Discrepant findings for Wada test and functional magnetic resonance imaging with regard to language function: use of electrocortical stimulation mapping to confirm results

2005 ◽  
Vol 102 (1) ◽  
pp. 169-173 ◽  
Author(s):  
Kuan H. Kho ◽  
Frans S. S. Leijten ◽  
Geert-Jan Rutten ◽  
Jan Vermeulen ◽  
Peter van Rijen ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Right Hemisphere ◽  
Test Results ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Wada Test ◽  
Content Type ◽  
Language Functions ◽  
Imaging Results ◽  
The Right

✓ The Wada test is still considered the gold standard for determining the language-dominant hemisphere prior to brain surgery. The authors report on a 34-year-old right-handed woman whose Wada test results indicated that the right hemisphere was dominant for language. In contrast, functional magnetic resonance (fMR) imaging was indicative of bilaterally represented language functions. Activation in the left hemisphere demonstrated on fMR imaging was most pronounced in the Broca area. Importantly, fMR imaging results in this area were confirmed on electrocortical stimulation mapping. These contradictory findings indicated that a right hemispherre dominance for language according to the Wada test should be questioned and verified using electrocortical stimulation. Nonetheless, the question remains whether involvement of these areas in the left frontal hemisphere is critical for language, as these were spared during surgery.

scholarly journals Language activation in monozygotic twins discordant for schizophrenia

2004 ◽  
Vol 184 (2) ◽  
pp. 128-135 ◽  
Author(s):  
Iris E. C. Sommer ◽  
Nick F. Ramsey ◽  
René C. W. Mandl ◽  
Clarine J. Van Oel ◽  
René S. Kahn
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Right Hemisphere ◽  
Monozygotic Twins ◽  
Monozygotic Twin ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Language Activation ◽  
The Right ◽  
Discordant Twin

BackgroundIn previous functional magnetic resonance imaging (fMRI) studies, participants with schizophrenia showed decreased language lateralisation, resulting from increased activation of the right hemisphere compared with controls.AimTo determine whether decreased lateralisation and increased right cerebral language activation constitute genetic predispositions for schizophrenia.MethodLanguage activation was measured using fMRI in 12 right-handed monozygotic twin pairs discordant for schizophrenia and 12 healthy right-handed monozygotic twin pairs who were matched for gender, age and education.ResultsLanguage lateralisation was decreased in discordant twin pairs compared with the healthy twin pairs. The groups did not differ in activation of the language-related areas of the left hemisphere, but language-related activation in the right hemisphere was significantly higher in the discordant twin pairs than in the healthy pairs. Within the discordant twin pairs, language lateralisation was not significantly different between patients with schizophrenia and their co-twins.ConclusionsDecreased language lateralisation may constitute a genetic predisposition for schizophrenia.

scholarly journals Event-Related Functional Magnetic Resonance Imaging Study of the Extrastriate Cortex Response to a Categorically Ambiguous Stimulus Primed by Letters and Familiar Geometric Figures

2001 ◽  
Vol 21 (11) ◽  
pp. 1330-1341 ◽  
Author(s):  
Hélène Gros ◽  
Kader Boulanouar ◽  
Gérard Viallard ◽  
Emmanuelle Cassol ◽  
Pierre Celsis
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Right Hemisphere ◽  
Extrastriate Cortex ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Ambiguous Stimulus ◽  
Form Processing ◽  
Geometric Figures

Functional neuroimaging studies have suggested a specific role of the extrastriate cortex in letter string and visual word form processing. However, this region has been shown to be involved in object recognition and its specificity for the processing of linguistic stimuli may be questioned. The authors used an event-related functional magnetic resonance imaging design with category priming to record the response elicited by the passive viewing of single letters, geometric figures, and of the categorically ambiguous stimulus “O” that pertains to both sets of familiar symbols. Bilateral activations in the extrastriate cortex were found, with a left predominance particularly pronounced for the ambiguous stimulus. Individual analysis of spatial extent and signal intensity showed a priming × stimulus × hemisphere interaction. When primed by the congruous categoric set, a bilateral decrease in activation was observed for letters and geometric figures. The ambiguous stimulus behaved as a letter for the left hemisphere, with decreased activation when primed by letters, whereas in the right hemisphere, an adaptation effect occurred when primed by geometric figures. These priming effects suggest that, for the ambiguous stimulus, letter processing was systematically involved in the left extrastriate cortex. The current results support the existence of a neural substrate for the abstract category of letters.

