A single serious brain injury can significantly increase the risk of developing Alzheimer’s disease, new research suggests.
Tufts University School of Medicine researchers, writing in the Journal of Neuroscience, determined moderate-to-severe traumatic injury can disrupt proteins in the brain that regulate an enzyme associated with Alzheimer's.
The study, involving experiments in mice and studies of brain samples from Alzheimer's patients, identified the complex mechanisms that result in the rapid increase in that enzyme, BACE1, after an injury. It also points the way to developing new drug treatments that target this mechanism to slow the progression of Alzheimer's disease.
"A moderate-to-severe [injury], or head trauma, is one of the strongest environmental risk factors for Alzheimer's disease,” said lead researcher Kendall Walker, with the Tufts department of neuroscience. “A serious [injury] can lead to a dysfunction in the regulation of the enzyme BACE1 [and cause] elevated levels of amyloid-beta, the key component of brain plaques associated with senility and Alzheimer's disease."
The researchers said they will now seek to confirm their findings by examining the brains of Alzheimer’s patients who were known to have suffered moderate-to-severe traumatic brain injuries before they died.
Such injuries are caused most often by severe falls or motor vehicle accidents. According to the Centers for Disease Control and Prevention, 1.7 million people suffer such injuries each year, with concussions accounting for about 75 percent of them.
Alzheimer's disease currently affects as many as 5.1 million Americans and is the most common cause of dementia in adults age 65 and over.
This study was funded, in part, by the National Institutes of Health and the Cure Alzheimer's Fund.