Resection of Navigated Transcranial Magnetic Stimulation-Positive Prerolandic Motor Areas Causes Permanent Impairment of Motor Function.
BACKGROUND
Navigated transcranial magnetic stimulation (nTMS) helps to determine the distribution of motor eloquent areas prior to brain surgery. Yet, the eloquence of primary motor areas frontal to the precentral gyrus identified via nTMS is unclear.


OBJECTIVE
To investigate the resection of nTMS-positive prerolandic motor areas and its correlation with postsurgical impairment of motor function.


METHODS
Forty-three patients with rolandic or prerolandic gliomas (WHO grade I-IV) underwent nTMS prior to surgery. Only patients without ischemia within the motor system in postoperative MRI diffusion sequences were enrolled. Based on the 3-dimensional fusion of preoperative nTMS motor mapping data with postsurgical MRI scans, we identified nTMS points that were resected in the infiltration zone of the tumor. We then classified the resected points according to the localization and latency of their motor evoked potentials. Surgery-related paresis was graded as transient (≤6 weeks) or permanent (>6 weeks).


RESULTS
Out of 43, 31 patients (72%) showed nTMS-positive motor points in the prerolandic gyri. In general, 13 out of 43 patients (30%) underwent resection of nTMS points. Ten out of these patients showed postoperative paresis. There were 2 (15%) patients with a transient and 8 (62%) with a permanent surgery-related paresis. In 3 cases (23%), motor function remained unimpaired.


CONCLUSIONS
After resection of nTMS-positive motor points, 62% of patients suffered from a new permanent paresis. Thus, even though they are located in the superior or middle frontal gyrus, these cortical areas must undergo intraoperative mapping.
Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
Tobias
T
Moser
Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
Lucia
L
Bulubas
Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
Jamil
J
Sabih
Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
Neal
N
Conway
Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
Noémie
N
Wildschutz
Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
Nico
N
Sollmann
Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
Bernhard
B
Meyer
Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
Florian
F
Ringel
Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
Sandro M
SM
Krieg
D000328:Adult; D000368:Aged; D001931:Brain Mapping; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D010291:Paresis / Q000209:etiology*; D011183:Postoperative Complications / Q000209:etiology*; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult
Brain tumor; Motor evoked potentials; Motor function outcome; Prerolandic motor areas; Transcranial magnetic stimulation; Tumor resection