Contralateral migration of cerebral sparganosis through the splenium

Even though it has been known for some time that the cerebral sparganosis could migrate to the contralateral hemisphere, there have been no reports which described the route of migration. This paper reports a case of cerebral sparganosis which migrated from the right temporo-occipital lobe to the contralateral temporo-occipital lobe though the splenium over a period of 3 years. A 24-year-old man visited our hospital complaining of headache for about a month. Three years ago, non-contrast MRI had been performed in a local hospital, and the major finding was cortical atrophy and ventricular dilatation in the right temporo-occipital lobe area, which were compatible with cerebral sparganosis. After admission to our hospital, we performed MRI which showed a 2 cm-sized well-enhanced mass in the left temporo-occipital area. The findings of the right side were similar to the MRI checked 3 years ago. The presence of multiple calcifications and small enhanced lesions on the right side also indicated that the old lesion had been a cerebral sparganosis. The most important finding was that the FLAIR image showed that the entire splenium had high signal intensity which linked the high signal areas of both hemispheres. The patient underwent surgery with the guidance of neuronavigation. The mass was well-capsulated, and removed totally in an en bloc fashion. After opening the capsule, we found a long worm which showed the shape of a whole lava but no movement. The histopathological diagnosis was sparganosis.