This blog is part of the ‘Highlights from Glasgow’ collection of articles, where you can read about the content of some of the talks and posters presented at the 29th International Symposium on ALS/MND.
In the Epidemiology session (5C), several talks focused on the risk associated with various lifetime events, and the demographics of people who develop MND categorised by onset at various body regions. Susan Peters (C37) and her colleagues studied a group of 1,500 people with MND and 3,000 control participants, and found that people who had suffered head trauma after the age of 55 had an increased risk of developing the disease compared to those without this type trauma. They further found reduced risk in people currently/recently taking antihypertensive and cholesterol-lowering medication, but this risk was significantly increased in people who were taking these medications earlier in life. These findings now need to be explored further to investigate the underlying mechanisms that would explain these differences.
Adriano Chio (C39) presented his data on the development of different motor variants within MND (e.g. bulbar, flail arm, upper motor neurone), and how these are likely to be driven by various mechanisms, depending on factors such as age, sex, and genetics. For example, his findings show that the bulbar variant of MND is more often observed in older age groups (especially over 80 years of age), females, and those with the C9ORF72 genetic variation. The fact that different variants of the disease can be dependent on specific factors proposes that the disease mechanisms might vary across people living with MND.
We have also heard from Jane Parkin Kullmann (C40) who discussed her study looking into the impact of psychological stress using a newly-developed questionnaire ALS-Quest, which asked 850 people about any potentially stressful life events. While the findings did not show any impact of stress on the development of MND, people with the disease were found to be more resilient compared to healthy controls, showing their increased ability to respond to life stressors. The reasons for this association now need to be looked at further, as resilience is thought to be linked to biological, social, and environmental factors.
In the final talk of the Symposium, Pamela Shaw (C109) took us through the anecdotal reports and studies looking at the connection between physical activity and MND, highlighting that the evidence has been quite conflicting. In one study, increased physical activity in adulthood (such as daily 20min jog) was associated with increase odds of developing MND, which was also confirmed by other studies. Other studies, however, failed to find such association and in some, reduction of risk was observed instead. Professor Shaw concluded by saying that physical activity may amplify the disease mechanisms known to contribute to the development of MND, however, this might only be the case in people who are more susceptible, with genetics playing an important role. Therefore, while for some people exercise will not lead to MND, those with a specific genetic variation might be more likely to develop the disease following increased exposure to physical activity. Further work will now focus on the interaction between environmental and genetic factors to confirm this theory.
Further research studies were presented in the poster session, where Jane Parkin Kullmann (EPI-09) and her team found that exposure to mercury from eating seafood or from having dental fillings containing mercury did not increase risk of developing MND, and any associated link could be due to other sources of exposure or due to increased susceptibility to mercury toxicity in some people.
You can read abstracts of other poster presentations that focused on Epidemiology online.
Find out more about the topics discussed in Glasgow on our Periodic table of Symposium at www.mndassociation.org/symplive.
