ≤3 h were divided into the NIHSS score >3 points and NIHSS score ≤3 points groups, and the NIHSS score improvement rate was compared 24 h later. A total of 989 patients were included in the study; there were 783 patients with acute anterior circulation stroke (ACS) and 203 patients with acute PCS (of note, 2 patients had negative results from brain magnetic resonance imaging); 63 patients were treated with urokinase (UK) thrombolysis and 140 patients were treated with alteplase intravenous thrombolysis. The 140 patients that received alteplase thrombolytic therapy were divided into two groups, namely the ≤3 h group and 3-4.5 h group, which, on the basis of the ONT, no significant differences were found between the two the groups according to the NIHSS score before thrombolysis (P>0.05). The NHISS scores in the ≤3 h group were significantly lower than those in the 3-4.5 h group following thrombolysis therapy, and the differences between the two groups were statistically significant (P<0.05); the patients with acute PCS treated with rt-PA in the ≤3 h group were divided into the NIHSS score ≤3 points group and the NIHSS score >3 points group. In this ≤3 h group, the average NIHSS score improvement rate following rt-PA thrombolysis was 0.535 (53.5%) in the NIHSS score ≤3 points group and that in the NIHSS score >3 points group was 0.336 (33.6%); the difference between the two groups was statistically significant (P<0.05). The patients treated with intravenous alteplase thrombolysis within 3 h following stroke onset benefited more than those treated with thrombolysis therapy within 3 to 4.5 h after stroke onset. On the whole, the present study demonstrates that the patients with mild stroke (NIHSS score ≤3 points) who were treated at an earlier stage (received alteplase thrombolysis therapy within 3 h after stroke onset) benefited to a greater extent from the therapy.

Posterior Circulation Ischaemic Stroke

Posterior circulation ischaemic stroke (PCIS) is a disease of high burden. They account for 20-25% of all ischaemic strokes. However, it is relatively under-researched and requires more clinical attention, since it carries worse functional outcomes. Vertigo, visual disturbances and sensory/motor disturbances are found in PCIS. Large artery atherosclerosis and embolism are main causes of PCIS, while there is growing evidence that vertebrobasilar dolichoectasia is a key association. Hypertension is the commonest risk factor, while diabetes mellitus is more specific to PCIS. PCIS is diagnosed through neuroimaging techniques, which examine structural brain abnormalities, vascular patency and perfusion. PCIS, in line with ischaemic stroke in general, requires medical treatment and lifestyle modifications. This includes smoking cessation, weight control, and dietary alterations. Aspirin use also significantly improves survival outcomes. While intravascular and intra-arterial thrombolysis improve clinical outcomes, this is not proven conclusively for stenting and angioplasty. Future research on PCIS can focus on multi-centre epidemiological studies, clinically significant anatomical variants, and collateralisation.

Acute Treatment of Isolated Posterior Cerebral Artery Occlusion: Single Center Experience

BACKGROUND AND OBJECTIVES

Randomized trials for mechanical thrombectomy (MT) excluded patients with ischemic strokes due to isolated posterior cerebral artery occlusion (IPCAO), and there is no evidence for best acute treatment strategy in these patients. We aimed to assess the effectiveness and safety of MT in acute IPCAO.

METHODS

We retrospectively analyzed consecutive patients with acute stroke due to IPCAO submitted to MT and/or intravenous thrombolysis (IVT), between 2015-2019. Effectiveness outcomes (recanalization rate, first-pass effect, NIHSS 24h improvement and 3-month Modified Ranking Scale - mRS) and safety outcomes (complications, symptomatic intracranial hemorrhage (SICH) and 3-month mortality) were described and compared between groups.

RESULTS

A total of 38 patients were included, 25 underwent MT and 13 had IVT alone. Successful and complete recanalization were achieved in 68% and 52% of MT patients, respectively. NIHSS improvement at 24h was found in 56% of MT patients versus 30.8% of patients submitted to IVT alone (OR [95% CI]=2.86 [0.69-11.82]) and excellent functional outcome at 3 months (mRS≤1) was achieved in 54.2% of MT patients versus 38.5% in the IVT group (OR [95% CI]=1.60 [0.41-6.32]). Complications occurred in 3 (12%) procedures and there were no SICH. Mortality at 3 months was 20% in the MT group and 15.4% in patients submitted to IVT alone.

