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Your probably thinking of the jimmy neutron episode Sheen's Brain which has a very similar plot to what you describe.
I think it's most likely "Dexter and Computress Get Mandark!"
from Dexter's Laboratory, since it was broadcasted in '98. (starts at :28, also the pitch has been shifted a whole step and a half/3 notes higher than the original)
This is live action, which makes those two seem unlikely. This is the second "head-explode" we've gotten lately.
Nonono, it's Live Action. I think the heads were kind of egg shaped at the top or something, I might be remembering some details wrong they might not have been psychic at all but I do remember a man with a large head that extends at the top, it's not like a blown up head it's like the top part of the cranium is larger or something.
This makes me think of DC Comics' Hector Hammond but no live-action versions existed in the 90s.
I remember a show when I was a little kid in the 90's where someone had an incredibly large head and might have been in a hospital or something, but it might also have been a control room I might be remembering wrong, but his head was going to explode or something I think until he calmed down or something like that? He might not have actually been psychic I might be wrong on that. I think a woman was talking to him and his head might have returned to normal after that.