Coerced training of the nondominant hand resulting in cortical reorganization: a high-field functional magnetic resonance imaging study

2004 ◽  
Vol 101 (2) ◽  
pp. 310-313 ◽  
Author(s):  
Tsutomu Nakada ◽  
Yukihiko Fujii ◽  
Ingrid L. Kwee
Keyword(s):  
Magnetic Resonance Imaging ◽  
High Field ◽  
Cortical Reorganization ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Content Type ◽  
Hand Motion ◽  
Left Handed ◽  
The Right ◽  
Fine Print

Object. The authors investigated brain strategies associated with hand use in an attempt to clarify genetic and nongenetic factors influencing handedness by using high-field functional magnetic resonance imaging. Methods. Three groups of patients were studied. The first two groups comprised individuals in whom handedness developed spontaneously (right-handed and left-handed groups). The third group comprised individuals who were coercively trained to use the right hand and developed mixed handedness, referred to here as trained ambidexterity. All trained ambidextrous volunteers were certain that they were innately left-handed, but due to social pressure had modified their preferred hand use for certain tasks common to the right hand. Although right-handed and left-handed volunteers displayed virtually identical cortical activation, involving homologous cortex primarily located contralateral to the hand motion, trained ambidextrous volunteers exhibited a clearly unique activation pattern. During right-handed motion, motor areas in both hemispheres were activated in these volunteers. During left-handed motion, the right supplemental motor area and the right intermediate zone of the anterior cerebellar lobe were activated significantly more frequently than observed in naturally right-handed or left-handed volunteers. Conclusions. The results provide strong evidence that cortical organization of spontaneously developed right- and left-handedness involves homologous cortex primarily located contralateral to the hand motion, and this organization is likely to be prenatally determined. By contrast, coerced training of the nondominant hand during the early stages of an individual's development results in mixed handedness (trained ambidexterity), indicating cortical reorganization.

scholarly journals Resting-State Functional Magnetic Resonance Imaging and Functional Connectivity Density Mapping in Patients With Optic Neuritis

2021 ◽  
Vol 15 ◽  
Author(s):  
Ke Song ◽  
Yong Wang ◽  
Mei-Xia Ren ◽  
Jiao Li ◽  
Ting Su ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Connectivity ◽  
Functional Magnetic Resonance Imaging ◽  
Optic Neuritis ◽  
Resting State ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Functional Connectivity Density ◽  
The Right

Background: Using resting-state functional connectivity (rsFC), we investigated alternations in spontaneous brain activities reflected by functional connectivity density (FCD) in patients with optic neuritis (ON).Methods: We enrolled 28 patients with ON (18 males, 10 females) and 24 healthy controls (HCs; 16 males, 8 females). All subjects underwent functional magnetic resonance imaging (fMRI) in a quiet state to determine the values of rsFC, long-range FCD (longFCD), and short-range FCD (IFCD). Receiver operating characteristic (ROC) curves were generated to distinguish patients from HCs.Results: The ON group exhibited obviously lower longFCD values in the left inferior frontal gyrus triangle, the right precuneus and the right anterior cingulate, and paracingulate gyri/median cingulate and paracingulate gyri. The left median cingulate and paracingulate gyri and supplementary motor area (SMA) were also significantly lower. Obviously reduced IFCD values were observed in the left middle temporal gyrus/angular gyrus/SMA and right cuneus/SMA compared with HCs.Conclusion: Abnormal neural activities were found in specific brain regions in patients with ON. Specifically, they showed significant changes in rsFC, longFCD, and IFCD values. These may be useful to identify the specific mechanism of change in brain function in ON.

Functional Magnetic Resonance Imaging of Language Function in Children

2002 ◽  
Vol 3 (2) ◽  
pp. 132-139 ◽  
Author(s):  
Dianne P. Anderson
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Case Studies ◽  
Clinical Samples ◽  
Language Function ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Normal Children ◽  
Language Functions

AbstractFunctional magnetic resonance imaging (fMRI) has been recognised as a neuroimaging technique suitable for examination of higher cognitive function in children. It has been used to elucidate cognitive neural networks associated with various aspects of language function in several group and case studies of school-aged children. Language function has been lateralised and localised with fMRI in clinical samples, neurologically normal children and children with developmental language disorders. Issues of plasticity of language function during development and following injury have also been considered. Several paediatric case studies have also raised questions with respect to the interpretation of fMRI language activation. In spite of methodological challenges, fMRI has proved a useful technique for examination of the brain-behaviour relationship in developmental language functions. This paper reviews fMRI studies of language, including reading, in children.

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