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Toshihiko Wakabayashi - One of the best experts on this subject based on the ideXlab platform.
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Selective Propofol Injection into the M1 Segment of the Middle Cerebral Artery (MCA Wada Test) Reduces Adverse Effects and Enhances the Reliability of the Wada Test for Determining Speech Dominance
World Neurosurgery, 2011Co-Authors: Masazumi Fujii, Shigeru Miyachi, Noriaki Matsubara, Takeshi Kinkori, Shigenori Takebayashi, Takashi Izumi, Tomotaka Ohshima, Arihito Tsurumi, Osamu Hososhima, Toshihiko WakabayashiAbstract:OBJECT: The Wada Test is had been the most reliable for determining speech dominance. Drugs injected into the internal carotid artery, however, may be heterogeneously distributed as the result of asymmetry of the anterior cerebral arteries and the presence of a fetal-type posterior cerebral artery. Variations in drug distribution could occasionally alter consciousness and complicate the evaluation of the Test results. We examined selective propofol injection into the M1 segment of the middle cerebral artery (MCA Wada Test). METHODS: For the MCA Wada Test (17 patients), 7 or 8 mg of propofol was injected via a microcatheter navigated into the M1 segment, and language function was evaluated by patient performing several tasks. The conventional Wada Test (internal carotid artery [ICA] Wada Test) was performed in four patients (both the ICA and MCA Wada Tests were performed in one patient). The efficacy and adverse effects of both procedures were evaluated; all Tests were performed by well-trained interventional neuroradiologists. RESULTS: Immediately after propofol injection during the MCA Wada Test, patients developed transient contralateral hemiplegia and transient aphasia (in the case of injection on the dominant side). Confusion and other severe adverse effects did not occur during the MCA Wada Test, but two of four patients who underwent the ICA Wada Test showed altered consciousness that affected the performance of the Test. CONCLUSIONS: The MCA Wada Test is a feasible and reliable preoperative evaluation, if performed by a trained team of interventional neuroradiologists.
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Selective propofol injection into the M1 segment of the middle cerebral artery (MCA Wada Test) reduces adverse effects and enhances the reliability of the Wada Test for determining speech dominance.
World neurosurgery, 2011Co-Authors: Masazumi Fujii, Shigeru Miyachi, Noriaki Matsubara, Takeshi Kinkori, Shigenori Takebayashi, Takashi Izumi, Tomotaka Ohshima, Arihito Tsurumi, Osamu Hososhima, Toshihiko WakabayashiAbstract:The Wada Test is had been the most reliable for determining speech dominance. Drugs injected into the internal carotid artery, however, may be heterogeneously distributed as the result of asymmetry of the anterior cerebral arteries and the presence of a fetal-type posterior cerebral artery. Variations in drug distribution could occasionally alter consciousness and complicate the evaluation of the Test results. We examined selective propofol injection into the M1 segment of the middle cerebral artery (MCA Wada Test). For the MCA Wada Test (17 patients), 7 or 8 mg of propofol was injected via a microcatheter navigated into the M1 segment, and language function was evaluated by patient performing several tasks. The conventional Wada Test (internal carotid artery [ICA] Wada Test) was performed in four patients (both the ICA and MCA Wada Tests were performed in one patient). The efficacy and adverse effects of both procedures were evaluated; all Tests were performed by well-trained interventional neuroradiologists. Immediately after propofol injection during the MCA Wada Test, patients developed transient contralateral hemiplegia and transient aphasia (in the case of injection on the dominant side). Confusion and other severe adverse effects did not occur during the MCA Wada Test, but two of four patients who underwent the ICA Wada Test showed altered consciousness that affected the performance of the Test. The MCA Wada Test is a feasible and reliable preoperative evaluation, if performed by a trained team of interventional neuroradiologists. Published by Elsevier Inc.
David W. Loring - One of the best experts on this subject based on the ideXlab platform.
