Transcranial Doppler is valid for determination of the lower limit of cerebral blood flow autoregulation.

• DOI: 10.1161/01.str.25.10.1985
• Publication Date: 2011-06-17T20:08:03Z
• Authors: F S Larsen; K S Olsen; B A Hansen; O B Paulson; G M Knudsen
• Keywords: Transcranial Doppler; Cerebral autoregulation; Stroke

This study validates transcranial Doppler sonography (TCD) for determination of the lower limit cerebral blood flow (CBF) autoregulation and establishes a relation between global CBF mean velocity (Vmean) in middle artery. Relative changes Vmean were compared 12 normal volunteers (2 women 10 men; median age, 30 years [range, 21 to 61 years]). Catheters was placed left radial artery bulb right internal jugular vein, respectively. Baseline measured by single-photon emission computed tomography scanning; concomitantly, samples drawn calculation arteriovenous oxygen difference. Then arterial pressure (MAP) induced, relative calculated according Fick's principle assuming constant metabolism. MAP increased mm Hg norepinephrine infusion decreased body negative pressure. 2-MHz probe, at intervals 5 Hg. values 122 (range, 110 140) 48 34 75) measured. The (the under which is off) as determined did not differ significantly from that CBF: 91 41 108) 79 53 113) Hg, A significant correlation demonstrated below (R2 = .73, P < .001; -6.3 + 1.0.Vmean). Above both stable. TCD valid autoregulation, may be reliably evaluated during perfusion subjects.