Epilepsy as a Network Disorder (2): What can we learn from other network disorders such as dementia and schizophrenia, and what are the implications for translational research?

Abstract

There is common agreement that many disorders of the central nervous system are 'complex', that is, there are many potential factors that influence the development of the disease, underlying mechanisms, and successful treatment. Most of these disorders, unfortunately, have no cure at the present time, and therapeutic strategies often have debilitating side effects. Interestingly, some of the 'complexities' of one disorder are found in another, and the similarities are often network defects. It seems likely that more discussions of these commonalities could advance our understanding and, therefore, have clinical implications or translational impact. With this in mind, the Fourth International Halifax Epilepsy Conference and Retreat was held as described in the prior paper, and this companion paper focuses on the second half of the meeting. Leaders in various subspecialties of epilepsy research were asked to address aging and dementia or psychosis in people with epilepsy (PWE). Commonalities between autism, depression, aging and dementia, psychosis, and epilepsy were the focus of the presentations and discussion. In the last session, additional experts commented on new conceptualization of translational epilepsy research efforts. Here, the presentations are reviewed, and salient points are highlighted.

Neuronal Surface Antibody-Medicated Autoimmune Encephalitis (Limbic Encephalitis) in China: A Multiple-Center, Retrospective Study

“…This result is similar to another study in southwestern China (abnormal in 50%, mainly insular/hippocampal abnormality) ( 8 ). This result might explain the high incidence of epileptic seizures in patients with AE, as medial temporal structures, including the hippocampus, are critical in the neural circuits that play an important role in seizure propagation ( 28 , 29 ). Abnormal signals in other areas of the cortex, diencephalon, brainstem, and cerebellum have also been reported ( 27 ).…”

Longitudinal analysis of interictal electroencephalograms in patients with temporal lobe epilepsy with hippocampal sclerosis

“…Our study, which included a large series of well-characterized and homogeneous patients with TLE-HS, showed that the proportion of normal EEGs decreased over time in parallel to an increase in IEDs ipsilateral to the HS or with repercussions in the contralateral hemisphere (bilateral IEDs). This may be related to the progression of epilepsy and may have implications for worsening cognition and other comorbidities [23,36].…”

Parvalbumin Role in Epilepsy and Psychiatric Comorbidities: From Mechanism to Intervention

“…Despite this complex and intricate puzzle investigating schizophrenic epilepsy comorbidity, the subject has gained significant attention, reflecting the debate on the possible common pathways ( Kristensen and Sindrup, 1978 ; Wolf and Trimble, 1985 ; Diehl, 1989 ). There is a natural converging link between psychosis and epilepsy comorbidity, which is the impairment of limbic circuits, but the exact mechanism that promotes psychotic symptoms in epilepsy is still objected of intense discussion ( Ma and Leung, 2002 , 2004 ; Gutierrez-Galve et al, 2012 ; Nakahara et al, 2018 ; Scharfman et al, 2018 ). A group of researchers poses it is mainly related to the glutamatergic system, which could explain the change in hippocampal excitability and, consequently, the hyperactivity ( Nissinen et al, 2000 ; Schobel et al, 2013 ; Bossong et al, 2019 ).…”