Cerebral sparganosis in children: epidemiological, clinical and MR imaging characteristics

Abstract

Background: Cerebral sparganosis in children is an extremely rare disease of central nervous system, and caused by a tapeworm larva from the genus of Spirometra. In this study, we discussed and summarized epidemiological, clinical and MR imaging characteristics of eighteen children with cerebral sparganosis for a better diagnosis and treatment of the disease.

Methods: Eighteen children with cerebral sparganosis verified by pathology, serological tests and MR presentations were retrospectively investigated, and the epidemiologic and clinical characteristics of the disease were studied.

Results: Twenty-seven lesions were found in the eighteen children. Twelve lesions in twelve patients were solitary while the lesions in the rest six patients were multiple and asymmetrical. The positions of the lesions were: seven in frontal, eleven in parietal, four in temporal and two in occipital lobes, one in basal ganglia, one in cerebella hemisphere and one in pons. The lesions were presented as slight hypointensity on T1-weighted images but moderate hyperintensity on T2-weighted images with perilesional brain parenchyma edema. Enhanced MR scans by using Gadopentetic Acid Dimeglumine Salt were performed in the patients, and the images demonstrated abnormal enhancements with the patterns of a peripheral ring, or a tortuous beaded, or a serpiginous tubular shape. Follow-up MR scans were preformed for eight patients, and three out of the eight cases exposed migrations and changes in shapes of the lesion areas.

Conclusions: The MR presentations in our study in general were similar to those in previous studies. However serpiginous tubular and comma-shaped enhancements of lesions have not been previously reported. The enhanced MR imaging and follow-up MR scans with the positive results from serological tests are the most important methods for the clinical diagnosis of cerebral sparganosis in children.

Figure 1

MR images for the case 2. A. The T1W image shows there is an irregular large patchy area of hypointensity in the right parietal lobe. B. The T2W image shows there is a serpiginous tubular hyperintense lesion (Black arrow) with a perilesional large patchy irregular edema (White arrow) in the right parietal lobe. The edema shows low signal on the T1W image and high signal on the T2W image. C and D. The enhanced T1W images show a serpiginous tubular enhancement for the lesion.

Figure 2

MR images for the case 8. A. The T1W image shows there are two white matter irregular patchy with hypointensity in the parietal lobes. B. The T2W images shows there are two white matter irregular patchy with hyperintensity in the parietal lobes. C and D. The enhanced T1W images show a beaded enhancement for the lesion. E and F. The images from the MR follow-up scans after 5 months shows the location and shape for the enhancing lesion was changed (C and E).

Figure 3

MR images for the case 12. A. The T2W image shows there is a serpiginous shape with inhomogeneous slight hyperintensity (Black arrow) in the left parietal lobe including mainly white matter area. Irregular large patchy edema can be seen in the perilesional parenchyma (White arrow) which is high signal on the T2W image. B. The enhanced T1W image shows a serpiginous tubular enhanced lesion with a diameter of 6.1 cm (which is the longest in the study). C. The enhanced T1W image from the MR follow-up after 7 months shows change in location and shape for the enhanced lesion. The lesion area was slightly moved medially and posteriorly, and appears as a comma shaped and ring enhancement. D. After the surgery, the worm was still alive, and its length was 13 cm.

Figure 4

MRI images for the case 15 in the three-month follow-up. A. The T1W image shows there is an irregular large patchy area with hypointensity in the left parietal lobe including white matter, gray-white matter junction, and gray mater areas. Parenchymal atrophy was seen as decrease in the size of ipsilateral gyrus and sulcus, but increase in the size of corresponding fissures of the lesion and the left ventricle. B. The T2W image shows there is an irregular large patchy area with hyperintensity in the left parietal lobe including white matter, gray-white matter junction, and gray mater areas. Atrophy of parenchyma is seen as the same as seen in the T1W image. C. The enhanced T1W image shows a few beaded enhancing lesions. D. The MRA slice shows decrease in the size and number of the branches in the left posterior artery.

Figure 5

MRI images for the case 9. A. The T1W image shows there is an irregular large patchy area with hypointensity in the right parietal lobe including white matter, gray-white matter junction, and gray mater areas. B. The T2W image shows there is an irregular large patchy area with hypointensity (Black arrow) in the right parietal lobe including white matter, gray-white matter junction, and gray mater areas. Large patchy areas of the edema was seen in the area surrounding the lesion (White arrow). The edema on a T1W image appears as low signal but on a T2W image is high signal. C. The enhanced T1W image shows a ring-enhanced lesion. D. is the microscopic appearance of post surgery of the cerebral sparganosis (HE × 200). Pathological diagnosis proved cavitations due to fibroplasias of cerebral tissue with degenerated larva, partly necrotized substances and calcification. There was fibrosis of surrounding the brain tissue with several granulomas and infiltration of inflammatory cells and gliosis. These findings highly suggested granulomas due to parasitic infection.

Figure 6

MR images for the case 4. A. The T1W image shows there is an irregular large patchy area with hypointensit in the left frontal lobe including the areas of the white matter, gray-white matter junction, and gray mater. B. The T2W image shows there is an irregular large patchy area with hyperintensity in the left frontal lobe including the areas of the white matter, gray-white matter junction, and gray mater. C. The enhanced T1W image shows a few ring-enhanced lesion areas.