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- Börjesson, L., et al.
(författare)
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Comparison between fMRI and Wada test
- 2004
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Ingår i: Epilepsia. - : Wiley-Blackwell. - 0013-9580 .- 1528-1167. ; 45:Suppl. 3, s. 84-84
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Language lateralisation in patients with epilepsy is more often atypical compared to a normal population. The Wada procedure for testing language and memory has some shortcomings; it is invasive and there is always a risk that the patient becomes too sedated, leading to difficulties in performing the tests. fMR1have shown promising results, showing good correlation to the Wadaprocedure concerning language-lateralisation. The aim of this studywas to investigate if fMRI could be used to determine which hemisphere was language dominant and compare the fMR1 results with the Wada-tests with a focus on patients with a complicated lateralisation.Method: 4 subjects were tested and they had a heterogeneous (I left handed, I ambidexter and 2 right handed) lateralisation and one had a severe dyslexia. A standard Wada procedure was used and compared with a fMRl investigation using a language paradigm.Results: The patients studied showed different language lateralisation patterns (2 left hemisphere and 2 bilateral). In two patients the two tests were fully concordant, in the others the fMRI showed a more bilateral pattern.Conclusion: fMR1 adds valuable information in the pre-surgical investigation for patients with a complex language lateralisation.
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| 2. |
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| 3. |
- Lampinen, Björn, et al.
(författare)
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Tensor-valued diffusion MRI differentiates cortex and white matter in malformations of cortical development associated with epilepsy
- 2020
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Ingår i: Epilepsia. - : Wiley. - 0013-9580 .- 1528-1167. ; 61:8, s. 1701-1713
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Tidskriftsartikel (refereegranskat)abstract
- Objective Delineation of malformations of cortical development (MCD) is central in presurgical evaluation of drug-resistant epilepsy. Delineation using magnetic resonance imaging (MRI) can be ambiguous, however, because the conventional T-1- and T-2-weighted contrasts depend strongly on myelin for differentiation of cortical tissue and white matter. Variations in myelin content within both cortex and white matter may cause MCD findings on MRI to change size, become undetectable, or disagree with histopathology. The novel tensor-valued diffusion MRI (dMRI) technique maps microscopic diffusion anisotropy, which is sensitive to axons rather than myelin. This work investigated whether tensor-valued dMRI may improve differentiation of cortex and white matter in the delineation of MCD. Methods Tensor-valued dMRI was performed on a 7 T MRI scanner in 13 MCD patients (age = 32 +/- 13 years) featuring periventricular heterotopia, subcortical heterotopia, focal cortical dysplasia, and polymicrogyria. Data analysis yielded maps of microscopic anisotropy that were compared with T-1-weighted and T-2-fluid-attenuated inversion recovery images and with the fractional anisotropy from diffusion tensor imaging. Results Maps of microscopic anisotropy revealed large white matter-like regions within MCD that were uniformly cortex-like in the conventional MRI contrasts. These regions were seen particularly in the deep white matter parts of subcortical heterotopias and near the gray-white boundaries of focal cortical dysplasias and polymicrogyrias. Significance By being sensitive to axons rather than myelin, mapping of microscopic anisotropy may yield a more robust differentiation of cortex and white matter and improve MCD delineation in presurgical evaluation of epilepsy.
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