Stroke; a journal of cerebral circulation
-
Transcranial Doppler ultrasound can reliably detect both gaseous and solid cerebral emboli. However, conventional equipment is unable to discriminate between gaseous and solid emboli. This is a major limitation in situations in which the 2 coexist, because they may have very different clinical relevance. Recently, a novel Embo-Dop system, using insonation at 2 ultrasound transducer frequencies, has been developed. An initial study with a small sample size suggested it provided excellent discrimination. We performed a validation study in subjects with embolic signals of known nature. ⋯ The Embo-Dop dual-frequency system allows better discrimination than a simple intensity threshold but it is not accurate enough for use in clinical or research studies. Further work is needed to develop reliable clinical systems for discrimination of emboli.
-
Establishment of stroke centers, combined with accurate paramedic diagnosis and rapid transport, is essential to deliver acute stroke therapy. We wanted to measure and improve paramedic and hospital performance through implementation of the Brain Attack Coalition and American Stroke Association guidelines. ⋯ A multilevel educational program improves rapid hospitalization and paramedic diagnostic accuracy and increases the number of patients presenting for evaluation within the 3-hour tissue plasminogen activator window. Stroke center development supports safe thrombolytic practice in community settings.
-
Multicenter Study Clinical Trial
Safety and efficacy of mechanical embolectomy in acute ischemic stroke: results of the MERCI trial.
The only Food and Drug Administration (FDA)-approved treatment for acute ischemic stroke is tissue plasminogen activator (tPA) given intravenously within 3 hours of symptom onset. An alternative strategy for opening intracranial vessels during stroke is mechanical embolectomy, especially for patients ineligible for intravenous tPA. ⋯ A novel endovascular embolectomy device can significantly restore vascular patency during acute ischemic stroke within 8 hours of stroke symptom onset and provides an alternative intervention for patients who are otherwise ineligible for thrombolytics.
-
Clinical studies using ultrasound at diagnostic frequencies in transcranial Doppler devices provided encouraging results in enhancing thrombolysis with tissue plasminogen activator (tPA) in acute stroke. Low-frequency ultrasound does not require complex positioning procedures, penetrates through the skull better, and has been demonstrated to accelerate thrombolysis with tPA in animal experiments in wide cerebrovascular territories without hemorrhagic side effects. We therefore conducted the first multicenter clinical trial to investigate safety of tPA plus low-frequency ultrasound (300 kHz). ⋯ This study demonstrated bioeffects from low-frequency ultrasound that caused an increased rate of cerebral hemorrhages in patients concomitantly treated with intravenous tPA.
-
Serum B-type natriuretic peptide (BNP) is elevated after subarachnoid hemorrhage (SAH), as well as in the setting of congestive heart failure and myocardial infarction. The aim of this study was to prospectively quantify the relationship between BNP levels and cardiac outcomes after SAH. ⋯ Early after SAH, elevated BNP levels are associated with myocardial necrosis, pulmonary edema, and both systolic and diastolic dysfunction of the left ventricle. These findings support the hypothesis that the heart releases BNP into the systemic circulation early after SAH.