Some viral infections could cause cognitive decline

Certain chronic viral infections could contribute to cognitive decline in otherwise healthy older adults.

A new study published in the journal Alzheimer’s Disease and Associated Disorders found exposure to cytomegalovirus (CMV), Herpes Simplex Virus type 2 (HSV-2) or Toxoplasma gondii (TOX) is associated with cognitive decline independent of aging.

"Our study is one of the few to assess viral exposure and cognitive functioning measures over a period of time in a group of older adults," says lead investigator Vishwajit Nimgaonkar, MD, PhD, psychiatry professor at the University of Pittsburgh School of Medicine in a university-issued news release. "It’s possible that these viruses, which can linger in the body long after acute infection, are triggering some neurotoxic effects."

CMV is related to the viruses that cause chickenpox and infectious mononucleosis. HSV-2 is genital herpes, a sextually transmitted infection. TOX causes a disease known as toxoplasmosis, which may not manifest symptoms and may not require treatment.

Herpes Simplex virus type 1 which causes cold sores or fever blisters on the mouth and lips, was not found to have a significant effect.

"This is important from a public health perspective, as these infections are very common and several options for prevention and treatment are available," says senior investigator Mary Ganguli, MD, MPH, psychiatry professor at Pitt. "As we learn more about the role that infectious agents play in the brain, we might develop new prevention strategies for cognitive impairment."

The researchers plan to study whether some people are more vulnerable to the effects of chronic viral infection.

Topics: Clinical