Earlier today, The New York Times broke some startling news about a presidential candidate. According to a 2012 deposition, Robert F. Kennedy Jr. once suffered from, in his own words, “a worm that got into my brain and ate a portion of it and then died.” The vague yet alarming description could apply to any number of parasitic ailments, among them angiostrongyliasis, baylisascariasis, toxocariasis, strongyloidiasis, and trichinosis. But some experts immediately suspected a condition called neurocysticercosis (NCC), in which the larvae of the pork tapeworm Taenia solium post up in the brain.The condition might sound terrifying—and, to some observers, darkly hilarious. Literal brain worms! But it does not actually involve any brain-munching, or even your standard-issue worm. The brain-invading culprit is instead a tapeworm (strictly, a kind of helminth) that typically makes its home in pigs. As far as parasitic infections go, this is “the most common one in the brain,” Laila Woc-Colburn, an infectious-disease physician at Emory University, told me. And globally, it’s one of the most common causes of epilepsy in adults.NCC typically begins after people have been exposed to feces that contain the eggs of a pork tapeworm, say while on a pig farm or handling uncooked, contaminated food. After the eggs are swallowed, they hatch into larvae in the gut. Because people aren’t the appropriate host for the young tapeworms, they end up on a fruitless journey, meandering through the body in a desperate attempt to find pig muscle. A common final destination for the larvae is the brain, where they enclose themselves into cysts in the hopes of maturing; eventually, unable to complete their life cycle, they die, leaving behind little more than a calcified nub.[Read: Flatworms are metal]This is, to put it scientifically, some pretty gnarly stuff. But many cases are “completely asymptomatic,” Boghuma Kabisen Titanji, also an infectious-disease physician at Emory University, told me. In other people, though—especially those with a lot of larval cysts—the presence of the foreign invaders can spark a wave of inflammation, which in turn triggers swelling and tissue destruction. Individuals with cysts in their brain may develop headaches or seizures, though those problems can take years or even decades to manifest, Titanji said.Experts estimate that millions of people may be afflicted with NCC worldwide, most of them concentrated in Latin America, sub-Saharan Africa, East Asia, and India. In the U.S., though, NCC is rather rare, with just a few thousand diagnoses made each year, many of them related to travel or immigration. “This is a disease of poverty,” Woc-Colburn told me. Which would make the multimillionaire Kennedy—if he had the infection at all—“an atypical patient.”There is, at least, some comforting news. NCC is pretty easily preventable with solid hand-washing habits. And in the U.S., where CT scans are fairly accessible, “it can be diagnosed very easily,” Woc-Colburn said, particularly once doctors have a good sense of a patient’s exposure history. Doctors generally know to look for it in patients who come in with headaches and seizures. (Kennedy first sought help after experiencing memory loss and mental fogginess, though he recently told the Times that those symptoms have since resolved and that he hadn’t received treatment for the parasite.) The infection is also treatable with standard antiparasitics. And caught early, it isn’t expected to leave lingering damage. In more serious cases, though, years of severe, unmanaged seizures can lead to certain cognitive defects.[Read: America’s never-ending battle against flesh-eating worms]None of this is to say that Kennedy definitely had NCC. All the public knows is that, in 2010, he said that he was battling neurological symptoms, and that an unusual blemish appeared on a brain scan. (The memory loss and mental fogginess may very well have been attributable to mercury poisoning from Kennedy’s diet at the time, which was high in tuna and perch, according to the same 2012 deposition.) Even if a parasite was definitely to blame, “at least six or seven” others could have ended up in his brain, Titanji told me. Like the pork-tapeworm larvae, several of them would have ended up there accidentally, only to die a quick death without gulping down any brain tissue.The most comforting news about NCC is that—again—it is uncommon in the United States. Still, now that this news has broken, Woc-Colburn worries that her clinic is going to fill up with people who think they’re afflicted. Given the odds, many of them will be wrong. If anyone’s really worried about their gray matter becoming lunch, they shouldn’t fear worms, but Naegleria fowleri, a rare amoeba that camps out in warm bodies of water. That one, I regret to report, really does eat your brain.

