Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2003-10-21
pubmed:abstractText
Functional MRI is based on the vascular response due to neuronal activation. The underlying mechanism of fMRI is the blood oxygenation level-dependent (BOLD) effect-a complex interplay between changes in the cerebral metabolisation rate of oxygen (CMRO2), neurovascular coupling, and the resulting hemodynamic response. An intact neurovascular coupling is essential for the detection of the BOLD signal and it seems likely that a disturbed cerebrovascular reserve capacity (CVRC) alters the BOLD response. We tested the hypothesis that extra- or intracranial artery disease influences the BOLD signal. Twenty-one patients with extra- or intracranial stenosis were studied with BOLD sensitive T2*-weighted MRI. All patients presented with transient or prolonged reversible ischemic symptoms ipsilateral to the artery disease but were asymptomatic at the time point of the MRI study. fMRI was performed employing a simple motor task (fist closure right and left). Additionally, the CVRC was assessed applying carbogen gas during serial T2*-weighted MRI for the calculation of CO(2) reactivity maps of the relative signal change. Signal differences between both hemispheres were compared in individual subjects and with healthy subjects. Patients with disturbed CVRC in the CO(2) reactivity maps showed either a significantly reduced (n = 5) or a negative (n = 1) BOLD signal in the affected compared to the unaffected primary sensorimotor cortex during fist closure. Patients with intact CVRC showed no significant BOLD signal differences between affected and unaffected hemisphere. Extra- or intracranial artery disease influences CVRC and consequently the BOLD signal. This observation is important for the clinical application of fMRI paradigms.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1053-8119
pubmed:author
pubmed:issnType
Print
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1393-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
The influence of extra- and intracranial artery disease on the BOLD signal in FMRI.
pubmed:affiliation
Department of Neurology, University Hospital Eppendorf, Hamburg, Germany. hamzei@uke.uni-hamburg.de
pubmed:publicationType
Journal Article, Clinical Trial, Research Support, Non-U.S. Gov't