MRI of CNS parasitic diseases

Isolated neurocysticercosis of the spine presenting with low back pain and cauda equina syndrome: a case report

INTRODUCTION

Cysticercosis, caused by Cysticercus cellulosae, is one of the common parasitic diseases that can affect the central nervous system (neurocysticercosis, NCC). Isolated involvement of cysticercosis of the spine, without the involvement of the brain, has been very rarely reported.

CASE PRESENTATION

This report presented a case, who was presenting with low back pain with radiation and cauda equina syndrome (CES). On MRI, the patient was found to have a subarachnoid cystic lesion at the level of lumbosacral vertebrae. Under neurosurgery, the patient underwent L5/S1 laminectomy, decompression, and excision of the cyst. On histopathological examination, the patient was diagnosed of having Cysticercosis. Immediately after surgery, the patient had neurological deterioration. However, at the end of 1 year, the patient had significant improvement both neurologically and functionally.

DISCUSSION

Spinal NCC should be considered in the differential diagnosis for a patient, who presents with a cystic lesion in the spinal subarachnoid space. Surgical exploration and excision of the cysts should be conducted not only to establish the diagnosis but also to decompress the cord and peripheral nerves.

Distant migration of gel filler: imaging findings following breast augmentation

Recently, many attempts have been made to use injectable materials in the subcutaneous fat layer anywhere in the body, including the breast and face, for cosmetic purposes. A 56-year-old woman presented with multiple palpable lumps without tenderness or skin color changes on the anterior and lateral chest and the abdominal walls. Magnetic resonance imaging showed fluid-like collections without surrounding soft tissue inflammatory changes in the chest wall, abdominal wall, and deeper within the abdomen. The lesions penetrated the peritoneum and were observed adjacent to the liver dome. Ultrasonography also showed hypoechogenicity suggestive of fluid collection in the left axilla and trunk. The differential diagnosis based on radiologic findings included parasite manifestation, non-specific inflammatory conditions, and chronic granulomatous infections such as tuberculosis or non-tuberculous mycobacterial infections. However, these conditions are usually accompanied by changes in the adjacent subcutaneous fat layers, but our patient did not show any other abnormalities in the adjacent soft tissue. After biopsy and aspiration analysis, the patient was found to have a history of filler injection for breast augmentation approximately 17 years prior. It is often difficult to make a differential diagnosis without detailed knowledge of the patient's medical history. Here we describe a rare case of distant migration of the filler to the axilla, chest wall, abdominal wall, and peritoneum following breast augmentation with filler injection. Knowledge of the radiologic characteristics and migration patterns of gel fillers and their related complications is useful for making an accurate diagnosis.

Lesionectomy for cerebral sparganosis and concomitant epilepsy: A case series of 15 patients

OBJECTIVE

To report the clinical characteristics and surgical outcomes of patients with cerebral sparganosis and concomitant epilepsy.

METHODS

We retrospectively collected the clinical data of all patients with cerebral sparganosis and concomitant epilepsy who underwent lesionectomy as treatment at Xiangya Hospital, Central South University between January 2015 and August 2019. Seizure outcomes were evaluated according to the International League Against Epilepsy (ILAE) classification. ILAE classes 1 and 2 were defined as favorable seizure outcomes, whereas ILAE classes 3-6 were defined as unfavorable seizure outcomes.

RESULTS

Fifteen patients with cerebral sparganosis and concomitant epilepsy who underwent lesionectomy as treatment met the inclusion criteria. Live worms were surgical removed in 80 % of patients. With a mean follow-up of 2.4 ± 1.1 years, 66.7 % of patients demonstrated favorable seizure outcomes, with improvement of symptoms other than seizures. Longer seizure duration associated with unfavorable seizure outcomes.

CONCLUSIONS

Lesionectomy is an effective treatment for patients with cerebral sparganosis and concomitant epilepsy. Early surgical treatment may offer more benefits to such patients.

Intraspinal Paragonimiasis in Children: MRI Findings and Suggestions for Pathogenesis

BACKGROUND AND PURPOSE

Intraspinal paragonimiasis is a rare entity for which imaging findings have seldom been described. The present study investigated the MR imaging features of spinal paragonimiasis, thus providing diagnostic imaging evidence and exploring the possible pathogenesis of intraspinal paragonimiasis.

