Angiographic features, collaterals, and infarct topography of symptomatic occlusive radiation vasculopathy: a case-referent study.

BACKGROUND AND PURPOSE: Occlusive radiation vasculopathy (ORV) predisposes head-and-neck cancer survivors to ischemic strokes. METHODS: We analyzed the digital subtraction angiography acquired in 96 patients who had first-ever transient ischemic attack or ischemic strokes attributed to ORV. Another age-matched 115 patients who had no radiotherapy but symptomatic high-grade (>70%) carotid stenoses were enrolled as referent subjects. Digital subtraction angiography was performed within 2 months from stroke onset and delineated carotid and vertebrobasilar circulations from aortic arch up to intracranial branches. Two reviewers blinded to group assignment recorded all vascular lesions, collateral status, and infarct pattern. RESULTS: ORV patients had less atherosclerotic risk factors at presentation. In referent patients, high-grade stenoses were mostly focal at the proximal internal carotid artery. In contrast, high-grade ORV lesions diffusely involved the common carotid artery and internal carotid artery and were more frequently bilateral (54% versus 22%), tandem (23% versus 10%), associated with complete occlusion in one or both carotid arteries (30% versus 9%), vertebral artery (VA) steno-occlusions (28% versus 16%), and external carotid artery stenosis (19% versus 5%) (all P<0.05). With comparable rates of vascular anomaly, ORV patients showed more established collateral circulations through leptomeningeal arteries, anterior communicating artery, posterior communicating artery, suboccipital/costocervical artery, and retrograde flow in ophthalmic artery. In terms of infarct topography, the frequencies of cortical or subcortical watershed infarcts were similar in both groups. CONCLUSIONS: ORV angiographic features and corresponding collaterals are distinct from atherosclerotic patterns at initial stroke presentation. Clinical decompensation, despite more extensive collateralization, may precipitate stroke in ORV.

Intra-arterial revascularisation therapy for acute ischaemic stroke: initial experience in a Hong Kong hospital.

OBJECTIVES: To assess the outcome of acute ischaemic stroke patients who received intra-arterial therapy in our unit. DESIGN: Case series. SETTING: A tertiary hospital in Hong Kong. PATIENTS: Patients with ischaemic stroke due to large artery occlusion treated within 6 hours from symptom onset between January 2007 and May 2011. INTERVENTION: Acute intra-arterial revascularisation therapy. MAIN OUTCOME MEASURES: Primary outcome was functional independence (modified Rankin Scale score of ≤ 2) at 3 months. Secondary outcome was rate of recanalisation. Safety outcomes were symptomatic intracranial haemorrhage and 3-month mortality. RESULTS: Twenty-one patients with a mean age of 67 years fulfilled the inclusion criteria. Their mean National Institutes of Health Stroke Scale score was 18. The mean onset-to-puncture time was 212 minutes. Nine received intra-arterial tissue plasminogen activator alone, 11 had an adjunctive mechanical thrombectomy, and one received balloon angioplasty without tissue plasminogen activator. At the end of the procedure, thrombolysis grade 2a or better was attained in 18 (86%) of the patients, and 8 (38%) achieved functional independence at 3 months. Rates of symptomatic intracranial haemorrhage and 3-month mortality were 10% and 24%, respectively. CONCLUSION: In this setting, intra-arterial revascularisation therapy appeared safe and efficacious for this selected group of ischaemic stroke patients with large artery occlusions. Experience gained from this pilot study may help improve clinical outcomes of such patients.

Significance of good collateral compensation in symptomatic intracranial atherosclerosis.

BACKGROUND: Collateral circulation stabilizes cerebral blood flow in patients with acute occlusion, but its prognostic role is less studied in intracranial atherosclerosis and appears different in moderate to severe stenosis. We aimed to study the associations between antegrade flow across stenosis, collateral flow via leptomeningeal anastomosis, and the neurological outcome and recurrence risk in patients with symptomatic intracranial stenosis. METHODS: We examined a cohort of consecutive patients admitted for stroke or transient ischemic attack (TIA) with symptomatic intracranial stenosis confirmed by digital subtraction angiography in a single-center retrospective study. Angiograms were graded systematically in a blinded fashion for antegrade and collateral flow, using Thrombolysis in Cerebral Infarction (TICI) and American Society of Intervention and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) grading, respectively, and integrated to a simple composite circulation score. Demographic and clinical variables, modified Rankin Scale (mRS) scores at 3 months, recurrent stroke or TIA in 12 months were collected. Uni- and multivariate analyses were performed to identify independent predictors of good outcome (mRS 0-2) and recurrence in a logistic regression model. RESULTS: Among 69 patients with pure intracranial atherosclerosis ≥ 50%, compromised antegrade flow (TICI 0-2a) was observed in 26 (36%) patients and was associated with more severe arterial stenosis (mean 86 vs. 74%, p = 0.001). Poor collateral compensation resulting in a poor composite circulation score was observed in 8 (12%) patients. Patients with a good circulation score (n = 61, 88%) had preserved flow, which was associated with more favorable outcome (OR 7.50, 95% CI 1.11-50.7, p = 0.04) and less recurrent TIA or stroke (OR 0.18, 95% CI 0.04-0.96, p = 0.04). Prognosis was not significantly associated with antegrade or collateral grade per se. CONCLUSION: Good collateral compensations are more important in patients with symptomatic intracranial stenosis and compromised antegrade flow, and are associated with favorable outcome and less recurrence risk. The feasibility of composite flow assessment should be explored in future studies to identify high-risk intracranial stenosis with compromised hemodynamics.

