Diagnostic and therapeutic approaches in refractory insular epilepsy.

Due to heterogenous seizure semiology and poor contribution of scalp EEG signals, insular epilepsy requires the use of appropriate diagnostic tools for its diagnosis and characterization. The deep location of the insula also presents surgical challenges. The aim of this paper is to review current diagnostic and therapeutic tools and their contribution to the management of insular epilepsy. Magnetic resonance imaging, isotopic imaging, neurophysiological imaging, and genetic testing should be used and interpretated with caution. Isotopic imaging and scalp electroencephalography have demonstrated a lower value in epilepsy from insular compared to temporal origin, which increases the interest of functional magnetic resonance imaging and magnetoencephalography. Intracranial recording with stereo-electroencephalography is often required. The insular cortex, being highly connected and deeply located under highly functional areas, is difficult to reach, and its ablative surgery raises functional issues. Tailored resection based on stereo-electroencephalography or alternative curative treatments, such as radiofrequency thermocoagulation, laser interstitial thermal therapy or stereotactic radiosurgery, have produced encouraging results. The management of insular epilepsy has benefited from major advances in the last years. Perspectives for diagnostic and therapeutic procedures will contribute to better management of this complex form of epilepsy.