MATERIALS AND METHODS

The clinical and imaging findings of spinal paragonimiasis in 6 children were analyzed retrospectively. Spinal MR imaging was performed in all patients, 5 of whom also underwent enhanced MR imaging. The diagnosis was confirmed by enzyme-linked immunosorbent assay in all cases and postoperative pathology in 4 cases.

RESULTS

All cases manifested as fusiform-shaped or beanlike masses in the extradural space in the thoracic spine. The extradural masses were connected with pleural lesions through the intervertebral foramen. The plain MR imaging scan showed mixed signals with predominant isointensity on T1WI and hyperintensity on T2WI, among which 5 (5/6) masses presented as patchy hemorrhage with hyperintensity on T1WI. On enhanced scans, all masses (5/5) showed heterogeneous marked enhancement, with thickening and enhancement in the adjacent spinal meninges (5/5). Various degrees of spinal cord compression and edema were found in 5 cases (5/6).

CONCLUSIONS

MR imaging is sensitive for detecting and characterizing spinal paragonimiasis. The MR imaging features of intraspinal granulomas included localization to the extradural space and thoracic segment, connections between intraspinal lesions and pleural lesions through the intervertebral foramen, and hemorrhagic foci within the mass. These findings support an intraspinal mode of paragonimiasis pathogenesis: The Paragonimus larvae migrate from the chest into the extradural space through the intervertebral foramen.

Cerebral sparganosis presenting with atypical postcontrast magnetic resonance imaging findings: a case report and literature review

Background

Sparganosis, a rare and severe parasitic infection caused by the larvae of Spirometra species or simply sparganum, generally involves subcutaneous tissue or muscle. But occasionally, sparganum can also invade the human brain, resulting in cerebral sparganosis.

Case presentation

A 33-year-old woman presented with a 10-day history of headache. Postcontrast magnetic resonance imaging (MRI) revealed an irregular lesion with enhancement and the tunnel-shaped focus extending to the contralateral hemiphere. Cerebrospinal fluid (CSF) analysis disclosed pleocytosis (166 cells/μL) and an elevated protein concentration (0.742 g/L). Enzyme-linked immunosorbent assay (ELISA) revealed positive sparganum-specific antibody in both blood and CSF. Finally, the diagnosis of cerebral sparganosis was comfirmed. She received praziquantel treatment and got a favorable outcome during six-month follow-up.

Conclusions

Irregular enhancement and the tunnel sign that extends to the contralateral hemisphere on postconstrast MRI are unusual presentations of cerebral sparganosis. ELISA for sparganum-specific antibody can help confirm the diagnosis. Although surgery is the preferred treatment for cerebral sparganosis, praziquantel might also achieve satisfying outcomes.

A case of mammary sparganosis due to infection with Spirometra mansoni

The authors report the case of a 56-year-old woman with mammary sparganosis due to infection with a plerocercoid tapeworm larva of Spirometra mansoni. Magnetic resonance imaging revealed an area of heterogeneous density in outer upper quadrant of the right breast, with a high likelihood of malignancy. During surgery for the removal of a granuloma, the parasite was discovered and excised. The authors review the pathological and imaging features of mammary sparganosis.

A blind passenger: a rare case of documented seroconversion in an Angiostrongylus cantonensis induced eosinophilic meningitis in a traveler visiting friends and relatives

Background

Eosinophilic meningitis (EOM) is a rare condition that is caused by various communicable and non-communicable factors. The rat-lungworm Angiostrongylus cantonensis, which is associated with consumption of raw or undercooked paratenic or intermediate hosts, is the most common cause of parasitic eosinophilic meningitis worldwide. While the majority of A. cantonensis cases are reported from endemic regions, cases in travelers pose a challenge to clinicians in non-endemic countries. Here we report a rare case of eosinophilic meningitis caused by A. cantonensis in a Swiss traveler who was diagnosed after returning from Thailand.

Case presentation

A 33-year old woman with a travel history to rural north-eastern Thailand presented to an emergency department in Switzerland with severe headache and vomiting. Eosinophilic meningitis was confirmed as the cause of the symptoms; however, serologic investigations failed to confirm an A. cantonensis infection on the first evaluation. Nevertheless, empirical treatment with an anthelminthic and steroid regimen led to a rapid alleviation of symptoms. Repeated serology confirmed seroconversion 2 weeks after treatment initiation.

Discussion

Parasitic etiology must be considered in returning travelers who present with symptoms compatible with a central nervous system infection. A thorough medical history, including types of food consumed, is paramount and can often suggest differential diagnosis. Neuroangiostrongyliasis is rare and might be missed if serology does not cover possible seroconversion.

