Browsing by Author "Solomons, Daniel"

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    Assessing Language Lateralization through Gray Matter Volume: Implications for Preoperative Planning in Brain Tumor Surgery
    (2024) Solomons, Daniel; Rodriguez-Fernandez, Maria; Mery-Munoz, Francisco; Arrano-Carrasco, Leonardo; Costabal, Francisco Sahli; Mendez-Orellana, Carolina
    Background/Objectives: Functional MRI (fMRI) is widely used to assess language lateralization, but its application in patients with brain tumors can be hindered by cognitive impairments, compensatory neuroplasticity, and artifacts due to patient movement or severe aphasia. Gray matter volume (GMV) analysis via voxel-based morphometry (VBM) in language-related brain regions may offer a stable complementary approach. This study investigates the relationship between GMV and fMRI-derived language lateralization in healthy individuals and patients with left-hemisphere brain tumors, aiming to enhance accuracy in complex cases. Methods: The MRI data from 22 healthy participants and 28 individuals with left-hemisphere brain tumors were analyzed. Structural T1-weighted and functional images were obtained during three language tasks. Language lateralization was assessed based on activation in predefined regions of interest (ROIs), categorized as typical (left) or atypical (right or bilateral). The GMV in these ROIs was measured using VBM. Linear regressions explored GMV-lateralization associations, and logistic regressions predicted the lateralization based on the GMV. Results: In the healthy participants, typical left-hemispheric language dominance correlated with higher GMV in the left pars opercularis of the inferior frontal gyrus. The brain tumor participants with atypical lateralization showed increased GMV in six right-hemisphere ROIs. The GMV in the language ROIs predicted the fMRI language lateralization, with AUCs from 80.1% to 94.2% in the healthy participants and 78.3% to 92.6% in the tumor patients. Conclusions: GMV analysis in language-related ROIs effectively complements fMRI for assessing language dominance, particularly when fMRI is challenging. It correlates with language lateralization in both healthy individuals and brain tumor patients, highlighting its potential in preoperative language mapping. Further research with larger samples is needed to refine its clinical utility.
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    Brain structural Changes Over Time in the Presence of a Brain Tumour and their Connection with Language Lateralization Changes and Language-Based Behavioural Outcomes
    (2024) Solomons, Daniel; Sahli Costabal, Francisco; Rodríguez Fernández, María; Mendez Orellana, Carolina; Pontificia Universidad Católica de Chile. Instituto de Ingeniería Biológica y Médica
    La fMRI se usa comúnmente para evaluar la lateralización del lenguaje, pero su eficacia puede verse afectada por deterioros cognitivos, neuroplasticidad y movimiento. En cambio, el análisis del volumen de materia gris (GMV) con VBM ofrece un enfoque complementario y más estable. Esta tesis explora cómo el GMV en regiones relacionadas con el lenguaje se correlaciona con la lateralización derivada de la fMRI, analizando datos de participantes sanos y pacientes con tumores cerebrales. Los hallazgos sugieren un papel matizado del hemisferio derecho en el lenguaje.