Cold stimulus headache or ‘brain freeze’ happens when the unprotected head is exposed to a cold environment (such as diving into cold water) or by ingesting cold materials that pass over the palate and posterior pharynx. The mechanism is not fully understood but may be related to sensory stimulation of the trigeminal nerve causing cerebral vasoconstriction.

The word humour is Latin for fluid, and you can thank doctors for your ‘sense of humour’.

Ancient Greek and Roman physicians developed a medical system based on the belief that the human body consisted of four humours (blood, phlegm, yellow bile and black bile). Illness resulted from an imbalance in the mixture of those humours. The theory of humoralism was further expanded by philosophical and metaphorical concepts so that unbalanced humours became linked to emotions and temperaments. The word ‘humour’ naturally evolved to describe a person’s mood (ill-humoured/good-humoured). Altering someone’s mood became “humouring” someone. Ultimately, humour came to represent something that could change your mood by making you laugh—such as a joke or a comedic play.

How would you describe a girl with an hourglass figure? A waist of time….

The smallest recorded waist belonged to Ethel Granger, who tightlaced for most of her life to achieve a waist of 13 inches (33 cm). Guinness World Record holder for the smallest waist on a living person, Cathie Jung, has a corseted waist measuring 15 in (38.1 cm). Uncorseted, it measures 21 in (53.3 cm).

“Of corset was a terrible waist” when female impersonator Joseph Hennella died in 1912 after collapsing on stage; possibly due to a constrictive corset. “The hospital physicians said [his] tight lacing had caused a kidney trouble, and induced a tendency to apoplexy. Hennella was of medium height, and inclined to be stout. He was 40 years old. In his younger days it was easy for him to get the feminine lines, but lately his increasing girth made it necessary for him to lace extremely tight to create the illusion.”

Rates of identical twins are relatively constant worldwide at about 4 per 1000 births. Fraternal twins, on the other hand, show considerable variation in prevalence. African nations account for the highest number of naturally-conceived fraternal twins, while Asia has the lowest. In one report, twin rates were 1.3 per 1000 births in Japan, 8 per 1000 births in the United States and Europe, and 50 per 1000 births in Nigeria!

The Yoruba community of south-western Nigeria has the highest twinning rate in the world. Twin births have been woven into the fabric of Yoruba culture through a belief system that endows twins with special names and powers. Wooden statuettes, called Ibejis, represent the souls of deceased newborn twins and are involved in elaborate rituals.

According to The Guinness World Records, the oldest twins ever were born in Japan in 1892 (identical twins Kin Narita and Gin Kanie). Kin died in 2000, at the age of 107 years. The oldest male twins both lived to 105 years of age (Glen and Dale Moyer; born in 1895).

Crying is not just an allergic reaction to sadness. Tears triggered by emotions have a different chemical composition compared to the tears our eye makes for lubrication (basal tears) or to flush away irritants (reflex tears). Emotional tears (psychic tears) contain higher levels of stress hormones and natural painkillers (endorphins).

Only humans appear to shed tears of sadness. Other animals and primates cry communicatively, and as distress signals, but they do not weep.

Adults are less likely to cry from physical pain than children but are more likely to indulge in sentimental sobbing.

**”Birds fly, and babies cry”. Most human babies will cry without tears until 2 to 4 months of age, and the average baby will cry about 2 hours per day during the first six weeks of life. Doctors set the diagnostic limits of crying by the “rule of three”. Infant crying, for no apparent reason, lasting >3 hours per day and occurring >3 days per week in an otherwise healthy infant ❤ months of age indicates infantile colic.

Here are 5 medical questions from the Canadian citizenship test for foreigners. Do you know the answers?

1. Who was the first Canadian woman to practise medicine in Canada and what else is she famous for?
2. Which medical doctor (nicknamed the “Man of Bronze”) used to be Canada’s most-decorated Olympian for several years? 
3. Which surgeon was known as “the greatest living Canadian.”
4. Which Canadian invented the pacemaker?
5. Who discovered insulin?

Doctors remove dead skin with pineapples. No, not the way you think.

Pineapple is the only natural source of a protein-digesting enzyme called bromelain. Bromelain is used in a topical medication called NexoBrid that removes dead tissue in severe skin burns. The meat dissolving action of bromelain led to a myth that workers who harvest and handle pineapples eventually lose their fingerprints. Bromelain does not eat away human fingerprints but it is a useful meat tenderizer.

In Greek legend, the Sphinx devoured travellers who failed to answer this riddle: “What is the creature that walks on four legs in the morning, two legs at noon and three in the evening?” Oedipus correctly answered, “Man.”

