Conus medullaris neuroschistosomiasis mimicking Guillain–Barre syndrome: A case of delayed diagnosis leading to permanent neurological damage

Abstract

Key Clinical Message

In the evaluation of acute flaccid paralysis, particularly in pediatric populations within endemic areas for schistosomiasis infection, clinicians must maintain a high index of suspicion for neuroschistosomiasis. Prompt identification is imperative to mitigate the risk of irreversible neurological sequelae.

Abstract

Spinal cord involvement in neuroschistosomiasis (NS) is considerably rare, with even fewer reported cases affecting the conus medullaris in children. While NS's neurological sequelae are typically thought to be reversible, delayed diagnosis and treatment can lead to permanent deficits. We report a case of a 9‐year‐old boy who presented with 3 weeks of progressive bilateral lower extremity weakness. A spinal MRI showed patchy gadolinium enhancement in an expanded conus medullaris, leading to a presumed diagnosis of Guillain–Barre syndrome, and the patient was treated with intravenous immunoglobulin. However, the lack of improvement necessitated surgical laminectomy. The post‐operative histopathological examination confirmed the presence of a schistosomal parasite. Despite initiating therapy with corticosteroid and praziquantel, the patient did not exhibit clinical improvement, resulting in persistent flaccid paralysis, bladder, and bowel incontinence. In conclusion, spinal NS should be considered in patients presenting with myeloradicular symptoms in regions endemic for schistosomal infection, as delayed recognition can result in irreversible outcomes.

1. INTRODUCTION

After malaria, schistosomiasis is the most common parasitic disease worldwide. This systemic illness primarily affects the gastrointestinal and urological tracts. ¹ Rarely, it can involve the nervous system causing neuroschistosomiasis (NS), which is estimated to affect 1%–4% of patients with systemic schistosomal infections. ² The notable patterns of spinal NS presentation include the medullary form, acute/subacute lower‐limb myeloradiculopathy, and conus medullaris syndrome. The latter presents more indolently with slower progression of asymmetrical flaccid weakness, compared to the medullary form, which presents with severe, symmetrical myelopathy. ² Nonetheless, the presentation of NS can be nonspecific, mimicking transverse myelitis or intra‐axial spinal tumors, particularly with conus intramedullary extension. ³ Achieving positive treatment outcomes is heavily reliant on early detection and timely treatment with the administration of high‐dose steroids and praziquantel. ⁴ Despite the relatively favorable prognosis, delayed recognition and intervention can be associated with permanent neurological deficits. ² While post‐mortem studies have indicated a three to four times higher prevalence rate of asymptomatic NS cases, ⁵ the variability of clinical presentation and low index of suspicion can lead to misdiagnosis, even among symptomatic cases. ² , ⁶ , ⁷ Herein, we report a case of conus intramedullary NS that mimicked transverse myelitis, and was misdiagnosed as Guillain–Barre syndrome, and subsequently led to delayed treatment and permanent neurological deficit in a 9‐year‐old boy.

2. CASE PRESENTATION

2.1. Patient information

A 9‐year‐old Yemeni child presented with lumbar pack pain associated with lower extremity weakness that progressed to both legs within 3 weeks, which confined him to a wheelchair. The patient had concurrent urinary and fecal incontinence with no other urinary tract symptoms. The patient has had a history of exposure to unclean water, and household pets including farm sheep. Otherwise, the patient had an updated vaccination history, including poliovirus, and had no medical or family history of neurological, metabolic, autoimmune, or malignant disease.

2.2. Clinical findings

The patient was alert and oriented with no apparent distress, and his examination was remarkable for lower‐limb flaccid paralysis, which was prominent distally, with asymmetrical distribution, predominantly on the right, with a power of 0/5 at the left ankle and a score of 1/5 at the right ankle, 2–3 at both knees and 4/5 at both hips without muscle atrophy. Furthermore, the rectal tone, deep tendon reflexes, and plantar reflex were absent. Additionally, there was a loss of sensation in the lower limbs up to the hypogastrium. Otherwise, upper limbs, meningeal signs, and cranial nerves examinations were unremarkable.

2.3. Diagnostic assessment

The laboratory evaluation showed leukocytosis (13.5 × 10³/mL) with eosinophilia (7%), with thrombocytosis (757,000/mm³). Inflammatory markers, namely C‐reactive protein and erythrocyte sedimentation rate, were at 3 mg/L and 51 mm/h, respectively. The stool examination and urine analyses were negative for schistosomal parasite infection, while other laboratory test results, such as liver and renal function tests, were within normal ranges. Anti‐schistosomal antibodies in serum were weakly positive 1/160 (Positive ≥1/160), while schistosomal antigen in serum was negative. The patient underwent a lumbar puncture, and the patient's cerebrospinal fluid (CSF) analysis revealed elevated protein levels of 1.08 g/dL, while other parameters including cell count, glucose, and cytology were normal. Magnetic resonance imaging (MRI) of the spine showed an ill‐defined intramedullary T1 hypointense and T2 hyperintense lesions with cord extension spanning a long segment (T12‐L2) with patchy enhancements. The post‐contrast image indicated the existence of intramedullary‐enhancing lesions with expanded conus medullaris, suggestive of transverse myelitis; however, other myelopathy causes, such as Guillain–Barre syndrome and potential neoplastic conditions, were not definitively excluded (Figure 1).

