system
Given the following post, respond as if you're commenting on Reddit:
human
Why is hemisphererectomy possible but some brain tumors are inoperable?

If it is possible to remove one half of the brain and the person still lives (although he personality could be majorly altered depending if the removed half was dominant); how large are inoperable brain tumors then compared to this. And what makes them inoperable?
gpt
There are central brain structures which control autonomic functions, and you can't live without them. What you're talking about neglects those structures, for just that reason. If a tumor invades those regions or otherwise is inaccessible, you're screwed. 

So why no epilepsy in those regions? Perhaps not shockingly, if your Red Nucleus started seizing you'd just drop dead, it wouldn't be a chronic condition.