Neuroimaging of Sudden Unexpected Death in Epilepsy (SUDEP): Insights From Structural and Resting-State Functional MRI Studies

Abstract

The elusive nature of sudden unexpected death in epilepsy (SUDEP) has led to investigations of mechanisms and identification of biomarkers of this fatal scenario that constitutes the leading cause of premature death in epilepsy. In this short review, we compile evidence from structural and functional neuroimaging that demonstrates alterations to brain structures and networks involved in central autonomic and respiratory control in SUDEP and those at elevated risk. These findings suggest that compromised central control of vital regulatory processes may contribute to SUDEP. Both structural changes and dysfunctional interactions indicate potential mechanisms underlying the fatal event; contributions to individual risk prediction will require further study. The nature and sites of functional disruptions suggest potential non-invasive interventions to overcome failing processes.

Keywords: MRI; SUDEP; biomarkers; functional connectivity; structural imaging biomarkers.

Figure 1

Summary of structural findings from imaging studies in SUDEP and populations at high-risk of SUDEP. (A) Shows cortical thickness changes in patients with GTCS (32). (B,C) Show sub-cortical gray matter alterations in SUDEP [(20), B and (21), C]. (D,E) Depict brainstem and cerebellar volume loss related to SUDEP [(33), D and (21), E].

Figure 2

Summary of rs-FC findings in patients at risk of SUDEP. Altered connectivity between cortical and sub-cortical autonomic- and breathing-related sites. (A,B) Show reduced functional connectivity in patients at high risk [Adapted from (51), A and (52), B], while (C) Shows increased connectivity between primarily frontal and limbic sites in those at high-risk [Adapted from (52)].