Alternative language paradigms for functional magnetic resonance imaging as presurgical tools for inducing crossed cerebro-cerebellar language activations in brain tumor patients.

OBJECTIVES: Crossed cerebro-cerebellar BOLD activations have recently come to light as additional diagnostic features for patients with brain tumors. The covert verb generation (VG) task is a widely used language paradigm to determine these language-related crossed activations. Here we demonstrate these crossed activations in two additional language paradigms, the semantic and phonological association tasks. We propose the merit of these tasks to language lateralization determination in the clinic as they are easy to monitor and suitable for patients with aphasia. METHODS: Patients with brain tumors localized at different cortical sites (n = 71) performed three language paradigms, namely the VG task as well as the semantic (SA) and phonological (PA) association tasks with button-press responses. Respective language activations in disparate cortical regions and the cerebellum were assigned laterality. Agreements in laterality between the two new tasks and the verb generation task were tested using Cohen's kappa. RESULTS: Both tasks significantly agreed in cortical and cerebellar lateralization with the verb generation task in patients. Additionally, a McNemar test confirmed the presence of crossed activations in the cortex and the cerebellum in the entire subject population. CONCLUSION: We demonstrated that the semantic and phonological association tasks resulted in crossed cerebro-cerebellar language lateralization activations as those observed due to the covert verb generation task. This may suggest the possibility of these tasks being used conjointly with the traditional verb generation task, especially for subjects that may be unable to perform the latter. KEY POINTS: • The semantic and phonological association tasks can be useful as additional presurgical fMRI language lateralization paradigms for brain tumor patients along with the standard verb generation task. • All three tasks also confirm the presence of crossed cerebro-cerebellar language activations in the current subject population.

[Evaluation of the crossed cerebro-cerebellar activation to determine language lateralization in patients with brain tumors]. / Evaluación de la actividad cerebro-cerebelar cruzada para determinar la lateralidad del lenguaje en pacientes con tumores cerebrales.

BACKGROUND: The crossed cerebro-cerebellar (CCC) activation facilitates the diagnosis of cortical language lateralization, but needs to be explored with language tasks suitable for patients with different age ranges, educational attainment and eventual presence of language deficits. AIM: To determine the effect of demographic variables in the performance of three language tasks in healthy volunteers and to determine the CCC activation of these tasks as a functional magnetic resonance imaging (fMRI) paradigm in brain tumor patients. MATERIAL AND METHODS: The behavioral performance (correct responses and reaction time) of three language tasks (verbal fluency, semantic and phonological decision tasks) was first examined in 76 healthy volunteers balanced by age and educational level. Later, these tasks were implemented as fMRI paradigms to explore CCC language activation of 20 patients with potential diagnosis of brain tumors. RESULTS: The performance of the verbal fluency task was affected by age. The CCC language activation was reproducible with the semantic and phonological tasks. The combination of the tasks determined typical and atypical language lateralization in 60% and 40% of our patients, respectively. CONCLUSIONS: The verbal fluency task must be implemented with care as a clinical fMRI paradigm. Our results suggest that semantic and phonological tasks can be a good alternative for brain tumor patients with language deficits.

Evaluación de la actividad cerebro-cerebelar cruzada para determinar la lateralidad del lenguaje en pacientes con tumores cerebrales / Evaluation of the crossed cerebro-cerebellar activation to determine language lateralization in patients with brain tumors

Background: The crossed cerebro-cerebellar (CCC) activation facilitates the diagnosis of cortical language lateralization, but needs to be explored with language tasks suitable for patients with different age ranges, educational attainment and eventual presence of language deficits. Aim: To determine the effect of demographic variables in the performance of three language tasks in healthy volunteers and to determine the CCC activation of these tasks as a functional magnetic resonance imaging (fMRI) paradigm in brain tumor patients. Material and Methods: The behavioral performance (correct responses and reaction time) of three language tasks (verbal fluency, semantic and phonological decision tasks) was first examined in 76 healthy volunteers balanced by age and educational level. Later, these tasks were implemented as fMRI paradigms to explore CCC language activation of 20 patients with potential diagnosis of brain tumors. Results: The performance of the verbal fluency task was affected by age. The CCC language activation was reproducible with the semantic and phonological tasks. The combination of the tasks determined typical and atypical language lateralization in 60% and 40% of our patients, respectively. Conclusions: The verbal fluency task must be implemented with care as a clinical fMRI paradigm. Our results suggest that semantic and phonological tasks can be a good alternative for brain tumor patients with language deficits.