Spinal schistosomiasis: Cases in Egyptian population.

BACKGROUND: Spinal cord involvement by schistosomiasis is considered to be rare. Clinical presentation of spinal schistosomiasis ranges from radicular pain to myelopathy causing flaccid paraplegia, bladder incontinence, and dysesthesia. We reported six cases with spinal schistosomiasis.
METHODOLOGY: We did a retrospective analysis of the records in our department from March 1995 to March 2015, and we found that six cases of proved spinal schistosomiasis were documented, with follow-up period more than a year, aiming to find an assumption for a guideline for this ambiguous issue.
RESULTS: We found five cases from six were males and average age group was 26 years old (14-43). All had motor deficit (100%) which was variable, only two (33.33%) had dense weakness (G0) at time of presentation, three (50%) patients had sphincter disturbance also, and 50% of the patients presented with back pain as initial symptom. Only one of six patients had a positive history of the infestation. All patients went through surgical intervention, which was decompression laminectomy then biopsy or excision. Total excision was feasible only in two cases (33.33%), which had a well-defined lesion in imaging, while in others, lesion was ill defined and adherent, so biopsy was done. Steroids up to 2-month duration were used in all patients (100%) and praziquantel in repeated cycles after surgical excision or biopsy was used in all patients (100%).
CONCLUSION: History of travelling to endemic areas should raise the suspicion which may be the cornerstone of diagnosis, particularly in conus/epiconus intramedullary lesions. Surgical excision and spinal canal decompression are the best line of treatment in cases of schistosomiasis even if this excision was not total but to confirm and exclude other forms of pathology. Steroids and oral Praziquantel in repeated cycles are the best medication regimen in case of myelitis and in postoperative treatment.

INTRODUCTION

Schistosomiasis, also known as bilharzia, is a chronic disease caused by parasitic infestation that lives in certain types of freshwater snails. It is considered to be the second parasite after malaria as the most endemic parasitic disease in tropical countries. The infection is endemic to Africa, South America, and most parts of Asia.[1] In Sub-Saharan Africa, >200,000 deaths/year are due to this infestation according to the WHO sources. The number of people reported having been treated for schistosomiasis increased by 40% between 2011 and 2012 to 42.1 million. At least 249 million people required preventive treatment in 2012. Schistosomiasis transmission has been reported from 78 countries; in 2012, reports on preventive treatment for schistosomiasis were received from 31 countries.[1] The typical manifestations of schistosomiasis are urogenital, intestinal, and hepatolienal, and involvement of other organs, especially the central nervous system, is uncommon.[2] The central nervous system becomes infected either by migration of pairs of adult worms or by embolization of eggs through retrograde venous flow into the Batson venous plexus, a valveless paravertebral venous system from the mesenteric venous system. Clinical presentation of spinal schistosomiasis ranges from radicular pain to myelopathy causing flaccid paraplegia, bladder incontinence, and dysesthesia.[3] Hence, we collected the documented cases in our department over the past 20 years, trying to introduce an assumption for the management for spinal schistosomiasis, which is still infesting in endemic areas.

METHODOLOGY

We did a retrospective analysis of the records in our department from March 1995 to March 2015, and we found that six cases of proved spinal schistosomiasis were documented, with follow-up period more than a year, aiming to find an assumption for a guideline for this ambiguous issue.

Demographic data and presentation were documented; presence of a motor deficit, sphincteric disturbance, pain. Past-history of bilharzias infestation rather than nervous system. Imaging studies such as computed tomography (CT), myelography and contrasted magnetic resonance imaging (MRI) criteria. Laboratory investigation were analyzed such as serum serology, cerebrospinal fluid (CSF), and direct microscopic urine or stool examination. Treatment modalities included and if there is a medical regimen followed and the surgical technique describing the intraoperative criteria of the pathology and its resection capability. Postoperative outcome at 6 and 12 months.

All descriptive statistical analyses were performed using statistical software (QuickCalcs, GraphPad Software, San Diego, CA, USA).

