Blood Flow Patterns Induced in the Dominant Hemisphere by Speech and Reading

Ingvar, David H.; Schwartz, Martin S.

doi:10.1093/brain/97.1.273

Cited by 166 publications

(37 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mean rCBF decreases in the basal ganglia have been dem onstrated by use of the CBA to be of functional importance for learning a finger movement skill . Local rCBF decreases have also been observed in rCBF measurements with the 133Xe technique and have been ascribed to redistribution (Ingvar and Schwartz, 1974). Since decreases of the rCBF and rCMR of glucose can experimentally be induced by l'-aminobutyrate ag onists (Kelly and McCulloch, 1984;Roland and Friberg, 1988) and have been shown to parallel a decrease in oxygen consumption (Eriksson et aI.…”

Section: Determination Of Signficant Rcbf Changesmentioning

confidence: 97%

Accuracy and Precision of the Computerized Brain Atlas Programme for Localization and Quantification in Positron Emission Tomography

Seitz¹,

Bohm

Greitz³

et al. 1990

J Cereb Blood Flow Metab

111

View full text Add to dashboard Cite

Summary:The computerized brain atlas programme (CBA) provides a powerful tool for the anatomical anal ysis of functional images obtained with positron emission tomography (PET). With a repertoire of simple transfor mations, the data base of the CBA is first adapted to the anatomy of the subject's brain represented as a set of magnetic resonance (MR) or computed tomography (CT) images. After this, it is possible to spatially standardize (reformat) any set of tomographic images related to the subject, PET images, as well as CT and MR images, by applying the inverse atlas transformations. From these reformatted images, statistical images, such as average images and associated error images corresponding to dif ferent groups of subjects, may be produced. In all these images, anatomical structures can be localized using the atlas data base and the functional values can be evaluated quantitatively. The purpose of this study was to deter mine the spatial and quantitative accuracy and precision of the calculated regional mean values. Therefore, the CBA was applied to regional CBF (rCBF) measurements with [ 11 C]fluoromethane and PET on 26 healthy male vol unteers during rest and during three different physiolog ical stimulation tasks. First, the spatial accuracy and pre cision of the reformation process were determined by measuring the spread of defined anatomical structures in the reformatted MR images of the subjects. Second, the mean global CBF and the mean rCBF in the average PET images were compared with the global CBF and rCBF in the original PET images. Our results demonstrate that the reformation process accurately transformed the individReceived July 24, 1989; revised November 24, 1989; accepted November 28, 1989. Address correspondence and reprint requests to Dr. R. J. Seitz at Department of Clinical Neurophysiology, Karolinska Hospital, Box 60500, S-10401 Stockholm, Sweden.Abbreviations used: CBA, computerized brain atlas pro gramme; CT, computed tomography; MR, magnetic resonance; PET, positron emission tomography; rCBF, regional CBF; rCMR, regional CMR; ROl, region of interest. For image types, see Table I. . O wing to this high sampling resolution, it was possible to differentiate the mean rCBF changes in adjacent activated fields such as the left motor hand area from the sensory hand area and the left premotor cortex. (c) By calculating the rela tion of the mean rCBF change to the SEM of the mean rCBF change on a pixel-by-pixel basis, areas with signif icant rCBF changes could be determined. By use of the CBA, it was found that there was a high intersubject con sistency in location of stimulation-induced rCBF changes. Furthermore, the rCBF changes in specifically stimulated areas were of similar magnitude among the subjects. It was shown that the stimulation-induced mean rCBF increases may be accompanied by mean rCBF de creases in other areas. Key Words: Computerized brain atlas-Magnetic resonance imaging-Physiological stim ulation-Positron emission tomography.Positron emission tomography (PET) is a no...

show abstract

Section: Determination Of Signficant Rcbf Changesmentioning

confidence: 97%

Accuracy and Precision of the Computerized Brain Atlas Programme for Localization and Quantification in Positron Emission Tomography

Seitz¹,

Bohm

Greitz³

et al. 1990

J Cereb Blood Flow Metab

111

View full text Add to dashboard Cite

show abstract

“…and our recirculation corrected H/A 10 . 5 by both methods is nearly equivalent. Our kj values for the normal subjects using intravenous 133 Xe input are comparable with those reported by Obrist 13 using…”

Section: K T Values Of Right Side Versus Left Side For Two Normal Gromentioning

confidence: 86%

Cerebral blood flow studies in man using recirculation corrected height/area (H/A) computations for intravenous injection of 133Xenon.

