Hospital Stays for Critical Illness, Infection Linked to Dementia-Related Brain Changes, Study Finds

A study published in the Journal of the American Geriatrics Society suggests hospitalization, critical illness, and major infection can trigger brain structure changes and accelerate cognitive decline, reports Johns Hopkins Magazine . "We believe our study is one of the first to look specifically at how both critical illness and infection might promote brain changes that set the stage for late-life cognitive decline, and serve as independent risk factors for dementia," says Johns Hopkins University's Keenan Walker. The investigators used data from the Atherosclerosis Risk in Communities Study, including magnetic resonance imaging scans showing brain structure, in addition to social, demographic, and hospital information for a large group of participants followed over 24 years. Of the 1,689 participants analyzed, 72 percent were hospitalized, 4 percent had a critical illness, and 14 percent had a major infection. Hospitalization during the follow-up period, regardless of the reason, was tied to 9 percent greater white matter hyperintensity volume and significantly lower integrity of white matter microstructure. Hospitalized participants who had one or more critical illnesses had a 3 percent smaller brain volume in brain regions such as the hippocampus that are implicated in Alzheimer's. Major infection was linked with both smaller brain volume in regions vulnerable to Alzheimer's and 10 percent larger brain ventricle volume.