====== Navigated transcranial magnetic stimulation indications ======

While gaining importance in the preoperative planning process in motor eloquent regions, its usefulness for reliably identifying language areas is still being discussed. 

Preoperative nTMS results correlate well with [[direct cortical stimulation]] (DCS) data in the identification of the primary motor cortex. Repetitive nTMS can also be used for mapping of speech-sensitive cortical areas.

===== Navigated transcranial magnetic stimulation for language mapping =====

see [[Navigated transcranial magnetic stimulation for language mapping]].
----


It has become established as an accurate noninvasive technique for mapping the functional [[motor cortex]] for the representation areas of upper and lower limb muscles, facial muscles in the lower part of the face. Instead of using the motor threshold (MT) of the abductor pollicis brevis, the stimulus intensity during mapping should be proportioned to the MT of a facial muscle
((Säisänen L, Julkunen P, Kemppainen S, Danner N, Immonen A, Mervaala E, Määttä 
S, Muraja-Murro A, Könönen M. Locating and Outlining the Cortical Motor
Representation Areas of Facial Muscles With Navigated Transcranial Magnetic
Stimulation. Neurosurgery. 2015 Sep;77(3):394-405. doi:
10.1227/NEU.0000000000000798. PubMed PMID: 26035404.
)).

Its functional information benefits surgical decision making and changes the treatment strategy in one-fourth of cases
((Takahashi S, Vajkoczy P, Picht T. Navigated transcranial magnetic stimulation 
for mapping the motor cortex in patients with rolandic brain tumors. Neurosurg
Focus. 2013 Apr;34(4):E3. doi: 10.3171/2013.1.FOCUS133. Review. PubMed PMID:
23544409.
)).

[[Magnetic resonance]] images are being increasingly deployed in conjunction with navigated transcranial magnetic stimulation (nTMS) to account for inter-individual differences in brain anatomy as well as to reduce the variability of mapping findings.

Navigated transcranial magnetic stimulation (nTMS) has been recently established as a reliable [[tool]] for distinguishing resectable from nonresectable [[cortical]] tissue in the [[motor area]]s
((Picht P, Schmidt S, Brandt S, et al. Preoperative functional mapping for rolandic brain tumor surgery: comparison of navigated transcranial magnetic stimulation to direct cortical stimulation. Neurosurgery 2011;69(3):581-589.))
((Tarapore PE, Tate MC, Findlay AM, et al. Preoperative multimodal motor mapping: a comparison of magnetoencephalography imaging, navigated transcranial magnetic stimulation, and direct cortical stimulation. J Neurosurg 2012;117(2):354-362.)).

Within the [[primary motor cortex]], navigated transcranial magnetic stimulation (nTMS) has been shown to yield maps strongly correlated with those generated by direct [[cortical]] [[stimulation]] (DCS). 

Provides crucial data for [[preoperative planning]] and surgical [[resection]] of [[tumor]]s involving essential [[motor area]]s. Expanding surgical indications and extent of resection based on nTMS enables more patients to undergo surgery and might lead to better neurological [[outcome]]s and higher survival rates in [[brain tumor]] patients
((Frey D, Schilt S, Strack V, Zdunczyk A, Rösler J, Niraula B, Vajkoczy P, Picht
T. Navigated transcranial magnetic stimulation improves the treatment outcome in 
patients with brain tumors in motor eloquent locations. Neuro Oncol. 2014 Jun 12.
pii: nou110. [Epub ahead of print] PubMed PMID: 24923875.)).



====Tractography implementation====
The implementation of [[tractography]] based on nTMS increases the accuracy of fiber tracking. Moreover, this combination of methods has the potential to become a supplemental tool for guiding electrode implantation
((Forster MT, Hoecker AC, Kang JS, Quick J, Seifert V, Hattingen E, Hilker R,
Weise LM. Does Navigated Transcranial Stimulation Increase the Accuracy of
Tractography? A Prospective Clinical Trial Based on Intraoperative Motor Evoked
Potential Monitoring During Deep Brain Stimulation. Neurosurgery. 2015
Jun;76(6):766-776. PubMed PMID: 25988930.)).