When George Schappell came out as transgender in 2007, he joined a population at the center of medical and ethical controversy. Schappell was used to this. He had been born in West Reading, Pennsylvania, in 1961 with the left side of his face, some of his skull, and a portion of his brain conjoined with those of his sister, Lori. Following doctors’ advice, their parents put them in an institution for children with intellectual disabilities.At the time, children with “birth defects” were routinely consigned to what the activist Harriet McBryde Johnson termed the “disability gulag,” a network of facilities designed in part to care for such children and in part to keep them out of the public view. Conditions could be abysmal, but even better-maintained facilities cut residents off from society and deprived them of autonomy. In their early 20s, the twins fought their way out by enlisting the help of Pennsylvania’s first lady, whose stepson was disabled.[From the September 2023 issue: The ones we sent away]As George and Lori Schappell navigated independence, the growing disability-rights movement began to allow many other people with disabilities to do the same. Their physical bodies did not fit easily into the structures of a world that was not designed to receive them. George and Lori, who died last month at 62, spent their adult lives finding their way through that world. But American society is still struggling to determine whether to accommodate bodies like theirs—bodies that fail to conform to standards of gender, ability, and even individuality.In the 1980s and early ’90s, while the Schappells were establishing their independent lives, the American public was enthralled by a procession of sensationalized operations to separate conjoined twins. These experimental procedures could be brutal. Many conjoined twins did not come apart easily; in many cases they have an odd number of limbs or organs shared between them. Patrick and Benjamin Binder, whose 1987 separation at six months made a young Ben Carson a star, both sustained profound neurological damage from the surgery and never spoke. In 1994, surgeons sacrificed newborn Amy Lakeberg to save her twin, but Angela died less than a year later, never having left the hospital. Lin and Win Htut shared a single pair of genitals; in 1984 doctors designated the more “aggressive” of the 2-year-old boys to retain their penis, while the other was given a surgically constructed vagina and reassigned as a girl. By the time he was 10, he had reasserted his identity as a boy.Other twins’ separation surgeries were the subject of occasional controversy from the 1980s into the early 2000s. Doctors justified them as giving children a chance at a “normal” life, and usually portrayed them as well-intentioned even if they failed. But many were not clearly medically necessary. Ethicists such as Alice Dreger, the author One of Us: Conjoined Twins and the Future of Normal, argued against a risky medical “cure” performed on children who could not consent to it. Meanwhile, the Schappells were living in their own apartment. George’s spina bifida had impeded his growth, so he was much smaller than his twin; they got around with George perched on a barstool-height wheelchair so he could roll along beside Lori as she walked. Lori got a job at a hospital, and they pursued hobbies (George: country music; Lori: bowling) and made friends (Lori also dated). They kept pets, including a Chihuahua and a fish whom they named George years before George chose that name as his own. They went to bars, where a bartender once refused service to George because he looked underage, but agreed to pour drinks for Lori. They did not live “normal” lives: They lived their lives.[Read: Why is it so hard to find jobs for disabled workers?]But as the public became familiar with the model of separation for conjoined twins, the Schappells found themselves asked, repeatedly, to explain their continued conjoined existence. In 1992, they gave what seem to be their first interviews, to The Philadelphia Inquirer and the Philadelphia Daily News; the news hook was local doctors’ decision not to separate another pair of twins who were joined, like the Schappells, at the head. The Schappells initially explained to reporters that medical science hadn’t been advanced enough for separation when they'd been born. But later they would stress that they wouldn’t have wanted to be separated even if they had been given the choice. “I don’t believe in separation,” Lori told the Los Angeles Times in 2002. “I think you are messing with God’s work.”Not long after those first articles were published, the twins began appearing more frequently in the media. They did the rounds of the great 1990s freak shows—Maury, Jerry Springer, Sally, Howard Stern. They became the most visible non-separated conjoined twins of the era. Observers, journalists, and talk-show audiences tended to overwrite the Schappells with their own perceptions. The twins were inspirational, or pitiable; they epitomized cooperation, or individualism. I can’t imagine your lives, people would say, even as they proceeded to do just that. The Virginia Quarterly Review once published a poem written in Lori’s voice, in which the poet took it upon herself to warn an imagined observer: “You don’t know the forest / of two minds bound by weeds / grown from one to the other, / the synapses like bees / cross-pollinating / our honeyed brain.”The twins, though, did not seem overly concerned about whether others understood them, and they did not go out of their way to change the world. They were not activists. George pursued a career as a country singer; they traveled; they grew older. When their Chihuahua lost the use of its hind legs, George made it a tiny wheelchair. The world slowly changed around them. Institutionalization for disabled people is less common today, though it still happens.[From the March 2023 issue: Society tells me to celebrate my disability. What if I don’t want to?]Conjoined twins now occupy far less space in the public imagination. The pair currently most famous are Abby and Brittany Hensel, who have constructed their public image as so aggressively unexceptional that a reality show about their lives was, in at least one viewer’s words, “super boring.” (Their public performance of ordinariness is not always successful; earlier this year, when Today reported that Abby had gotten married, the reaction was predictable, mingling pity and prurience.)Separation surgeries are still performed today, but they are no longer the subject of intense public debate. Instead, one of the most visible medical controversies of our era, gender transition for young people, is related to another aspect of George’s identity. Although children who identify as trans aren’t eligible for medical interventions before the onset of puberty and only some choose hormones or surgery in their late teens, the idea of little kids receiving those treatments has helped inflame panic over whether they should be allowed at all, even for adults.In the case of 2-year-old Win Htut, surgical transition was seen as restoring “normality.” But today, medical transition is often seen as creating difference. When you consider that history, a devotion to “normality” seems to be the primary motivator behind a recent raft of state laws outlawing transition care for transgender youth. After all, most of these laws carve out exceptions for children born with ambiguous genitalia. “Corrective” genital operations are still a routine practice for intersex infants, despite the protests of intersex adults, who say they would not have chosen to be surgically altered.[Read: Young trans children know who they are]George didn’t say much publicly about being trans, and never mentioned running up against any anti-trans bigotry. But when the twins’ obituaries ran on the website of a local funeral home last month, they were described as their parents’ “daughters,” and George was listed under his birth name. Whatever the intent in doing so, the obituary posthumously obscured his identity by correcting his “abnormality”—despite the fact that, in life, the twins had never apologized for being different.