The research is not so much saying that concussion causes Alzheimer’s disease, more that those who are at risk from the condition could see the process accelerated should concussion occupy. This is based on medical cases whereby concussion seems to speed up Alzheimer’s disease-related brain atrophy and cognitive decline in people who have an identified genetic risk for the condition.
The medical cases indicated that moderate and severe traumatic brain injury present a key external (or ‘environmental’) factor for the subsequent development of Alzheimer’s disease. What is less clear is the impact of a mild case of concussion and whether this elevates the risk.
The cases, Medical News Today reports, were drawn from 160 Iraq and Afghanistan war veterans, who were studied by neuroscientists from the Boston University School of Medicine. The studies consisted of magnetic resonance images of the brain, together with physical measurements like the thickness of the brain’s cerebral cortex (measured across seven regions).
The outcomes, according to Professor Jasmeet Hayes, were that the research team “found that having a concussion was associated with lower cortical thickness in brain regions that are the first to be affected in Alzheimer’s disease.”
She added: “Our results suggest that when combined with genetic factors, concussions may be associated with accelerated cortical thickness and memory decline in Alzheimer’s disease relevant areas.”
Being a longitudinal study, some of the cases of concussion related to people aged as young as 32 years; however, the influence of the concussion on later neurodegeneration couldbe tracked across a person’s lifetime. Further research will be required to assess how concussion leads to later neurodegenerative diseases.
The implications of the research are that greater care may be needed with those who have suffered from concussion and who are at risk from developing Alzheimer’s disease. What form such treatment can take is not yet clear. The research has been published in the journal Brain. The paper is headed “Mild traumatic brain injury is associated with reduced cortical thickness in those at risk for Alzheimer’s disease.”