CONCLUSIONS

Our results reflect a real-world scenario in a single center and seem to support the recently growing literature showing that MT is a feasible and safe treatment in IPCAO, with favorable effectiveness.

Mechanical thrombectomy versus intravenous alteplase alone in acute isolated posterior cerebral artery occlusion: a systematic review

BACKGROUND

Acute isolated posterior cerebral artery occlusions (aPCAOs) were excluded or under-represented in major randomized trials of mechanical thrombectomy (MT). The benefit of MT in comparison to intravenous tissue plasminogen activator (alteplase; IV-tPA) alone in these patients remains controversial and uncertain.

METHODS

We performed a systematic search of PubMed, MEDLINE, and EMBASE databases for articles comparing MT with or without bridging IV-tPA and IV-tPA alone for aPCAO using keywords ('posterior cerebral artery', 'thrombolysis' and 'thrombectomy') with Boolean operators. Extracted data from patients reported in the studies were pooled into groups (MT vs IV-tPA alone) for comparison. Estimated rates for favorable outcome (modified Rankin scale score 0-2), symptomatic intracranial hemorrhage (sICH), and mortality were extracted.

RESULTS

Seven articles (201 MT patients, 64 IV-tPA) were included, all retrospective. There was no statistically significant difference between pooled groups in median age, median presentation National Institutes of Health Stroke Scale (NIHSS) score, PCAO segment, and median time from symptom onset to puncture or needle. The recanalization rate was significantly higher in the MT group than the IV-tPA group (85.6% vs 53.1%, p<0.00001). Odds ratios for favorable outcome (OR 1.5, 95% CI 0.8 to 2.5), sICH (OR 1.1, 95% CI 0.2 to 5.5), and mortality (OR 1.4, 95% CI 0.5 to 3.6) did not significantly favor any modality.

CONCLUSIONS

We found no significant differences in odds of favorable outcome, sICH, and mortality in MT and IV-tPA in comparable aPCAO patients, despite superior MT recanalization rates. Equipoise remains regarding the optimal treatment modality for these patients.

IV-Thrombolysis in Ischemic Stroke With Unknown Time of Onset-Safety and Outcomes in Posterior vs. Anterior Circulation Stroke

Background: rt-PA for ischemic stroke in the unknown or extended time window beyond the first 4. 5 h after symptom onset is safe and effective for certain patients after selection by multimodal neuroimaging. However, the evidence for this approach comes mainly from patients with anterior circulation stroke (ACS), while the data on posterior circulation stroke (PCS) are scarce.

Methods: Ischemic stroke patients treated with IV-thrombolysis in the unknown or extended time window between January 2011 and May 2019 were identified from an institutional registry. The patients were categorized into PCS or ACS based on clinico-radiological findings. We analyzed the hemorrhagic complications, clinical and imaging efficacy outcomes, and mortality rates by comparing the PCS and ACS patient groups. Adjusted outcome analyses were performed after propensity score matching for the relevant factors.

Results: Of the 182 patients included, 38 (20.9%) had PCS and 144 (79.1%) had ACS. Symptomatic acute large vessel occlusion (LVO) was present in 123 patients on admission [27 (22.0%) PCS and 96 (78.0%) ACS]. The score on the National Institutes of Health Stroke Scale (NIHSS), the time from last seen normal, and the door-to-needle times were similar in PCS and ACS. In patients with LVO, the NIHSS score was lower [8 (5–15) vs. 14 (9–18), p = 0.005], and infarction visible on follow-up imaging was less common [70.4 vs. 87.5%; aRD, −18.9% (−39.8 to −2.2%)] in the PCS patient group. There was a trend toward a lower risk for intracranial hemorrhage (ICH) following intravenous thrombolysis in PCS vs. ACS, without reaching a statistical significance [5.3 vs. 16.9%; aRD, −10.4% (−20.4 to 4.0%)]. The incidence of symptomatic ICH [according to the ECASS III criteria: 2.6 vs. 3.5%; aRD, −2.9% (−10.3 to 9.2%)], efficacy outcomes, and mortality rates were similar in PCS and ACS patients.

