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5 Case Studies that Taught Us About the Body

Anatomical model of face, jaw,cheek, nose
Anatomy Insider/Shutterstock

When everything is going well, our bodies just kind of work. All the complicated biological systems simply run in the background, and we’ve no idea what’s really going on. But sometimes we learn a lot when things break down. Here are five crazy case studies that taught science a huge amount about how the body works, because something went wrong.

Mary Mallon

Mary Mallon, more famously known as Typhoid Mary, was an Irish cook in New York. She was the first asymptomatic carrier of typhoid fever identified. In other words, although she didn’t herself show any symptoms of typhoid, she was capable of passing it on.

Mallon worked as a cook for wealthy families and typhoid infections followed her. During the course of her career, she infected over 50 people and was responsible for three deaths.

Mallon was first identified and quarantined in 1907, although she insisted she did not carry the disease, despite all evidence to the contrary. She was released in 1910 after agreeing to no longer work as a cook. However, after a few years as a laundress, she changed her name to Mary Brown and resumed working as a cook, again spreading the disease. She was finally tracked down and, again, quarantined in 1915. She was held on North Brother Island near Manhattan until her death in 1938.

Modern science is only just beginning to understand how asymptomatic carriers are able to carry and spread disease, without being affected by it. They present particular difficulties for public health officials because they are so hard to identify, as Mallon’s ability to spread typhoid shows.

Phineas Gage

phineas gage
Originally from the collection of Jack and Beverly Wilgus, and now in the Warren Anatomical Museum, Harvard Medical School.

On the 13th of September, 1848, railway worker Phineas Gage was clearing rocks for a new line with explosives. He had to drill a hole, fill it with gunpowder, and pat it down with a metal rod called a tamping iron. Distracted by other workers, Gage accidentally leaned over the rod as it sparked against a rock, igniting the gunpowder. The 1.25-inch wide, almost 14-pound rod shot from the hole like a ballista bolt passing straight through Gage’s head, and landed roughly 80 feet away, still smeared with his blood and brains.

Gage collapsed, briefly convulsing, but within a few minutes was speaking and walking with assistance. He sat upright on an oxcart that brought him to the nearest doctor, about 0.75 of a mile away. Gage, however, was not alright. Over the next few weeks, he varied being comatose and delirious and suffered from an infection. And, of course, his brain was permanently damaged.

How much the injury changed Gage is a subject of much debate. Some ignore the facts and paint a lurid picture of a once-pleasant man turned into a psychopath unable to hold down a job, while others insist he was not at all changed, again largely against the evidence. Even the doctors who treated at him at the time don’t agree, describing him as both, “a child in his intel­lec­tu­al capacity and man­i­fes­ta­tions” and suffering from “no impairment whatever of his mental faculties.”

Whatever the case, Gage’s injury was hugely important to the relatively new fields of neurology and psychology, as it showed that the brain was not a monolithic thing. Instead, different areas of it correspond to different functions, and that damage to one would not mean problems in all.

Louis Victor Leborgne

Pierre Paul Broca was a nineteenth-century French physician and anatomist. In 1861, he examined a patient called Louis Victor Leborgne who, over the preceding 21 years, had lost the ability to speak—all he could say was “tan,” which became his nickname in the scientific literature—but had no loss of comprehension or other mental faculties.

A few days later Tan died of an unrelated infection, so Broca performed an autopsy and found a lesion in the frontal lobe of the left cerebral hemisphere. He concluded that this must be where speech production was localized within the brain and that it was separate from language processing. Over the next few years, Broca autopsied 13 more subjects who’d experienced speech loss, finding similar lesions in their brains, in an area now called Broca’s Area.

Alexis St. Martin

Lead buckshot next to a shotgun shell
Sergey Sharonov/Shutterstock

On the 6th of June, 1822, Alexis St. Martin, a Canadian fur trader, was accidentally shot in the stomach with a shotgun loaded with buckshot. He was rushed to the hospital, which in 1822 was more for show because there was little hope of helping him. Even Dr. William Beaumont who treated him expected him to die.

However, St. Martin somehow pulled through, although the wound didn’t fully heal. It left a hole in his stomach through which any food could be watched digesting—which is exactly what Beaumont decided to do.

No longer in mortal danger, St. Martin was kicked out of the hospital and taken in by Beaumont. In return for a place to stay and medical care, St. Martin did odd jobs around the house and enabled Beaumont to experiment on him.

Over the next decade, Beaumont performed around 200 experiments on St. Martin, and in the process learning huge amounts about how the human digestive system worked and how different foods broke down.

St. Martin, unlike most other medical case studies, ended up living a long, and presumably happy enough, life. He was 28 when he was shot and lived for another 50 years, despite the wound never closing. He married, fathered six children, and returned to fur trading and farming after he stopped letting medical professionals experiment on him. His family buried his body in an unmarked grave—to keep the doctors away at the end.

David Reimer

david raimer

How much of gender identity is biological and how much is sociological is something that’s still not entirely clear. However, there’s one important case study that sheds some light on it.

David Reimer was born on the 22nd of August, 1965, and circumcised a few months later. Unfortunately, the procedure was botched by the urologist and Reimer’s penis was severely burned.

Reimer’s parents took him to see John Money, a psychologist at Johns Hopkins who studied sexual development and gender identity. Money believed that gender was primarily learned in early childhood and that it could be changed, so he recommended sexual reassignment surgery for the infant Reimer. The surgery was performed and David became Brenda at the age of 22 months.

Money continued to see Reimer through his early childhood to assess how the reassignment was proceeding. It was a perfect, if highly unethical, scientific experiment: Reimer had an identical twin brother who had not undergone the surgery to use as a control. Things, however, did not proceed as planned.

Money’s own behavior was highly dubious and, according to Reimer, he forced the twins to act in accordance with their assigned genders. By the time he was 13, Reimer was suffering from suicidal depression and threatened to take his own life if he was made to see Money again. Eventually, when he was 14, his parents admitted that he had been born a boy, and he began the process of transitioning back, taking the name David.

The details of Reimer’s case only became known when Milton Diamond, a sexologist, convinced Reimer to let him report the outcomes of the failed experiment. Money had portrayed it as a success for 30 years, influencing treatment courses for babies in similar situations.

Sadly, Reimer continued to battle with depression throughout adulthood. He took his own life in 2004 when he was 38.

Harry Guinness Harry Guinness
Harry Guinness is a photography expert and writer with nearly a decade of experience. His work has been published in newspapers like the New York Times and on a variety of other websites, including Lifehacker. Read Full Bio »