SPINAL CORD SCHISTOSOMIASIS

Abstract

Fourteen patients with schistosomiasis of the spinal cord are described. They fall into two groups: 7 patients had clinical and computer-assisted myelographic evidence of lesions in the conus medullaris or cauda equina, or both. The clinical picture in the remaining 7 patients was usually that of acute or subacute transverse myelitis with normal or equivocal CT myelographic appearances. Granulomas containing bilharzial ova were found in 2 female patients with conus swelling subjected to laminectomy and biopsy. In 1 of these the ova were identified as S. haematobium while in the second, unidentified bilharzial ova were found. A presumptive diagnosis of spinal cord schistosomiasis was made in the remaining 12 patients based on characteristic clinical and investigative profiles. All 13 patients tested showed evidence of bilharzial infection based on positive blood serology or the detection of bilharzial ova, or both. All but 1 patient showed at least one of the following abnormalities on CSF examination: pleocytosis, an elevated protein content and as indicated by the presence of oligoclonal IgG bands, an elevated IgG index and an increased CSF IgG synthesis rate. A CSF bilharzia enzyme-linked immunosorbent assay (ELISA) test, developed to indicate the presence of schistosomal infection within the theca, was found to be sensitive although not entirely specific for the diagnosis of spinal cord schistosomiasis. Eleven of the 14 patients showed rapid clinical improvement, 8 after praziquantel and corticosteroid treatment, 2 after operation and 1 spontaneously. Significant reductions in the CSF cell count, protein concentration and bilharzia ELISA titre, and in intrathecal antibody production, occurred following praziquantel and corticosteroid therapy. The CSF sugar level showed a significant rise. A reduction in conus size was observed in 3 patients when CT myelography was repeated after medical therapy. The normalization of most of the laboratory parameters after combined medical treatment with praziquantel and corticosteroids, together with clinical and radiological improvement, strengthened the presumptive diagnosis of cord schistosomiasis and supports the policy of early intensive medical treatment (as opposed to surgical therapy) for this condition when diagnosed on indirect evidence.