Darwin's illness and other Christmas tales from BMJ
Despite his contributions to sciences, Charles Darwin -- born 200 years ago -- was a very sick individual. During his voyages on the HMS Beagle, he was incapacitated by seasickness most of the time. Even on land, he suffered a variety of symptoms, including nausea, vomiting, intermittent abdominal pain, weakness and lethargy, headache, dizziness, visual disturbances, "inordinate flatulence" and diarrhea. At times, he was so disabled by his illness that he became a virtual recluse. Scholars have attributed these symptoms to a variety of disorders, both mental and physical, but a reexamination suggests that the evolution pioneer suffered from a genetic disorder known as cyclical vomiting syndrome, Dr. John A. Hayman of Monash University in Melbourne, Australia, reports today in the BMJ, formerly the British Medical Journal.
The report is one of several odd but interesting tidbits that the journal editors collect through the course of the year, then publish in their annual Christmas issue. Others in this issue include the futility of listening to "Nellie the Elephant" during CPR training, an unusual relationship between diastolic and systolic blood pressures in healthy people, and perceived age as a predictive marker for aging.
Scholars examining Darwin's life have speculated that he might have suffered such psychological conditions as hypochondria, panic disorders, "repressed anger toward his father" and guilt over his rejection of his early religious beliefs. Potential physical explanations include a middle ear infection, arsenic poisoning and a tropical parasitic disease. But Hayman noted that all of these can be rejected for good cause. His symptoms began before he was exposed to any tropical parasites, for example, he never suffered deafness or tinnitus (which would have been associated with a middle ear infection) and he never received sufficient arsenic-containing drugs to cause the symptoms. The illness was present for 50 years and eased in his old age. Darwin died at age 73 from heart problems, but an autopsy showed no internal physical abnormalities. Despite the illness, he fathered not only the modern theory of evolution, but also 10 healthy children, all conceived during his ill health.
The best explanation for all his symptoms, Hayman said, is cyclical vomiting syndrome, or CVS, which is caused by a mutation in a gene called MTTL1 in mitochondrial DNA. The disease "is neither well-known nor well-recognized," he wrote, but is related to classical migraine without an aura. It is primarily a disease of children, but it may persist into adulthood or appear for the first time in adulthood. People with the disorder experience abdominal, circulatory and cerebral symptoms, including headaches and anxiety.
In addition to the match in symptoms, research shows that Darwin's mother, Susannah, suffered vomiting and boils and motion sickness as a child, as well as excessive sickness during pregnancies. She died with abdominal pain when Charles was 8. Her younger brother, Tom, had similar symptoms, and a sister, Sarah, said that Tom and Charles had the same illness. That is consistent with a mitochondrial genetic defect, which is passed down through the maternal line.
Cardiopulmonary resuscitation or CPR is a lifesaving technique. Studies have shown that CPR initiated by bystanders to heart attack victims in the minute or two before paramedics arrive can double survival rates from 21% to 43%. Although it appears simple, however, many people taught CPR quickly forget what to do. Studies have shown that as little as two weeks after training, only about 40% of students remember how to perform it.
One technique to get users to remember how to perform CPR is to set it to music. A previous small study has shown that the BeeGees song "Stayin' Alive" is about 100 beats per minute, which is the correct timing for CPR if chest compression is performed on the beat. That study has not been followed up, however.
A team at the Birmingham University School of Medicine in England attempted to teach CPR to 130 volunteers using either a common nursery rhyme called "Nellie the Elephant," K.C. & the Sunshine Band's "That's the Way (I Like It)" or no music. Listening to "Nellie" significantly increased the number of volunteers who applied compressions at the proper rate of close to 100 per minute (32%), compared with 9% for "That's the Way" and 12% for no music. Unfortunately, it also increased the proportion of compressions that were too shallow, meaning the effort did not force air to be expelled form the lungs. Listening to either song could not be recommended, they concluded.
Further research would be useful, they also said. Songs that might be considered include Queen's "Another One Bites the Dust," the Backstreet Boys' "Quit Playing Games (With My Heart)" and, for those with a country bent, Billy Ray Cyrus' "Achy Breaky Heart."
The golden ratio is a principle found widely in nature and in architecture, one that is believed to be especially pleasing to the eye. Two quantities are said to be in the golden ratio when the ratio between their sum and the larger one is the same as that between the larger and the smaller. That ratio, called by the Greek letter phi, is 1.6180339887.... The Italian mathematician Leonardo Pisano, called Fibonacci, discovered a mathematical sequence from which phi can be calculated.
Examples of phi in nature include leaf branches, the florets in a cauliflower head and the face of George Clooney. In architecture, phi is found in the proportions of the Notre Dame Cathedral in Paris, the Parthenon in Athens and the works of Le Corbusier.
Statistician Hanno Ulmer of the Innsbruck Medical University in Austria and his colleagues decided to look for phi in blood pressures. They examined 377 people in a primary care group in the far west of Austria who had been offered routine screening for at least two decades. They found that the ratio of systolic to diastolic blood pressures in those who survived the entire 20 years had a mean of 1.618, virtually identical to phi, and those who died had a mean ratio of 1.7459.
"This finding suggests that blood pressure values in 'well' individuals, but not in those who are at risk of dying, exhibit the golden ratio," they wrote. They also concluded, however, that this discovery is unlikely to be of clinical value for individual patients.
And finally, a team led by Dr. Kaare Christensen of the University of Southern Denmark studied how perceived age correlates with lifespan. They studied 1,826 Danish twins whose physical health was monitored. Photographs of the twins were shown to a panel of 20 female geriatric nurses, 10 male student teachers, and 11 older women, who evaluated their perceived age. The survival of the twins was then monitored for seven years. The team concluded that the member of each twin set who looked older was more likely to die first. They speculated that perceived age is a good general indication of a patient's overall health.
-- Thomas H. Maugh II
Photos: Top, Charles Darwin. Middle, the BeeGees' "Stayin' Alive" is sometimes used to time CPR compressions; credit: Lennox McLendon / Associated Press. Bottom, George Clooney's facial proportions exhibit the golden ratio, explaining why he is generally viewed as handsome; credit: Jason Merrit / Getty Images.