People at increased risk of MND might be the human equivalent of high performance cars – built for speed and agility but becoming unreliable once they reach a high mileage.
There is much anecdotal evidence amongst MND clinicians and those affected by the disease that people who develop MND tend to have been relatively physically fit before their diagnosis, often having been involved in various athletic pursuits throughout their life. This prompted MND Association-funded researcher Dr Martin Turner to ask the intriguing question: Is an athletic physique an outward sign of a subtle predisposition to MND? But how could he make a sensible measurement of ‘athletic physique’ in order to answer such a question? Or as he put it in his presentation on Thursday morning, do people with MND have motor system run to death, or is it a motor system born to run?
A pragmatic way of looking at this was to look at the history of coronary heart disease and whether this is linked to a likelihood of developing MND later in life. Dr Turner has recently published this study in the Journal of Neurology, Neurosurgery and Psychiatry). Through very careful examination of hospital medical records, he and his colleagues compared numbers of MND cases in over a hundred thousand people with a history of coronary heart disease to an even larger group with no known heart problems.
The study did reveal a slightly increased occurrence of MND in the group with healthy hearts, providing indirect evidence that MND is more likely to occur in people with greater levels of ‘fitness’. Dr Turner’s results were in fact corroborated by the findings of another more general study of lifestyle and environmental factors presented in the same session. Dr Marc Huisman’s meticulously executed and much admired questionnaire-based study of the Dutch population also suggested that people with MND were less likely to have relatives with heart disease, indicating a more genetically robust cardiovascular system, amongst many other findings.
Dr Turner’s findings are intriguing but there is still plenty more work to do and many questions are left unanswered. There are other studies that support the possibility of an increased MND risk in people with a healthy cardiovascular system and lean build but of course these two characteristics are also a result of undertaking higher levels of exercise – the question of whether exercise itself contributes to MND still won’t go away. However, Dr Turner’s work supports the concept that if you’re born with a natural leaning towards athletic prowess, you may excel at sport (or in evolutionary terms, hunting down your dinner) but your nervous system wiring may also be more vulnerable to MND as you age – a factor that’s only become problematic with the dramatic increases in life expectancy that have come about in the last couple of hundred years.
As Dr Turner put it at one our spring conferences this year, people with MND may well come from amongst the Ferraris of the human race. With clearer identification of risk factors, prevention of MND becomes a more realistic possibility. It may be that in future the Ferraris can undertake a specialised servicing schedule to ensure they have a greater chance of breaking the 100,000 mile barrier with their electrics in good working order!
Read our official press release on day two of the symposium.