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History of the Wada Test
The Oxford Handbook of History of Clinical Neuropsychology, 2019Co-Authors: David W. Loring, Kimford J. MeadorAbstract:This chapter discusses the origins and development of the Wada Test. Wada Testing, named after Juhn A. Wada, M.D., is the technique of arterial administration of amobarbital (or other short acting barbiturate) to transiently inactivate brain function in the distribution of the injected artery during which cognitive Testing is performed. The procedure was developed to establish cerebral language dominance in the late 1940s, and it became a routine component of the preoperative evaluation for epilepsy surgery in the mid-1950s. However, the use of Wada Testing as the primary technique to identify cortical language regions and predict risk of post-operative memory decline has been increasingly displaced by electroencephalogram (EEG) video monitoring, magnetic resonance imaging (MRI) of hippocampus, positron emission tomography (PET), single photon emission computed tomography (SPECT), functional MRI (fMRI), and even multi-modality imaging.
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The Wada Test: Current Perspectives and Applications
Handbook on the Neuropsychology of Epilepsy, 2014Co-Authors: David W. Loring, Kimford J. MeadorAbstract:The Wada Test has been an integral part of the preoperative evaluation for epilepsy surgery since the 1950s. Originally designed to establish cerebral language laterality, it was subsequently modified by including a memory component to estimate postoperative risk to recent memory function following unilateral temporal lobe resection. This chapter will briefly review the use of Wada Testing, discuss the various approaches used to transiently anesthetize brain regions prior to cognitive assessment, and conclude with the specific methods developed at the Medical College of Georgia (MCG). The Wada Test is not only employed to predict postoperative risks of language and memory deficits but is also a marker of temporal lobe dysfunction and as such should be sensitive to seizure-onset laterality in patients with temporal lobe epilepsy. Wada Test results should always be interpreted within the context of other clinical and diagnostic Test findings. The lessons learned from pitfalls in Wada Testing should be carefully considered in the development and application of other techniques to assess focal cerebral function/dysfunction.
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The Wada Test for language and memory lateralization.
Neurology, 2005Co-Authors: Kimford J. Meador, David W. LoringAbstract:Kirsch et al. examine the clinical value of Wada memory asymmetry to predict postoperative seizure freedom and postoperative verbal memory. Wada memory asymmetry in the unexpected direction may signal increased risk of poor surgical outcome after nondominant temporal lobectomy. It is not a predictor of persistent postoperative verbal memory decline. see page 676 Commentary by Kimford J. Meador, MD, and David W. Loring, PhD For over 50 years, the Wada Test has been a component of the preoperative evaluation for epilepsy surgery. Juhn Wada introduced the intracarotid amobarbital procedure to lateralize language in 1949, and soon thereafter, Brenda Milner included memory Testing during the procedure to help determine risk for postoperative amnesia. …
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The Wada Test in the evaluation for epilepsy surgery.
Neurosciences (Riyadh Saudi Arabia), 2000Co-Authors: David W. Loring, Kimford J. Meador, Michael WesterveldAbstract:The Wada Test is the standard part of the pre-operative evaluation for epilepsy surgery. The procedure involves the slow injection of sodium amobarbital (typically 100-500mg) into the internal carotid artery following a transfermoral approach. The amobarbital anesthetizes the anterior two-thirds of the ipsilateral cerebral hemisphere for approximately 5-10 minutes. During this period of hemispheric anesthesia, assessment of expressive and receptive language can establish cerebral language representation. In addition, the procedure provides a reversible model to assess the risk of significant memory change following surgery. This is important because patients undergoing surgery involving the temporal lobe may experience significant memory decline following surgical resection of a temporal lobe seizure focus. This paper will represent information about the use of Wada Testing, and discuss issues involved in establishing cerebral language representation, lateralization of temporal lobe dysfunction, seizure and memory outcome prediction, and future directions of this technique.
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The Wada Test: controversies, concerns, and insights.