Namon¹,

Reinmuth²,

Schwelm³

1982

Stroke

View full text Add to dashboard Cite

SUMMARY Our height/area (recirculation-corrected) non-invasive cerebral blood flow method compares well with k t values and k average as determined from k 1( k 2 , Pi and p 2 by Obrist computations. The height/area method provides regional flow measurements with less variability than k t due to low regional head counts, head motion and end-tidal gas sample variations.Derivation of the mathematical model is for a single flow compartment and suited for tomographic measurements such as PET. Collimated detector data using our computation provides a good approximation of flow even for multiple compartments. Our approach permits a lower counting rate by either a smaller isotope dose or better detector collimation than multicompartment curve fitting methods.

show abstract

“…Langfitt and Kassell (1968) reported that focal electrical stimulation of the brain invariably altered EEG and produced an increase in CBF without a change in blood pressure in spinally tran sected monkey anesthetized with pentobarbital so dium. An increase in regional CBF of distinct brain areas has been observed during increased motor performance (Olesen, 1971;lngvar and Schwartz, 1974;Halsey et aI., 1977) and after cutaneous af ferent stimulation (lngvar et aI., 1975;Winn et aI., 1981). Such observations indicate that blood flow is heterogeneous and is likely coupled to local changes in neuronal function.…”

Section: Discussionmentioning

confidence: 99%

Cortical Vasodilatation Produced by Vasoactive Intestinal Polypeptide (VIP) and by Physiological Stimuli in the Cat

Yaksh¹,

Wang²,

et al. 1987

J Cereb Blood Flow Metab

View full text Add to dashboard Cite

Summary: In chloralose-urethanized cats, vasoactive in testinal peptide (VIP), applied by superfusion in steady state concentration (10-10_10-6 M) onto cortical vessels in situ resulted in a rapid concentration-dependent vaso dilatation in vessels that were mildly constricted by prosta glandin Fzo< (PGFzo<) (5 x 10-5 M) or hypocarbia (PaC02 = 26), The maximum dilatation produced by VIP (10-6 M) was about 60% over baseline in pial arteries and 40% in pial veins, Blockade of local neuronal activity with tetro dotoxin (TTX) (10-5 M) had no effect on the VIP-evoked dilation of pial vessels, Activation of the cortex by either direct electrical stimulation or indirectly by stimulation of the mesencephalic reticular formation (MRF) resulted in a rapid dilatation of pial arterioles and venules, The vaso dilatory effects of VIP and of cortical activation via direct cortical stimulation were not blocked by phentolamine (10-4 M), propranolol (10-4 M), atropine (10-4 M), or naloxone (10-4 M), indicating that the stimulated vasodi latation was not mediated by adrenergic. cholinergic, orIncreasing neuronal activity in the cerebral cortex results in an immediate increase in focal ce rebral blood flow. One possible mechanism under lying such a close coupling is the local release of vasoactive substances secondary to neuronal ac tivity.Transmural stimulation of cerebral vessels fre quently evokes a prominent vasodilation that re mains following removal of the endothelium. 315opiate receptors, The dilatory effects of MRF, but not direct cortical stimulation, were not blocked by TTX . VIP antiserum (I :25) preincubated in cortical cups had no effect on resting vessel diameter, but resulted in a signifi cant, though subtotal, reduction in the vasodilatation elicited by direct cortical and MRF stimulation. Normal rabbit sera or VIP antiserum pre incubated with saturating amounts of VIP were ineffective . In similar experiments, pial arteriolar and venular dilation evoked by hypercarbia was not attenuated by cortically applied VIP antisera. These observations suggest that pial dilation evoked by local increases in neuronal activity may be mediated in part by the local release of VIP from intrinsic neurons. Such a substrate would define a close obligatory coupling between local neuronal activation and local perfusion, such that nutritive flow could be enhanced prior to the onset of any metabolic deficit.

show abstract

Blood Flow Patterns Induced in the Dominant Hemisphere by Speech and Reading

Cited by 166 publications

References 0 publications

Accuracy and Precision of the Computerized Brain Atlas Programme for Localization and Quantification in Positron Emission Tomography

Accuracy and Precision of the Computerized Brain Atlas Programme for Localization and Quantification in Positron Emission Tomography

Cerebral blood flow studies in man using recirculation corrected height/area (H/A) computations for intravenous injection of 133Xenon.

Cortical Vasodilatation Produced by Vasoactive Intestinal Polypeptide (VIP) and by Physiological Stimuli in the Cat

Contact Info

Product

Resources

About