*4.3. Associations with Aphasia*

The number of language-positive nTMS points was significantly associated with aphasia grading. The higher the aphasia grading is (i.e., the more severe language impairment is), the higher the number of language-positive nTMS spots. A higher frequency of language-positive nTMS spots among more impaired patients according to pre- and postoperative as well as follow-up examinations makes sense as a decline in language function should be associated with higher stimulation-induced errors, although this may bias the results of nTMS language mapping. A previous study is in good accordance with this finding and showed that aphasia as measured by the Berlin Aphasia Score correlated significantly with the incidence of errors during nTMS language mapping; yet, correlations were only evaluated for the preoperative status of language function [51]. Moreover, higher aphasia grading for the postoperative and follow-up status was associated with lower ratios in volume for U-fibers. Hence, this finding may underline the important role of short association fibers for keeping of language function as their impairment, e.g., in the direct perioperative course of tumor resection or related to even subtle perioperative ischemia, could result in language worsening.
