Language mapping in healthy volunteers and brain tumor patients with a novel navigated TMS system: evidence of tumor-induced plasticity.
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.


CONCLUSIONS
The right hemisphere's increased sensitivity to rnTMS suggests reorganization in language representation in brain tumor patients.


CONCLUSIONS
rnTMS is a novel technology for exploring cortical language representation. This study proves the feasibility and safety of rnTMS in patients with brain tumor.
Department of Neurosurgery, Charité University Hospital, Berlin, Germany.
J
J
Rösler
Department of Neurosurgery, Charité University Hospital, Berlin, Germany.
B
B
Niraula
Department of Neurosurgery, Charité University Hospital, Berlin, Germany.
V
V
Strack
Department of Neurosurgery, Charité University Hospital, Berlin, Germany.
A
A
Zdunczyk
Department of Neurosurgery, Charité University Hospital, Berlin, Germany.
S
S
Schilt
Nexstim Ltd., Helsinki, Finland; Neuroscience Unit, Institute of Biomedicine/Physiology, University of Helsinki, Helsinki, Finland.
P
P
Savolainen
BioMag Laboratory, HUS Medical Imaging Center, Hospital District of Helsinki and Uusimaa, Helsinki, Finland.
P
P
Lioumis
BioMag Laboratory, HUS Medical Imaging Center, Hospital District of Helsinki and Uusimaa, Helsinki, Finland.
J
J
Mäkelä
Department of Neurosurgery, Charité University Hospital, Berlin, Germany.
P
P
Vajkoczy
Department of Neurosurgery, Charité University Hospital, Berlin, Germany.
D
D
Frey
Department of Neurosurgery, Charité University Hospital, Berlin, Germany. Electronic address: thomas.picht@charite.de.
T
T
Picht
D000328:Adult; D000368:Aged; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D001932:Brain Neoplasms / Q000473:pathology* / Q000503:physiopathology* / Q000601:surgery; D003399:Craniotomy; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007802:Language; D007807:Language Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009473:Neuronal Plasticity; D057234:Preoperative Period; D011578:Psycholinguistics; D012660:Semantics; D050781:Transcranial Magnetic Stimulation / Q000379:methods*
Brain tumors; Hemispheric dominance; Language mapping; Language plasticity; Transcranial magnetic stimulation