RESULTS

We found that five cases from 6 cases were males and average age group was 26 years old (14–43). All the patients (100%) were from agriculture community. All had motor deficit (100%) which was variable, only 2 (33.33%) had dense weakness (G0) at time of presentation, 3 (50%) patients had sphincter disturbance also, and 50% of the patients presented with back pain as initial symptom. Only one of six patients had a positive history of the infestation. CT myelography was done in the other first three cases, which showed a filling defect at the suspected levels. While contrasted MRI used in the last three patients only showed lesions, which were either ill defined or well defined in contrasted T1 image with homogeneous hyperintense signal, isointense to the cord in T1, and hyperintense in T2-weighted images, and also a mild expansion of the distal spinal cord and conus noticed in one case [Figures 1 and 2]. The entire lesions were in dorsolumber region (100%). All patients went through surgical intervention, which was decompression laminectomy then biopsy or excision. Total excision was feasible only in two cases (33.33%), which had a well-defined lesion in imaging, while in others, lesion was ill defined and adherent, so biopsy was done. Steroids up to 2-month duration were used in all patients (100%) and praziquantel in repeated cycles after surgical excision or biopsy was used in all patients (100%). No new permeant neurological deterioration occurred postoperative. Only in two out of the three cases who had serology test done after pathological results appear, had positive serology. While one ovum was seen in only one of three cases whom were investigated for the ovum by direct microscope. Two cases had immediately postoperative mild deterioration in sphincters and motor power, which improved over 3 months. The improvement in excision group was rapidly than the ill-defined group where biopsy was taken only. The postoperative outcome showed that the more the neurological deficit was, the prognostic outcome was worse. This was seen in two cases whom had paraplegia (G0) and showed no improvement postoperative even after prolonged medical regimen. Also the early treatment and intervention showed better prognosis than the late one. There was no recurrence of infection in neural axis till one year of follow-up duration in all the cases[Table 1].

Figure 1

T1W contrasted image, sagittal view showing expanding intramedullary cord lesion

Figure 2

T1W contrasted image, axial view showing expanding intramedullary cord lesion

Table 1

Summarize cases management in the study

DISCUSSION

We reviewed six cases, which were operated in our department between 1995 and 2015. Spinal schistosomiasis usually occurs in males in a young age group.[4] In our series, most of the cases were males (5/6). The average age group was 26 years old. The clinical manifestations of spinal schistosomiasis can be diverse, and there should be a high index of suspicion for all patients from endemic areas.[56] Three species of these worms are prevalent in Africa, South America, the Middle East, and South-East Asia; Hematobium, Mansoni, and Japonicum.[4] All of our patients were from agriculture community in Egypt, which is known to be an endemic area for Hematobium and Mansoni, even if patients were not directly involved in agriculture.

While spinal cord involvement by schistosomiasis is considered to be rare,[7] Schistosoma mansoni causes almost always spinal cord disease.[8910] Infections with S. mansoni and Schistosoma haematobium usually produce myeloradicular damage, while infection with Schistosoma japonicum results in lesions in the brain.[11] There are some spinal schistosomiasis cases reported with S. japonicum.[12]

Fifty percent of patients represented by back pain as an initial symptom and all had motor deficits which were variable but only two of the six had G0 weakness which did not show any improvement later, and half of the patients had developed sphincteric disturbance. One of six patients had a positive history of infestation, which was previously diagnosed. Neurological manifestations are as a result of the inflammatory response of the host to the eggs’ deposition in the brain, and spinal cord is usually seen in patients with recent infection with no evidence of systemic illness yet in the most common locations of involvement. Severe disease can lead to flaccid paraplegia with areflexia, sphincter dysfunction, and sensory disturbance.[13] Although the onset of the disease may vary from sudden to chronic, the manifestations of impairments of the spinal cord or roots usually arise in a subacute or chronic presentation, with the signs and symptoms progressively appear. However, in some cases, it was reported that there is an improvement or even full regression of pain, which is the most frequent early symptom to appear, as the remaining manifestations arose. After all, the symptoms and signs of the impaired spinal cord cannot easily guide to a specific diagnosis, especially in patients with chronic pattern.[14]

