Similar to laryngospasms caused by seizures via laryngeal branches of the vagus nerve (as demonstrated by Nakase et al), is it possible that phrenic nerve hyperstimulation could occur from seizure? If so, this might induce diaphragm spasms and resulting diaphragm fatigue. Perhaps persistent fatigue relates to the SUDEP deaths identified in the MORTEMUS study where cardiac arrest occurred secondary to "terminal apneas"?

Our DCC theory in SUDEP (diaphragm cramp-like contracture) proposes that it is responsible for the terminal, postictal apneas. In SIDS, it is triggered by diaphragm work overload in REM-sleep whereas perhaps in SUDEP, postictal acidosis is the catalyst.

References:

Nakase K, Kollmar R, Lazar J, Arjomandi H, Sundaram K, Silverman J, et al. Laryngospasm, central and obstructive apnea during seizures: Defining pathophysiology for sudden death in a rat model. Epilepsy Res. 2016 Dec;128:126-139. PMID: 27835782.

Ryvlin P, Nashef L, Lhatoo SD, Bateman LM, Bird J, Bleasel A, et al. Incidence and mechanisms of cardiorespiratory arrests in epilepsy monitoring units (MORTEMUS): a retrospective study. Lancet Neurol. 2013 Oct;12(10):966-77. PMID: 24012372.