FIGURE 1.

Spinal magnetic resonance imaging reveals the presence of ill‐defined intramedullary T1 hypointense (A) and T2 hyperintense lesions (B) with cord extension spanning a long segment (T12‐L2) with patchy enhancements (C). The post‐contrast image indicated the existence of intramedullary‐enhancing lesions (D).

2.4. Therapeutic interventions

The patient left our facility prematurely due to the distance and cost of transfer and was managed as a case of GBS in a closer facility. He received intravenous immunoglobulin (IVIG) with supportive measures. Unfortunately, no improvement was observed upon his return 2 months later. Following revision of the patient's MRI findings, a decompression laminectomy (Figure 2), and subsequent histopathological examination revealed the presence of schistosome parasites exhibiting a ventral horn, in addition to extensive necrosis areas encircled by inflammatory infiltrates.

FIGURE 2.

Site of laminectomy surgery.

2.5. Follow‐up and outcome

The patient received a regimen of daily prednisolone (2 mg/kg), praziquantel (50 mg/kg), with acid‐suppressant syrup for 5 days before being discharged home. On a 1‐month follow‐up, no neurological improvements were noticed, other than flickering of the toes, with persistent urinary and fecal incontinence. Subsequently, physiotherapy was initiated, and low‐dose steroid tapering was continued. In a 2‐year follow‐up visit, no neurological improvement was observed, and he developed a pressure ulcer due to being bedridden for a prolonged period, necessitating surgical intervention. In the latest follow‐up visits, which took place 3 years after diagnosis, the patient did not exhibit any neurological improvement.

3. DISCUSSION

Schistosomiasis represents a diagnostic challenge across various clinical settings. The lower prevalence, along with nonspecific or chronic presentation with multi‐organ system involvement, contributes to delayed identification and management, even within endemic regions. Rarely, the dissemination of schistosomal eggs into the nervous system incites granulomatous inflammation, predominantly impacting the cerebrum or spinal cord. ⁸ , ⁹ Notably, spinal NS results from Schistosoma mansoni or haematobium, which usually involves the spine medulla. Nonetheless, the inflammation and fibrosis progression may result in compressive‐like myeloradiculopathy. Another distinctive form of spinal NS is called “conus intramedullary Ns” which presents similarly to transverse myelitis, or intra‐axial spinal tumors with mass effect. ² , ⁵

Clinical manifestations of spinal NS may include lower back pain, motor deficits, sensory loss, ataxia, paresis, and disturbances in bladder or bowel control. ² , ¹⁰ These presentations are critical to recognize, particularly the spectrum of acute flaccid paralysis, which can closely resemble acute transverse myelitis. This resemblance was evident in the initial diagnosis of our patients, aligning with similar cases reported in the literature. ¹¹ , ¹² Chronic spinal NS, although rare, can lead to myeloradiculopathy, even in patients without a prior diagnosis of infection. However, it is crucial to note that the combination of symptoms, such as lower back pain, flaccid paraplegia, and urinary and bladder dysfunction, is not unique to spinal NS. As these symptoms can also indicate conditions like cauda equina and conus medullaris syndromes. ¹³ Our patient exhibited lumbar pack pain associated with lower extremity weakness that progressed to both legs within 3 weeks, in addition to concurrent urinary and fecal incontinence. Notably, the patient had a history of river water exposure that was obtained retrospectively.

Parasitic infections, including the case of our patient, are often associated with eosinophilia. This observation led to serum anti‐schistosomal antibodies testing which was weakly positive 1/160 (Positive ≥1/160). Subsequently, the patient underwent a lumbar puncture, with CSF analysis showing elevated protein. Typically, the CSF findings of spinal NS are nonspecific, including raised protein levels and occasional oligoclonal bands. ³ In addition, CSF pleocytosis is reported in more than 90% of the cases; however, our patient's CSF analysis showed normal cell counts. Alternatively, testing urine or stool for schistosome ova could provide indirect supportive evidence of schistosomiasis. ⁸ These findings, however, have low sensitivity were only observed in about 60% of the cases, and were negative in our patient.

