title: Transcranial ultrasound-improved thrombolysis: diagnostic vs. therapeutic ultrasound.
abstract: Success of stroke treatment with rt-PA depends on rapid vessel recanalization. Enzymatic thrombolysis may be enhanced by additional transcranial application of ultrasound (US). We investigated this novel technique using a 185-kHz probe and compared it to standard diagnostic US. In vitro studies were performed in a continuous pressure tubing system. Clots were placed in a postmortem skull and treated with rt-PA together with or without transtemporal 185-kHz US insonation (2W/cm(2)) and in comparison to 1-MHz diagnostic US (0.5 W/cm(2)). Recanalization time was significantly (p < 0.01) shorter in the 185-kHz (14.1 min) and 1-MHz (17.1 min) US rt-PA treatment group compared to rt-PA treatment alone (29.3 min.). Flow rate was significantly higher (p < 0.025) and increased faster in the combined treatment group with rt-PA + 185-kHz US compared to rt-PA + 1-MHz US. We investigated the blood-brain barrier in rats after 90-min exposure time of the brain with 185-kHz US, but no damage was observed. Results suggest efficacy and safety of the 185-kHz transducer, which is superior to diagnostic US. Such a novel US probe may be able to optimize thrombolytic stroke treatment.
authors.affiliation: Department of Neurology, Universitaetsklinikum Mannheim, University of Heidelberg, 68135 Mannheim, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Behrens
authors.forename: K
authors.initials: K
authors.lastname: Spengos
authors.forename: M
authors.initials: M
authors.lastname: Daffertshofer
authors.forename: H
authors.initials: H
authors.lastname: Schroeck
authors.forename: C E
authors.initials: CE
authors.lastname: Dempfle
authors.forename: M
authors.initials: M
authors.lastname: Hennerici
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects / Q000502:physiology; D001812:Blood-Brain Barrier; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012886:Skull; D020521:Stroke / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000628:therapy*; D015912:Thrombolytic Therapy / Q000379:methods*; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D014464:Ultrasonic Therapy; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator