Transcranial Doppler and Cerebral Augmentation in Acute Ischemic Stroke.
ABSTRACT BACKGROUND: Collateral flow augmentation using partial aortic occlusion may improve cerebral perfusion in acute stroke. We assessed the effect of partial aortic occlusion on arterial flow velocities of acute stroke patients. METHODS: Patients with neurological deficits following thrombolysis were treated with partial aortic occlusion. Transcranial Doppler ultrasound (TCD) was used to measure arterial flow velocities at baseline, before and during balloon inflation. The augmented mean flow velocity (MFV), peak systolic velocity (PSV), and end diastolic velocity flow percentages (aMFV%, aPSV%, aEDV%) were calculated and compared based on outcome. RESULTS: Of 11 patients, 3 did not have a temporal window and thus were excluded from our analysis. Six of the remaining 8 patients had middle cerebral artery (MCA) occlusions; the final 2 had terminal internal carotid artery (TICA) occlusions. Three of these 8 patients had good outcome at 90 days (mRS < 3). Before intra-aortic balloon inflation (IABI), the mean affected artery MFV was 23 ± 11 cm/s; during the procedure it was 26 ± 12 cm/s (P = .2). Mean affected artery PSV at baseline and during balloon inflation were 37 ± 16 and 46 ± 23, respectively (P = .1). Mean augmented affected artery MFV% in patients with good long-term outcome was 65.4 ± 46, while the result in those with poor outcome was -3.7 ± 21 (P = .03). Three patients developed anterior cross-filling, and of these 2 had good long-term outcome. CONCLUSION: TCD monitoring of patients treated with IABI may help in predicting outcome in this novel device. J Neuroimaging 2012;XX:1-6.
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ABSTRACT: Enhanced external counterpulsation (EECP) has been shown to reduce angina and to improve objective measures of myocardial ischemia in patients with refractory angina. Prospective clinical studies and large treatment registries suggest that a course of EECP is associated with prolongation of the time to exercise-induced ST-segment depression and resolution of myocardial perfusion defects, as well as with enhanced exercise tolerance and quality of life. With a growing knowledge base supporting the safety and beneficial clinical effects associated with EECP, this therapy can be considered a valuable treatment option, particularly in patients who have exhausted traditional revascularization methods and yet remain symptomatic despite optimal medical care. However, although the concept of external counterpulsation was introduced almost four decades ago, and despite growing evidence supporting the clinical benefit and safety of this therapeutic modality, little is firmly established regarding the mechanisms responsible for the beneficial effects associated with this technique. Suggested mechanisms contributing to the clinical benefit of EECP include improvement in endothelial function, promotion of coronary collateralization, enhancement of ventricular function, peripheral effects similar to those observed with regular physical exercise, and nonspecific placebo effects. This review summarizes the current evidence for a contribution of these mechanisms to the clinical benefit associated with EECP.Journal of the American College of Cardiology 07/2003; 41(11):1918-25. · 15.34 Impact Factor
- Journal of Neurosurgery 07/1972; 36(6):700-13. · 3.23 Impact Factor
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ABSTRACT: The duration of cerebral blood flow impairment correlates with irreversibility of brain damage in animal models of cerebral ischemia. Our aim was to correlate clinical recovery from stroke with the timing of arterial recanalization after therapy with intravenous tissue plasminogen activator (tPA). Patients with symptoms of cerebral ischemia were treated with 0.9 mg/kg tPA IV within 3 hours after stroke onset (standard protocol) or with 0.6 mg/kg at 3 to 6 hours (an experimental institutional review board-approved protocol). National Institutes of Health Stroke Scale (NIHSS) scores were obtained before treatment, at the end of tPA infusion, and at 24 hours; Rankin Scores were obtained at long-term follow-up. Transcranial Doppler (TCD) was used to locate arterial occlusion before tPA and to monitor recanalization (Marc head frame, Spencer Technologies; Multigon 500M, DWL MultiDop-T). Recanalization on TCD was determined according to previously developed criteria. Forty patients were studied (age 70+/-16 years, baseline NIHSS score 18.6+/-6.2). A tPA bolus was administered at 132+/-54 minutes from symptom onset. Recanalization on TCD was found at the mean time of 251+/-171 minutes after stroke onset: complete recanalization occurred in 12 (30%) patients and partial recanalization occurred in 16 (40%) patients (maximum observation time 360 minutes). Recanalization occurred within 60 minutes of tPA bolus in 75% of patients who recanalized. The timing of recanalization inversely correlated with early improvement in the NIHSS scores within the next hour (polynomial curve, third order r(2)=0.429, P<0.01) as well as at 24 hours. Complete recanalization was common in patients who had follow-up Rankin Scores if 0 to 1 (P=0.006). No patients had early complete recovery if an occlusion persisted for >300 minutes. The timing of arterial recanalization after tPA therapy as determined with TCD correlates with clinical recovery from stroke and demonstrates a 300-minute window to achieve early complete recovery. These data parallel findings in animal models of cerebral ischemia and confirm the relevance of these models in the prediction of response to reperfusion therapy.Stroke 08/2000; 31(8):1812-6. · 6.02 Impact Factor