The influence of lesion type and lesion location on the prediction of language laterality in patients with cerebral vascular malformations using functional MRI.

OBJECTIVE

Predicting language lateralization using functional MRI (fMRI) in patients with cerebral vascular malformations close to language areas is essential for treatment decision-making and patient outcomes. Functional MRI-based prediction is challenged because of potential remodeling processes and hemodynamic phenomena. However, there is a lack of possible factors influencing laterality prediction. The authors hypothesized that there might be an impact of lesion type and location on language lateralization.

METHODS

This retrospective study included 24 patients with arteriovenous malformations (AVMs), 11 patients with cavernomas, and 15 healthy controls. Participants performed a subvocal verb-generation task during fMRI. Data analysis in Statistical Parametric Mapping (SPM) 12 involved realignment, coregistration, and smoothing for preprocessing. The authors conducted a whole brain analysis using the general linear model approach at the individual level and calculated the lateralization indices (LIs) using the LI toolbox implemented in SPM independently based on the frontal, temporal, and parietal lobes.

RESULTS

The mean absolute LIs were above 0.2 in all groups. Distribution between groups varied significantly (p = 0.032, f = 0.34). A significant difference was found between patients with AVMs and healthy controls (p = 0.038, r = 0.628). Specifically, patients with frontal AVMs showed significantly lower frontal LIs than did healthy controls (p = 0.032, r = 0.435). In contrast, LIs in cavernoma patients did not differ significantly from controls (p = 0.313). No significant difference was observed between language-adjacent and language-distant lesions (p = 0.14).

CONCLUSIONS

The results of this study suggest that lesion type and location influence language lateralization prediction. Frontal AVMs exhibit significantly lower LIs, requiring caution and experience in interpreting results to ensure patient safety. Cavernomas did not influence LI. Further research with larger cohorts is necessary to understand the underlying causality and neuroplastic changes involved.