Conclusions: In this real-world clinical cohort, the safety and the efficacy of rt-PA for ischemic stroke in the unknown or extended time window did not show relevant differences between PCS and ACS, with a trend toward less hemorrhagic complications in PCS. The findings reconfirm the clinician in the usage of rt-PA beyond the first 4.5 h also in selected patients with PCS.

Novel Treatments for Transient Ischemic Attack and Acute Ischemic Stroke

The treatment of acute ischemic stroke is one of the most rapidly evolving areas in medicine. Like all ischemic vascular emergencies, the priority is reperfusion before irreversible infarction. The central nervous system is sensitive to brief periods of hypoperfusion, making stroke a golden hour diagnosis. Although the phrase "time is brain" is relevant today, emerging treatment strategies use more specific markers for consideration of reperfusion than time alone. Innovations in early stroke detection and individualized patient selection for reperfusion therapies have equipped the emergency medicine clinician with more opportunities to help stroke patients and minimize the impact of this disease.

Safety and Outcomes of Intravenous Thrombolysis in Posterior Versus Anterior Circulation Stroke: Results From the Safe Implementation of Treatments in Stroke Registry and Meta-Analysis

Background and Purpose- Posterior circulation stroke (PCS) accounts for 5% to 19% of patients with acute stroke receiving intravenous thrombolysis. We aimed to compare safety and outcomes following intravenous thrombolysis between patients with PCS and anterior circulation stroke (ACS) and incorporate the results in a meta-analysis. Methods- We included patients in the Safe Implementation of Treatments in Stroke Thrombolysis Registry 2013 to 2017 with computed tomography/magnetic resonance angiographic occlusion data. Outcomes were parenchymal hematoma, symptomatic intracerebral hemorrhage (SICH) per SITS-MOST (Safe Implementation of Thrombolysis in Stroke Monitoring Study), ECASS II (Second European Co-operative Stroke Study) and NINDS (Neurological Disorders and Stroke definition), 3-month modified Rankin Scale score, and death. Adjustment for SICH risk factors (age, sex, National Institutes of Health Stroke Scale, blood pressure, glucose, and atrial fibrillation) and center was done using inverse probability treatment weighting, after which an average treatment effect (ATE) was calculated. Meta-analysis of 13 studies comparing outcomes in PCS versus ACS after intravenous thrombolysis was conducted. Results- Of 5146 patients, 753 had PCS (14.6%). Patients with PCS had lower median National Institutes of Health Stroke Scale: 7 (interquartile range, 4-13) versus 13 (7-18), P<0.001 and fewer cerebrovascular risk factors. In patients with PCS versus ACS, parenchymal hematoma occurred in 3.2% versus 7.9%, ATE (95% CI): -4.7% (-6.3% to 3.0%); SICH SITS-MOST in 0.6% versus 1.9%, ATE: -1.4% (-2.2% to -0.7%); SICH NINDS in 3.1% versus 7.8%, ATE: -3.0% (-6.3% to 0.3%); SICH ECASS II in 1.8% versus 5.4%, ATE: -2.3% (-5.3% to 0.7%). In PCS versus ACS, 3-month outcomes (70% data availability) were death 18.5% versus 20.5%, ATE: 6.0% (0.7%-11.4%); modified Rankin Scale score 0-1, 45.2% versus 37.5%, ATE: 1.7% (-6.6% to 3.2%); modified Rankin Scale score 0-2, 61.3% versus 49.4%, ATE: 2.4% (3.1%-7.9%). Meta-analysis showed relative risk for SICH in PCS versus ACS being 0.49 (95% CI, 0.32-0.75). Conclusions- The risk of bleeding complications after intravenous thrombolysis in PCS was half that of ACS, with similar functional outcomes and higher risk of death, acknowledging limitations of the National Institutes of Health Stroke Scale for stroke severity or infarct size adjustment.

