Ein TCD-Steh-Test zur klinischen Prüfung der zerebralen Autoregulation

Abstract

Description of a TCD test designed for the clinical investigation of cerebral autoregulation. The Doppler shift frequency of the middle cerebral artery is recorded using of a transducer fixed to the patient's head by an elastic ribbon and a ball joint type probe-holder, and on-line digitally analysed to calculate the TCD flow index (signal power times velocity). Blood pressure is measured every 30 seconds at the right index hold at the level of the heart, using a special sphygmomanometer. The patient sits on a foot-stool. After 1.5 minutes of measurement he rises to remain in upright position for another 2 minutes. The flow index normalised to its average over the sitting period quantitatively indicates the evolution of volume flow brought about by the change of the body position. The change in arterial blood pressure is off-line calculated from its periodic measurements. In a pilot study this test has been successfully used in 30 healthy volunteers and 2 patients suffering from orthostatic dysregulation of blood pressure.

Sex differences in cerebral haemodynamics across the physiological range of PaCO2

“…In agreement with several previous reports (Vriens et al 1989, Muller andSchimrigk 1994, Marinoni et the main reason for this difference might be the smaller diameter of the MCA, or other large intracranial arteries, in females, rather than hormonal differences with males (Muller et al 1991). One advantage of our study is the use of a two-parameter model to describe the instantaneous pressure-velocity curves of the cerebral circulation to examine the separate contributions of CrCP and RAP (Panerai 2003).…”

Einfluß medikamentöser Dilatation basaler Hirnarterien mittels Nitroglyzerin auf Strömungsgeschwindigkeit und Volumenfluß in der A. cerebri media

“…Key words: Transcranial doppler sonography -Flow Index -Nitroglycerin -Vasodilation -Middle cerebral artery 50 11 auch be i Kalib e rschwankungen des beschallten Ce fafses die Messung relativer Anderungen de s Volumenflusses erm oglich en [7,8] . Der Fluls-lndex erlaubt jedoc h nicht, ein en Absolutwert des Flusses (m ljmi n ) zu mes sen , so nde rn nur prozentuale Anderungen de sselben.…”