The insular cortex is an extensively connected brain region that has recently gained considerable interest due to its elusive role in several pathological conditions and its involvement in a variety of functions. Structural connectivity studies have identified connections to the frontal, temporal, and parietal cortices, with both a rostro-caudal and a dorso-ventral organizational pattern. The insula is also widely connected to subcortical structures. The use of diffusion-weighted imaging in insular epilepsy has not yet reached its full potential; however, it may still provide some insights into its pathophysiology, assess long-term consequences, and help prevent operative complications. This chapter explores the insula’s structural connectivity and promising applications in the field of insular epilepsy.

Epilepsy surgery patients played a pioneering role in our early understanding of the insula in Penfield’s stimulation studies. Following the advent of functional imaging, epilepsy patients are once again helping us understand the role of this critical structure in human behavior. The insular cortex is involved in a wide range of complex human functions, including auditory processing, language function, attention, emotional processing, social cognition, and decision-making. In this chapter, we review this literature and report new data on the postoperative neuropsychological function of a series of 31 patients who have undergone partial or complete insular resections at the Centre Hospitalier de l’Université de Montréal (CHUM). Standard neuropsychological assessments reveal few cognitive impairments specific to insular epilepsy or its surgery. Specialized assessments are required to fully assess the impact of insular resection on socio-emotional processing and behavioral features of executive function that can be compromised following surgery.

Insular epilepsy has come into focus quite late in the field of epileptology. This entity was forgotten between the 1960s and 1980s by the last generation of epileptologists who were busy leading the fight for a localization approach and anatomo-electro-clinical correlations. This lengthy period is well documented in the first chapter of this work. This drift may be attributed to various restrictions, mostly technical: the insular cortex does not appear on the surface of the brain but is the seat of a plethoric vascularization that supplies blood to motor fibers in the centrum ovale through its network of perforating arteries. Therefore, it could not be operated without exposing the patient to unreasonable risks for the goal intended. It could not also be explored invasively without the risk of causing a hemorrhage due to the necessity of crossing a triple curtain of pial arteries. The condemnation was heard: “exploring the insula, at best, is useless, and at worst, dangerous.”

Insular lobe seizures (ILS) may present with several subjective and objective symptoms. Somatosensory and viscerosensory symptoms, notably paresthesia and laryngeal constriction, are symptoms frequently encountered with ILS. Other manifestations may become only evident after the ictal discharge spreads to extra-insular structures. Depending on propagation pathways, ILS exhibit two main clinical patterns: (1) a perisylvian /temporo-perisylvian pattern and (2) a frontal-like pattern. Other miscellaneous clinical presentations include epileptic spasms, ecstatic, gelastic, reflex, and autonomic seizures.

The insular cortex is gaining attention in the epilepsy literature; however, characteristics of insular epilepsy on non-invasive electrophysiological studies are still being defined. In this chapter, we review this emerging literature with a focus on electroencephalography and present the ictal and interictal findings of 106 patients collected in the literature. Despite the location of the insula in the depth of the Sylvian fissure, a majority of patients have ictal and interictal epileptiform abnormalities on scalp EEG, which are most commonly found in the frontal or fronto-temporal electrodes. The distribution of these findings follows an antero-posterior gradient in keeping with the connectivity pathways of the insular cortex. Multifocal abnormalities are common in the pediatric population and should not preclude surgical evaluation. Evidence is increasingly favoring magnetoencephalography as a complementary modality to EEG and its use will likely be more prominent. Scarce data is available on the utility of high-density EEG, and more studies are thus needed.

The EU-Vietnam Investment Protection Agreement (‘EVIPA’) includes the new trend of a two-tier permanent dispute resolution system called the ‘Investment Tribunal System’ (‘ITS’). The inclusion of the untested ITS in the EVIPA has unsurprisingly been met with mixed opinion from scholars and practitioners all over the world. A number of new issues, such as the constitution and operation of the tribunal system, the dispute resolution procedure, and the transparency of the dispute resolution process, is foreign to the traditional model that Vietnam usually follows. Furthermore, the enforcement of the awards rendered through the ITS, which are primarily to be enforced as the judgment of the contracting states’ courts and shall be also deemed as arbitral awards falling within the scope of the 1958 New York Convention on Recognition and Enforcement of Foreign Arbitral Awards, also poses a challenge for Vietnam and has given rise to serious concern in the community. Notwithstanding these matters, Vietnam should be well prepared for its participation in the EVIPA. This chapter reviews the procedure of the new system and critically analyse the situation of Vietnam, as well as some challenges that Vietnam may face when dealing with the new mechanism of investment dispute resolution under the EVIPA.