No specific clinical picture is pathognomonic of bilharzias although the clinical picture of conus and cauda syndrome with intramedullary lesion in an endemic area should be suggestive of schistosomiasis.[515] The severity of the clinical picture was different among the patients.[8] A patient from an endemic area presenting as transverse myelitis or a spinal cord tumor, and with eosinophilia, should alert the physician to the possibility of schistosomiasis of the spinal cord.[15] The diagnosis of schistosomiasis may be missed in countries where the disease is not endemic but should be considered when investigating spinal cord disease in patients’ native to an endemic area or international travelers.[16] It is also necessary to demonstrate the schistosomal infection and to exclude other causes of myelopathy.[17]

MRI is very important for diagnosis and early treatment. Saleem et al. reported eight cases of spinal schistosomiasis and their MRI findings. Abnormalities were isointense to cord in T1 and patchy hyperintense in T2-weighted spin-echo images. Three forms of contrast enhancement were recognized:

(1) intramedullary nodular, (2) peripheral, and (3) linear radicular. Intramedullary nodular enhancement was correlated to multiple schistosomiasis microtubercles. Peripheral enhancing lesions correlated to thickened leptomeninges infested by chronic granulomatous inflammatory cells and Schistosoma eggs. Linear radicular enhancement correlated with thickened resected nervous roots infested by granulomatous cells and Schistosoma eggs.[2]

The diagnosis can be confirmed by direct or indirect methods. Direct methods are visualization of the parasite itself at any of its stages like rectal biopsy, which can show eggs of Mansoni and Hematobium. While indirect include serology and CSF analysis which may show an inflammatory pattern with or without eosinophils and/or immunoglobulin G against Schistosoma antigens.[818] While we did not do any CSF analysis as all were diagnosed postoperative and the CSF samples would not be accurate postoperatively, Livramento et al. described a CSF pattern such cases showing mild lymphocytic pleocytosis with eosinophils, elevated protein level, and low or normal glucose level.

Some authors suggest that corticosteroids such as “oral prednisone 40 mg/day” should be maintained until CSF normalization, but this is controversial.[19] We used steroids in our cases with the same mentioned dose, which showed even a mild improvement in one case preoperative, and all patients were kept postoperative on a daily dose of steroids, and the maximum was 6 weeks, which followed by gradual withdrawal, according to the clinical condition. Steroids also may be stopped according to radiological improvement or clinical condition.[20] The best line of bilharzial myelitis (demonstrated in contrasted MRI by the absence of a swelling) should be treated by praziquantel and steroids.[413] It is suggested that patients with “myelopathy of unknown origin” who come from an endemic area be given a therapeutic trial of praziquantel, especially if the serological findings are positive for schistosomiasis and the lower cord is involved.[21] Surgical resection is the proper intervention for granulomatous mass type, inform of decompressive laminectomy and resection. meanwhile if the mass is diffuse and ill-defined at least a small excisional biopsy, to be followed by histopathological examination to confirm the diagnosis then anti-schistosomal medical treatment to be initiated.[412] If the mass is a well-defined granuloma, then total excision, which provides the fastest and most complete improvement. Many authors argue against surgical treatment and suggest that medical treatment will be adequate.[2223] It is true that there is a risk of neurological deficit which may be permanent after surgery in addition to the usual incomplete excision of the diffuse infiltrating lesion and its rapidly progressive nature. However conservative medical treatment will take several weeks or months to shrink the lesion, noticing that Praziquental is not an ovicidal drug[23], which is long enough for neurological manifestations to become permanent.[4]

CONCLUSION

The most vulnerable age groups are the second, third and fourth decades to schistosoma infestation with slight male predominance. Living in endemic areas or history of traveling to, should raise the suspicion which may be the cornerstone of the diagnosis, especially in conus/epiconus intramedullary lesions. History of infection is not mandatory to find. Direct tests are the only sure diagnostic to rule out myelitis in case of schistosomiasis while other investigation is not essential to be positive. Surgical excision and spinal canal decompression are the best line of treatment in cases of Schistosomiasis even if this excision was not total but to confirm and exclude other forms of pathology. Both steroids administration and oral Praziquental in repeated cycles based on each endemic area recommendations, are the best treatment regimen for myelitis and as a postoperative treatment. The earlier the intervention, the more defined lesion and the less preoperative deficit carried better outcome.

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Nil.

Conflicts of interest

There are no conflicts of interest.