The investigation of functional brain lateralization by transcranial Doppler sonography

Deppe, Michael; Ringelstein, E. B.; Knecht, Stefan

doi:10.1016/j.neuroimage.2003.10.016

Cited by 147 publications

(127 citation statements)

References 110 publications

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“…Our work builds on work by Rune Aaslid, who co-introduced TCD in 1982, and Stefan Knecht, Michael Deppe and their colleagues at the University of Münster, who pioneered the use of simultaneous measurements of left-and right middle cerebral artery blood flow, and devised a method of correcting for heart beat activity. This made it possible to see a clear increase in left-sided blood flow during language generation, with lateralization agreeing well with that obtained using other methods 3 .…”

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confidence: 87%

Assessment of Cerebral Lateralization in Children using Functional Transcranial Doppler Ultrasound (fTCD)

Bishop

Badcock

Holt

2010

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There are many unanswered questions about cerebral lateralization. In particular, it remains unclear which aspects of language and nonverbal ability are lateralized, whether there are any disadvantages associated with atypical patterns of cerebral lateralization, and whether cerebral lateralization develops with age. In the past, researchers interested in these questions tended to use handedness as a proxy measure for cerebral lateralization, but this is unsatisfactory because handedness is only a weak and indirect indicator of laterality of cognitive functions 1 .Other methods, such as fMRI, are expensive for large-scale studies, and not always feasible with children 2 .Here we will describe the use of functional transcranial Doppler ultrasound (fTCD) as a cost-effective, non-invasive and reliable method for assessing cerebral lateralization. The procedure involves measuring blood flow in the middle cerebral artery via an ultrasound probe placed just in front of the ear. Our work builds on work by Rune Aaslid, who co-introduced TCD in 1982, and Stefan Knecht, Michael Deppe and their colleagues at the University of Münster, who pioneered the use of simultaneous measurements of left-and right middle cerebral artery blood flow, and devised a method of correcting for heart beat activity. This made it possible to see a clear increase in left-sided blood flow during language generation, with lateralization agreeing well with that obtained using other methods .The middle cerebral artery has a very wide vascular territory (see Figure 1) and the method does not provide useful information about localization within a hemisphere. Our experience suggests it is particularly sensitive to tasks that involve explicit or implicit speech production. The 'gold standard' task is a word generation task (e.g. think of as many words as you can that begin with the letter 'B') 4 , but this is not suitable for young children and others with limited literacy skills. Compared with other brain imaging methods, fTCD is relatively unaffected by movement artefacts from speaking, and so we are able to get a reliable result from tasks that involve describing pictures aloud 5,6 . Accordingly, we have developed a child-friendly task that involves looking at video-clips that tell a story, and then describing what was seen. Video LinkThe video component of this article can be found at http://www.jove.com/video/2161/ Protocol Using fTCD to Assess Language Lateralization in Children1. Where possible, we familiarise the child with pictures showing characters from the video stories in a separate session before introducing them to Doppler system. 2. It is important that the procedure includes sufficient trials to get a reliable measure: ideally 20 or more, though we have obtained useful data with as few as 10 to 15 trials. Each trial involves a period of relaxation, to be used as a baseline, followed by language activation. Blood flow velocity during the period of activation is compared against the baseline. We have found that it is possible to u...

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confidence: 87%

Assessment of Cerebral Lateralization in Children using Functional Transcranial Doppler Ultrasound (fTCD)

Bishop

Badcock

Holt

2010

JoVE

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“…Subjects were righthanded as assessed by the Edinburgh Handedness Inventory (Oldfield, 1971) and left hemisphere dominant for language as assessed by transcranial Doppler sonography (Deppe et al, 2004).…”

Section: Subjectsmentioning

confidence: 99%

Tonic Dopaminergic Stimulation Impairs Associative Learning in Healthy Subjects

Breitenstein

Korsukewitz

Flöel

et al. 2006

Neuropsychopharmacol

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Endogenous dopamine plays a central role in salience coding during associative learning. Administration of the dopamine precursor levodopa enhances learning in healthy subjects and stroke patients. Because levodopa increases both phasic and tonic dopaminergic neurotransmission, the critical mechanism mediating the enhancement of learning is unresolved. We here probed how selective tonic dopaminergic stimulation affects associative learning. Forty healthy subjects were trained in a novel vocabulary of 45 concrete nouns over the course of 5 consecutive training days in a prospective, randomized, double-blind, placebo-controlled design. Subjects received the tonically stimulating dopamine-receptor agonist pergolide (0.1 mg) vs placebo 120 min before training on each training day. The dopamine agonist significantly impaired novel word learning compared to placebo. This learning decrement persisted up to the last follow-up 4 weeks post-training. Subjects treated with pergolide also showed restricted emotional responses compared to the PLACEBO group. The extent of 'flattened' affect with pergolide was related to the degree of learning inhibition. These findings suggest that tonic occupation of dopamine receptors impairs learning by competition with phasic dopamine signals. Thus, phasic signaling seems to be the critical mechanism by which dopamine enhances associative learning in healthy subjects and stroke patients.

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“…This strong correlation establishes the use of fTCD as a noninvasive and practical tool for the determination of language dominance and psychophysiologic research (Deppe et al, 2004;Duschek and Schandry, 2003). Functional transcranial Doppler can assess FV changes at a high temporal resolution, a capability that is the greatest asset of this method compared with other functional imaging techniques.…”

Section: Introductionmentioning

confidence: 62%

Evaluation of the Stability of Blood Flow over Time in the Dominant Hemisphere: A Functional Transcranial Doppler Study

Vadikolias

Artemis

Mitsias

et al. 2007

J Cereb Blood Flow Metab

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Functional transcranial Doppler (fTCD) has been used for the identification of cerebral hemispheric dominance in various cognitive tasks. In our study, we have used fTCD with the aim to compare blood flow patterns in the hemispheres not only during the task activation periods but also in the post-stimulus phase. Normal volunteers, 25 right and 25 left-handed, were included. Mean flow velocities (FVs) in the bilateral middle cerebral arteries were recorded during the performance of six cognitive tasks and during the intervals between tasks. The lateralization index (LI) was calculated separately for each test (LI1-6), on the basis of the percent change of blood FV from baseline. To estimate flow fluctuations, a novel index, the LI-variability, was also calculated using a formula constituted by the minimum and maximum mean values recorded at specific time intervals during the entire procedure. Laterization indices, LI-3 and LI-4, corresponding to word generation and reading aloud tasks, produced the highest degree of activation. A perfect agreement (Cohen's j = 1.000, P < 0.001) was observed among LI-3, LI-4, and LI-V. The repetition of recordings gave excellent test-retest reliability in 10 randomly selected participants. Our results suggest that the hemisphere that is characterized as dominant by fTCD maintains a more stable flow pattern during the performance of successive cognitive tasks. Although it could not be considered as a clinically useful tool as yet, this observation introduces a novel parameter such as the stability of blood flow over time, which could potentially provide insight in the study of cerebral functions.

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The investigation of functional brain lateralization by transcranial Doppler sonography

Cited by 147 publications

References 110 publications

Assessment of Cerebral Lateralization in Children using Functional Transcranial Doppler Ultrasound (fTCD)

Assessment of Cerebral Lateralization in Children using Functional Transcranial Doppler Ultrasound (fTCD)

Tonic Dopaminergic Stimulation Impairs Associative Learning in Healthy Subjects

Evaluation of the Stability of Blood Flow over Time in the Dominant Hemisphere: A Functional Transcranial Doppler Study

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