The role of magnetic resonance imaging in the management of schistosomal myeloradiculopathy

Abstract

Schistosomiasis is a chronic, parasitic disease caused by blood flukes (trematode worms) of the genus Schistosoma 1 . First reports of what most likely correspond to the disease were found in Egyptian medical papyri, and eggs of the worms were found in mummies 2,3 . In spite of being recognized more than 30 centuries ago, recent data indicate that more than 207 million people are infected worldwide, with an estimate of 700 million people at risk in endemic countries 1 . However, even outside endemic areas, its importance has been rising in recent years, since today' s highly mobile, interdependent, and interconnected world provides myriad opportunities for its spread.Involvement of the central nervous system (neuroschistosomiasis) is caused by infection with S. mansoni, S. haematobium, or S. japonicum. Schistosomal myeloradiculopathy (SMR), usually related to S. mansoni infection, is the most frequently recognized presentation of neuroschistosomiasis, although it is still considered underdiagnosed in endemic areas 4 . Diagnosis of SMR is usually presumptive, relying on a positive epidemiology and pertinent neurological picture (spinal cord and/or nerve root involvement, most often the lower portions of the cord and cauda equina). It is also necessary to demonstrate the schistosomal infection and to exclude other causes of myelopathy.There are undoubtedly a couple of issues related to demonstration of the infection: parasite load is small in SMR compared to other forms of the disease, causing difficulties in obtaining positive stool samples (rectal biopsies present higher sensitivity, however); serological tests lack specificity especially in endemic areas; and immunodiagnostic tests in the cerebrospinal fluid (CSF), although promising, need validation before their widespread use 4 . In this scenario, magnetic resonance imaging (MRI) demonstrates high sensitivity but unfortunately not high specificity. However, MRI is a relevant tool, not only helping to increase the likelihood of SMR in a given patient but also in the potential recognition of other diseases mimicking it. Most commonly, one can find enlargement of the lower spinal cord and/or cauda equina roots, presenting hyperintensity in T2-weighted images and variable post-contrast enhancement 5,6 . This constellation of findings supports the diagnosis when associated with pertinent clinical and epidemiological data, especially when an elevated eosinophil count is present in the CSF analysis.Patterns of gadolinium enhancement related to SMR, which can coexist in a single patient and even change during the course of the disease, include intramedullary nodules, lesions in the cord surface and enhancing thickened nerve roots 5 . In a small sample (three patients), a more specific pattern was described, characterized by an ' arborized' appearance derived from central linear enhancement surrounded by multiple enhancing punctate nodules 7 . Taken together, these studies can advocate for the diagnosis of SMR when multiple enhancing intramedullary nodules are seen in...

Spinal schistosomiasis: Cases in Egyptian population

“…[ 16 ] It is also necessary to demonstrate the schistosomal infection and to exclude other causes of myelopathy. [ 17 ]…”

Mielorradiculopatia esquistossomótica

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