title: Probabilistic map of critical functional regions of the human cerebral cortex: Broca's area revisited.
abstract: The organization of basic functions of the human brain, particularly in the right hemisphere, remains poorly understood. Recent advances in functional neuroimaging have improved our understanding of cortical organization but do not allow for direct interrogation or determination of essential (versus participatory) cortical regions. Direct cortical stimulation represents a unique opportunity to provide novel insights into the functional distribution of critical epicentres. Direct cortical stimulation (bipolar, 60 Hz, 1-ms pulse) was performed in 165 consecutive patients undergoing awake mapping for resection of low-grade gliomas. Tasks included motor, sensory, counting, and picture naming. Stimulation sites eliciting positive (sensory/motor) or negative (speech arrest, dysarthria, anomia, phonological and semantic paraphasias) findings were recorded and mapped onto a standard Montreal Neurological Institute brain atlas. Montreal Neurological Institute-space functional data were subjected to cluster analysis algorithms (K-means, partition around medioids, hierarchical Ward) to elucidate crucial network epicentres. Sensorimotor function was observed in the pre/post-central gyri as expected. Articulation epicentres were also found within the pre/post-central gyri. However, speech arrest localized to ventral premotor cortex, not the classical Broca's area. Anomia/paraphasia data demonstrated foci not only within classical Wernicke's area but also within the middle and inferior frontal gyri. We report the first bilateral probabilistic map for crucial cortical epicentres of human brain functions in the right and left hemispheres, including sensory, motor, and language (speech, articulation, phonology and semantics). These data challenge classical theories of brain organization (e.g. Broca's area as speech output region) and provide a distributed framework for future studies of neural networks.
authors: 1 Department of Neurosurgery, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611, USA 2 Department of Neurosurgery, Gui de Chauliac Hospital, Montpellier University Medical Centre, F-34295Montpellier, France.
authors: Matthew C
authors: MC
authors: Tate
authors: 2 Department of Neurosurgery, Gui de Chauliac Hospital, Montpellier University Medical Centre, F-34295Montpellier, France 3 INSERM U1051, Institute for Neuroscience of Montpellier, F-34091 Montpellier, France.
authors: Guillaume
authors: G
authors: Herbet
authors: 2 Department of Neurosurgery, Gui de Chauliac Hospital, Montpellier University Medical Centre, F-34295Montpellier, France.
authors: Sylvie
authors: S
authors: Moritz-Gasser
authors: 4 Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, Ontario M5S 3G4, Canada.
authors: Joseph E
authors: JE
authors: Tate
authors: 2 Department of Neurosurgery, Gui de Chauliac Hospital, Montpellier University Medical Centre, F-34295Montpellier, France 3 INSERM U1051, Institute for Neuroscience of Montpellier, F-34091 Montpellier, France h-duffau@chu-montpellier.fr.
authors: Hugues
authors: H
authors: Duffau
mesh_terms: D000328:Adult; D000465:Algorithms; D000849:Anomia / Q000503:physiopathology; D001921:Brain / Q000601:surgery; D001931:Brain Mapping; D001932:Brain Neoplasms / Q000601:surgery; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology*; D016000:Cluster Analysis; D003399:Craniotomy; D004558:Electric Stimulation; D005260:Female; D005625:Frontal Lobe / Q000033:anatomy & histology / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D005910:Glioma / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009415:Nerve Net / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D012660:Semantics; D013060:Speech / Q000502:physiology; D013065:Speech Intelligibility / Q000502:physiology
keywords: Broca's area; brain mapping; direct cortical electrostimulation; language; probabilistic map