Neurology, 1999Co-Authors: Kimford J. Meador, David W. LoringAbstract:In 1949, Juhn Wada described the use of the intracarotid amobarbital procedure (i.e., Wada Test) to determine cerebral language dominance.1 The procedure was later modified at the Montreal Neurological Institute to also assess hemispheric memory,2 and has become a standard component of presurgical evaluation for epilepsy surgery. The Wada memory Test is used to evaluate the risk of postoperative amnesia, to assess the risk of material specific memory deficits, to lateralize hemispheric dysfunction, and to predict postoperative seizure outcome. Four articles in the current issue of Neurology address controversies and important concerns regarding the Wada Test.3-6 At times, agitation or obtundation during the Wada Test make determination of language dominance problematic. To circumvent this limitation, Rihs et al. employ functional transcranial Doppler sonography (fTCD) to assess simultaneous differential left/right changes in middle cerebral artery blood flow to language and visuospatial tasks.3 Language lateralization via fTCD and the Wada Test were highly correlated, suggesting that fTCD may offer a noninvasive alternative to the Wada Test. Similar findings have recently been demonstrated for functional MRI (fMRI); fTCD is less expensive …
Masazumi Fujii - One of the best experts on this subject based on the ideXlab platform.
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Selective Propofol Injection into the M1 Segment of the Middle Cerebral Artery (MCA Wada Test) Reduces Adverse Effects and Enhances the Reliability of the Wada Test for Determining Speech Dominance
World Neurosurgery, 2011Co-Authors: Masazumi Fujii, Shigeru Miyachi, Noriaki Matsubara, Takeshi Kinkori, Shigenori Takebayashi, Takashi Izumi, Tomotaka Ohshima, Arihito Tsurumi, Osamu Hososhima, Toshihiko WakabayashiAbstract:OBJECT: The Wada Test is had been the most reliable for determining speech dominance. Drugs injected into the internal carotid artery, however, may be heterogeneously distributed as the result of asymmetry of the anterior cerebral arteries and the presence of a fetal-type posterior cerebral artery. Variations in drug distribution could occasionally alter consciousness and complicate the evaluation of the Test results. We examined selective propofol injection into the M1 segment of the middle cerebral artery (MCA Wada Test). METHODS: For the MCA Wada Test (17 patients), 7 or 8 mg of propofol was injected via a microcatheter navigated into the M1 segment, and language function was evaluated by patient performing several tasks. The conventional Wada Test (internal carotid artery [ICA] Wada Test) was performed in four patients (both the ICA and MCA Wada Tests were performed in one patient). The efficacy and adverse effects of both procedures were evaluated; all Tests were performed by well-trained interventional neuroradiologists. RESULTS: Immediately after propofol injection during the MCA Wada Test, patients developed transient contralateral hemiplegia and transient aphasia (in the case of injection on the dominant side). Confusion and other severe adverse effects did not occur during the MCA Wada Test, but two of four patients who underwent the ICA Wada Test showed altered consciousness that affected the performance of the Test. CONCLUSIONS: The MCA Wada Test is a feasible and reliable preoperative evaluation, if performed by a trained team of interventional neuroradiologists.
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Selective propofol injection into the M1 segment of the middle cerebral artery (MCA Wada Test) reduces adverse effects and enhances the reliability of the Wada Test for determining speech dominance.
World neurosurgery, 2011Co-Authors: Masazumi Fujii, Shigeru Miyachi, Noriaki Matsubara, Takeshi Kinkori, Shigenori Takebayashi, Takashi Izumi, Tomotaka Ohshima, Arihito Tsurumi, Osamu Hososhima, Toshihiko WakabayashiAbstract:The Wada Test is had been the most reliable for determining speech dominance. Drugs injected into the internal carotid artery, however, may be heterogeneously distributed as the result of asymmetry of the anterior cerebral arteries and the presence of a fetal-type posterior cerebral artery. Variations in drug distribution could occasionally alter consciousness and complicate the evaluation of the Test results. We examined selective propofol injection into the M1 segment of the middle cerebral artery (MCA Wada Test). For the MCA Wada Test (17 patients), 7 or 8 mg of propofol was injected via a microcatheter navigated into the M1 segment, and language function was evaluated by patient performing several tasks. The conventional Wada Test (internal carotid artery [ICA] Wada Test) was performed in four patients (both the ICA and MCA Wada Tests were performed in one patient). The efficacy and adverse effects of both procedures were evaluated; all Tests were performed by well-trained interventional neuroradiologists. Immediately after propofol injection during the MCA Wada Test, patients developed transient contralateral hemiplegia and transient aphasia (in the case of injection on the dominant side). Confusion and other severe adverse effects did not occur during the MCA Wada Test, but two of four patients who underwent the ICA Wada Test showed altered consciousness that affected the performance of the Test. The MCA Wada Test is a feasible and reliable preoperative evaluation, if performed by a trained team of interventional neuroradiologists. Published by Elsevier Inc.
