Ictal neural oscillatory alterations precede sudden unexpected death in epilepsy.
Bin GuNoah G LevineWenjing XuRachel M LynchFernando Pardo-Manuel de VillenaBenjamin D PhilpotPublished in: Brain communications (2022)
Sudden unexpected death in epilepsy is the most catastrophic outcome of epilepsy. Each year there are as many as 1.65 cases of such death for every 1000 individuals with epilepsy. Currently, there are no methods to predict or prevent this tragic event, due in part to a poor understanding of the pathologic cascade that leads to death following seizures. We recently identified enhanced seizure-induced mortality in four inbred strains from the genetically diverse Collaborative Cross mouse population. These mouse models of sudden unexpected death in epilepsy provide a unique tool to systematically examine the physiological alterations during fatal seizures, which can be studied in a controlled environment and with consideration of genetic complexity. Here, we monitored the brain oscillations and heart functions before, during, and after non-fatal and fatal seizures using a flurothyl-induced seizure model in freely moving mice. Compared with mice that survived seizures, non-survivors exhibited significant suppression of brainstem neural oscillations that coincided with cortical epileptic activities and tachycardia during the ictal phase of a fatal seizure. Non-survivors also exhibited suppressed delta (0.5-4 Hz)/gamma (30-200 Hz) phase-amplitude coupling in cortex but not in brainstem. A connectivity analysis revealed elevated synchronization of cortex and brainstem oscillations in the delta band during fatal seizures compared with non-fatal seizures. The dynamic ictal oscillatory and connectivity features of fatal seizures provide insights into sudden unexpected death in epilepsy and may suggest biomarkers and eventual therapeutic targets.
Keyphrases
- temporal lobe epilepsy
- resting state
- functional connectivity
- white matter
- young adults
- heart failure
- escherichia coli
- mouse model
- diabetic rats
- oxidative stress
- high fat diet induced
- genome wide
- gene expression
- risk factors
- adipose tissue
- drug induced
- skeletal muscle
- radiation therapy
- type diabetes
- room temperature
- subarachnoid hemorrhage
- solid state