In the cold Canadian winter, I have noticed that the tip of my right middle finger numbs much sooner than any of my other digits despite wearing warm gloves. The most compelling clue to explain this mystery is that the sensitive finger also happens to be my percussive finger. Percussion is part of the physical examination I perform on a daily basis as a medical doctor. It involves striking the body with (in my case) the middle finger and listening to the resulting sound to elicit information about underlying organ structures. Dr Leopold Auenbrugger is credited with introducing the percussive technique to modern medicine. His father was an innkeeper and he likely learnt it from watching men tap wine barrels to determine how full or empty they were. Dr Auenbrugger was also a skilled musician (he wrote the libretto for the comic opera Der Rauchfangkehrer by Antonio Salieri) so he had an ear for sounds. I lack the trained ear of Auenbrugger but I wonder if we shared the same temperature-plagued finger affliction. After all, my teenage finger-tapping days (while learning to play electric guitar solos) had already set that middle digit up for future problems. A 2016 medical case report described secondary Raynaud’s phenomenon in a slap bass player’s right second and third fingers due to occupational exposure.

A similar finger problem started afflicting professional yo-yo performer Dave Schulte (“Dazzling Dave”) in 2005. In his case, the index finger of his right hand was compromised. He was diagnosed with vasospasm secondary to the repetitive impact of the yo-yo striking his hand when catching it.

Unwittingly, Henrietta Lacks made an unparalleled contribution to medical science. In 1951, Henrietta Lacks sought help for abnormal vaginal bleeding. A tumour on her cervix was biopsied, and she was diagnosed with cervical cancer. Despite treatment, she died within a year. A sample of her cancer cells, taken without her knowledge or consent, was sent to Dr George Gey. Dr Gey was astonished because, unlike other human cells he had tried to grow in the lab, these cells did not die within a few generations. Henrietta’s cancer cells were immortal. They were called ‘HeLa’ cells, after the first two letters of her first and last name. HeLa cells have helped develop the polio vaccine and furthered our understanding of cellular biology without having to experiment on live humans. HeLa cells were even sent into space during the first explorations to determine if humans can survive in zero gravity. The cells from Henrietta Lacks are the oldest and most commonly used human cell lines in scientific research today.

The father of gynaecology, Dr J Marion Sims, is one of the most controversial figures in medicine. In 2018, New York City removed his statue from Central Park. Dr Sims was a “plantation physician”, who conducted his experimental operations on black slave women in the 19th century. Dr Sims also erroneously thought that neonatal tetanus resulted from the movement of a newborn’s skull bones during a prolonged birthing process. He tried to use a shoemaker’s awl to experimentally re-align infantile skull bones with consistently fatal results. He invented the precursor of the modern vaginal speculum by adapting a pewter spoon. He also performed the first successful operation for vesicovaginal fistula. Vesicovaginal fistula, a complication of obstructed childbirth, results in urinary leakage from the vagina.

Guillain-Barré syndrome (GBS) is a rare condition in which a person’s immune system attacks nerves, resulting in muscle weakness and paralysis.

GBS received media attention at the end of 2018 when a Las Vegas man blamed the flu shot for triggering the disease in him. This association between GBS and the flu shot dates back to a 1976 outbreak in the US after the swine influenza program. A subsequent study conducted over 15 years showed “the relative incidence of GBS within 90 days of influenza immunization was 0.76 as opposed to 7.35 within 90 days of influenza-like illness.” If you’re worried about that rare GBS, you’d be crazy not to get the flu shot! A person is far more likely to get GBS from the flu than from a vaccine. Two-thirds of people with GBS report a history of gastroenteritis or influenza-like illness weeks before the onset of neurologic symptoms. The most common infectious trigger is Campylobacter jejuni. About 1 in every 1,000 reported Campylobacter illnesses leads to GBS. Between 2016 and 2018, puppies sold through Petland in the US created a multidrug-resistant Campylobacter infection outbreak.

Yes, you are more likely to get GBS from a puppy (or the flu) than from a vaccine.

