Medical Bulletin 23/ December/ 2024

Here are the top health news for the day:

Study Shows How Thalamus May Cause Long-term Disability After Stroke

A recent study from Simon Fraser University researchers has revealed how an overlooked type of indirect brain damage contributes to ongoing disability after a stroke.

The paper, published in Proceedings of the National Academy of Sciences, shows how the thalamus – a sort of central networking hub that regulates functions such as language, memory, attention and movement – is affected months or years after a person has experienced a stroke, even though it was not directly damaged itself. The findings may lead to new therapies that could reduce the burden of chronic stroke, which remains one of the leading causes of disability in the world.

For the study, researchers recorded the brain activity from 18 chronic stroke patients and used computer models to understand how this brain activity reflects abnormal thalamus function when compared to healthy individuals.

By studying the brain activity and anatomy of stroke survivors, SFU researchers say there appears to be a link between the amount of indirect damage suffered to the thalamus and the level of impairment a patient experiences.

Researchers explain that the thalamus communicates widely with the rest of the brain via many long connections, called axons, which makes it susceptible to indirect damage. When axons are injured by stroke in other regions of the brain, the damage can travel along the cell and damage neurons in the thalamus, causing its function to be impaired.

This impairment also has a knock-on effect of disrupting the functions that the now-damaged thalamus would normally regulate in other, undamaged parts of the brain. If certain treatments, such as drugs or brain stimulation, could restore normal function in the thalamus, or mitigate the impact of damage travelling to the thalamus and keep it operating normally, researchers believe some long-term impacts of stroke could be alleviated.

Reference: P.R. Johnston, J.D. Griffiths, L. Rokos, A.R. McIntosh, J.A. Meltzer, Secondary thalamic dysfunction underlies abnormal large-scale neural dynamics in chronic stroke, Proc. Natl. Acad. Sci. U.S.A., 121 (46) e2409345121,

https://doi.org/10.1073/pnas.2409345121 (2024).

Recommendations to Ensure Safe and Effective Use of Medical AI

A new set of recommendations published in The Lancet Digital Health and NEJM AI aims to help improve the way datasets are used to build Artificial intelligence (AI) health technologies and reduce the risk of potential AI bias.

An international initiative called ‘STANDING Together (STANdards for data Diversity, INclusivity and Generalisability)’ has published recommendations as part of a research study involving more than 350 experts from 58 countries. These recommendations aim to ensure that medical AI can be safe and effective for everyone. They cover many factors which can contribute to AI bias, including:

• Encouraging medical AI to be developed using appropriate healthcare datasets that properly represent everyone in society, including minoritised and underserved groups;

• Helping anyone who publishes healthcare datasets to identify any biases or limitations in the data;

• Enabling those developing medical AI technologies to assess whether a dataset is suitable for their purposes;

• Defining how AI technologies should be tested to identify if they are biased, and so work less well in certain people.

The STANDING Together recommendations aim to ensure that the datasets used to train and test medical AI systems represent the full diversity of the people that the technology will be used for. This is because AI systems often work less well for people who aren’t properly represented in datasets. People who are in minority groups are particularly likely to be under-represented in datasets, so may be disproportionately affected by AI bias. Guidance is also given on how to identify those who may be harmed when medical AI systems are used, allowing this risk to be reduced.

Reference: Tackling algorithmic bias and promoting transparency in health datasets: the STANDING Together consensus recommendations, Alderman, Joseph E et al.The Lancet Digital Health, Volume 0, Issue 0

Can Moderate Amount of Wine Lower Risk of Serious Cardiovascular Disease?

Drinking a small or moderate amount of wine may lower the risk of serious cardiovascular disease in people at a higher risk who are following a Mediterranean diet, according to research published in the European Heart Journal.

The new research is part of a larger Spanish study investigating the effect of a Mediterranean diet on people with a higher risk of developing cardiovascular disease. All the people taking part had no cardiovascular disease at the start of the study, but they either had type-2 diabetes, or they had a combination of cardiovascular disease risk factors such as smoking, high blood pressure, high cholesterol, being overweight and/or a family history of cardiovascular disease.

As well as completing questionnaires about what they ate and drank, participants gave urine samples at the beginning of the study and after a year of following a Mediterranean diet. To investigate the effect of drinking wine, researchers included a total of 1,232 participants. Participants were followed up for four to five years and during that time, there were 685 cases of cardiovascular disease during the study.

In this group of people at high risk of cardiovascular disease who were following a Mediterranean diet, researchers found that the risk of developing a cardiovascular event was reduced by 50% in light-to-moderate wine drinkers, defined as consuming half to one glass of wine per day, compared to those drinking very little or no wine. Light drinking (between one glass per week and less than half a glass per day) reduced cardiovascular risk by 38%. However, this protective effect disappears in people who drank more than one glass per day.

The researchers took account of other factors that are known to influence the risk of cardiovascular disease, but they acknowledge that the design of the study means it can only show a link between drinking wine and cardiovascular events, and other factors cannot be ruled out.

Reference: Inés Domínguez-López, Rosa M Lamuela-Raventós, Cristina Razquin, Camila Arancibia-Riveros, Polina Galkina, Jordi Salas-Salvadó, Ángel M Alonso-Gómez, Montserrat Fitó, Miquel Fiol, José Lapetra, Enrique Gómez-Gracia, José V Sorlí, Miguel Ruiz-Canela, Olga Castañer, Liming Liang, Lluis Serra-Majem, Frank B Hu, Emilio Ros, Miguel Ángel Martínez-González, Ramon Estruch, Urinary tartaric acid as a biomarker of wine consumption and cardiovascular risk: the PREDIMED trial, European Heart Journal, 2024;, ehae804, https://doi.org/10.1093/eurheartj/ehae804

Improvements in Education, Nutrition and Sanitation Combat Age Related Declines: Study Finds

A new study from the Robert N. Butler Columbia Aging Center at the Mailman School of Public Health reveals significant improvements in the health of older adults in England when compared to previous generations. Rather than considering health through the presence or absence of disease, the study, published in Nature Aging, applied a new approach that examined trends in people’s functioning – their cognitive, locomotor, psychological, and sensory capacities.

Using data from the English Longitudinal Study of Aging, the study found that older adults today experience higher levels of physical and mental functioning than previous generations did at the same age.

“These improvements were large,” said John Beard, MBBS, PhD, Irene Diamond Professor of Aging in Health Policy and Management in the Butler Columbia Aging Center of Columbia University Mailman School of Public Health and author of the study. For example, a 68-year-old born in 1950 had a similar capacity to a 62-year-old born a decade earlier, and those born in 1940 had better functioning than those born in 1930 or 1920. Beard noted, “If we had compared someone born in 1950 with someone born in 1920, we would have likely observed even greater improvements.”

Beard says that improvements in education, nutrition, and sanitation over the course of the twentieth century are likely to have played a key role. Medical advances—such as joint replacements and better treatments for chronic conditions—were also likely to be contributing factors. The researchers caution, however, that their observations are for a specific period and in a single country. The same trends may not have been seen in the US, or across the whole of the population.

“We were surprised by just how large these improvements were, particularly when comparing people born after World War Two with earlier-born groups.” said Beard. “But there is nothing to say we will continue to see the same improvements moving forward, and changes such as the increasing prevalence of obesity may even see these trends reverse. It is also likely that more advantaged groups will have experienced greater gains than others. But overall, the trends were very strong and suggest that, for many people, 70 really may be the new 60.”

Reference: https://www.publichealth.columbia.edu/news/study-finds-slowing-age-related-declines-older-adults