January 25, 2002 – A study in mice highlights the relationship between repeated trauma to the head and the acceleration of the development of Alzheimer’s disease. This study was carried out in particular with the aim of better identifying the consequences of the blows that boxers and American football players can receive to the head.
The researchers found that mice who received repeated blows to the head developed deposits (plaques) of the beta-amyloid protein, characteristic of Alzheimer’s disease, faster than mice without trauma. These deposits therefore seem to appear in response to inflicted injuries.1
The accumulation of this substance around brain cells concentrates in toxic plaques which destroy brain tissue. This degeneration, often detected after 60 years, seems irreversible: the number of nerve cells decreases, which can lead to a 50% reduction in brain weight. For the person affected, this results in memory loss, language problems, disorientation in space and time, etc.,2 leading to a total loss of autonomy.
This study is not the first to associate Alzheimer’s disease with shocks to the head since an analysis was carried out from the medical files of veterans of the Second World War and their health check 50 years plus late. The prevalence of Alzheimer’s disease and other types of dementia was compared in three groups of soldiers who suffered head trauma of different severity. The risk of Alzheimer’s disease or dementia was twice as high as normal for trauma with loss of consciousness or amnesia from 30 minutes to 24 hours and four times for those with loss of consciousness or amnesia of more than 24 hours.3.4
January is Alzheimer’s Disease Awareness Month. For the occasion, the Alzheimer Society of Canada publishes a new document Shared experiences: suggestions for people with Alzheimer’s disease.5 In 2001, there were 238,000 Canadians over the age of 65 with the disease.
Élisabeth Mercader – PasseportSanté.net
According to InteliHealth, January 13, 2002
1. Uryu K, Laurer H, McIntosh T, Pratico D, Martinez D, Leight S, Lee VM, Trojanowski JQ. Repetitive mild brain trauma accelerates Abeta deposition, lipid peroxidation, and cognitive impairment in a transgenic mouse model of Alzheimer amyloidosis. J Neurosci 2002 Jan 15; 22 (2): 446-54.
2. Alzheimer Society. Alzheimer’s disease. Ten warning signs. [Consulté le 24 janvier 2002].http: //www.alzheimer.ca/english/disease/warningsigns.htm
3. Plassman BL, Havlik RJ, Steffens DC, Helms MJ, Newman TN, Drosdick D, Phillips C, Gau BA, Welsh-Bohmer KA, Burke JR, Guralnik JM, Breitner JC. Documented head injury in early adulthood and risk of Alzheimer’s disease and other dementias. Neurology 2000 Oct 24; 55 (8): 1158-66.
4. National Institutes of Health. New Study Links Head Injury, Severity of Injury, with Alzheimer’s Disease. [Consulté le 24 janvier 2002]. http://www.nia.nih.gov/news/pr/2000/1023.htm
5. Alzheimer Society. I have Alzheimer’s disease Shared experiences. [Consulté le 25 janvier 2002]. http://www.alzheimer.ca/french/haveAD/sharedexperiences.htm
