gms | German Medical Science

Objective: The frontal language area has several functions, which are active during language processes. Activations of subsystems of Broca’s area were studied during different language tasks. During tests the kind of deficiencies of language functions and their extent due to lesions and surgeries were observed.

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. Especially tasks, which engage syntax processing, were used during preoperative mapping of patients. DTI was used with 1.9 mm slices and 6 directions to reconstruct fibre connections of language areas. Language tests were conducted pre- and postoperatively to show the recovery of neurological function. Intraoperative MRI was 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. Additionally 9 volunteers were examined to compare language paradigms.

Results: As a consequence of lesions in the frontal language areas following deficiencies were observed: phonologic disturbances, articulation problems, not remembering words or syntactic problems. Syntactic problems can occur in building past tense, conjugate words, understanding prepositions and interrogative particles. 137 patients with surgery adjacent to Broca's area obtained language mapping. We were able to localize language areas in all cases; especially areas for syntax processing were obtained. Syntactic activity was found in the sulcus frontalis inferior at the top of the gyrus frontalis inferior pars opercularis and triangularis. Language deficiencies resolved a few days after surgery in all cases except one patient. In this patient the whole operculum was resected. This patient had a reorganisation of all Broca language areas to the opposite hemisphere. Mild language distortions persisted 10 days after surgery, when he was released from hospital.

Conclusions: Functional mapping including syntax processing enables to perform save surgery with maximized tumour removal.