Concerns about the risks of heading in football just won’t go away. In the past these have focused on the possibility of chronic brain injury, but a recent study from Italy poses a different scenario: that footballers are at increased risk of suffering motor neurone disease (MND), a progressive, incurable and usually fatal degenerative disorder of the nervous system (‘A cause for concern’, Br J Sports Med 2005; 39:249).
In this study, cited in an editorial in the British Journal of Sports Medicine, five diagnosed cases of motor neurone disease (MND) were found in a sub-population of 7,435 players of the top two Italian divisions who were active in the period 1970-2001. Although these numbers were small, they exceeded the statistical likelihood among this population of developing MND, around seven per hundred thousand.
A previous report from the Italian soccer leagues raised similar concerns. A four-year study of every player in Serie A and B between 1960 and 1997 found that eight of 24,000 former players had died from motor neurone disease (MND), while a further follow-up of those who had died or fallen ill since 1997 found 32 more cases.
Motor neurone disease (MND) is known to have claimed a number of former players in England in recent years, including Don Revie, Rob Hindmarch of Derby and Sunderland, Middlesbrough’s Willie Maddren and the former Celtic winger Jimmy Johnstone.
Trauma has long been hypothesised but never proven as a risk factor for motor neurone disease (MND), and the editorial poses the question: could the effect of repeated heading of soccer balls be somehow related to the development of motor neurone disease (MND) in the presence of a genetic predisposition?
The author P McCrory, himself the leader of a recent study on brain injury and heading in football, writes: ‘It would appear that we have some epidemiological evidence of a link between neurotrauma and the development of MND…To date, this evidence is inconclusive and a prospective cohort study is desperately needed…’ Given the low prevalence of motor neurone disease (MND) in the general population, it is unlikely that a definitive answer will be available for many years.