Anatomofunctional organization of the insular cortex: A study using intracerebral electrical stimulation in epileptic patients
Article first published online: 13 OCT 2010
Wiley Periodicals, Inc. © 2010 International League Against Epilepsy
Volume 51, Issue 11, pages 2305–2315, November 2010
How to Cite
Afif, A., Minotti, L., Kahane, P. and Hoffmann, D. (2010), Anatomofunctional organization of the insular cortex: A study using intracerebral electrical stimulation in epileptic patients. Epilepsia, 51: 2305–2315. doi: 10.1111/j.1528-1167.2010.02755.x
- Issue published online: 26 OCT 2010
- Article first published online: 13 OCT 2010
- Accepted August 20, 2010; Early View publication October 13, 2010.
- Oblique electrode;
- Electrical stimulation;
Purpose: Different lines of evidence suggest that the insular cortex has many important functional roles. Direct electrical stimulation (ES) of the human insular cortex during surgical procedures for epilepsy, functional imaging techniques, and lesion studies also occasionally induces clinical responses.
Methods: In this study, we evaluated 25 patients with drug-refractory focal epilepsy by stereotactically implanting at least one electrode into the insular cortex using an oblique approach (transfrontal or transparietal). One hundred twenty-eight insular sites (each situated between two contiguous contacts within the same electrode) were examined within the gyral substructures. We located each stimulation site by fusing preimplantation three-dimensional (3D) magnetic resonance imaging (MRI) images with the postimplantation 3D computed tomography (CT) scans that revealed the electrode contacts.
Results: Sixty-seven stimulations induced at least one clinical response. Stimulation from within the insular cortex evoked 83 responses, without evidence of afterdischarge in the insular or extrainsular regions. We classified the principal responses as sensory (paresthesias and localized warm sensations), motor, pain, auditory, oropharyngeal, speech disturbances (including speech arrest and reduced voice intensity) and neurovegetative phenomena, such as facial reddening, generalized sensations of warmth or cold, hypogastric sensations, anxiety attacks, respiratory accelerations, sensations of rotation, and nausea.
Conclusions: These findings may indicate a functional specificity for the insular gyri and show the need for exploring this structure during invasive presurgical evaluation of epileptic patients according to seizure manifestations.