The common cold you had last week could contribute to memory loss later in life.
Credit: iStockphoto
WASHINGTON: Central nervous system infections such as the common cold could be linked to memory loss late in life, according to a new study.
"Our study suggests that virus-induced memory loss could accumulate over the lifetime of an individual and eventually lead to clinical cognitive memory deficits," said Charles Howe, a Mayo Clinic neuroscientist and an author of the study, which is published in the international journal Neurobiology of Disease.
The family of viruses known as picornaviruses are the most common infectious agents in humans, infecting more than one billion people worldwide each year.
Most people have two to three infections a year caused by enteroviruses (associated with respiratory and gastro-intestinal ailments) or rhinoviruses (associated with the common cold). Picornaviruses also cause encephalitis, meningitis, polio and hepatitis A.
Scientists at the Mayo Clinic studied the link between picornaviruses and memory loss by infecting mice and observing their spatial memory as they navigated a maze.
"The degree of memory impairment, which ranged from no discernible damage to complete devastation, was directly correlated to the number of dead brain cells in the hippocampus of the mouse's brain," according to the researchers.
"The degree of brain damage in humans infected with a picornavirus infection is not known, but the evidence from the mouse study suggests this is an area of research that should be explored further," they said.
Among children infected with enterovirus 71 in Asia, the virus has been seen to attack the brain, leading to conditions from lethargy to coma, said the researchers.
"Our findings suggest that picornavirus infections throughout the lifetime of an individual may chip away at the cognitive reserve, increasing the likelihood of detectable cognitive impairment as the individual ages," the authors wrote.
"We hypothesize that mild memory and cognitive impairments of unknown etiology may, in fact, be due to accumulative loss of hippocampus function caused by repeated infection with common and widespread neurovirulent picornaviruses."