People are bad at risk assessment. We tend to overestimate rare and scary problems and overlook common ones. Every day I see patients who are terrified of cancer but completely unconcerned about their high risk of cardiovascular disease.

In 2013, four villagers from Kenya chased down and captured two cheetahs responsible for killing their goats. Humans are the only surviving primates that use persistence hunting. Persistence hunting (or endurance hunting) involves pursuing a prey until it succumbs to exhaustion. Cheetahs, the fastest animals on Earth, generate speeds of at least 104km/h (64mph). The men waited for the hottest part of the day and chased the cheetahs down over a distance of four miles (6.4km). As hairless apes, humans are incredibly efficient at cooling their bodies. The cheetahs were no match for human endurance in the hot African sun. They were captured alive and handed over to the Kenya Wildlife Service.

The field of epigenetics has revived interest in life experiences and their role in premature ageing and cancer. Doctors generally accept that stress shortens telomeres and survivors of childhood traumas can expect their lives, on average, to be almost 20 years shorter. I was intrigued when, in 2016, Yisrael Kristal became the oldest living man. He was also the oldest Holocaust survivor. Kristal had lived through World War I, World War II, and survived the Auschwitz concentration camp. During the Holocaust, he suffered the deaths of his wife and two children.

His story reminded me of Charles Brunier who claimed to be the real Papillon. Papillon is an autobiography written by Henri Charrière (Charrière’s nickname was Papillon). Henri Charrière wrote about the unspeakable suffering he endured during captivity in the penal colony of French Guiana. It is well-known that Charrière blended truth and fiction so that many of the experiences he claimed as his own were stories stolen from other prisoners. At the age of 104 years, Charles Brunier said he was the genuine Papillon. He had done time on Devil’s Island and sported a butterfly (papillon in French) tattoo. Brunier lived to be 105 years old. He fought in World War I and World War II. He escaped from prison on more than one occasion.

What made Charles Brunier and Yisrael Kristal different? How were they able to dance with the devil and not go gently into that good night? What made them continue to live and rage against the dying of the light?

Research on Holocaust survivors in 2013 revealed a surprising result. Over 55, 000 Jewish members of the same generation were studied to compare the lifespans of those who endured the Holocaust to those who fled Europe. Survivors of the genocide tended to outlive those who escaped it. On closer scrutiny, the effect was driven by men. Female Holocaust survivors had the same average life-expectancy as women of their generation who had not experienced the genocide. The men, however, created a medical mystery. Surprisingly, male Holocaust survivors lived longer than their peers who had escaped the genocide.

Two possible explanations exist. There is the possibility that trauma might develop resilience in certain individuals. The other reason could be that the physically and mentally fit were more likely to survive the ordeal in the first place.

In war, the word ‘infantry’ invokes youth. From the French ‘infanterie’ and the Italian ‘infanteria’ (both referencing youth), infantry is a term for young and inexperienced foot soldiers. It seems a terrible waste that young lives are squandered so wantonly, but humans seldom miss an opportunity to profit from tragedy. Dead young men provided an excellent source of mint quality human teeth and bones.

Before the late 19th century, human teeth were in high demand to fit dentures in the rotting mouths of the rich. Grave robbers supplied low-quality products obtained from the old and diseased. Procuring cheap teeth from the poor also yielded inferior dentures.

“Waterloo teeth” were excellent quality dentures with teeth sourced from the mouths of healthy young men who had died on the battlefield at Waterloo. Looters and scavengers would pull teeth from these fallen soldiers, sort them, and sell them off to dentists for a small fortune.

George Washington’s dentures contained teeth sourced from horses, donkeys, cows, and dead people.

As for the dead soldiers’ young bones–rich in minerals–they were valued as fertiliser. Dead men and horses were removed from the battlefield of Waterloo and shipped to bone-grinders. In 1822, The Observer published: “It is now ascertained beyond a doubt, by actual experiment on an extensive scale, that a dead soldier is a most valuable article of commerce; and, for aught known to the contrary, the good farmers of Yorkshire are, in a great measure, indebted to the bones of their children for their daily bread.”