Advances in Serological Diagnosis of Taenia solium Neurocysticercosis in Korea

Cysticercosis, a parasitic disease caused by Taenia solium metacestode (TsM), has a major global public health impact in terms of disability-adjusted life years. The parasite preferentially infects subcutaneous tissue, but may invade the central nervous system, resulting in neurocysticercosis (NC). NC is an important neglected tropical disease and an emerging disease in industrialized countries due to immigration from endemic areas. The prevalence of taeniasis in Korea declined from 0.3%–12.7% during the 1970s to below 0.02% since the 2000s. A survey conducted from 1993 to 2006 revealed that the percentage of tested samples with high levels of specific anti-TsM antibody declined from 8.3% to 2.2%, suggesting the continuing occurrence of NC in Korea. Modern imaging modalities have substantially improved the diagnostic accuracy of NC, and recent advances in the molecular biochemical characterization of the TsM cyst fluid proteome also significantly strengthened NC serodiagnosis. Two glycoproteins of 150 and 120 kDa that induce strong antibody responses against sera from patients with active-stage NC have been elucidated. The 150 kDa protein showed hydrophobic-ligand binding activities and might be critically involved in the acquisition of host-derived lipid molecules. Fasciclin and endophilin B1, both of which play roles in the homeostatic functions of TsM, showed fairly high antibody responses against calcified NC cases. NC is now controllable and manageable. Further studies should focus on controlling late-onset intractable seizures and serological diagnosis of NC patients infected with few worms. This article briefly overviews diagnostic approaches and discusses current issues relating to NC serodiagnosis.

Report of three imported cases of neurocysticercosis in Guadeloupe

BACKGROUND

Neurocysticercosis is endemic in most countries of Central and South America but has rarely been described in the French West Indies. We aimed to better understand the clinical and radiological presentation of our cases.

CASE PRESENTATION

We report three cases of neurocysticercosis in patients living in Guadeloupe, with different clinical and radiological presentations.

CONCLUSION

Given the eventuality of autochtonous transmission, the diagnosis should be considered in all patients living in Guadeloupe presenting with seizures.

A case of disseminated central nervous system sparganosis

Background:

Sparganosis is a very rare parasitic infection in various organs caused by the larvae of tapeworms called spargana. The larva usually lodges in the central nervous system (CNS) and the orbit. However, lumbar spinal canal involvement, as noted in the present case, is extremely rare. We report a rare case of disseminated CNS sparganosis involving the brain and spinal canal and review the literature.

Case Description:

A 54-year-old man presented with progressive low back pain and neurological deficit at the lumbosacral level for 2 months. Imaging indicated arachnoiditis and an abnormal lesion at the L4-5 vertebral level. The patient underwent laminectomy of the L4-5 with lesionectomy and lysis of adhesions between the nerve roots. Microscopic examination indicated sparganum infection. Further brain imaging revealed evidence of chronic inflammation in the left parieto-occipital area without evidence of live parasites. In addition, an ophthalmologist reported a nonactive lesion in the right conjunctiva. The patient recovered well after surgery, although he had residual back pain and bladder dysfunction probably due to severe adhesion of the lumbosacral nerve roots.

Conclusion:

CNS sparganosis can cause various neurological symptoms similar to those of other CNS infections. A preoperative enzyme-linked immunosorbent assay is helpful for diagnosis, especially in endemic areas. Surgical removal of the worm remains the treatment of choice.

Isolated lumbar intradural extra medullary spinal cysticercosis simulating tarlov cyst

Spinal cysticercosis is a very uncommon manifestation of neurocysticercosis, which is caused by the larvae of Taenia solium. Here, we present a rare case of isolated lumbar intradural extramedullary neurocysticercosis, initially thought to be Tarlov cyst. A 40-year-old man, presented with low backache for 1-year with radiation of pain to right leg for 3 months. The patient was treated successfully with the surgical removal of the cyst, followed by medical treatment. Spinal neurocysticercosis should be considered in the differential diagnosis in high-risk populations, with new symptoms suggestive of a spinal mass lesion.

Imaging in neurologic infections I: bacterial and parasitic diseases

Often presenting as medical emergencies, nervous system infections can be diagnostically challenging. Knowledgeable utilization of neuroimaging modalities and the understanding of characteristic imaging findings facilitate early diagnosis and treatment. In the first part of this two-part review, we address common and unique diagnostic imaging features of bacterial and parasitic nervous system infections.

