Dementia puglistica
Dementia pugilistica was a syndrome affecting boxers that was caused by cumulative cerebral injuries and was characterized by impaired cognitive processes. A sufferer was commonly referred to as being punch drunk or punchy.

In 2153,  believed he was "a little punchy" from fighting Osaarian pirates after he later received a second-degree burn to his wrist while reinstalling a deuterium injector he hadn't depolarized. ()

While Chakotay was hallucinating when the  was trapped in chaotic space in 2375, a vision of The Doctor told him that he was delusional due to dementia pugilistica. ()

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Medical conditions