Now if the riddle of the Sphinx is anything to go by, Frank Lentini took the morning and afternoon off.

Lentini was born with a parasitic twin attached to the base of his spine, leaving him with three legs, four feet, and two sets of genitals. Surgery was deemed too risky, so the young Frank grew up learning to control his extra leg. A travelling puppeteer discovered Lentini and took him to America where he began performing in circuses. The Great Lentini ‘s popularity soared as a “Three-Legged Football Player”. Despite the perceived advantage his extra leg gave him while he swam, Lentini would joke that even with three legs, he still did not have a pair. That was because all three legs were different lengths. Frank would complain about having to buy two pairs of shoes but joked that he had a friend with just one leg that would use the extra shoe. When asked how he dealt with the extra limb, he said, “If you lived in a world where everyone had just one arm, how would you cope with two?”

Lentini capitalized on the curiosity evoked by his two sets of functioning genitals by selling educational booklets to the public containing information about reproductive health. Lentini went on to father four children.

Retiring from circus life, he settled in Gibtown; A place where several other sideshow performers like Priscilla the Monkey Girl, the Alligator Man, the Lobster family, and Dotty the Fat Lady lived.

A Canadian electrical engineer, John Hopps, invented the first cardiac pacemaker.

In 1949, cardiac surgeon Dr Wilfred Bigelow and his research fellow Dr John Callaghan, experimented by cooling the bodies of dogs to try to decrease the heart’s oxygen requirements, interrupt the circulation, and–ultimately–operate on a bloodless heart.

The problem was to restart a heart once hypothermia had stopped it. Before Dr Bigelow’s experiment in Toronto, a device (defibrillator) to externally jump-start the heart had already been tested on a dog and used in a human. It was possible to zap the heart back to produce a pulse, but Bigelow and Callaghan needed repetitive stimuli (pacing) to do this over a prolonged time. They approached John Hopps to see if he could develop a specialized machine for restoring a heartbeat. By 1950, Hopps had come up with a working shoebox-sized machine that acted as the first practical artificial pacemaker-defibrillator. The invention was too large to be used internally but when transistor circuitry became available, a similar device could be shrunk down and left in a patient’s chest (the implantable pacemaker).

John Hopps paved the way for the modern implantable pacemaker. In 1984, a heart condition required that he had one implanted in himself. He went on to have another pacemaker operation in 1997 when the battery needed replacing.

At the time, the Canadian Medical Association’s headline rang: “Canadian engineer left to his own devices.”

Comedy can be divisive among people but requires integrative brain function in the individual. Doctors find it particularly interesting when a person’s sense of humour changes because neurological and psychiatric diseases disturb our sense of humour.

In the late 19th century, Herman Oppenheim and Moritz Jastrowitz described addiction to inappropriate joking and cheerfulness in patients with brain tumours.

“Witzelsucht”, from the German words for joke (Witz) and addiction (Sucht), refers to a compulsive need to make inappropriate jokes. “Moria of Jastrowitz” is a term that refers to childish or silly excitement. Witzelsucht and moria arise from brain tumours, strokes, infections, brain trauma, frontotemporal dementia and other lesions involving the frontal lobe of the brain (especially on the right side).

Interestingly, these patients don’t seem to find other people’s jokes funny but respond with uncontrollable mirth to their own gags. They do better with slapstick and puns than complex or unfamiliar humour; mostly enjoying simple, silly jokes.

The brain does not regard a sense of humour and laughter as the same thing. The former sometimes causes the latter, but in cases of pathological laughter, patients have fits of uncontrollable, excessive laughter in response to no stimulus or a trivial one. They may even burst into laughter when they are angry or sad, and sometimes abruptly switch between uncontrollable crying and laughing. Pathological laughter can result from brain injury and neurological diseases like strokes, amyotrophic lateral sclerosis, multiple sclerosis, and Parkinson’s Disease. A rare manifestation of epilepsy (gelastic epilepsy or laughing seizures) can also cause bursts of unprovoked laughter.

An ordinary sense of humour is changed by developmental or genetic conditions which display specific personality traits, such as Angelman or the “happy puppet” syndrome, Williams syndrome, and Down’s syndrome. Although autistics struggle to process social and emotional aspects of humour, they may retain some appreciation for physical comedy and slapstick.

I recall a pithy from one of my older professors. He frequently reminded us: “We don’t see things as they are; we see them as we are.” The same can be said of comedy. The meaning your brain attributes to a joke and how you respond to that joke tells a contemplative comic more about you than you may realize.