Sparganosis presenting as cauda equina syndrome with molecular identification of the parasite in tissue sections

A 52-year-old woman presented with lower back pain, progressive symmetrical paraparesis with sensory impairment, and sphincter disturbance. Magnetic resonance imaging (MRI) of the whole spine revealed multiple intradural extramedullary serpiginous-mass lesions in the subarachnoid space continuously from the prepontine to the anterior part of the medulla oblongata levels, C7, T2-T8, and T12 vertebral levels distally until the end of the theca sac and filling-in the right S1 neural foramen. Sparganosis was diagnosed by demonstration of the sparganum in histopathological sections of surgically resected tissues and also by the presence of serum IgG antibodies by ELISA. DNA was extracted from unstained tissue sections, and a partial fragment of mitochondrial cytochrome c oxidase subunit 1 (cox1) gene was amplified using a primer set specific for Spirometra spp. cox1. After sequencing of the PCR-amplicon and alignment of the nucleotide sequence data, the causative agent was identified as the larva of Spirometra erinaceieuropaei.

Added value of antigen ELISA in the diagnosis of neurocysticercosis in resource poor settings

Background

Neurocysticercosis (NCC) is the most common cause of acquired epilepsy in Taenia solium endemic areas, primarily situated in low-income countries. Diagnosis is largely based upon the “Del Brutto diagnostic criteria” using the definitive/probable/no NCC diagnosis approach. Neuroimaging and specific T. solium cysticercosis antibody detection results are at the mainstay of this diagnosis, while antigen detection in serum has never been included. This study aimed at evaluating the addition of antigen detection as a major diagnostic criterion, especially in areas where neuroimaging is absent.

Methods

The B158/B60 monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) for the detection of circulating cysticercus antigen was carried out retrospectively on serum samples collected during a hospital-based study from 83 people with epilepsy (PWE) in an endemic area.

Results

The addition of antigen results as a major criterion allowed the correct diagnosis of definitive NCC in 10 out of 17 patients as opposed to 0/17 without antigen results in the absence of neuroimaging. A sensitivity of 100% and a specificity of 84% were determined for the diagnosis of active NCC using antigen ELISA. While the use of a higher cutoff improves the specificity of the test to 96%, it decreases its sensitivity to 83%.

Conclusions

In areas where neuroimaging is absent, NCC diagnosis according to the existing criteria is problematic. Taking into account its limitations for diagnosis of inactive NCC, antigen detection can be of added value for diagnosing NCC in PWE by supporting diagnostic and treatment decisions. Therefore, we recommend a revision of the “Del Brutto diagnostic criteria” for use in resource poor areas and suggest the inclusion of serum antigen detection as a major criterion.

Neurocysticercosis is a parasitic infection of the central nervous system and a common cause of epilepsy in Taenia solium cysticercosis endemic countries. According to the current diagnostic criteria proposed by Del Brutto and colleagues, the diagnosis of neurocysticercosis is mainly based on neuroimaging and detection of specific antibodies. Unfortunately, especially neuroimaging is rarely available in endemic countries. The authors analyzed the value of a test that detects antigens that are excreted by living cysts in people with epilepsy. Different diagnostic scenarios and cut-off values are discussed with the respective sensitivity and specificity of the test. When using the antigen-detecting test, considerably more people with epilepsy were diagnosed correctly with neurocysticercosis. There are some concerns about possible false positive results in other cases. The test was useful for the detection of people with living cysts (active neurocysticercosis), who need further diagnostic evaluation and specific treatment. The authors recommend the addition of this test in the diagnostic criteria for neurocysticercosis.

