title: Vestibular responses to direct stimulation of the human insular cortex.
abstract: OBJECTIVE
  The present study provides a functional mapping of vestibular responses in the human insular cortex.
  
  
  METHODS
  A total of 642 electrical stimulations of the insula were performed in 219 patients, using stereotactically implanted depth electrodes, during the presurgical evaluation of drug-refractory partial epilepsy. We retrospectively identified 41 contacts where stimulation elicited vestibular sensations (VSs) and analyzed their location with respect to (1) their stereotactic coordinates (for all contacts), (2) the anatomy of insula gyri (for 20 vestibular sites), and (3) the probabilistic cytoarchitectonic maps of the insula (for 9 vestibular sites).
  
  
  RESULTS
  VSs occurred in 7.6% of the 541 evoked sensations after electrical stimulations of the insula. VSs were mostly obtained after stimulation of the posterior insula, that is, in the granular insular cortex and the postcentral insular gyrus. The data also suggest a spatial segregation of the responses in the insula, with the rotatory and translational VSs being evoked at more posterior stimulation sites than other less definable VSs. No left-right differences were observed.
  
  
  CONCLUSIONS
  These results demonstrate vestibular sensory processing in the insula that is centered on its posterior part. The present data add to the understanding of the multiple sensory functions of the insular cortex and of the cortical processing of vestibular signals. The data also indicate that lesion or dysfunction in the posterior insula should be considered during the evaluation of vestibular epileptic seizures.
authors.affiliation: Neurology Department, University Hospital, St-Etienne; Team "Central Integration of Pain", Lyon Neuroscience Research Center, National Institute of Health and Medical Research Unit 1028, National Center for Scientific Research Mixed Unit of Research 5292, Lyon; Jean Monnet University, St-Etienne.
authors.forename: Laure
authors.initials: L
authors.lastname: Mazzola
authors.forename: Christophe
authors.initials: C
authors.lastname: Lopez
authors.forename: Isabelle
authors.initials: I
authors.lastname: Faillenot
authors.forename: Florian
authors.initials: F
authors.lastname: Chouchou
authors.forename: François
authors.initials: F
authors.lastname: Mauguière
authors.forename: Jean
authors.initials: J
authors.lastname: Isnard
mesh_terms: D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology*; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult