TMS motor mapping in brain tumor patients: more robust maps with an increased resting motor threshold
Por:
Lam, S, Lucente, G, Schneider, H and Picht, T
Publicada:
1 may 2019
Ahead of Print:
29 mar 2019
Resumen:
ObjectiveNavigated transcranial magnetic stimulation (nTMS) has found widespread usage across many clinical centers as part of their surgical planning routines. NTMS offers a non-invasive approach to delineation of the motor cortex, in which the region is outlined through electromagnetic stimulation and electromyographic recordings of target muscles. Several neurophysiological parameters such as the motor evoked potential (MEP) and its derivatives, the resting motor threshold (RMT) and motor latency, are collected. The present study investigates the clinical feasibility and reproducibility of increasing the MEP threshold in brain tumor patients, with the goal to improve the robustness of the procedure.Materials and methodsTwenty-three subjects with peri-motor cortex tumors underwent motor mapping with nTMS. RMT was calculated with both conventional 50-V and experimental 500-V MEP amplitude thresholds. Motor mapping was performed with 105% of both RMTs stimulator intensity using the FDI as the target muscle.ResultsMotor mapping was possible in 20 patients with both the conventional and experimental thresholds. No significant differences in area size were found between motor area maps generated with a conventional 50-V threshold in comparison to those generated with the higher 500-V threshold (50V 272.56mm(2) [170.47-434.31] vs. 500V 240.54mm(2) [169.77-362.84], P=0.34). Latency time was significantly reduced in 500-V recordings relative to 50-V recordings (50V 23.38ms [22.55-24.51] vs. 500V 22.57ms [21.41-23.70], P<0.001). Both electric field intensity (50V 63.81V/m [54.26-76.11] vs. 500V 77.83V/m [65.21-93.94], P<0.001) and RMT (50V 33 MSO% [28-36] vs. 500V 39.5 MSO% [32-44], P<0.001) were significantly greater with the higher 500-V threshold.ConclusionsOur study demonstrates the feasibility of increasing the MEP detection threshold to 500V in brain tumor patients for RMT determination and motor area mapping with nTMS.
Filiaciones:
Lam, S:
Charite Univ Med Berlin, Dept Neurosurg, Berlin, Germany
:
Hosp Univ Germans Trias I Pujol, Neurosci Dept, Carretera Canyet S-N, Badalona 08916, Spain
UAB, Med Dept, Barcelona, Spain
Schneider, H:
Charite Univ Med Berlin, Dept Neurosurg, Berlin, Germany
Picht, T:
Charite Univ Med Berlin, Dept Neurosurg, Berlin, Germany
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