To the Editor: We have two areas of concern about the data on cysticercosis presented by Vazquez and Sotelo (Sept. 3 issue).1 First, the findings they report for groups 1 and 2 (patients with lesions without inflammation) are inconsistent with other data on the pathogenesis and natural history of the disease. Cysts within the brain parenchyma have a limited life expectancy. From natural-history studies among British expatriates who have spent a limited time in an area of endemic disease, we know that an asymptomatic interval (mean, 4.8 years) precedes symptomatic disease.2 This asymptomatic period corresponds to the expected life span… © 1992, Massachusetts Medical Society. All rights reserved.