Thrombectomy and Thrombolysis of Isolated Posterior Cerebral Artery Occlusion

Background and Purpose—

We investigated efficacy and safety of acute revascularization with intravenous thrombolysis (IVT) and endovascular treatment (EVT) in ischemic stroke from isolated posterior cerebral artery occlusion, by assessing recanalization, disability, visual, cognitive outcomes, and hemorrhagic complications.

Methods—

For this retrospective single-center cohort study, we selected all consecutive patients with stroke with isolated posterior cerebral artery occlusion from the Acute Stroke Registry and Analysis of Lausanne registry between January 2003 and July 2018, and compared (1) IVT with conservative treatment (CTr) and (2) EVT to best medical therapy (BMT, ie, CTr or IVT) in terms of 3-month disability and visual field defect, and cognitive domains impaired after stroke. Unadjusted analysis, multivariable logistic regression, and propensity score matched analyses were performed.

Results—

Among 106 patients with isolated posterior cerebral artery occlusion, 21 received EVT (13 bridging), 34 IVT alone, and 51 CTr. Median age was 76 years, 47% were female and median National Institutes of Health Stroke Scale score was 7. Complete 24-hour recanalization was more frequent with IVT than CTr (51% versus 9%; OR [95% CI]=10.62 [2.13–52.92]) and with EVT compared with BMT (68% versus 34%; OR [95% CI]=4.11 [1.35–12.53]). Higher proportions of good disability, visual and cognitive outcomes were observed in IVT versus CTr, adj ORs (95% CI)=1.65 (0.60−4.52), 2.01 (0.58−7.01), 2.94 (0.35−24.4), respectively, and in EVT versus BMT, adj ORs (95% CI)=1.44 (0.51−4.10), 4.28 (1.00−18.29), 4.37 (0.72−26.53), respectively. Hemorrhagic complications and mortality did not increase with IVT or EVT.

Conclusion

s—We show increased odds of recanalization following IVT and even higher after EVT. We observed a trend for a positive effect on disability, visual, and cognitive outcomes with IVT over CTr and with EVT over BMT.

Is Functional Outcome Different in Posterior and Anterior Circulation Stroke?

Background and Purpose- Posterior circulation stroke (PCS) account for 20% of all ischemic strokes. There is limited evidence whether functional outcome of PCS is comparable to that of anterior circulation stroke (ACS). We aimed to analyze whether 3-month functional outcome is different in PCS and ACS. Methods- Patients with acute ischemic stroke prospectively enrolled within the Austrian Stroke Unit Registry were stratified by infarct localization according to the Oxfordshire Community Stroke Project Classification. Propensity score matching was used to control for covariate imbalances and to match patients with PCS and ACS. Patients were matched for stroke severity, recombinant tissue-type plasminogen activator treatment, and demographic and vascular risk factors. Main outcomes were the distribution of modified Rankin Scale after 3 months and multiple proportional odds models to estimate the influence of the infarct localization on the functional outcome. Results- From a total of 90 484 patients enrolled within the Austrian Stroke Unit Registry, 9208 (4604 PCS/4604 ACS) were matched, of those 954 (477 in each group) were treated with recombinant tissue-type plasminogen activator. We detected a significant shift towards better 3-month functional outcome in patients with ACS compared with PCS (odds ratio [OR], 1.19; 95% CI, 1.1-1.28; P<0.0001). In particular, functional outcome was worse in PCS with onset-to-door-time >270 minutes (OR, 1.34; 95% CI, 1.17-1.54; P<0.0001) and in PCS with unknown onset-to-door-time (OR, 1.26; 95% CI, 1.13-1.42; P<0.0001); however, we did not detect any difference in functional outcome between ACS and PCS in patients with an onset-to-door-time ≤270 minutes (1-180 minutes: OR, 0.92, 95% CI, 0.78-1.09, P=0.3554; 181-270 minutes: OR, 1.04, 95% CI, 0.79-1.37, P=0.7689). In patients treated with recombinant tissue-type plasminogen activator, functional outcome was not significantly different between PCS and ACS. Conclusions- PCS was associated with worse outcome compared with ACS in patients arriving later than 4.5 hours at hospital or in those with unknown onset of symptoms. Our results urge for implementation of symptoms found in the posterior circulation into preclinical patient-triage tools.

