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, Trip Tucker 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. (ENT: "Anomaly (ENT)")
While Chakotay was hallucinating when the USS Voyager was trapped in chaotic space in 2375, a vision of The Doctor told him that he was delusional due to dementia pugilistica. (VOY: "The Fight")