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.
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    Hearing Loss Rehabilitation and Its Contribution to Cognitive-Linguistic Performance in Healthy Older Adults: A Systematic Review
    (2025) Mansilla-Jara, Francisca; Julio-Ramos, Teresa; Godoy-Díaz, Álvaro; Solomons, Daniel; Cigarroa, Igor; Toloza Ramírez, David Isaias
    Introduction. Hearing loss (HL) rehabilitation involves using different hearing technologies, such as hearing aids or cochlear implants. The efficacy of HL rehabilitation strategies and their cognitive benefits has been reported for clinical populations, such as those with mild cognitive impairment or dementia. However, up to date, there is no clarity about the cognitive-linguistic implications of HL rehabilitation for healthy older adults. Therefore, increasing knowledge about its benefits in healthy older people is critical to generating early intervention strategies that could delay the progression to pathological stages. Aim. To profile cognitive-linguistic performance after HL rehabilitation in healthy older adults. Methodology. Systematic literature review following the PRISMA guidelines. We included randomized and non-randomized clinical trials from Medline by PubMed, Scopus, and Web of Science databases (January 2000 to May 2024). Results. We identified 410 titles, from which five papers were qualitatively analyzed. Results suggest that after HL rehabilitation, healthy older adults improve their performance in specific abilities such as working memory, delayed recall, attention, semantic and phonological fluency, and language comprehension. We highlight an association between working memory improvement and semantic skills’ benefits, especially in subjects with mild to moderate HL. Conclusion. HL rehabilitation programs should consider cognitive-linguistic stimulation programs in healthy older adults to prevent cognitive dysfunction or neurodegenerative conditions. We only analyzed a few studies; thus, we suggest interpreting the information carefully. Indeed, promoting more follow-up studies to clarify the benefits of using hearing devices and their cognitive-linguistic implications in healthy people is still necessary.
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    Neuropsychological and anatomical-functional effects of transcranial magnetic stimulation in post-stroke patients with cognitive impairment and aphasia: Systematic review
    (2024) Pezoa-Peña, Ignacio; Julio Ramos, Teresa Paz; Cigarroa, Igor; Martella, Diana; Solomons, Daniel; Toloza Ramírez, David Isaias
    Transcranial magnetic stimulation (TMS) has been found to be promising in the neurorehabilitation of post-stroke patients. Aphasia and cognitive impairment (CI) are prevalent post-stroke; however, there is still a lack of consensus about the characteristics of interventions based on TMS and its neuropsychological and anatomical-functional benefits. Therefore, studies that contribute to creating TMS protocols for these neurological conditions are necessary. To analyze the evidence of the neuropsychological and anatomical-functional TMS effects in post-stroke patients with CI and aphasia and determine the characteristics of the most used TMS in research practice. The present study followed the PRISMA guidelines and included articles from PubMed, Scopus, Web of Science, ScienceDirect, and EMBASE databases, published between January 2010 and March 2023. In the 15 articles reviewed, it was found that attention, memory, executive function, language comprehension, naming, and verbal fluency (semantic and phonological) are the neuropsychological domains that improved post-TMS. Moreover, TMS in aphasia and post-stroke CI contribute to greater frontal activation (in the inferior frontal gyrus, pars triangularis, and opercularis). Temporoparietal effects were also found. The observed effects occur when TMS is implemented in repetitive modality, at a frequency of 1 Hz, in sessions of 30 min, and that last more than 2 weeks in duration. The use of TMS contributes to the neurorehabilitation process in post-stroke patients with CI and aphasia. However, it is still necessary to standardize future intervention protocols based on accurate TMS characteristics.
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    Right hemisphere engagement in language abilities in older adults: indication of compensation rather than decline
    (2025) Solomons, Daniel; Rodríguez Fernández, María; Mery Muñoz, Francisco Javier; Arraño Carrasco, Leonardo Marcelo; Toloza Ramírez, David Isaias; Sahli Costabal, Francisco; Méndez Orellana, Carolina Patricia
    Introduction: Structural brain changes during aging have been used as specific markers to distinguish normal aging from dementia. Changes in specific cognitive abilities such as episodic memory, processing speed, and executive functions, are observed in healthy aging. Limited evidence reports changes in linguistic functions alongside structural and functional brain changes. This study investigates correlations between language performance, gray matter volume (GMV), and neural activity in language regions, adjusted for demographic factors, in healthy older adults. Methods: Twenty-seven right-handed participants aged 60–87 were evaluated for overall linguistic performance using the Spanish version of ScreeLing (SCL) test and phonemic fluency and semantic verbal fluency tasks (PF and SF). Participants also underwent an MRI session during which they performed a functional MRI language task. T1-weighted MRI scans were used to measure GMV in specific language-related regions and assess language lateralization. Correlational analyses were conducted between language scores, GMV, years of education, age, sex, and fMRI lateralization. Results: In the right hemisphere (RH), significant positive correlations were found between SCL scores and GMV in the orbital inferior frontal gyrus (r = 0.5402; p = 0.0044) and the superior temporal gyrus (r = 0.516; p = 0.007). Furthermore, SCL and Phonemic fluency positively correlated with years of education, indicating that higher education enhances speech performance. No significant correlations were found in the left hemisphere (LH). Age, sex, and fMRI lateralization did not significantly correlate with specific linguistic scores. Discussion: These results challenge the current view of the role of the right hemisphere in language performance as increased GMV in specific right hemisphere language regions is associated with better language performance, highlighting the role of the right hemisphere in supporting language skills during healthy aging.
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    Semantic and phonological processing in adults and healthy older adults: An FMRI study
    (2023) Toloza-Ramirez, David; Julio Ramos, Teresa Paz; Solomons, Daniel; Santibanez, Rodrigo; Arraño Carrasco, Leonardo Marcelo; Méndez Orellana, Carolina Patricia
    Semantic and phonological processing (SP and PP, respectively) are described within the dorsal and ventral stream model. Studies have related both types of processing to specific brain areas; however, neuroimaging findings suggest that no exclusive brain areas exist for SP and PP. Overt and covert task paradigms in fMRI have been proposed to examine language processing. However, cognitive processing differs in both paradigms, generating different patterns of neural activity. Covert paradigms do not change language lateralization and provide essential information for understanding language networks. Bilateral activation in frontal areas for SP and PP has been reported as a response to lower task performance in older adults. However, understanding the activation pattern for SP and PP in healthy adults and older adults is still challenging. Therefore, this study aims to determine phonological and semantic auditory processing using a receptive modality task in healthy adults and older people.