Abstracts

Presurgical Language Mapping in Bilingual Children Using Transcranial Magnetic Stimulation: A Case Report

Abstract number : 2.338
Submission category : 11. Behavior/Neuropsychology/Language / 11B. Pediatrics
Year : 2019
Submission ID : 2421781
Source : www.aesnet.org
Presentation date : 12/8/2019 4:04:48 PM
Published date : Nov 25, 2019, 12:14 PM

Authors :
Savannah Gibbs, Le bonheur Childrens Hospital; Stephen Fulton, UTHSC and Le Bonheur Children's Hospital; Basanagoud Mudigoudar, UTHSC and Le Bonheur Children's Hospital; Adeel Siddiqui, UTHSC and Le Bonheur Children's Hospital; Asim Fiaz F. Choudhri, UTHS

Rationale: Presurgical mapping of eloquent cortex is critical in pediatric patients undergoing neurosurgery for timely intervention, surgical planning, and minimizing post-operative deficits. Given that two-thirds of the world’s population speak two or more languages [1], an increasing number of neurosurgical candidates present with language-specific concerns best addressed by noninvasive presurgical mapping. Functional MRI (fMRI) and magnetoencephalography (MEG) in children are often performed under sedation, limiting repeated mapping and often precluding localization of language function altogether [2]. Direct cortical stimulation (DCS) also has limited success in younger children and even when successful, detailed multilingual mapping is not feasible due to time sensitivity and increased risk of complications [3]. Transcranial magnetic stimulation (TMS) is well suited to evaluate language areas in children, since it is unaffected by patient movement and can be repeated to test multiple languages. Here we report a case managed at an academic teaching hospital where TMS was effectively used to localize bilingual language cortices in a thirteen-year-old child with brain tumor. Methods: A thirteen-year-old bilingual male patient with a history of new onset seizures refractory to anti-epileptic drugs characterized by word-finding and articulation difficulties was found to have a tumor involving the left parietal lobe and deep occipital white matter. He underwent presurgical functional evaluation at our institution. Language mapping was performed in fMRI using a verb generation task in English, while using object, color, and number naming tasks in English and Italian during application of repetitive TMS, language-specific cortices were localized by TMS. Results: Video EEG found rare left posterior temporal focal epileptiform discharges suggesting a tendency for focal onset seizures from this region and focal slowing seen over the left parietal and occipital regions. Both fMRI and TMS found English to be bilaterally represented, TMS confirmed that Italian was also represented in the same language areas in the temporal lobes (Figure 1). The patient underwent a stealth frameless stereotactic MRI-guided left parietal craniotomy and tumor resection under intraoperative MRI and electrocorticography guidance (Figure 2). Post-operatively, the patient had intact bilingual speech and was referred for chemotherapy and radiation. Tumor pathology was found to be consistent with the diagnosis of WHO grade 1V Glioblastoma. Conclusions: This case report represents the challenges of managing a bilingual child with malignant brain tumor. While both fMRI and TMS were successful in mapping English language cortex, second language mapping in this child was performed only with TMS. Despite the patient’s complex disease presentation, critical bilingual language cortices were successfully localized in both temporal lobes using TMS. The finding of bilateral representation of language in this child provided insight into his specific language organization and aided in educating the family about the risks of postsurgical language deficits and the likelihood of preserved language function. Additionally, TMS finding helped to inform surgical planning such that language function, and consequently quality of life, was maximally preserved. Consistent with our expectations, the patient had no deficits in language function following surgery. This case illustrates the use of TMS as a safe, noninvasive tool for successfully mapping language function in bilingual children.1. Ferjan Ramírez (2016). Bilingual language learning in children.2. Birg L (2013). Neurodiagn J;53(3):229-40.3. Sweet JA (2013). Epilepsia;54(9):66-71. Funding: No funding
Behavior/Neuropsychology/Language