Objective: This article explores the feasibility of a novel repetitive navigated transcranial magnetic stimulation (rnTMS) system and compares language mapping results obtained by rnTMS in healthy volunteers and brain tumor patients. Methods: Fifteen right-handed healthy volunteers and 50 right-handed consecutive patients with left-sided gliomas were examined with a picture-naming task combined with time-locked rnTMS (5-10. Hz and 80-120% resting motor threshold) applied over both hemispheres. Induced errors were classified into four psycholinguistic types and assigned to their respective cortical areas according to the coil position during stimulation. Results: In healthy volunteers, language disturbances were almost exclusively induced in the left hemisphere. In patients errors were more frequent and induced at a comparative rate over both hemispheres. Predominantly dysarthric errors were induced in volunteers, whereas semantic errors were most frequent in the patient group. Conclusion: The right hemisphere's increased sensitivity to rnTMS suggests reorganization in language representation in brain tumor patients. Significance: rnTMS is a novel technology for exploring cortical language representation. This study proves the feasibility and safety of rnTMS in patients with brain tumor.
- Brain tumors
- Hemispheric dominance
- Language mapping
- Language plasticity
- Transcranial magnetic stimulation