Risk factors in MND
What causes MND is the biggest and possibly one of the most frequently asked questions we are asked about research. Scientists believe that
sporadic MND is likely to be caused by many small contributory risk factors, including subtle
genetic and environmental influences, that in combination may tip the balance towards someone developing the disease.
Lifestyle & environment
The field of research investigating the environmental and lifestyle causes of disease is known as epidemiology. Exposure to environmental factors that might contribute to the development of sporadic MND has been extensively studied over the years. These studies have identified possible links with prior exposure to mechanical and/or electrical trauma, military service, high levels of exercise, agricultural chemicals and variety of heavy metals. However, the evidence obtained in these studies has often been circumstantial or conflicting and there are no clear conclusions. With such limited information it is not possible to provide advice or guidance to reduce the risk of developing MND.
Research news on the epidemiology of MND:
Epidemiology of MND
Generally, epidemiology research is approached from two points of view:-
Firstly where a possible risk factor has been identified; a larger, more rigorous study would be conducted to explore this risk (an example of such an approach would be the Italian footballers study mentioned in the
15th International Symposium Highlights (373kb) ).
The second point of view is looking at a distinct group of people or population where a higher than expected number of people developed MND than could be accounted for by chance (a "cluster"). The high incidence of the MND-like condition ALS-PDC on the the South Pacific island of Guam is a good example (see
Highlights of the 17th International Symposium (818 kb) ).
In the second type of study, it is necessary to establish that the numbers of people affected really are higher than can be accounted for by chance, before explanations can be explored.