Clinical fMRI: Implementation and Experience

Thulborn, Keith R.; Davis, Denise; Erb, Patricia; Strojwas, Magda; Sweeney, John A.

doi:10.1006/nimg.1996.0060

Cited by 38 publications

(24 citation statements)

References 8 publications

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“…The direction of movement (right or left) was unpredictable except at the Ϯ9°location when the next target was always toward the screen center. Visual stimuli were generated using locally developed CIGAL software [Voyvodic, 1996] and an in-house visual presentation system [Thulborn et al, 1996a]. Stimuli were projected onto a rear projection screen spanning 10°vertically and 20°horizontally, which subjects viewed from an angled mirror fixed to the head coil.…”

Section: Paradigmsmentioning

confidence: 99%

Cortical networks subserving pursuit and saccadic eye movements in humans: An FMRI study

et al. 1999

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High-field (3 Tesla) functional magnetic resonance imaging (MRI) was used to investigate the cortical circuitry subserving pursuit tracking in humans and compare it to that for saccadic eye movements. Pursuit performance, relative to visual fixation, elicited activation in three areas known to contribute to eye movements in humans and in nonhuman primates: the frontal eye field, supplementary eye field, and intraparietal sulcus. It also activated three medial regions not previously identified in human neuroimaging studies of pursuit: the precuneus and the anterior and posterior cingulate cortices. All six areas were also activated during saccades. The spatial extent of activation was similar for saccades and pursuit in all but two regions: spatial extent was greater for saccades in the superior branch of the frontal eye field and greater for pursuit in posterior cingulate cortex. This set of activations for smooth pursuit parallels the network of oculomotor areas characterized in nonhuman primates and complements recent studies showing that common cortical networks subserve oculomotor functions and spatial attention in humans.

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Section: Paradigmsmentioning

confidence: 99%

Cortical networks subserving pursuit and saccadic eye movements in humans: An FMRI study

et al. 1999

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“…In addition to its increasing popularity within the cognitive and basic neuroscience communities, it is also becoming increasingly popular for clinical purposes since the first applications in epileptic [Jackson et al, 1994] and schizophrenic patients [Wenz et al, 1994], which have led to the introduction of the concept of 'clinical fMRI' [Levin et al, 1995;Thulborn et al, 1996]. Clinical fMRI has thus been applied to patients with various pathologies to assess the functional reorganisation and plasticity after brain damage [for review, see Detre and Floyd, 2001;Matthews et al, 1999;Powell et al, 2004;Price and Crinion, 2005].…”

Section: Introductionmentioning

confidence: 99%

Group analysis and the subject factor in functional magnetic resonance imaging: Analysis of fifty right‐handed healthy subjects in a semantic language task

Seghier¹,

Lazeyras²,

Pegna³

et al. 2007

Human Brain Mapping

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Before considering a given fMRI paradigm as a valid clinical tool, one should first assess the reliability of functional responses across subjects by establishing a normative database and defining a reference activation map that identifies major brain regions involved in the task at hand. However, the definition of such a reference map can be hindered by inter-individual functional variability. In this study, we analysed functional data obtained from 50 healthy subjects during a semantic language task to assess the influence of the number of subjects on the reference map and to characterise inter-individual functional variability. We first compared different group analysis approaches and showed that the extent of the activated network depends not only on the choice of the analysis approach but also on the statistical threshold used and the number of subjects included. This analysis suggested that, while the RFX analysis is suitable to detect confidently true positive activations, the other group approaches are useful for exploratory investigations in small samples. The application of quantitative measures at the voxel and regional levels suggested that while approximately 15-20 subjects were sufficient to reveal reliable and robust left hemisphere activations, >30 subjects were necessary for revealing more variable and weak right hemisphere ones. Finally, to visualise inter-individual variability, we combined two similarity indices that assess the percentages of true positive and false negative voxels in individual activation patterns relative to the group map. We suggest that these measures can be used for the estimation of the degree of 'normality' of functional responses in brain-damaged patients, where this question is often raised, and recommend the use of different quantifications to appreciate accurately the inter-individual functional variability that can be incorporated in group maps.

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“…8,9,17 The comprehensive MRI protocol for patient studies, involving anatomic, diffusion, perfusion, and sodium imaging, has been reported elsewhere. 18 Acquisition parameters for fMRI using gradient-echo echo-planar imaging at 3.0 T were as follows: TRϭ4000 ms; TEϭ25 ms; field of view (FOV), 40ϫ20; voxel size, 3.1ϫ3.1ϫ3.0 mm 3 ; slice thickness/ gap, 3/1 mm; and nϭ18 slices.…”

Section: Imaging Protocolmentioning

confidence: 99%

Plasticity of Language-Related Brain Function During Recovery From Stroke

Thulborn

Carpenter

Just

1999

Stroke

Self Cite

380

190

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Background and Purpose-This study was undertaken to correlate functional recovery from aphasia after acute stroke with the temporal evolution of the anatomic, physiological, and functional changes as measured by MRI. Methods-Blood oxygenation level-dependent contrast and echo-planar MRI were used to map language comprehension in 6 normal adults and in 2 adult patients during recovery from acute stroke presenting with aphasia. Perfusion, diffusion, sodium, and conventional anatomic MRI were used to follow physiological and structural changes. Results-The normal activation pattern for language comprehension showed activation predominately in left-sided Wernicke's and Broca's areas, with laterality ratios of 0.8 and 0.3, respectively. Recovery of the patient confirmed as having a completed stroke affecting Broca's area occurred rapidly with a shift of activation to the homologous region in the right hemisphere within 3 days, with continued rightward lateralization over 6 months. In the second patient, in whom mapping was performed fortuitously before stroke, recovery of a Wernicke's aphasia showed a similar increasing rightward shift in activation recruitment over 9 months after the event. Conclusions-Recovery of aphasia in adults can occur rapidly and is concomitant with an activation pattern that changes from left to a homologous right hemispheric pattern. Such recovery occurs even when the stroke evolves to completion. Such plasticity must be considered when evaluating stroke interventions based on behavioral and neurological measurements. (Stroke. 1999;30:749-754.)

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Clinical fMRI: Implementation and Experience

Cited by 38 publications

References 8 publications

Cortical networks subserving pursuit and saccadic eye movements in humans: An FMRI study

Cortical networks subserving pursuit and saccadic eye movements in humans: An FMRI study

Group analysis and the subject factor in functional magnetic resonance imaging: Analysis of fifty right‐handed healthy subjects in a semantic language task

Plasticity of Language-Related Brain Function During Recovery From Stroke

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