Nick F. Ramsey - One of the best experts on this subject based on the ideXlab platform.
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Can fMRI safely replace the Wada Test for preoperative assessment of language lateralisation? A meta-analysis and systematic review
Journal of neurology neurosurgery and psychiatry, 2013Co-Authors: Prisca R. Bauer, Johannes B. Reitsma, Bernard M Houweling, Cyrille H. Ferrier, Nick F. RamseyAbstract:Recent studies have shown that fMRI (functional magnetic resonance imaging) may be of value for pre-surgical assessment of language lateralisation. The aim of this study was to systematically review and analyse the available literature. A systematic electronic search for studies comparing fMRI with Wada Testing was conducted in the PubMed database between March 2009 and November 2011. Studies involving unilateral Wada Testing, study population consisting exclusively of children younger than 12 years of age or involving five patients or fewer were excluded. 22 studies (504 patients) were included. A random effects meta-analysis was conducted to obtain pooled estimates of the positive and negative predictive values of the fMRI using the Wada Test as the reference standard. The impact of several study features on the performance of fMRI was assessed. The results showed that 81% of patients were correctly classified as having left or right language dominance or mixed language representation. Techniques were discordant in 19% of patients. fMRI and Wada Test agreed in 94% for typical language lateralisation and in 51% for atypical language lateralisation. Language production or language comprehension tasks and different regions of interest did not yield statistically significant different results. It can be concluded that fMRI is reliable when there is strong left-lateralised language. The Wada Test is warranted when fMRI fails to show clear left-lateralisation.
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involuntary language switching in two bilingual patients during the Wada Test and intraoperative electrocortical stimulation
Brain and Language, 2007Co-Authors: Kuan Hua Kho, Frans S.s. Leijten, Peter C. Van Rijen, Nick F. Ramsey, Hugues Duffau, Peggy Gatignol, G J M RuttenAbstract:We present two bilingual patients without language disorders in whom involuntary language switching was induced. The first patient switched from Dutch to English during a left-sided amobarbital (Wada) Test. Functional magnetic resonance imaging yielded a predominantly left-sided language distribution similar for both languages. The second patient switched from French to Chinese during intraoperative electrocortical stimulation of the left inferior frontal gyrus. We conclude that the observed language switching in both cases was not likely the result of a selective inhibition of one language, but the result of a temporary disruption of brain areas that are involved in language switching. These data complement the few lesion studies on (involuntary or unintentional) language switching, and add to the functional neuroimaging studies of switching, monitoring, and controlling the language in use.
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Discrepant findings for Wada Test and functional magnetic resonance imaging with regard to language function: use of electrocortical stimulation mapping to confirm results. Case report.
Journal of neurosurgery, 2005Co-Authors: Kuan Hua Kho, Frans S.s. Leijten, Geert-jan Rutten, Jan Vermeulen, Peter C. Van Rijen, Nick F. RamseyAbstract: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.
Kimford J. Meador - One of the best experts on this subject based on the ideXlab platform.
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History of the Wada Test
The Oxford Handbook of History of Clinical Neuropsychology, 2019Co-Authors: David W. Loring, Kimford J. MeadorAbstract:This chapter discusses the origins and development of the Wada Test. Wada Testing, named after Juhn A. Wada, M.D., is the technique of arterial administration of amobarbital (or other short acting barbiturate) to transiently inactivate brain function in the distribution of the injected artery during which cognitive Testing is performed. The procedure was developed to establish cerebral language dominance in the late 1940s, and it became a routine component of the preoperative evaluation for epilepsy surgery in the mid-1950s. However, the use of Wada Testing as the primary technique to identify cortical language regions and predict risk of post-operative memory decline has been increasingly displaced by electroencephalogram (EEG) video monitoring, magnetic resonance imaging (MRI) of hippocampus, positron emission tomography (PET), single photon emission computed tomography (SPECT), functional MRI (fMRI), and even multi-modality imaging.