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.

Prehospital pathways of occipital stroke patients with mainly visual symptoms

OBJECTIVES

Occipital ischemic strokes typically cause homonymous visual field defects, for which means of rehabilitation are limited. Intravenous thrombolysis is increasingly and successfully used for their acute treatment. However, recognition of strokes presenting with mainly visual field defects is challenging for both patients and healthcare professionals. We studied prehospital pathways of occipital stroke patients with mainly visual symptoms to define obstacles in their early recognition.

MATERIALS & METHODS

This observational, retrospective, registry-based study comprises occipital stroke patients with isolated visual symptoms treated at the neurological emergency department of Helsinki University Central Hospital in 2010-2015. We analyzed their prehospital pathways, including time from symptom onset to admission at the neurological emergency department (ODT), the number of points of care, the percentage of patients with ODT≤4.5 hours, and factors associated with delay.

RESULTS

Among 245 patients, only 20.8% arrived within 4.5 hours and 6.5% received IV thrombolysis. Delayed arrival was most often due to patients' late contact to health care. Of the patients, 27.3% arrived through at least two points of care, and differential diagnostics to ophthalmologic disorders proved particularly challenging. ODT≤4.5 hours was associated with EMS utilization, direct arrival, and atrial fibrillation; a visit at an ophthalmologist and initial misdiagnosis were associated with ODT>4.5 hours. After multivariable analysis, only direct arrival predicted ODT≤4.5 hours.

CONCLUSIONS

Occipital stroke patients with visual symptoms contact health care late, are inadequately recognized, and present with complex prehospital pathways. Consequently, they are often ineligible for IV thrombolysis. This presents a missed opportunity for preventing permanent visual field defects.

Less thrombolysis in posterior circulation infarction-a necessary evil?

OBJECTIVES

Patients with posterior circulation infarction (PCI) have more subtle symptoms than anterior circulation infarction (ACI) and could come too late for acute intervention. This study aimed to describe the clinical presentation, management, and outcome of PCI in the NORSTROKE registry.

METHODS

All patients with PCI admitted to the Department of Neurology at Haukeland University Hospital and registered in the NORSTROKE database 2006-2013 were included (n=686). Patients with ACI (n=1758) were used for comparison.

RESULTS

Patients with PCI were younger (68.2 vs 71.8, P<.001), had longer median time from symptom onset to admission (3.8 hours vs 2.2 hours, P<.001), and were less likely to arrive at hospital within 4.5 hours from symptom onset (56.2% vs 72.5%, P<.001, ictus known). Patients with PCI scored lower on baseline National Institute of Health Stroke Scale (NIHSS) total score (3.2 vs 6.3, P<.001), and lower or equally on all items of NIHSS, except for ataxia in two limbs. Patients with PCI were less likely to receive i.v. thrombolytic treatment (9.9% vs 21.5%, OR 0.66, CI 0.47-0.94). On day 7, patients with PCI scored lower on NIHSS (2.8 vs 4.9, P<.001), modified Rankin Scale (2.0 vs 2.3, P<.001), and higher on Barthel Index (84.5 vs 76.0, P<.001).

CONCLUSIONS

Our study is, to our knowledge, the largest series reporting comprehensively on PCI verified by diffusion-weighted imaging. PCI patients are younger than ACI and have better outcome. PCI and ACI are equally investigated in the acute setting, but thrombolysis rates remain 50% lower in PCI.

