gms | German Medical Science

Objective: The frontal language area consists of subsystems with distinct functions. To maximize the extent of resection during surgery within or adjacent to this area, a detailed functional mapping of these areas is necessary.

Method: Preoperative functional imaging with fMRI was performed. For fMRI we used a 1.5T MR scanner with echo planar imaging (Sonata, Siemens Medical Solutions) and a block paradigm with 180 measurements in 6 blocks (rest alternating with activation, 25 slices, 3 mm thickness & resolution TR=2470, TE=60). During the activation intervals patients had to perform language tasks with words presented visually. At least one of the tasks was chosen to engage syntax processing. DTI was used with 1.9 mm slices and 6 directions to reconstruct fibre connections of language areas or the pyramidal tract. Language tests were conducted pre- and postoperatively to show the recovery of neurological function. Intraoperative MRI were used and registered to the functional images to show the extent of resection, the brain shift and an update of the relation to functional structures. Before and after surgery language tests were performed.

Results: Out of 287 patients with language mapping there were 102 patients with surgery close to Broca's area. We were able to localized language areas in all cases, especially areas for syntax processing were obtained. Lesions were located in front of Broca areas, above them, between Broca and motor areas, below the Broca areas located in the insula and in one case the lesion was directly in the operculum frontale, were Broca areas were located in. In this case no shift of language function to the opposite hemisphere occurred. In one other case we observed a reorganization to the opposite hemisphere, which was shown by a postoperative language mapping. No permanent aphasia occurred in all the cases.

Conclusions: Resection close and even within the operculum frontale is possible without permanent language deficit. This demands a detailed mapping of language areas and an ongoing update of navigation.