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The Wada Test: Current Perspectives and Applications
Handbook on the Neuropsychology of Epilepsy, 2014Co-Authors: David W. Loring, Kimford J. MeadorAbstract:The Wada Test has been an integral part of the preoperative evaluation for epilepsy surgery since the 1950s. Originally designed to establish cerebral language laterality, it was subsequently modified by including a memory component to estimate postoperative risk to recent memory function following unilateral temporal lobe resection. This chapter will briefly review the use of Wada Testing, discuss the various approaches used to transiently anesthetize brain regions prior to cognitive assessment, and conclude with the specific methods developed at the Medical College of Georgia (MCG). The Wada Test is not only employed to predict postoperative risks of language and memory deficits but is also a marker of temporal lobe dysfunction and as such should be sensitive to seizure-onset laterality in patients with temporal lobe epilepsy. Wada Test results should always be interpreted within the context of other clinical and diagnostic Test findings. The lessons learned from pitfalls in Wada Testing should be carefully considered in the development and application of other techniques to assess focal cerebral function/dysfunction.
-
The Wada Test for language and memory lateralization.
Neurology, 2005Co-Authors: Kimford J. Meador, David W. LoringAbstract:Kirsch et al. examine the clinical value of Wada memory asymmetry to predict postoperative seizure freedom and postoperative verbal memory. Wada memory asymmetry in the unexpected direction may signal increased risk of poor surgical outcome after nondominant temporal lobectomy. It is not a predictor of persistent postoperative verbal memory decline. see page 676 Commentary by Kimford J. Meador, MD, and David W. Loring, PhD For over 50 years, the Wada Test has been a component of the preoperative evaluation for epilepsy surgery. Juhn Wada introduced the intracarotid amobarbital procedure to lateralize language in 1949, and soon thereafter, Brenda Milner included memory Testing during the procedure to help determine risk for postoperative amnesia. …
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The Wada Test in the evaluation for epilepsy surgery.
Neurosciences (Riyadh Saudi Arabia), 2000Co-Authors: David W. Loring, Kimford J. Meador, Michael WesterveldAbstract:The Wada Test is the standard part of the pre-operative evaluation for epilepsy surgery. The procedure involves the slow injection of sodium amobarbital (typically 100-500mg) into the internal carotid artery following a transfermoral approach. The amobarbital anesthetizes the anterior two-thirds of the ipsilateral cerebral hemisphere for approximately 5-10 minutes. During this period of hemispheric anesthesia, assessment of expressive and receptive language can establish cerebral language representation. In addition, the procedure provides a reversible model to assess the risk of significant memory change following surgery. This is important because patients undergoing surgery involving the temporal lobe may experience significant memory decline following surgical resection of a temporal lobe seizure focus. This paper will represent information about the use of Wada Testing, and discuss issues involved in establishing cerebral language representation, lateralization of temporal lobe dysfunction, seizure and memory outcome prediction, and future directions of this technique.
-
The Wada Test: controversies, concerns, and insights.
Neurology, 1999Co-Authors: Kimford J. Meador, David W. LoringAbstract:In 1949, Juhn Wada described the use of the intracarotid amobarbital procedure (i.e., Wada Test) to determine cerebral language dominance.1 The procedure was later modified at the Montreal Neurological Institute to also assess hemispheric memory,2 and has become a standard component of presurgical evaluation for epilepsy surgery. The Wada memory Test is used to evaluate the risk of postoperative amnesia, to assess the risk of material specific memory deficits, to lateralize hemispheric dysfunction, and to predict postoperative seizure outcome. Four articles in the current issue of Neurology address controversies and important concerns regarding the Wada Test.3-6 At times, agitation or obtundation during the Wada Test make determination of language dominance problematic. To circumvent this limitation, Rihs et al. employ functional transcranial Doppler sonography (fTCD) to assess simultaneous differential left/right changes in middle cerebral artery blood flow to language and visuospatial tasks.3 Language lateralization via fTCD and the Wada Test were highly correlated, suggesting that fTCD may offer a noninvasive alternative to the Wada Test. Similar findings have recently been demonstrated for functional MRI (fMRI); fTCD is less expensive …
