title: Changes in blood flow velocity in the middle and anterior cerebral arteries evoked by walking.
abstract: OBJECTIVE
  Transcranial Doppler sonography (TCD) is an established method for assessing changes in blood flow velocity (BFV) coupled to brain activity. Our objective was to investigate whether walking induces measurable changes in BFV in healthy subjects.
  
  
  METHODS
  Changes in BFV in both middle cerebral arteries (MCAs) of 40 healthy adult subjects during walking on a treadmill were measured using bilateral TCD. In 8 of the 40 subjects, 1 anterior cerebral artery (ACA) was monitored simultaneously with the contralateral MCA. The percentage increase in BFV (BFVI%) compared with the baseline velocity (V(0)), the percentage decrease in BFV (BFVD%) compared with the V(0), and the normalized ACA-MCA ratio were analyzed.
  
  
  RESULTS
  The overall mean (+/- standard deviation [SD]) V(0) was 59.9 +/- 11.6 cm/second in the left MCA and 60.1 +/- 12.9 cm/second in the right MCA. Women had higher V(0) values than men had. Walking evoked an initial mean overall BFVI% in both left (8.4 +/- 5.1%) and right MCAs (9.1 +/- 5.1%), followed by a decrease to below baseline values in 38 of 40 subjects. A statistically significant increase of the normalized ACA-MCA ratio was measured, indicating that changes in BFV in the ACA territory were coupled to brain activation during walking.
  
  
  CONCLUSIONS
  The use of functional TCD showed different changes in BFV in the ACAs and MCAs during walking. This method may be an interesting tool for monitoring progress in patients with motor deficits of the legs, such as paresis.
authors.affiliation: Department of Neurology, Inselspital, University of Bern, CH-3010 Bern, Switzerland.
authors.forename: Krassen
authors.initials: K
authors.lastname: Nedeltchev
authors.forename: Marcel
authors.initials: M
authors.lastname: Arnold
authors.forename: Arto
authors.initials: A
authors.lastname: Nirkko
authors.forename: Mathias
authors.initials: M
authors.lastname: Sturzenegger
authors.forename: Frank
authors.initials: F
authors.lastname: Rihs
authors.forename: Robert
authors.initials: R
authors.lastname: Bühler
authors.forename: Heinrich P
authors.initials: HP
authors.lastname: Mattle
mesh_terms: D000293:Adolescent; D000328:Adult; D020771:Anterior Cerebral Artery / Q000000981:diagnostic imaging*; D001783:Blood Flow Velocity; D005080:Exercise Test; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging*; D011336:Probability; D011446:Prospective Studies; D012016:Reference Values; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*; D016138:Walking / Q000502:physiology*