Is stroke thrombolysis safe and efficacious in Hong Kong?

OBJECTIVE: To investigate the safety and efficacy of stroke thrombolysis in a local hospital. DESIGN: Historical cohort study. SETTING: A tertiary hospital in Hong Kong. PATIENTS: The outcome of acute ischaemic stroke patients treated with intravenous tissue plasminogen activator between October 2008 and May 2011 was compared to those admitted during the same period who were thrombolysis-eligible, but treated conservatively due to unavailability of the thrombolysis service after-hours. INTERVENTIONS: Intravenous tissue plasminogen activator. MAIN OUTCOME MEASURES: Primary outcome was functional independence (modified Rankin Scale score of 2 or below) at 3 months. Safety outcomes were symptomatic intracranial haemorrhage and 3-month mortality. Secondary outcomes were hospital length of stay, direct home discharge, and nursing home discharge. RESULTS: A total of 48 thrombolysis and 63 non-thrombolysis patients were identified. Fifty-two percent of the thrombolysis group achieved functional independence compared to 24% of non-thrombolysis group (P=0.003), without significant increase in mortality (15% vs 13%, P=0.51) or symptomatic intracranial haemorrhage (4% vs 2%, P=0.58). Twenty-nine percent of the thrombolysis group patients were discharged home directly, versus 6% of non-thrombolysis group (P<0.001). Mean length of stay was shorter for the thrombolysis group (25 vs 35 days; P=0.034). A similar percentage from each group was discharged to nursing homes. CONCLUSION: Implementation of the stroke thrombolysis service in Hong Kong appeared safe and efficacious. Patients who received thrombolysis had better outcomes compared to non-thrombolysis cohort. Further studies are needed to investigate the economics of stroke thrombolysis in Hong Kong, which may help to improve funding for provision of this service.

Acute encephalopathy associated with influenza A infection in adults.

We report acute encephalopathy associated with influenza A infection in 3 adults. We detected high cerebrospinal fluid (CSF) and plasma concentrations of CXCL8/IL-8 and CCL2/MCP-1 (CSF/plasma ratios > or =3), and interleukin-6, CXCL10/IP-10, but no evidence of viral neuroinvasion. Patients recovered without sequelae. Hyperactivated cytokine response may play a role in pathogenesis.

Stroke caused by small vessel occlusion in a patient taking etoricoxib and thalidomide.

We report a 33-year-old man with seronegative arthritis who had an acute infarct at the left lentiform nucleus while taking etoricoxib and thalidomide regularly. Extensive investigations did not find any evidence of large artery atherosclerosis, vasculitis, cardioembolic source or anti-phospholipid antibodies. While it is possible that a short smoking history, hyperlipidemia, and the use of thalidomide could have contributed to the thrombosis of a small penetrator vessel, we postulated that the prolonged use of etoricoxib is another possible contributing factor.

Intravenous alteplase for Chinese patients with stroke and borderline eligibility.

Lack of efficacy and safety data among Chinese patients with stroke have contributed to the slow development of stroke thrombolysis as standard-of-care for these patients. We examined a retrospective cohort of 57 patients who received intravenous alteplase for acute ischemic stroke to identify predictors of outcome, including age, stroke severity, onset-to-treatment time, and early ischemic changes on brain CT scan. Overall, the mean National Institute of Health Stroke Scale (NIHSS) score was 15.7 and the mean onset-to-treatment time was 142 minutes. Twenty-nine (51%) patients had a favorable outcome with modified Rankin Scale (mRS) score of ≤2 at three months. Ten (17.5%) patients were deceased at three months. Four (7%) patients developed symptomatic intracranial hemorrhage (sICH). For patients aged >80 years (n=18), five (28%) achieved favorable outcome, six (33%) were deceased at three months and three (17%) had sICH. Prognosis was worst for patients with NIHSS score >25 (n=5); one (20%) was dependent (mRS 4) and the other four (80%) were deceased. Multivariate analysis found that the Alberta Stroke Program Early CT Score (ASPECTS) was associated with favorable outcome (odds ratio [OR] 1.8, 95% confidence interval [CI] 1.1-3.0), and mortality (OR 0.5, 95% CI 0.3-0.9). Our findings showed advanced age and severe stroke were associated with less favorable outcome in Chinese patients receiving intravenous alteplase, ASPECTS can be used reliably to identify patients at risk of poor outcomes. Further studies are warranted.