Intra- and perioperative monitoring of language functions in patients withtumours in the left perisylvian area

Resections of brain tumours in the left perisylvian area (LPA) carry a risk of language impairment. Thus, intraoperative language monitoring devices a re used to explore the functional anatomy of the LPA and to detect beginnin g aphasia. Following recent approaches (Reulen et al. 1997, Herholz et al. 1997), the present study explored a combined monitoring procedure in 5 righ t-handed patients who were operated on brain tumours in and adjacent to the LPA. In addition, language and verbal memory was assessed pre- and postope ratively. Preoperatively, no patient was aphasic; however, most subjects sh owed minor impairments of language and memory. During the operation, which was performed in the wakeful patient, language functions were repeatedly te sted using both, a clinical monitoring and an extended electrocortical mapp ing procedure. The extent of tumour resection (total or subtotal) was adapt ed to the patient's intraoperative language status. Following these safety procedures, the outcome of surgery was generally favourable. Only one patie nt suffered an aphasia intraoperatively from which she recovered completely ; in the other subjects sporadical and minor impairments of language were o bserved which largely recovered over a period of several weeks. In subjects who had a preoperative deficit of immediate and long-term prose memory, an improvement of memory was evident on postoperative follow-up testing. Lang uage functions can be effectively monitored using clinical tasks and electr ocortical mapping during the removal of rumours in the LPA.