Surgical Intervention for Lumbar Spine

Abstract

INTRODUCTION: The role of the insula in the genesis of epileptic seizures has been poorly documented. Few data exist from human electophysiological studies performed in vivo by direct electrical stimulation of the insular cortex due to its deep anatomical position and dense surrounding vascular network. The determination of clinical signs related to the participation of the insula permits a more accurate analysis of the electroclinical data. METHODS: This retrospective study focused on more precisely determining the anatomo-functional organization of the insula by studying the effects of intracerebral electrical stimulations during stereoelectoencephalography exploration using an oblique approach. Twenty-five epileptic patients in whom at least one electrode was used to explore the insula were selected. A total of 313 stimulations were performed in 27 insula. A presurgical three-dimensional (3D) T1-weighted magnetic resonance imaging (MRI) scan and stereotactic software were used to target the insular cortex. A postoperative contrast-enhanced 3D computed tomographic scan enabled the fusion of the resulting image with the preoperative 3D MRI in the same stereotactic referenced system. The cortical location and anatomical position could then be determined in reference to gyri and sulci. RESULTS: The stereotactic coordinates of each stimulation site were individually reported on MRI. All results were discussed in terms of their anatomic and electrical significance. Our data demonstrate a much more elaborate organization of the insular cortex in terms of sulci and gyri compared with the earlier simple distinction between the anterior and posterior insula. We have been able to identify individual areas in which direct electrical stimulation evokes language disorder, painful phenomena, or sensorimotor responses. For the latter, we have identified a somatotopy. CONCLUSION: The large sampling allowed by this exploration using an oblique approach has enabled us to draw up the first anatomo-functional insular cortex organization in terms of sulcal and gyral anatomy.