In cases of cysticercosis, seizures and other symptoms occur in persons wit
h only calcified brain lesions. The presence of perilesional edema has been
documented in association with calcified lesions in symptomatic patients,
but the frequency of this complication and characteristics of the patients
who develop it are not known. Patients in Peru and the United States with n
eurocysticercosis, documented by positive results of serological testing an
d with only calcified lesions as shown using computerized tomography, were
studied using magnetic resonance imaging. Perilesional edema was observed i
n slightly more than one-third of the patients, and some patients had frequ
ent, severely disabling episodes. Those with an increased proportion of enh
ancing calcified lesions were more likely to show perilesional edema. Edema
around calcified lesions is common in this population and is associated wi
th seizures and neurological morbidity.