Magnetic resonance imaging (MRI) serves as an alternative diagnostic technique, typically revealing signs of intramedullary expansion. ¹⁴ Spinal MRI could show T2 patchy hyperintensity and T1 isointense to the cord over several segments without any blooming on susceptibility‐weighted imaging. ¹⁵ These radiographic findings paralleled those commonly seen in transverse myelitis or intra‐axial spinal tumors. Additionally, similar presentations can occur in demyelinating conditions, particularly GBS. ⁵ Alsomaili et al. and Mohamed et al. reported a similar case in which radiologic findings of intramedullary‐enhancing lesions mimicked spinal cord tumors. ⁶ , ⁷ In Ahmed et al. ² case, the radiologic findings of intramedullary‐enhancing lesions mimicked transverse myelitis.

In our patient, the observed albuminocytologic dissociation, along with the radiological findings led to an initial diagnosis of GBS, for which the patient was treated with IVIG. Such diagnostic conclusion may arise from the broad spectrum of symptoms overlapping in intramedullary lesions, including infection, demyelination, inflammation, and neoplasia. Nonetheless, a definitive diagnosis necessitates a spinal cord biopsy to confirm the presence of egg granuloma within the tissue. ⁵ Neves et al. ¹⁶ reported a series of five cases with spinal cord complications of acute schistosomiasis mansoni. One of these cases presented a similar clinical manifestation to the GBS, like our case. The misdiagnosis in our case likely stemmed from a combination of the patient's nonspecific presentation and cognitive biases that favored a GBS diagnosis over other potential conditions. Moreover, the regional endemicity of schistosomiasis, along with marginally positive antibody levels, may suggest prior exposure rather than an acute infection, thus overlooked. In addition, the considerable risks associated with spinal cord biopsies may influence initiating GBS treatment rather than seeking an alternative explanation for the patient's condition. However, this approach might not have been the most prudent initial step in the management of intramedullary spinal cord lesions, which typically warrants a therapeutic trial addressing any reversible or medically manageable causes. ¹⁵

Despite administering pulse prednisolone and praziquantel following laminectomy, the therapeutic outcomes in our case were unsatisfactory. This suboptimal response may be attributed to the prior administration of immunoglobulin before a precise diagnosis was established. Ferrari TC and colleagues observed a 14% non‐recovery rate in a cohort of 63 patients treated with steroids and anti‐parasitic agents. ¹⁷ A similar lack of favorable outcomes was noted in a case reported by Ahmed et al., ² where the patient developed acute flaccid paraplegia as a complication of schistosomal myeloradiculopathy.

This case exemplifies the diverse clinical manifestations of spinal NS. The presence of albuminocytologic dissociation in inpatient evaluations should not deter clinicians from considering alternative diagnoses, particularly in areas where schistosomiasis is prevalent. Furthermore, this case emphasizes the significance of early and accurate diagnosis, coupled with timely intervention. Such an approach is crucial in circumventing unnecessary surgical procedures and ensuring the prompt administration of appropriate medications, thereby potentially enhancing patient outcomes.

4. CONCLUSION

This study reports a significant neurological deficit caused by delayed undiagnosed conus intramedullary NS. Pediatric patients with myeloradicular symptoms in endemic regions should be evaluated for schistosomal infection. Prompt history and radiologic imaging can lead to early diagnosis. It is recommended to consider expert‐guided presumptive therapy to reduce these neurological complications.

AUTHOR CONTRIBUTIONS

Nabil Aljuma'ai: Conceptualization; data curation; formal analysis; funding acquisition; investigation; methodology; project administration; resources; software; validation; writing – original draft. Saif A. Ghabisha: Conceptualization; data curation; methodology; resources; supervision; visualization; writing – review and editing. Faisal Ahmed: Conceptualization; formal analysis; funding acquisition; investigation; project administration; resources; software; supervision; writing – original draft; writing – review and editing. Taha Al‐Mwald: Conceptualization; funding acquisition; investigation; methodology; supervision; writing – original draft. Abdullatif Almohtadi: Data curation; formal analysis; investigation; methodology; supervision; visualization; writing – original draft. Mohamed Badheeb: Formal analysis; investigation; methodology; resources; software; supervision; validation; writing – original draft; writing – review and editing.

FUNDING INFORMATION

This research received no specific grant from the public, commercial, or not‐for‐profit sectors.

CONFLICT OF INTEREST STATEMENT

No conflict of interest to disclose.

ETHICS STATEMENT

None.

CONSENT

Written informed consent was obtained from the patient's parents for the publication of this case report and accompanying images. A copy of the written consent is available for review by the editor in chief of this journal on request.

Aljuma’ai N, Ghabisha SA, Ahmed F, Al‐Mwald T, Almohtadi A, Badheeb M. Conus medullaris neuroschistosomiasis mimicking Guillain–Barre syndrome: A case of delayed diagnosis leading to permanent neurological damage. Clin Case Rep. 2024;12:e8475. doi: 10.1002/ccr3.8475

DATA AVAILABILITY STATEMENT

All data generated or analyzed during this study are included in this published article.