G. Vingerhoets et N. Stroobant, Lateralization of cerebral blood flow velocity changes during cognitive tasks - A simultaneous bilateral transcranial Doppler study, STROKE, 30(10), 1999, pp. 2152-2158
Background and Purpose-Transcranial Doppler ultrasonography (TCD) permits t
he assessment of cognitively induced cerebral blood Row velocity (BFV) chan
ges. We sought to investigate the lateralization of BFV acceleration induce
d by a variety of cognitive tasks and to determine the influence of age, ge
nder, IQ, and quality of the performance on the relative BFV changes.
Methods-Simultaneous bilateral TCD monitoring of BFV in the middle cerebral
arteries (MCAs) was performed in 90 normal right-handed volunteers during
13 verbal and visuospatial tasks and their preceding rest periods.
Results-All tasks induced a significant bilateral BFV increase in the MCAs
compared with the preceding rest periods. Five verbal tasks showed a signif
icant left-hemispheric BFV acceleration. Linguistic tasks that required act
ive or creative processing of the verbal stimuli, such as sentence construc
tion or word fluency, elicited the most asymmetric response. Five visuospat
ial tasks revealed a significant right-hemispheric BFV shift. Paradigms tha
t combined visuospatial attention and visuomotor manipulation showed the mo
st lateralized acceleration. Older volunteers (aged >50 years) showed highe
r relative BFV changes, but lateralization was not influenced by age. Gende
r, IQ, and performance quality did not reveal significant effects on BFV ch
ange.
Conclusions-Bilateral TCD is a noninvasive technique that has the potential
to connect the particular change in Row pattern of the MCA distribution wi
th selective cognitive activity and thus offers specific functional informa
tion of scientific and clinical value.