Parasitoses of the human central nervous system

Cerebral involvement in parasitoses is an important clinical manifestation of most of the human parasitoses. Parasites that have been described to affect the central nervous system (CNS), either as the dominant or as a collateral feature, include cestodes (Taenia solium (neurocysticerciasis), Echinococcus granulosus (cerebral cystic echinococcosis), E. multilocularis (cerebral alveolar echinococcosis), Spirometra mansoni (neurosparganosis)), nematodes (Toxocara canis and T. cati (neurotoxocariasis), Trichinella spiralis (neurotrichinelliasis), Angiostrongylus cantonensis and A. costaricensis (neuroangiostrongyliasis), Gnathostoma spinigerum (gnathostomiasis)), trematodes (Schistosoma mansoni (cerebral bilharziosis), Paragonimus westermani (neuroparagonimiasis)), or protozoa (Toxoplasma gondii (neurotoxoplasmosis), Acanthamoeba spp. or Balamuthia mandrillaris (granulomatous amoebic encephalitis), Naegleria (primary amoebic meningo-encephalitis), Entamoeba histolytica (brain abscess), Plasmodium falciparum (cerebral malaria), Trypanosoma brucei gambiense/rhodesiense (sleeping sickness) or Trypanosoma cruzi (cerebral Chagas disease)). Adults or larvae of helminths or protozoa enter the CNS and cause meningitis, encephalitis, ventriculitis, myelitis, ischaemic stroke, bleeding, venous thrombosis or cerebral abscess, clinically manifesting as headache, epilepsy, weakness, cognitive decline, impaired consciousness, confusion, coma or focal neurological deficits. Diagnosis of cerebral parasitoses is dependent on the causative agent. Available diagnostic tools include clinical presentation, blood tests (eosinophilia, plasmodia in blood smear, antibodies against the parasite), cerebrospinal fluid (CSF) investigations, imaging findings and occasionally cerebral biopsy. Treatment relies on drugs and sometimes surgery. Outcome of cerebral parasitoses is highly variable, depending on the effect of drugs, whether they are self-limiting (e.g. Angiostrongylus costaricensis) or whether they remain undetected or asymptomatic, like 25% of neurocysticerciasis cases.

Spinal cysticercosis mimicking a tumor in a pediatric patient

Parasitic infections of the central nervous system (CNS) occur mostly in underdeveloped regions of the world. Neurocysticercosis (NC) occurs when the larval form of the T. solium tapeworm invades the CNS. Spinal cysticercosis is an extremely rare type of NC and occurs when the cyst occupies the subarachnoid space of the spinal column. Previous cases have been successfully treated through both surgical and medical means. The current case describes the symptoms, diagnosis, and treatment of a patient with this extremely uncommon manifestation of neurocysticercosis.

Primary solitary hydatid cyst in paraspinal cervical muscles: a case report and review of the literature

Hydatid disease caused by Echinococcus granulosus and Echinococcus multilocularis commonly presents with pulmonary and hepatic cysts. Primary paraspinal muscle cysts are a rare presentation. We report a case of hydatid cyst within paraspinal muscles presenting with cervical mass and associated pain. The hydatid disease serological test was negative. Neither hepatic nor pulmonary cystic lesions were found. Radiographic findings were unspecific for hydatid cysts. Surgical resection was planned due to the provisional diagnosis of muscular cystic neoplasm. During surgery, a cyst containing a clear liquid was found. The cyst wall was excised and the surgical field was irrigated with hypertonic saline. The patient's symptoms resolved by discharge day. Postoperative pathological examinations revealed a muscular hydatid cyst.

Imaging features of intradural spinal paragonimiasis: a case report

Spinal paragonimiasis is a rare form of ectopic infestation caused by Paragonimus westermani. We report a case of pathologically proven intradural paragonimiasis associated with concurrent intracranial involvement. MRI revealed multiple well-defined intradural masses that were markedly hypointense on T(2) weighted images and hypointense with a peripheral hyperintense rim on T(1) weighted images. Contrast-enhanced T(1) weighted images showed slight peripheral rim enhancement.

Diagnosis and stereotactic aspiration treatment of cerebral sparganosis: summary of 11 cases

Object

Cerebral sparganosis is a rare but underestimated parasitic disease caused by infestation by sparganum. It is difficult to make a confirmed preoperational diagnosis of this disease given the absence of characteristic clinical manifestations. A detailed protocol for the diagnosis and treatment of cerebral sparganosis is still lacking in the literature. In this article the authors set out comprehensive procedures for the diagnosis and treatment of cerebral sparganosis, describing the use of a stereotactic aspiration technique complemented by microsurgery based on experience gained from multiple cases.

Methods

The disease history, clinical manifestations, imaging features, and therapeutic procedures for 11 patients with cerebral sparganosis were retrospectively analyzed. Stereotactic aspiration procedures were performed in all 11 patients and were complemented by microsurgeries in 3 patients. The learning and experience gained from these treatments were summarized, and a comprehensive protocol for the diagnosis and treatment of cerebral sparganosis was reviewed.

Results

Larvae of Spirometra mansoni were taken from all 11 patients: completely removed in 10 cases and partially removed in 1 case (discovered later). After surgery, clinical symptoms in all 11 patients were significantly improved. All epileptic symptoms were successfully cured, although in 1 case occasional seizures still occurred because of the incomplete removal of the larva. Muscle strength in the 4 patients who had hemiparesis prior to surgery recovered to normal. Symptoms in the 1 patient who had presented with partial body sensory disturbance resolved after surgery. There were no complications or deaths.

