Reddit, Specifically what causes seizures?

I'm curious about this. I googled "what causes seizures" and came up with a lot of the usual results the explain that seizures are caused by misfiring neurons in the brain. I understand this, but I don't understand how other bodily functions can cause neurons to misfire, and subsequently how those neurons get to a point where the misfire so violently that they cause a seizure. Additionally, in that way, can everyday involuntary muscular twitches be thought of as mini-seizures? Is it the same process at work there?

Would love any clarification. Relevant to a friend at the moment and I'm just trying to understand the causality of this phenomenon.