MRI in schistosomiasis of conus medullaris and lumbar spinal cord

The contribution made bySchistosomainfection to non-traumatic disorders of the spinal cord in Malawi

In Malawi, although schistosomal myelopathy has been reported in visitors from overseas who have swum in Lake Malawi, the incidence of this disorder in local residents has never been investigated. Consecutive patients with non-traumatic disorders of the spinal cord were therefore recruited in a hospital and a rehabilitation centre in Blantyre. Of the 33 patients investigated, 16 were presumed to be cases of schistosomal myelopathy as they had the markers of past or current schistosomiasis and apparently no other conditions that could explain their clinical features. There was microscopical and/or immunodiagnostic evidence indicating that eight of these presumptive cases had active schistosomiasis. All 16 presumptive cases had symptoms that were similar to those of 177 presumptive or proven cases of neuroschistosomiasis described in the scientific literature. Following antihelminthic treatment, eight of the presumptive cases showed marked improvement. Schistosomal myelopathy seems to occur relatively frequently in Malawi. Early treatment with praziquantel is strongly recommended for all patients with unexplained myelopathy and a history of exposure to schistosome cercariae.

[Schistosoma haematobium, a rare aetiology of spinal cord compression]

Human schistosomiasis is the second endemic disease after malaria. About 200 millions people are concerned, particularly in Africa, South America and Asia. Schistosomal spinal cord compression is under reported in Africa and not well known. Authors present the case of a 10-year-old boy with no suggestive past-medical story, admitted for spinal cord compression. MRI shows tumor like intra dural lesion. Schistosomal granuloma was found after lesion removal by posterior approach. Treatment was completed by praziquantel. Controversies of the treatment are presented.

Treatment of Schistosomal Myeloradiculopathy with Praziquantel and Corticosteroids and Evaluation by Magnetic Resonance Imaging: A Longitudinal Study

BACKGROUND

The best treatment for schistosomal myeloradiculopathy (SMR) remains undefined. There is also no longitudinal study to estimate the value of magnetic resonance imaging (MRI) in the diagnosis and follow-up of this disease.

METHODS

Patients with the following presentation were considered for study: lumbar and/or lower limb pain; lower limb weakness; anesthesia, hypoesthesia, or paresthesia; bladder and/or intestinal dysfunction; and sexual impotence. Sixteen patients with SMR were treated with oral praziquantel (50 mg/kg in a single dose) and methylprednisolone (15 mg/kg/day intravenously for 5 days) followed by prednisone (1 mg/kg/day orally for 6 months). Clinical outcome was prospectively evaluated in months 2 and 6 of treatment.

RESULTS

Image alterations were detected by MRI at diagnosis for all patients, and normalization or improvement was reported at the end of treatment. There was statistically significant clinical melioration at both the second and sixth months of therapy for most neurological alterations. However, the best clinical outcome was achieved when the steroid was given for >2 months.

CONCLUSIONS

Treatment with praziquantel associated with corticosteroids was successful in all cases. MRI proved to be a good method for the diagnosis of SMR and helpful in the evaluation of response to treatment.

Mielorradiculopatia esquistossomótica

A mielorradiculopatia esquistossomótica é a forma ectópica mais grave e incapacitante da infecção pelo Schistosoma mansoni. A sua prevalência em área endêmica tem sido subestimada. O diagnóstico baseia-se na presença de sintomas neurológicos decorrentes de lesões da medula espinhal em nível torácico baixo e/ou lombar alto, na demonstração da infecção esquistossomótica por técnicas microscópicas ou sorológicas e na exclusão de outras causas de mielite transversa. O tratamento precoce, com esquistossomicidas e corticoesteróides, mostra-se eficaz na maioria dos casos e os pacientes não tratados não se recuperam ou morrem. Não há consenso sobre doses e duração do tratamento, mas estudo recente sugere que os corticoesteróides devam ser usados por pelo menos seis meses. Como o diagnóstico é presuntivo e o tratamento essencialmente clínico, há que se manter alerta para a presença da doença, aperfeiçoar a propedêutica e, dessa forma, evitar-se a laminectomia rotineira. Com o advento da ressonância magnética da medula espinhal houve grande avanço no diagnóstico da esquistossomose medular. Como conseqüência, o número de casos de mielopatia esquistossomótica relatados tem aumentado rapidamente.

