The Idiot also dramatizes another well-known fact: Dostoevsky’s epilepsy.
In one thrilling passage, Myshkin, just before an epileptic seizure, remembers in detail what the experience is like. Remarkably enough, it resembles the moments before execution: time accelerates to infinity until he understands “the extraordinary saying [in the Book of Revelation] that ‘there shall be time no longer.’” Epilepsy differs from execution because it replaces the unfathomable horror of the condemned prisoner with an equally unimaginable bliss, which affords a mystical understanding of the very essence of existence. Just before he loses consciousness, Myshkin has time to say to himself, “Yes, for this one moment one might give one’s whole life!”
Readers might presume that such experiences enabled insights no other writer could attain.”
(from “Dostoevsky and His Demons,” Gary Saul Morson’s essay/review in NYRB 1 July 2021; the entire essay is a great read)
more (on Dostoyevski and Ecstatic Seizures)
this experience is associated with the pre-epileptic aura that Dostoyevski experienced