Research development of the pathogenesis pathways for neuroschistosomiasis

The infection of the central nervous system （CNS） by schistosome may or may not have clinical manifestations. When symptomatic, neuroschistosomiasis （NS） is one of the most severe presentations of schistosome infection. Among the NS symptoms, cerebral invasion is mostly caused by Schistosoma japonicum （S. japonicum）, and the spinal cord symptoms are mainly caused by S. mansoni or S. haematobium. There are 2 main pathways by which schistosomes cause NS： egg embolism and worm migration, via either artery or vein system, especially the valveless perivertebral Batson＇s plexus. The adult worm migrates anomalously through the above pathways to the CNS where they lay eggs. Due to the differences in species of schistosomes and stages of infection, mechanisms vary greatly. The portal hypertension with hepatosplenic schistosomiasis also plays an important role in the pathogenesis. Here the pathways through which NS occurs in the CNS were reviewed.

Spinal Cord Schistosomiasis: Report on Seven Adult Patients

Background: Spinal Cord Schistosomiasis (SCS) is the most disabling ectopic form of Schistosomal infection. It may or may not have clinical manifestations. They include low back pain and/or lower limb pain and weakness, and double incontinence. Early diagnosis and treatment provide a good outcome. Aim: To describe the clinical, radiologic, and therapeutic data of 7 patients with Spinal Schistosomiasis. Patients and Methods: In this retrospective clinical case study, the medical records of 7 patients with spinal cord pathologies admitted to Aswan University Hospital from May 2014 to May 2017 were reviewed. All were male aged from 17 to 30 years old (mean ± SD, 20 ± 9.5 yr.;median 21 yr.), with neurological deficit in the form of lower limb weakness and sphincter disturbance. All were treated by decompressive laminectomy and debulking of the intramedullary lesion followed by medical treatment. Results: The outcome of our patients was good as 4/7 patients (57%) presented a full recovery, 3/7 patients (43%) presented a partial recovery without functional limitations and none presented a partial recovery with limitations or no response. Conclusion: High index of suspicion should be raised in the differential diagnosis of patients with clinical or radiological evidence of Spinal Cord Schistosomiasis, as early diagnosis can guarantee a better prognosis and avoid the occurrence of serious sequels. The association of corticosteroids and antischistosomal drugs is related to the best outcome. The role of surgery is decompression, particularly in the granulomatous or pseudotumoral form, and to obtain material for definite histopathological diagnosis in doubtful cases.

Establishment of a cerebral schistosomiasis experimental model in rabbits

Objective The present study aimed to establish a cerebral schistosomiasis model in rabbits,to provide a valuable tool for morphological analysis,clinical manifestation observation,as well as investigations into immunological reactions and pathogenesis of focal inflammatory reaction in neuroschistosomiasis（NS）.Methods Sixty New Zealand rabbits were randomly assigned into operation,sham-operation and normal groups.Rabbits in the operation group received direct injection of dead schistosome eggs into the brain,while their counterparts in the sham-operation group received saline injection.Rabbits in the normal group received no treatment.Base on the clinical manifestations,rabbits were sacrificed on days 3,5,7,10,20,and 30 post injection,and brain samples were sectioned and stained with hematoxylin-eosin.Sections were observed under the microscope.Results The rabbits in the operation group exhibited various neurological symptoms,including anorexy,partial and general seizures,and paralysis.The morphological analysis showed several schistosome eggs in the nervous tissue on day 3 post operation,with very mild inflammation.On days 7-10 post operation,several schistosome eggs were localized in proximity to red blood cells with many neutrophilic granulocytes and eosinophilic granulocytes around them.The schistosome eggs developed into the productive granuloma stage on days 14-20 post operation.On day 30,the schistosome eggs were found to be in the healing-by-fibrosis stage,and the granuloma area was replaced by fibrillary glia through astrocytosis.The sham-operation group and the normal group showed negative results.Conclusion This method might be used to establish the cerebral schistosomiasis experimental model.Several factors need to be considered in establishing this model,such as the antigenic property of eggs,the time of scarification,and the clinical manifestations.