[Schistosomiasis of the spinal cord. Case report]

The authors report a case of a 34 year-old woman who, in the last four years, had travelled to Africa frequently, and developed a progressive clinical (about three months) dysfunction of the conus medullaris mainly consisting in sensitive disturbances. The MRI showed an intramedullary spinal cord lesion, and specific laboratory tests were negative. A biopsy for histologic diagnosis, showed a granulomatous tissue with eggs of S. Hematobium. After this diagnosis she was treated with praziquantel. We emphasize the relative frequency of the spinal cord location of schistosomiasis in endemic countries, and the importance of the laboratory diagnosis to start an early and effective antischistosomal treatment. Spinal cord schistosomiasis is uncommon but we must bear in mind this possibility in patients with a progressive spinal cord afectation.

Schistosomal myeloradiculopathy due to Schistosoma mansoni: report on 23 cases

Schistosoma mansoni infection is likely to be responsible for a significant proportion of cases of myelopathy occurring in areas where schistosomiasis is endemic. The aim of this study is to describe the clinical, laboratory and therapeutic data of 23 patients with schistosomal myeloradiculopathy. The medical records of 23 patients with schistosomal myelopathy admitted to two general hospitals of Belo Horizonte (MG), in Brazil, from 1995 to 1999, were reviewed retrospectively. Seventeen patients were male (74%). The mean age for the whole group was 27 years. Lower limb weakness and associated lumbar and/or lower limb pain were reported by 20 patients (87%), and 16 (70%) were unable to walk. All individuals presented urinary retention and 19 (83%) complained of intestinal dysfunction. The treatment was based on the association of antischistosomal drugs and corticosteroids. Five patients (22%) presented a full response to treatment, 13 (57%) partial response without functional limitations and 4 (17%) partial improvement with limitations or no response. Three out of the 4 patients who stopped steroids before 45 days of treatment developed recurrence of the symptoms and signs of myelopathy. Our cases demonstrate the severe presentation of the disease and the data disclosed here suggest that treatment with steroids should be kept for months after clinical improvement.

Spinal cord schistosomiasis. A report of 2 cases and review emphasizing clinical aspects

Schistosomal myeloradiculopathy (SMR) is a severe and little known form of presentation of schistosomiasis mansoni and hematobic schistosomiasis. The literature concerning the entity is scarce, and most publications are limited to isolated case reports. Thus, to consolidate and analyze the knowledge currently available about the disease, I reviewed 231 cases, with emphasis on clinical aspects. Although variations occur, in most cases the clinical picture of SMR is highly suggestive in individuals with epidemiologic antecedents of the infection. Thus, a patient with SMR is usually a young male with no other manifestations of schistosomal infection who presents with lumbar pain, often of a radicular nature, soon followed by weakness and sensory loss of rapid progression in the lower limbs associated with autonomic dysfunction, particularly bladder dysfunction. The most suggestive elements of the entity, and therefore of higher diagnostic value, are the low localization of the spinal cord lesion, the acute or subacute onset of the disease, and the association of manifestations due to medullary and radicular involvement. SMR is commonly classified into clinical or anatomoclinical forms. However, I observed no consensus in this classification even in terms of the terminology used. The analysis performed in this review permitted the introduction of a new concept not yet reported in the literature regarding the possibility that the disease consists of a continuous spectrum, with asymptomatic egg laying in the spinal cord at 1 end of the spectrum and devastating forms at the other end, with most cases occupying an intermediate position and with the various types of damage overlapping and associated to different degrees. This concept applies not only to different patients but also to the same patient at different stages of the disease. Chemical and cytomorphologic examination of cerebrospinal fluid (CSF) almost always revealed mildly or moderately increased total protein concentration and predominantly lymphocytic pleocytosis. Eosinophils, the least nonspecific finding, were detected in the CSF of less than half (40.8%) the patients. Myelography and computed tomography-myelography were altered in 63.3% of cases, but this proportion may be an overestimate. The most frequent changes were images of a filling defect due to expansion of the spinal cord and were almost always demonstrated by the 2 imaging modalities. Although still few in number, early reports suggest that magnetic resonance imaging is more sensitive; however, the changes are also nonspecific, such as those revealed by myelography and computed tomography-myelography. Parasite eggs were demonstrated frequently in a biologic specimen (88.3%), but difficulty in detection was not uncommon. Peripheral blood eosinophilia was detected in 64.5% of patients and represented a nonspecific finding. The detection of anti-Schistosoma antibodies in the serum or CSF was also frequent (94.9% and 84.8%, respectively). The presence of anti-Schistosoma antibodies in serum is of limited value for the diagnosis of schistosomiasis in general, especially among individuals living in endemic areas; however, their quantification in the CSF has proved to be promising for diagnosis in the few studies conducted for this purpose. The large number of variables concerning treatment (such as drugs used and duration of disease at the beginning of treatment), together with the relative lack of information about the natural history of the disease, limit the analysis of aspects related to treatment and prognosis. Nevertheless, it was possible to conclude that corticosteroids and antischistosomotic drugs have a favorable effect on disease outcome and should be administered as early as possible. In addition to early treatment, factors linked to the disease itself affect prognosis. The new cases of SMR reported here are typical and illustrate the data discussed in this literature survey.

