Persistent MR contrast enhancement of calcified neurocysticercosis lesions.

PURPOSE We sought to determine whether cysticercosis lesions in the brain continue to enhance after nodular involution and complete calcification, and to investigate the clinical significance of this finding with respect to seizure recurrence after cysticidal treatment.

METHODS Serial contrast-enhanced MR images were obtained in all patients with neurocysticercosis seen at our hospital over a 6-year period (1991-1997). From this group, all patients with nodular calcified lesions were selected for study.

RESULTS Sixteen of 29 patients with neurocysticercosis had nodular calcified lesions. Six of these 16 had rim enhancement of nodular calcified lesions for at least 1 year after imaging evidence of complete calcification. Three of these six patients with enhancing, calcified lesions continued to experience seizures. Three of the 10 patients without enhancement also continued to have seizures.

CONCLUSION Contrary to the literature, which states that enhancement and disease activity cease with calcification, six (38%) of 16 patients had lesions that continued to enhance after complete calcification. This abnormality may be a risk factor for posttreatment seizures or may suggest eventual resorption of the calcified lesion.