Long-term follow-up of neurocysticercosis - Changes in computed tomographic and magnetic resonance imaging findings compared with results of enzyme-linked immunosorbent assay

Purpose: To describe the changes in computed tomographic (CT) and magnetic resonance imaging (MRI) studies of neurocysticercosis during long-term follow-up (more than 5 years), and to correlate the imaging findings with results of serologic enzyme-linked immunosorbent assay (ELISA) for cysticercosis. Methods: Ten patients with neurocysticercosis were included in this study. Each had undergone follow-up CT/MRI and ELISA more than three times over a period of 5 years. Patients received treatment with anti-helminthic drugs and steroids, with or without ventriculoperitoneal shunting during the follow-up period. Duration of the followup period ranged from 5 to 10 years (mean 8.4 years); in 9 patients the follow-up period was longer than 7 years. Changes in CT/MRI staging of lesions (designated as the vesicular, colloidal vesicular, granular nodular, and nodular calcified stages by the Escobar classification) were correlated with results of ELISA in serum and cerebrospinal fluid (CSF). In addition, the presence or absence of recurrence was evaluated retrospectively. Results: In six patients, all lesions had changed to non-enhancing calcified nodules on the last CT/MRI study (i.e., in 5 to 10 years). In 4 patients the lesions remained in various stages at the final CT/MRI studies. The time interval required for change from vesicular or colloidal vesicular stage to calcified nodular stage ranged from 1.3 to 8.5 years (mean 3.7 years). New vesicular lesions developed over a period of 6 to 8 years in two patients. Results ELISA had correlated significantly with CT/MRI staging. Conclusion: Lesions of neurocysticercosis may remain in an active stage for more than 5 years. New lesions may develop despite medical and surgical management. CT/MRI staging correlates well with results of ELISA.