Fever in the returned traveler

The most important cause of fever in the returned traveler is malaria. All febrile patients in which malaria is epidemiologically possible require urgent evaluation for P. falciparum malaria, which can be rapidly fatal in the nonimmune patient. Early diagnosis and therapy can prevent severe morbidity and mortality. Other less common causes of undifferentiated fever include acute schistosomiasis, the enteric fevers, rickettsial diseases, leptospirosis, and dengue fever. Early empiric therapy for suspected leptospirosis and the rickettsial infections is encouraged to decrease morbidity and mortality. About a quarter of febrile patients do not have an etiologic agent determined for their illness but recover without sequelae. Patients with fever and hemorrhagic manifestations within 3 weeks of their return need to be isolated for the remote possibility of a highly transmissible agent. Although the febrile traveler is always a challenge, the real world differential diagnosis is limited and a systematic approach via the history, physical examination, and selected laboratory tests is usually sufficient to confirm the diagnosis or eliminate potentially serious infections.

Schistosomiasis in Australian travellers to Africa

OBJECTIVE

To determine the proportion of Australian travellers to Africa at risk of Schistosoma infection, and the proportion of those infected.

DESIGN AND PARTICIPANTS

Retrospective postal survey of 360 patients who had attended Fairfield Hospital travel clinic in 1994 and stated an intention to travel to Malawi, Zimbabwe or Botswana.

MAIN OUTCOME MEASURES

Self-reported risk status for Schistosoma infection. For those at risk, results of an indirect haemagglutination assay (IHA). For those with IHA titres > or = 1:32, results of enzyme-linked immunosorbent assay, urine microscopy and eosinophil count.

RESULTS

360 letters were sent; 35 were returned to sender. Of the 325 remaining, 250 (77%) either responded or had an IHA test; 19 of these were still overseas or did not travel. 117/231 (51%) returned travellers considered themselves at risk of infection. Significantly fewer older patients reported exposure (chi 2 = 66.6; P < 0.001). 109/117 (93%) of those at risk had IHA tests and 18 had titres > or = 1:32. Subsequent testing indicated infection in 10/117 travellers (8.5%; 95% CI, 4.2%-15.2%).

CONCLUSION

Our findings indicate that a considerable number of Australian travellers to Africa are at risk of schistosomiasis, and some are infected. As complications can be serious, screening is recommended for individuals with any risk of infection, and treatment should be offered to those infected.

Schistosomiasis in Lake Malawi

BACKGROUND

In 1992 two US Peace Corps volunteers (PCVs) developed central nervous system schistosomiasis due to infection with Schistosoma haematobium following recreational water exposure at Cape Maclear on Lake Malawi, an African lake considered by many to be free of schistosomiasis. To determine the transmission potential and risk for aquiring schistosomiasis in Lake Malawi, a cross-sectional survey of resident expatriates and visitors to Malawi was done during March and April, 1993.

METHODS

A volunteer cohort of expatriates and visitors representing a cross-section of Malawi's foregn population answered detailed questions about freshwater contact and provided blood specimens to determine the seroprevalence of S haematobium and S mansoni by ELISA and immunoblot analyses. A survey for vector snails was conducted along Lake Malawi's southwestern shore.

FINDINGS

The study population of 955 included 305 US citizens and 650 non-US foreign nationals. 303 of the study population had serological evidence of current or past schistosome infection. Seroprevalence was 32% (141/440) among expatriates whose freshwater exposure was limited to Lake Malawi; S haematobium antibodies were found in 135 of 141 (96%) seropositive specimens. Risk of seropositivity increased with the number of freshwater exposures at Lake Malawi resorts. Although many resort areas in the southwestern lake region posed a significant risk, Cape Maclear was the location most strongly associated with seropositivity (OR 2.9, 95% Cl 1.6-5.1). Schistosome-infected Bulinus globosus, the snail vector of S haematobium in Malawi, were found at Cape Maclear and other locations along the lakeshore.

INTERPRETATION

S haematobium infection is highly prevalent among expatriates and tourists in Malawi. Recreational water contact at popular resorts on Lake Malawi is the most likely source of infection. Transmission of schistosomiasis is occurring in Lake Malawi, a previously under-recognised site of transmission.