Dementia link not yet proven

An Otago academic leading a study into head impact detection in rugby says more evidence is needed to firmly establish a link between concussion and dementia.

University of Otago Associate Prof Melanie Bussey said it was ‘‘early days’’ in the understanding of the ‘‘mechanisms of dementia and concussion’’.

‘‘We are scratching the tip of the iceberg in our understanding of these connections and at the moment the evidence of the connection isn’t definitive, which is why we are trying to do as much research as possible.’’

Prof Bussey, who is an associate professor in biomechanics and director of the motion analysis research lab in the School of Physical Education, was contacted for comment following news former All Blacks and Highlanders prop Carl Hayman has been diagnosed with early onset dementia and chronic traumatic encephalopathy (CTE) at the age of 41.

Hayman has joined the lawsuit against World Rugby being prepared on behalf of more than 100 players who argue the governing body has failed to protect them.

‘‘While there is evidence of a link there, it is just so early in our understanding.

‘‘The problem we have [is that] up until very recently the only way to diagnose this connection between CTE was after death, so obviously the sample that has been used to study it is very small and very specific to people who already had symptoms.

‘‘It is a really difficult thing to study.’’

Prof Bussey is leading the University of Otago study into head impact detection in collaboration with World Rugby, New Zealand Rugby and Otago Rugby.

The study has collected data from about 40,000 head impacts from more than 600 players from all levels of rugby who were wearing impact-monitoring mouthguards.

‘‘Our goal is to get some information to help World Rugby make informed decisions around player welfare and what they can improve about the game in terms of reducing the risks of head impact for players.’’

The first results are expected to be available in the first quarter of next year.

Prof Bussey said despite the study being linked to World Rugby, ‘‘we are following the data wherever it takes us’’ and the study would be published no matter the results.