CLINICAL STUDIES 868 | VOLUME 66 | NUMBER 5 | MAY 2010 www.neurosurgery-online.com Vincent Lubrano, MD UMR Unité 825, Université Paul Sabatier, IFR 96, Pôle des Neurosciences, CHU Toulouse, Toulouse, France Louisa Draper, MD UMR Unité 825, Université Paul Sabatier, IFR 96, Toulouse, France Franck-Emmanuel Roux, MD, PhD UMR Unité 825, Université Paul Sabatier, IFR 96, Pôle des Neurosciences, CHU Toulouse, Toulouse, France Reprint requests: Franck-Emmanuel Roux, MD, PhD, CHU Toulouse, Service de Neurochirurgie, Hôpital Purpan, F-31059 Toulouse, France. E-mail: franck_emmanuel.roux@yahoo.fr Received, January 27, 2009. Accepted, September 27, 2009. Copyright © 2010 by the Congress of Neurological Surgeons I n 1906, Pierre Marie controversially refuted the idea that Broca’s area (the inferior frontal gyrus of the left cerebral hemisphere) played any role in speech. He opposed the work of Paul Broca, who had described the localization of cer- tain speech-related brain functions to this area. However, the same year, Christofredo Jakob, a German-born neuropathologist working in Buenos Aires, defended the existence of Broca’s area from an anatomofunctional point of view in an inno- vative article entitled “Does Broca’s Area Exist?” 1 Of major interest was the observation that dam- age to Broca’s area could occur without aphasia and that this could be attributed to compensation of language functions by other cortical areas. Similarly, it was noted that motor aphasia could occur with- out damage to Broca’s area, explained again by considering cortical connectivity more broadly. Since then, many studies using both brain lesions and neuroimaging have highlighted and refined the functional importance of this region, which is a crucial component in all classic neurobiolog- ical models of language. 2-7 Hence, injury to Broca’s area is still thought to be responsible for the severe expressive aphasia occurring after surgery involv- ing the inferior frontal cortex. Nevertheless, short literature series suggest that, provided the exact location of crucial cortical sites and fiber tracts implicated in language is assessed by direct brain mapping, 8-10 surgical resection can be performed around Broca’s area 8-10 with good functional out- comes. A number of different factors may explain the good surgical outcomes observed in the afore- mentioned cases. These are (1) the variability of language organization among individuals, (2) the What Makes Surgical Tumor Resection Feasible in Broca’s Area? Insights Into Intraoperative Brain Mapping OBJECTIVE: Surgical resection of mass lesions in Broca’s area is controversial. To demon- strate that pathology may influence the localization of functional areas and language per- formance, we reviewed our experience of awake craniotomies in Broca’s area. METHODS: Sixteen consecutive patients who underwent awake craniotomy and direct brain mapping for resective surgery in Broca’s area were analyzed. Six patients had well- circumscribed lesions, whereas 10 patients had infiltrative gliomas. A short version of the Boston Diagnostic Aphasia Examination test was used for language assessment. RESULTS: Inferior frontal language sites were found in all but 4 patients. In patients with cavernomas or well-circumscribed tumors, 9 of 9 (100%) of the positive sites were located in the classic Broca’s area (BA 44/45). By contrast, in those patients with gliomas, only 5 of 20 (25%) of the positive sites were located in BA 44/45. Patients with infiltra- tive gliomas demonstrated more deficits in the pre- and postoperative periods than those with well-circumscribed mass lesions. All patients returned to their baseline abil- ities within 6 months. CONCLUSION: Intraoperative language maps generated in cases with well-circumscribed lesions are different from those generated in cases with infiltrative gliomas. This supports the view that interindividual language variability and displacement of critical structures by mass effect should first be considered for circumscribed lesions, whereas reshaping should largely be attributed to brain plasticity in gliomas. Surgery in Broca’s area can be safely conducted using awake craniotomy and brain mapping. KEY WORDS: Brain mapping, Broca’s area, Language, Low-grade gliomas, Plasticity, Surgery mapping Neurosurgery 66:868-875, 2010 DOI: 10.1227/01.NEU.0000368442.92290.04 www.neurosurgery-online.com