Stroke Alert: A Review of Current Clinical Stroke Literature
Stroke Alert: A Review of Current Clinical Stroke Literature
By Matthew E. Fink, MD, Interim Chair and Neurologist-in-Chief, Director, Division of Stroke & Critical Care Neurology, Weill Cornell Medical College and New York Presbyterian Hospital
Harloff A, et al. Complex plaques in the proximal descending aorta: An underestimated embolic source of stroke. Stroke 2010;41:1145-1150.
Atherosclerotic plaques in the aortic arch are considered to be a potential source of embolism to the brain and a cause of some ischemic strokes, but the role of complex plaques (> 4 mm thickness, ulcerated, superimposed thrombi) in the proximal descending aorta (DAo) is uncertain. The investigators studied 94 consecutive patients who had aortic plaques > 3 mm in thickness in the aortic arch by transesophageal echocardiography, and studied the location and plaque morphology with MRI. They also measured 3-D aortic blood flow to determine if diastolic retrograde flow connected the plaque location to the origins of the great vessels of the aortic arch. Increased flow reversal was correlated with decreasing heart rate (p < 0.02) and retrograde flow reached the left subclavian artery in 58%, the left common carotid artery in 25% and the brachiocepahlic trunk in 14%. Using clinical classification of stroke types, potential embolization from DAo plaques could explain embolism in all brain territories and might be the cause of stroke in 25%-33% of patients. ■
Shi ZS, et al. Endovascular thrombectomy for acute ischemic stroke in failed intravenous tissue plasminogen activator versus non-intravenous tissue plasminogen activator patients. Stroke 2010; 41:1185-1192.
Intracranial thrombectomy is an option to treat patients with acute ischemic stroke who have a large vessel occlusion. The investigators compared results and complications of the MERCI device in 305 patients, 48 who failed IV TPA and 257 who were ineligible for IV TPA. Non-responders to IV TPA had similar rates of revascularization and less mortality (28% vs 40%) than the non-TPA group, and they had similar rates of symptomatic hemorrhage and procedural complications. Favorable outcomes at 90 days were similar in both groups, with no difference based on the site of occlusion. In both groups of patients, good outcomes were more frequent in revascularized patients. In the non-TPA group, revascularization correlated with good outcome (47% vs 4%) and less mortality (28% vs 60%).
The risks of hemorrhage and procedural complications after mechanical thrombectomy are not different in patients who receive IV TPA compared to those who do not, and this mode of therapy should be considered in IV TPA failures. After thrombectomy, good outcomes are correlated with successful revascularization. ■
Gaillard N, et al. Detection of paroxysmal atrial fibrillation with transtelephonic EKG in TIA or stroke patients. Neurology 2010; 74: 1666-1670.
Paroxysmal atrial fibrillation (PAF) is often underdiagnosed after stroke. Long-term monitoring studies suggest that as many as 15% of ischemic stroke patients may have PAF if monitored continuously for up to 12 months. The investigators studied 98 consecutive patients with a clinical diagnosis of non-cardioembolic stroke, using transtelephonic EKG monitoring (TTM), if they had a negative 24-hour Holter monitor. Seventeen PAF episodes were detected in 9.2% (9/98) of the patients, with estimated duration of PAF episodes ranging from four to 72 hours. Two predictors of PAF were identified: > 100 premature atrial ectopic beats on 24-hour Holter monitor (OR = 11.0, p < 0.007) and nonlacunar anterior circulation DWI signals on MRI (OR = 9.9, p < 0.004). In patients who had both predictive criteria, detection of PAF occurred in 43% of patients. TTM and other methods of long-term EKG monitoring should be considered in patients with cryptogenic stroke, especially of they have premature atrial contractions on Holter, and DWI signals in the anterior circulation. ■
Geraghty OC, et al. Low risk of rebound events after a short course of clopidogrel in acute TIA or minor stroke. Neurology 2010; 74:1891-1896.
The combination of aspirin and clopidogrel is standard therapy for treatment of acute coronary syndrome, and early cessation of clopidogrel has been associated with a rebound in coronary events. A similar effect is unknown in patients with TIA or minor stroke, but this question will be studied in upcoming clinical trials. The investigators looked at this question in an open-label, non-randomized observational study of 320 patients who were prescribed a 30-day course of aspirin 75 mg and clopidogrel 75 mg after TIA or minor stroke. Recurrent events were ascertained at face-to-face follow-up. There were five recurrent ischemic strokes and 7 TIAs during the aspirin and clopidogrel treatment, but no strokes and four TIAs during the 30 days after stopping clopidogrel. Compared to a group of 487 patients who were treated with aspirin alone, there was a similar trend, with 12 recurrent strokes in the initial period and five strokes in the subsequent 30 days. The findings in both groups are consistent with the known history of early recurrent strokes after TIA, but cessation of clopidogrel does not appear to induce a rebound effect. However, this question will only be definitively answered in a larger, randomized trial that is being started shortly (POINT). ■
It is with great sadness that we inform our readers that Dr. Fred Plum, emeritus editor of Neurology Alert for more than 25 years, has died at the age of 86. Dr. Plum was one of the great leaders in American neurology. He trained at New York Hospital-Cornell Medical Center under Dr. Harold Wolf and became chairman of the department of neurology at Cornell in 1963, holding that position until his retirememt in 1998. His research centered on disorders of consciousness, and he described, in collaboration with Dr. Jerome Posner, many of the syndromes that we now diagnose. Their classical textbook, The Diagnosis of Stupor and Coma, initially published in 1966, recently released a 4th edition, and inspired many medical students, including this one, to pursue a career in neurology. Many of his trainees went on to become leaders in neurology and will pass his knowledge down to other generations of trainees. Dr. Plum was a special individual who will be missed by all of us. Matthew E. Fink, MD, Editor in Chief
Atherosclerotic plaques in the aortic arch are considered to be a potential source of embolism to the brain and a cause of some ischemic strokes, but the role of complex plaques (> 4 mm thickness, ulcerated, superimposed thrombi) in the proximal descending aorta (DAo) is uncertain.Subscribe Now for Access
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