Stroke Alert: A Review of Current Clinical Stroke Literature
By Matthew E. Fink, MD, Professor and Chairman, Department of Neurology, Weill Cornell Medical College, and Neurologist-in-Chief, New York Presbyterian Hospital
Treatment and Outcome after Acute Cervical Artery Occlusion with Stroke
Source: Seet RC, et al. Stroke from acute cervical internal carotid artery occlusion: Treatment results and predictors of outcome. Arch Neurol 2012; doi:10.1001/archneurol.2012.2569 [Epub ahead of print].
Patients with acute cervical internal carotid artery (ICA) occlusion often have large infarcts and a threefold increased likelihood of poor recovery. They also are presumed to have a poor result from intravenous thrombolysis (IVrtPA), but there are scant data that support any such conclusions. In this retrospective study from the Mayo Clinic, all patients with acute cervical ICA occlusion and stroke admitted to St. Mary’s Hospital from 2006 until 2011 were identified, and records were reviewed for vascular risk factors, stroke severity, arterial recanalization, and functional recovery at 90 days.
Twenty-one patients with acute ICA occlusion were identified (median age = 67 years; median NIHSS = 13). Thirteen underwent treatment with IVrtPA and eight underwent primary endovascular treatment. Three patients underwent rescue endovascular treatment after failure of response to IVrtPA. The endovascular approaches varied depending on the clinical situation, and included various combinations of balloon angioplasty with stenting, as well as intra-arterial rtPA. Among 13 patients who underwent treatment with IVrtPA, six had early neurological recovery and seven patients reached favorable 90-day functional recovery (modified Rankin Scale score, 0-2). Among eight patients who underwent primary endovascular treatment, one had early neurological recovery and favorable outcome, but the remainder did not attain favorable outcomes by 90 days. Of three patients who underwent rescue endovascular therapy (after IVrtPA), two had successful recanalization and favorable outcome at 90 days. Good collateral distal flow was associated with favorable functional outcomes.
In this selected group of patients with acute cervical ICA occlusion and ischemic stroke, intravenous thrombolysis should be used as first-line therapy, and endovascular therapies reserved for those patients who do not show rapid improvement after administration of IVrtPA.
Continuous Transcranial Doppler Insonation Can Determine Recanalization Following Acute Ischemic Stroke
Source: Yeo LL, et al. Timing of recanalization after intravenous thrombolysis and functional outcomes after acute ischemic stroke. Arch Neurol 2012; doi:10.1001/2013.jamaneurol.547 [Epub ahead of print].
Intravenous (IV) tissue plasminogen activator (TPA) is the only approved therapy for reperfusion after acute ischemic stroke, but the frequency of recanalization is uncertain. Investigators in Singapore collected data from 2007 through 2012 on all ischemic stroke patients, and identified 240 who underwent treatment with IVtPA. The median age was 65 years, 44% were men, the median NIHSS score was 17 (range 3-35), and the median onset-to-treatment time was 149 minutes (range 46-270 mins). Complete data, including transcranial Doppler and CT angiography, were available for 160 patients.
Early recanalization was seen in 82 patients (51.3%) and 67 cases had persistent recanalization at 24 hours. Eighty-four cases (52.5%) had recanalization at 2 days based on follow-up CT angiography. Patients with early recanalization had a 3.048 odds ratio of having a favorable outcome (Rankin Score of 0 to 1) at 3 months and those with persistent recanalization had an odds ratio of 5.449 to have a favorable outcome. After treatment with IVtPA, recanalization, as documented by transcranial Doppler or CT angiography, predicts a favorable outcome, and vessel imaging can be used to select candidates for more aggressive rescue intra-arterial endovascular therapy.
Antithrombotic Therapy Appears to be Safe for Patients with Cerebral Cavernous Malformations
Source: Schneble HM, et al. Antithrombotic therapy and bleeding risk in a prospective cohort study of patients with cerebral cavernous malformations. Stroke 2012;43:3196-3199.
Cerebral cavernous malformations (CCMS) are common, often asymptomatic, brain lesions that may be found as isolated or multiple lesions. Based on MRI studies of healthy adults, they occur in 0.1-0.8% of the population. Between 10-40% of patients have multiple lesions and may have a family history of CCMs in first-degree relatives. It is estimated that the risk of spontaneous intracerebral hemorrhage (ICH) from CCMs is about 0.5% per year, but good prospective studies are limited. Because of this risk from ICH, current recommendations advise against the use of antiplatelet or antithrombotic medications in the presence of one or more CCMs, but there are limited studies to support this recommendation.
In a prospective cohort study of 87 patients (50 women, mean age = 44.8 years, mean follow-up of 3.9 years), harboring 738 CCMs, there were no episodes of ICH in any of the patients, including 16 (18%) who were receiving long-term antithrombotic treatment (11 = antiplatelet and 5 = oral anticoagulant). In a calculation using 5536 lesion-years of observation, there were no episodes of hemorrhage. The authors concluded that the use of antithrombotic treatments in patients with CCMs does not increase the risk of ICH. However, the mean follow-up period in the study was short (3.9 years) and the number of patients taking antithrombotic therapy was small (16/87), so the conclusions are not definitive. Careful risk-benefit analysis should be performed for each patient with CCMs before antithrombotic therapy is instituted.