A novel approach for monitoring writing interferences during navigated transcranial magnetic stimulation mappings of writing related cortical areas.
BACKGROUND
It has recently been shown that navigated repetitive transcranial magnetic stimulation (nTMS) is useful in preoperative neurosurgical mapping of motor and language brain areas. In TMS mapping of motor cortices the evoked responses can be quantitatively monitored by electromyographic (EMG) recordings. No such setup exists for monitoring of writing during nTMS mappings of writing related cortical areas.


METHODS
We present a novel approach for monitoring writing during nTMS mappings of motor writing related cortical areas.


CONCLUSIONS
To our best knowledge, this is the first demonstration of quantitative monitoring of motor evoked responses from hand by EMG, and of pen related activity during writing with our custom made pen, together with the application of chronometric TMS design and patterned protocol of rTMS.


RESULTS
The method was applied in four healthy subjects participating in writing during nTMS mapping of the premotor cortical area corresponding to BA 6 and close to the superior frontal sulcus. The results showed that stimulation impaired writing in all subjects. The corresponding spectra of measured signal related to writing movements was observed in the frequency band 0-20 Hz. Magnetic stimulation affected writing by suppressing normal writing frequency band.


CONCLUSIONS
The proposed setup for monitoring of writing provides additional quantitative data for monitoring and the analysis of rTMS induced writing response modifications. The setup can be useful for investigation of neurophysiologic mechanisms of writing, for therapeutic effects of nTMS, and in preoperative mapping of language cortical areas in patients undergoing brain surgery.
Laboratory for Human and Experimental Neurophysiology (LAHEN), Department of Neuroscience, School of Medicine, University of Split, Šoltanska 2, 21000 Split, Croatia. Electronic address: maja.rogic@mefst.hr.
Maja
M
Rogić Vidaković
Laboratory for Human and Experimental Neurophysiology (LAHEN), Department of Neuroscience, School of Medicine, University of Split, Šoltanska 2, 21000 Split, Croatia. Electronic address: dragan@sgm.hr.
Dragan
D
Gabelica
Faculty of Maritime Studies, University of Split, Zrinsko-Frankopanska 38, 21000 Split, Croatia. Electronic address: igor.vujovic@pfst.hr.
Igor
I
Vujović
Faculty of Maritime Studies, University of Split, Zrinsko-Frankopanska 38, 21000 Split, Croatia. Electronic address: josko.soda@pfst.hr.
Joško
J
Šoda
Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, University of Split, Croatia, R. Boškovića 32, 21000 Split, Croatia. Electronic address: nbatarel@fesb.hr.
Nikolina
N
Batarelo
Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, University of Split, Croatia, R. Boškovića 32, 21000 Split, Croatia. Electronic address: adzimbeg@fesb.hr.
Andrija
A
Džimbeg
Department of Neurosurgery, Clinical Unit for Intraoperative Neurophysiologic Monitoring, Clinical Medical Centre "Sisters of Mercy", Vinogradska cesta 29, 10000 Zagreb, Croatia. Electronic address: marina.zmajevic.2505@gmail.com.
Marina
M
Zmajević Schönwald
Department of Neurosurgery, Clinical Unit for Intraoperative Neurophysiologic Monitoring, Clinical Medical Centre "Sisters of Mercy", Vinogradska cesta 29, 10000 Zagreb, Croatia. Electronic address: kresimir.rotim@seens.eu.
Krešimir
K
Rotim
Laboratory for Human and Experimental Neurophysiology (LAHEN), Department of Neuroscience, School of Medicine, University of Split, Šoltanska 2, 21000 Split, Croatia. Electronic address: zdogas@mefst.hr.
Zoran
Z
Đogaš
D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000502:physiology*; D034201:Computers, Handheld; D004576:Electromyography / Q000379:methods; D005260:Female; D006225:Hand / Q000502:physiology*; D006801:Humans; D007807:Language Tests; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology*; D013067:Speech Perception / Q000502:physiology; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D014741:Video Recording / Q000379:methods; D014956:Writing; D055815:Young Adult
Dysgraphia; Language mapping; Power spectrum density; Preoperative planning; Transcranial magnetic stimulation; Writing