Impact of AVM Location on Language Cortex Right-hemisphere Reorganization: A Voxel-based Lesion-symptom Mapping Study

Objectives: Cerebral arteriovenous malformations (AVMs) are congenital malformations, and right-sided dominance of the language cortex is not a rare phenomenon for patients with AVM involving language area. We tried to use voxel-based lesion-symptom mapping (VLSM) method to depict the location of AVM nidus and to demonstrate the relationship between AVM location and the pattern of language cortex reorganization.

Patients And Methods: The authors retrospectively reviewed clinical and imaging data of 70 adult patients with unruptured cerebral AVMs who underwent blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) of language task. All patients were right handed, and all lesions were located in the left cerebral hemisphere. Lateralization indexes (LI) of the BOLD signals were calculated for Broca and Wernicke areas separately and were used to reflect the degree of right-sided dominance of the two language areas. VLSM method was applied to study the relationship between AVM location and LI of language task activations.

Results: Statistical analysis revealed that the change of LI of Broca area was significantly associated with lesions located in the inferior frontal gyrus, pre- and post-central gyrus, supramarginal gyrus and middle frontal gyrus. The change of LI of Wernicke area was significantly associated with lesions located in the left superior, middle, inferior and transverse temporal gyrus.

Conclusion: These findings provide new evidence that the language cortex reorganization patterns in AVM patients have anatomic specificity.