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.


CONCLUSION
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.
['Moser|Tobias|T|', 'Bulubas|Lucia|L|', 'Sabih|Jamil|J|', 'Conway|Neal|N|', 'Wildschutz|Noémie|N|', 'Sollmann|Nico|N|', 'Meyer|Bernhard|B|', 'Ringel|Florian|F|', 'Krieg|Sandro M|SM|']
D000328:Adult D000368:Aged D001931:Brain Mapping D001932:Brain Neoplasms D019054:Evoked Potentials, Motor D005260:Female D005910:Glioma D006801:Humans D008279:Magnetic Resonance Imaging D008297:Male D008875:Middle Aged D009044:Motor Cortex D010291:Paresis D011183:Postoperative Complications D050781:Transcranial Magnetic Stimulation D055815:Young Adult
Prerolandic motor areas Transcranial magnetic stimulation Motor evoked potentials Brain tumor Motor function outcome Tumor resection