Intended for healthcare professionals

Minerva

Aneurysm analysis . . . and other stories

BMJ 2021; 372 doi: https://doi.org/10.1136/bmj.n400 (Published 18 February 2021) Cite this as: BMJ 2021;372:n400

Intracranial aneurysms

A French study collected data on 2500 patients with intracranial aneurysms. The researchers then compared the characteristics of unruptured aneurysms that had been discovered incidentally with ruptured aneurysms discovered during investigation for intracranial haemorrhage. On average, people with ruptured aneurysms were older and their aneurysms were larger and more likely to be located in the posterior cerebral circulation (Neurol Neurosurg Psych doi:10.1136/jnnp-2020-324371). Rather surprisingly, systemic hypertension wasn’t associated with rupture.

Disinfecting surfaces

It’s now clear that transmission of coronavirus SARS-CoV-2 is predominantly airborne. Under some conditions, the virus can survive on surfaces but spread by fomites seems to be rare (https://www.thelancet.com/pdfs/journals/laninf/PIIS1473-3099(20)30561-2.pdf). An editorial in Nature asks why public health agencies continue to emphasise that surfaces pose a threat and require frequent disinfection (https://www.nature.com/articles/d41586-021-00277-8). It’s surely time to update this advice and prioritise more effective ways of preventing the virus spreading.

Brown fat

White fat stores excess energy. Brown fat, on the other hand, is thermogenic and dissipates energy as heat. Brown fat is present in only a minority of humans but, according to a retrospective study of 50 000 patients who had positron emission scanning during diagnosis and treatment of cancer, it confers a metabolic advantage. Around 10% of patients had brown fat deposits, mainly in a supraclavicular or cervical location. Compared with those without brown fat they were less likely to have type 2 diabetes, dyslipidemia, cardiovascular disease, or hypertension (Nat Med doi:10.1038/s41591-020-1126-7).

Working outdoors

A case-control study from Denmark compared the occupational histories of 40 000 women with breast cancer with those of randomly selected women of the same age without cancer. Women older than 50 who had worked outside for 20 years or more had a slightly lower risk of breast cancer (Occup Env Med doi:10.1136/oemed-2020-107125). The investigators wonder if outdoor workers were exposed to more sunlight, boosting their levels of vitamin D and protecting them against the disease.

Vision influences hearing

Biphasic movements of the hand in time with the rhythms of speech—beat gestures—are a feature of many languages across the world. Experiments show that they influence the perception of lexical stress which, in turn, influences the vowel sounds that listeners hear. Rather like lip movements, beat gestures aid the interpretation of speech. They are part of the reason why face-to-face communication is less vulnerable to error than telephone conversations (Proc Royal Soc B doi:10.1098/rspb.2020.2419).

Vaccination

In the 18th century, it was folk knowledge that milkmaids rarely suffered smallpox. The Gloucestershire physician Edward Jenner took this observation a step further by inoculating a young boy with pus from a cowpox sore. However, the history of vaccination begins much earlier. Long before Jenner, precursors of vaccination such as variolation had been in use in many countries including Denmark, Switzerland, and Poland. And the Chinese had been blowing dried, ground-up smallpox material up the nose for centuries (https://www.lrb.co.uk/the-paper/v43/n03/steven-shapin/a-pox-on-the-poor).