Evidence is accumulating that the pathogenesis of Alzheimer disease (AD) and other neurodegenerative conditions involves mechanisms that operate outside the brain, and new research indicates that peripheral inflammation is an early event in the disease course of both AD and dementia with Lewy bodies (DLB). Eleanor King and co-workers at Newcastle University, UK, measured levels of inflammatory cytokines in plasma samples from 37 patients with DLB, 20 patients with AD, 48 patients with mild cognitive impairment (MCI) — 38 with a DLB profile and 20 with an AD profile — and 20 healthy controls. Levels of the inflammatory markers IL-1β, IL-2, IL-4 and IL-10 were elevated in both of the MCI groups but not in the patients with more-advanced disease. These findings suggest that the prodromal phases of AD and DLB provide a window of opportunity for intervention with anti-inflammatory therapies.