A Case of Acute Isolated Posterior Cerebral Artery Occlusion Successfully Treated with Endovascular Clot Aspiration

Posterior cerebral artery (PCA) strokes produce various symptoms. Therefore, the diagnosis is often delayed and patients arrive late for thrombolytic therapy. We report a case of acute isolated PCA occlusion that was successfully treated with endovascular clot aspiration. A 63-year-old man presented with right complete homonymous hemianopia. Diffusion-weighted image (DWI) showed a high-intensity area (HIA) in the occipital lobe, and magnetic resonance angiography (MRA) showed PCA occlusion. Emergency endovascular clot aspiration was performed immediately after the diagnosis. Blood flow in PCA completely recovered 210 min after symptom onset. DWI after surgery showed partial disappearance of HIA, and the patient recovered from the symptom of right complete homonymous hemianopia. Endovascular recanalization is useful for acute PCA occlusion. This is the first reported case of acute isolated PCA occlusion successfully treated with endovascular clot aspiration. Prompt reperfusion results in a good clinical course in patients with PCA stroke. In this case, endovascular clot aspiration resulted in prompt recanalization in a patient with acute isolated PCA occlusion.

The Oxfordshire Community Stroke Project classification system predicts clinical outcomes following intravenous thrombolysis: a prospective cohort study

Background

The Oxfordshire Community Stroke Project (OCSP) classification system is a simple stroke classification system that can be used to predict clinical outcomes. In this study, we compare the safety and efficacy of intravenous thrombolysis in Chinese stroke patients categorized using the OCSP classification system.

Patients and methods

We collected data from the Thrombolysis Implementation and Monitoring of Acute Ischemic Stroke in China registry. A total of 1,115 patients treated with intravenous thrombolysis with alteplase within 4.5 hours of stroke onset were included. Symptomatic intracranial hemorrhage (SICH), mortality, and 90-day functional outcomes were compared between the stroke patients with different stroke subtypes.

Results

Of the 1,115 patients included in the cohort, 197 (17.67%) were classified with total anterior circulation infarct (TACI), 700 (62.78%) with partial anterior circulation infarct, 153 (13.72%) with posterior circulation infarct, and 65 (5.83%) with lacunar infarct. After multivariable adjustment, compared to the patients with non-TACI, those with TACI had a significantly increased risk of SICH (odds ratio [OR] 8.80; 95% confidence interval [CI] 2.84–27.25, P<0.001), higher mortality (OR 5.24; 95% CI 3.19–8.62; P<0.001), and poor functional independence (OR 0.38; 95% CI 0.26–0.56; P<0.001) at 3-month follow-up.

Conclusion

After thrombolysis, the patients with TACI exhibited greater SICH, a higher mortality rate, and worse 3-month clinical outcomes compared with the patients with non-TACI. The OCSP classification system may help clinicians predict the safety and efficacy of thrombolysis.

Stent Retriever Thrombectomy of Small Caliber Intracranial Vessels Using pREset LITE: Safety and Efficacy

Purpose

Few devices are approved for thrombectomy of distal vessel branches, and clinical experience is limited. Here we report our experience with pREset LITE for thrombectomy of small intracranial vessels.

Methods

From an institutional database we selected consecutive patients treated with pREset LITE for an occlusion of small (≤ 2 mm), intracranial target vessels. Recanalization success was measured by applying the modified Thrombolysis In Cerebral Infarction (mTICI) score. To assess safety, we recorded device-related procedural events and potentially device-related hemorrhages on follow-up imaging. Infarcts in the dependent territory served as a measure for efficacy.

