Concordance Between TMS and Wada in Determining Hemispheric Dominance for Language
Abstract number :
2.314
Submission category :
11. Behavior/Neuropsychology/Language / 11B. Pediatrics
Year :
2022
Submission ID :
2204174
Source :
www.aesnet.org
Presentation date :
12/4/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:23 AM
Authors :
Negar Noorizadeh, PhD – Le Bonheur Children's Hospital, Memphis TN; James Wheless, MD – Professor and Director, Pediatric Neurology, Le Bonheur Children's Hospital Neuroscience Institute and University of Tennessee Health Science Center at Memphis; Stephen Fulton, MD – Associate Professor, Pediatric Neurology, Le Bonheur Children's Hospital Neuroscience Institute and University of Tennessee Health Science Center at Memphis; Basanagoud Mudigoudar, MD – Associate Professor, Pediatric Neurology, Le Bonheur Children's Hospital Neuroscience Institute and University of Tennessee Health Science Center at Memphis; Leigh Nevill, MS – Le Bonheur Children's Hospital Neuroscience Institute; Christen Mari Holder, Ph.D. – Associate Professor, Pediatric Neurology, Le Bonheur Children's Hospital Neuroscience Institute and University of Tennessee Health Science Center at Memphis; Shalini Narayana, Ph.D. – Professor, Pediatric Neurology, Le Bonheur Children's Hospital Neuroscience Institute and University of Tennessee Health Science Center at Memphis
Rationale: Brain surgery is a treatment option in patients with brain tumor or medically intractable epilepsy. In order to perform an optimal resection, it is crucial to localize critical language and motor cortices prior to surgery. With regards to assessment of language, the sodium amobarbital (Wada) test is the “gold standard” for determine the hemispheric dominance (HD). However, the Wada test is invasive, causes morbidity and discomfort for patients, has lower success rates in children, and cannot be repeated to verify the results. Transcranial magnetic stimulation (TMS), an emerging non-invasive language mapping tool, can successfully determine dominant hemisphere for language in patients who cannot tolerate other modalities. However, it still remains unclear whether TMS can replace the Wada test. To address this question, we investigated the concordance between Wada and TMS language mapping in individuals with epilepsy or brain tumor.
Methods: Through a retrospective review of patients who underwent pre-surgical evaluation for epilepsy or brain tumor at our institution, we identified 12 patients (mean age 18.8 y, range 11.8 – 25.2 y, 7 females) who had undergone both Wada and TMS language mapping. In the Wada test, determination of HD was based on a qualitative observation or a scoring system. TMS language mapping was done (Nexstim Inc., Atlanta, GA, USA) using the ‘virtual lesion’ paradigm. TMS was applied along the temporal and frontal lobes in both hemispheres while patients performed a naming task. By comparing the performance of each patient during TMS with corresponding baseline, errors were categorized to speech arrest, semantic- and performance errors (Figure. 1). The classic laterality index (LI) was calculated as Eleft – Eright / (Eleft + Eright), where Eleft and Eright are the total number of errors in the left and right hemispheres, respectively. A weighted LI was also calculated by weighting the speech arrests (3x) and the semantic errors (2x) more than the performance errors. The 0.1 ≤ LI < 1, and -1 ≤ LI < -0.1 represent left and right HD while -0.1 ≤ LI ≤ 0.1 indicates bilateral representation.
Behavior