Transcranial Doppler intravenous

Ribo M, Molina CA, Rovira A, Quintana M, Delgado P, Montaner J, Grive E, Arenillas JE, Alvarez-Sabin J. Safety and efficacy of intravenous tissue plasminogen activator stroke treatment in the 3- to 6-hour window using multimodal transcranial Doppler/MRI selection protocol. Stroke 2005 36 602-606. 

The cause of cocaine-related stroke and transient ischemic attacks has been studied by transcranial Doppler sonography, a continuous measure of cerebral blood flow velocity, to monitor the course of cerebral hemodynamic changes during acute intravenous injection of placebo, and of cocaine 10, 25, and 50 mg in seven cocaine abusers (150). There was a significant increase in mean and systolic velocity (lasting about 2 minutes) with all doses of cocaine but not with placebo. Cocaine produced an immediate brief period of vasoconstriction... 

A less-invasive alternative is to inject air bubbles or other echocontrast material intravenously if there is a patent foramen ovale, they can be detected by transcranial Doppler sonography of the middle cerebral artery, particularly with a provocative Valsalva maneuver. There is considerable variation in the methods used to detect patent foramen ovale and this influences the diagnostic sensitivity and specificity. It is also uncertain what size of shunt is "clinically relevant" and some bubbles may pass to the brain through pulmonary rather than cardiac shunts (Droste ef al. 1999, 2002 Schwarze ef al. 1999),... 

The safety of Sono Vue as an intravenous bolus injection of 0.3, 0.6, 1.2, or 2.4 ml in transcranial Doppler examination of the cerebral arteries has been investigated in 40 patients (mean age 64 years) (19). The interval between each dose was at least 10 minutes or until total disappearance of the contrast effect from the previous dose. Eight patients reported 12 adverse events. There were no serious adverse events and no patient withdrew because of an adverse event. The most common adverse events were pain at the injection site, headache, and a feeling of warmth all were mild. 

IMS 11 subjects treated with the EKOS catheter and IMS 1 subjects treated with the standard microcatheter demonstrated grade 2-3 recanalization rates at the specific site of arterial occlusion of 73% (24/33) in EKOS-treated subjects vs. 56% (33/59) in standard microcatheter-treated subjects (p=0.11) [57]. This device is being further investigated in the randomized IMS 111 trial. Likewise, enhanced fibrinolysis with intravenous rt-PA can be achieved with the use of continuous 2-MHz transcranial Doppler ultrasonography (CLOTBUST trial) [58]. 

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