Results

Of 536 patients treated between August 2013 and March 2015, 76 met the inclusion criteria. pREset LITE was used in 90 branches with an average diameter of 1.6 mm (1.3–2.0 mm). An mTICI score ≥ 2b was achieved in 70.0 %. Procedural events consisted of 5.6 % significant vasospasm, 2.2 % suspected dissections, 2.2 % downstream emboli, and 1.1 % self-limiting extravasations. On posttreatment imaging 2.2 % parenchymal hemorrhages type I (PHI) and 13.3 % focal subarachnoid hemorrhage (SAH) were potentially device related, but all of these events remained asymptomatic. After successful recanalization, 33.3 % developed no ischemia in the dependent territory while 41.7 % developed a partial infarct, and 25 % developed a complete infarct. Successful recanalization significantly increased the chance to develop no or only partial infarct compared with a complete infarction (p = 0.003, p = 0.013).

Conclusions

Thrombectomy of small vessels with pREset LITE is feasible with good recanalization and reasonable safety margins. Successful recanalization significantly reduces the risk of infarction in the dependent territory. The impact on the overall clinical outcome remains to be determined.

Susceptibility Vessel Sign for Intra-arterial Thrombus in Acute Posterior Cerebral Artery Infarction

BACKGROUND

Susceptibility vessel sign (SVS) on susceptibility-weighted imaging (SWI) has a high sensitivity and specificity to detect the intra-arterial thrombus in anterior circulation stroke. However, SVS has not been evaluated in posterior circulation stroke.

METHODS

We reviewed the data from patients with acute posterior cerebral artery (PCA) infarction within 24 hours from stroke onset. To elucidate the usefulness of SVS for the detection of intraluminal thrombus in acute PCA infarction, the frequency and location of SVS were compared with those of occlusion on magnetic resonance angiography (MRA) and hyperdense PCA sign on computed tomography (CT).

RESULTS

Twenty-five patients with acute PCA infarction were enrolled in the study. The SVS was found in 92% (23 of 25). MRA showed occlusions in 64% (16 of 25). The SVS was identified in 100% (16 of 16) of patients with occlusion on MRA. Patients without occlusion on MRA also showed the SVS in 78% (7 of 9; P = .0233). The positive SVS without occlusion on MRA was mainly identified in patients with occlusion of distal branches of PCA; P3 segment in 4 and P4 segment in 3. However, the hyperdense PCA sign on CT showed in only 8% (2 of 25) of all patients; its sensitivity was significantly lower than those of the SVS on SWI (P < .001).

CONCLUSIONS

SWI is more sensitive than MRA for the detection of intraluminal thrombus, especially peripheral one, in patients with acute ischemic stroke of the PCA territory. In addition, irrespective of thrombus location, SWI is significantly superior to CT in detecting thrombus in acute PCA infarction.

Lower NIH stroke scale scores are required to accurately predict a good prognosis in posterior circulation stroke

BACKGROUND

The NIH stroke scale (NIHSS) is an indispensable tool that aids in the determination of acute stroke prognosis and decision making. Patients with posterior circulation (PC) strokes often present with lower NIHSS scores, which may result in the withholding of thrombolytic treatment from these patients. However, whether these lower initial NIHSS scores predict better long-term prognoses is uncertain. We aimed to assess the utility of the NIHSS at presentation for predicting the functional outcome at 3 months in anterior circulation (AC) versus PC strokes.

METHODS

This was a retrospective analysis of a large prospectively collected database of adults with acute ischemic stroke. Univariate and multivariate analyses were conducted to identify factors associated with outcome. Additional analyses were performed to determine the receiver operating characteristic (ROC) curves for NIHSS scores and outcomes in AC and PC infarctions. Both the optimal cutoffs for maximal diagnostic accuracy and the cutoffs to obtain >80% sensitivity for poor outcomes were determined in AC and PC strokes.

RESULTS

The analysis included 1,197 patients with AC stroke and 372 with PC stroke. The median initial NIHSS score for patients with AC strokes was 7 and for PC strokes it was 2. The majority (71%) of PC stroke patients had baseline NIHSS scores ≤4, and 15% of these 'minor' stroke patients had a poor outcome at 3 months. ROC analysis identified that the optimal NIHSS cutoff for outcome prediction after infarction in the AC was 8 and for infarction in the PC it was 4. To achieve >80% sensitivity for detecting patients with a subsequent poor outcome, the NIHSS cutoff for infarctions in the AC was 4 and for infarctions in the PC it was 2.

