Funtabulously Frivolous Friday Five 068

• Charles Bonnet Syndrome
• According to whonamedit.com:

“Charles Bonnet in 1760 described vivid, complex visual hallucinations in his psychologically normal 87 year old grandfather, who had cataract operations on both eyes and was practically blind. His grandfather saw pictures of men, women, birds, carriages, buildings, tapestries and scaffolding patterns.”

• Afflicted patients vary from being indifferent to be being quite disturbed by the syndrome. Treatment is not well defined, though some suggest the use of SSRIs, and in most patients the perceptual disturbances resolve after a year or two. The condition is common — with a reported prevalence of 17.% in Australia!
• Watch the video to see and hear Oliver Sacks talking about the syndrome at TED:

• Lead poisoning — confirmed by the very high lead content of his bones, which suggested repeated exposure over a period of time.
• Pope Clement II was only pope for 9 months before he died. Surely the fact that he banned the sale of official positions had nothing to do with his death? He was replaced by the reinstated Pope Benedict IX.
• His poisoning could have been accidental — until it was later outlawed, lead oxide was used as sweetener in German wine. However, given the political climate of the time deliberate repeated poisoning is more likely.

Reference: Emsley, J. The Elements of Murder, Oxford University Press, 2005.

• This is Avogadro’s number.
• Avogadro’s number is the number of atoms in 12g of the isotope carbon-12. This can be generalised to any elemental substance, as a mole of any elemental substance has the exact same number of atoms (Avogadro constant).
• It’s a big number that is hard to conceive — if you had 24 consecutively numbered balls in a bag and randomly took one out at a time, the chance of you getting them out in numerical order is about 1 in Avogadro’s number!
• Amedeo Avogadro proposed his law in 1811 — Avogadro’s law states that the volume of a gas (at a given pressure and temperature) is proportional to the number of atoms or molecules regardless of the nature of the gas. Later, in 1909, Jean Perrin experimentally determined the value of Avogadro’s constant, and named it in Amedeo’s honour.

• Lassa fever
• All 3 conditions are feared viral hemorrhagic fevers but Lassa fever has the lowest case fatality rate (1-2%, compared to 65-88% for Ebola and 15-70% for CCHF).
• Lassa fever is endemic to West Africa, transmitted via the excrement of infected animals (usually rodents), and causes malaise, conjunctival injection, mucosal bleeding, gastrointenstinal symptoms and multi-organ dysfunction. It can be treated with ribavirn in addition to supportive care.

Reference: Cunha, BA. Infectious diseases in Critical Care Medicine (3rd edition), Informa Healthcare, 2010.

• The Northern Territory.
• Recent cases of ulceroglandular tularemia (aka type B tularemia) were reported in Tasmania and there have been claims (such as this in the Lancet) that they are a first for the southern hemisphere. However, the causative organism was first isolated from a foot wound in the Northern Territory and reported way back in 2003.

• The subspecies of F. tularensis that causes the more lethal type A tularemia is only found in North America.
• Reference: ProMED-mail.