cerebral toxoplasmosis; these brain cysts may or may not cause headaches, and they come in a wide variety of sizes & shapes; even upon close inspection, they can appear as the usual degenerative disease of the brain on imaging and pathology, with some soft spots here and there along the central fluid spaces; the "classic appearance" is more of an exception rather than the norm, for the textbooks of academons, once the evidence is no longer possible to ignore;

i don't think that absolutely all cats are infected, however a very large proportion of them are; i personally knew a decent friend who eventually went insane and went on Ozempic; he had many wild barn cats; his back ranch kitchen smelled of urine, and that's where he prepared the daily smoothies; he later got himself a female handler as well; it's a very sad story - The Great Creator gave that man everything...

if the cat is infected, it is smart enough to infect a man, no matter how clever he thinks he is at avoiding infestation; cats think in more dimensions than an average man;