CONCLUSION

The NIHSS cutoff that most accurately predicts outcomes is 4 points higher in AC compared to PC infarctions. There is potential for poor outcomes in patients with PC strokes and low NIHSS scores, suggesting that thrombolytic treatment should not be withheld from these patients based solely on the NIHSS. © 2014 S. Karger AG, Basel.

Intravenous thrombolysis in ischemic stroke patients with isolated homonymous hemianopia

BACKGROUND

Patients with posterior ischemic stroke were usually excluded from thrombolytic treatment in clinical trials and clinical practice, and little is known about effectiveness of thrombolysis treatment in such patients who may end up with severe disability.

AIMS OF THE STUDY

We aimed to describe the outcome of acute ischemic stroke patients presenting with isolated homonymous hemianopia and treated with intravenous thrombolysis.

METHODS

A case report of three patients presenting with homonymous hemianopia owing to posterior circulation stroke treated with intravenous thrombolysis at the Helsinki University Central Hospital. Main outcome measures were modified Rankin Scale and neuropsychological examination at 3 months after thrombolysis. We further evaluated Goldmann visual field examination at 6 months.

RESULTS

No acute findings appeared on admission non-contrast head-computed tomography scan. All patients had a perfusion deficit on admission-computed tomography perfusion imaging. All patients scored 0 on 3-month modified Rankin Scale, and their neuropsychological evaluation was normal. Goldmann examination revealed no visual field deficit in both female patients, and a modest visual field defect was detected in the male patient.

CONCLUSIONS

Our experience encourages application of intravenous thrombolytic treatment (especially when supported with multimodality neuroimaging) in patients with homonymous hemianopia, for which rehabilitation options are limited.

Infarctions in the vascular territory of the posterior cerebral artery: clinical features in 232 patients

Background

Ischemic stroke caused by infarction in the territory of the posterior cerebral artery (PCA) has not been studied as extensively as infarctions in other vascular territories. This single centre, retrospective clinical study was conducted a) to describe salient characteristics of stroke patients with PCA infarction, b) to compare data of these patients with those with ischaemic stroke due to middle cerebral artery (MCA) and anterior cerebral artery (ACA) infarctions, and c) to identify predictors of PCA stroke.

Findings

A total of 232 patients with PCA stroke were included in the "Sagrat Cor Hospital of Barcelona Stroke Registry" during a period of 19 years (1986-2004). Data from stroke patients are entered in the stroke registry following a standardized protocol with 161 items regarding demographics, risk factors, clinical features, laboratory and neuroimaging data, complications and outcome. The characteristics of these 232 patients with PCA stroke were compared with those of the 1355 patients with MCA infarctions and 51 patients with ACA infarctions included in the registry.

Infarctions of the PCA accounted for 6.8% of all cases of stroke (n = 3808) and 9.6% of cerebral infarctions (n = 2704). Lacunar infarction was the most frequent stroke subtype (34.5%) followed by atherothrombotic infarction (29.3%) and cardioembolic infarction (21.6%). In-hospital mortality was 3.9% (n = 9). Forty-five patients (19.4%) were symptom-free at hospital discharge. Hemianopia (odds ratio [OR] = 6.43), lacunar stroke subtype (OR = 2.18), symptom-free at discharge (OR = 1.92), limb weakness (OR = 0.10), speech disorders (OR = 0.33) and cardioembolism (OR = 0.65) were independent variables of PCA stroke in comparison with MCA infarction, whereas sensory deficit (OR = 2.36), limb weakness (OR = 0.11) and cardioembolism as stroke mechanism (OR = 0.43) were independent variables associated with PCA stroke in comparison with ACA infarction.

Conclusions

Lacunar stroke is the main subtype of infarction occurring in the PCA territory. Several clinical features are more frequent in stroke patients with PCA infarction than in patients with ischaemic stroke due to infarction in the MCA and ACA territories. In-hospital mortality in patients with PCA territory is low.