A symptom caused from a state inwhich one's brain is temporarily "drunk" due to one's unrestrained will to persue a mental exercise and refuse to satisfy certain physiological needs.
In order for a beer drinker to become drunk, he/she must have drank beer to the point that it became excessive to their body - neglecting their physiological needs. As a result, one of their symptoms is BEER* breath. Meaning, whenever this person talks, no matter what the hell they talk about, they blow an odor of beer to the crowd among them.
*Beer can be replaced in this example with whatever alcoholic beverage
Drawing the parallel from the model above:
In order for a mental exercist to become "brain drunk", he/she must have performed a mental excercise to the point that it became excessive to their body - neglecting their physiological needs. As a result one of their symptoms is brain breath. Meaning, whenever this person thinks, no matter what the hell they think about, they "blow an oder" of this mental exercise within their own brain.
"Even though I was so tired, I had to spend 13 hours last night to finish reading my philosophy book for homework. By the end of it I had brain breath. When I went to sleep, all I could think about was 'Aristotle this', 'existentialist that'. In fact, was so brain drunk that I even thought about ethics in my dreams. Now that I think about it, I'm not even sure if I even did fall asleep. I feel like i got a serious headache - you might even call it a hangover!"