It obviously didn’t spring up suddenly, but had been growing for some time before it was discovered and led to his death at age 40. Brain tumors are known to affect behavior, so it is quite possible that Atwater’s antagonistic attitudes and strategies, for which he eventually expressed regret, were the result of a disordered brain.
In that context, I offer the following from a study published by the NIH:
The personality changes are persistent, showing significant difference from previous personality patterns. The patient has unstable affect, disinhibition in impulse control, aggressive behavior, apathetic, paranoid, or a mix of symptoms. These changes are a part of frontal lobe syndrome, which exhibits slowing of the thinking process, impaired judgment, decreased curiosity, social withdrawal, and increased aggression. These patients appear apathetic and ignorant, but could be suddenly aggressive with impulsive disinhibition….
Depending on which regions of the frontal lobe are damaged, different symptoms can occur. Damage to the prefrontal cortex is generally associated with behavioral changes; damage to the dorsolateral region results in cognitive dysfunction. Common cognitive disturbances include problems with memory, motor skills, spatial processing, attention, verbal fluency, and concentration. Perhaps the most notable behavioral effect of frontal lobe dysfunction is personality change.
In this instance, the etiology of the frontal lobe syndrome has been identified and, after death, autopsies no doubt validate the location and source of the insult. But other causes are possible, such as, for example, shaking a baby moderately or dropping it on its head or even perinatal asphyxia during a “difficult delivery.”
Could that account for the dysfunctions exhibited by the Dude? I’d say yes. Is there a relationship between poor health care and crazy behavior?