title: Electrostimulation mapping of spatial neglect.
abstract: BACKGROUND
  Cortical and subcortical electrostimulation mapping during awake brain surgery for tumor removal is usually used to minimize deficits.
  
  
  OBJECTIVE
  To use electrostimulation to study neuronal substrates involved in spatial awareness in humans.
  
  
  METHODS
  Spatial neglect was studied using a line bisection task in combination with electrostimulation mapping of the right hemisphere in 50 cases. Stimulation sites were identified with Talairach coordinates. The behavioral effects induced by stimulation, especially eye movements and deviations from the median, were quantified and compared with preoperative data and a control group.
  
  
  RESULTS
  Composite and highly individualized spatial neglect maps were generated. Both rightward and leftward deviations were induced, sometimes in the same patient but for different stimulation sites. Group analysis showed that specific and reproducible line deviations were induced by stimulation of discrete cortical areas located in the posterior part of the right superior and middle temporal gyri, inferior parietal lobe, and inferior postcentral and inferior frontal gyri (P < .05). Fiber tracking identified stimulated subcortical areas important to spare as sections of fronto-occipital and superior longitudinal II fascicles. According to preoperative and postoperative neglect battery tests, the specificity and sensitivity of intraoperative line bisection tests were 94% and 83%, respectively.
  
  
  CONCLUSIONS
  In humans, discrete cortical areas that are variable in location between individuals but mainly located within the right posterior Sylvian fissure sustain visuospatial attention specifically toward the contralateral or ipsilateral space direction. Line bisection mapping was found to be a reliable method for minimizing spatial neglect caused by brain tumor surgery.
authors: INSERM 825 et Service de Neurochirurgie, Hôpital Purpan, F-31059 Toulouse, France. franck_emmanuel.roux@yahoo.fr
authors: Franck-Emmanuel
authors: FE
authors: Roux
authors: Olivier
authors: O
authors: Dufor
authors: Valérie
authors: V
authors: Lauwers-Cances
authors: Leila
authors: L
authors: Boukhatem
authors: David
authors: D
authors: Brauge
authors: Louisa
authors: L
authors: Draper
authors: Jean-Albert
authors: JA
authors: Lotterie
authors: Jean-François
authors: JF
authors: Démonet
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D001931:Brain Mapping; D001932:Brain Neoplasms / Q000150:complications / Q000601:surgery; D004558:Electric Stimulation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010468:Perceptual Disorders / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D011597:Psychomotor Performance / Q000502:physiology; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D055815:Young Adult