Conclusions

The authors concluded that an effective preoperative diagnosis of cerebral sparganosis can be made by detailed inquiry into the possible infection history and disease symptoms as well as careful scrutiny of characteristic radiological features and immunological testing results. In stereotactic operations performed to remove the larva, priority should be given to image-guided stereotactic aspiration given that it causes the smallest wounds. In cases in which stereotactic aspiration fails, stereotactic microsurgery should be performed to remove the larva. The surgeon must carefully avoid breaking the larva and leaving behind any larva residue during surgery.

Sparganosis in the lumbar spine : report of two cases and review of the literature

Sparganosis is a rare parasitic infection affecting various organs, including the central nervous system, especially the lumbar epidural space. This report describes the identification of disease and different strategies of treatments with preoperative information. A 42-year-old man presented with a 2-year history of urinary incontinence and impotence. He had a history of ingesting raw frogs 40 years ago. Magnetic resonance (MR) imaging showed an intramedullary nodular mass at conus medullaris and severe inflammation in the cauda equina. A 51-year-old woman was admitted with acute pain in the left inguinal area. We observed a lesion which seemed to be a tumor of the lumbar epidural space on MR imaging. She also had a history of ingesting inadequately cooked snakes 10 years ago. In the first patient, mass removal was attempted through laminectomy and parasite infection was identified during intra-operative frozen biopsy. Total removal could not be performed because of severe arachnoiditis and adhesion. We therefore decided to terminate the operation and final histology confirmed dead sparganum infection. We also concluded further surgical trial for total removal of the dead worm and inflammatory grannulation totally. However, after seeing another physician at different hospital, he was operated again which resulted in worsening of pain and neurological deficit. In the second patient, we totally removed dorsal epidural mass. Final histology and enzyme-linked immunosorbent assay (ELISA) confirmed living sparganum infection and her pain disappeared. Although the treatment of choice is surgical resection of living sparganum with inflammation, the attempt to remove dead worm and adhesive granulation tissue may cause unwanted complications to the patients. Therefore, the result of preoperative ELISA, as well as the information from image and history, must be considered as important factors to decide whether a surgery is necessary or not.

Herniated lumbar disc combined with spinal intradural extramedullary cysticercosis

Spinal cysticercosis is a very uncommon manifestation of neurocysticercosis which is caused by the larvae of Taenia solium. However, it can develop as a primary infection through blood stream or direct larval migration. It can result in high recurrence and severe neurologic morbidity if not treated appropriately. We report the case of a 43-year-old woman who presented with severe lower back pain and left leg radiating pain in recent 2 weeks. Magnetic resonance image (MRI) of lumbar spine demonstrated extruded disc at the L5-S1 level combined with intradural extramedullary cystic lesion. We performed the open lumbar microdiscectomy (OLM) at L5-S1 on the left with total excision of cystic mass. After surgery, the patient showed an improvement of previous symptoms. Diagnosis was confirmed by histopathological examination as intradural extramedullary cysticercosis. We discuss clinical features, diagnostic screening, and treatment options of spinal cysticercosis.

A very rare cause of childhood paraparesis: primary intradural extramedullary spinal hydatid cyst

Hydatid disease is caused by the larval form of Echinococcus. Lung and liver are the most commonly affected sites. Primary intradural extramedullary hydatid disease is extremely rare; a 13-year-old girl with primary intradural hydatid cyst who presented with symptoms of paraparesis is discussed in this article.

Intradural extramedullary primary hydatid cyst of the spine in a child: a very rare presentation

Spinal hydatid cyst is a serious but fortunately uncommon manifestation of the parasite Echinococcus, involving less than 1% patients with hydatid disease. Intradural hydatid cysts are extremely rare compared to other types of spinal hydatid cysts. We report a rare case of intradural, extramedullary spinal hydatid cyst in a 9-year-old male boy, who presented with weakness of both lower limbs for the last 4 months that was confirmed histopathologically; a better understanding of this rare but clinically challenging disease is intended by reporting this case.

Unusual MRI findings in a patient with history of frontal fracture and skin infestation by fly larvae, as a possible sign of intracerebral myiasis

We report a case of an 11-year-old columbian immigrant with mild non-specific cephalalgia. He had a previous history of frontal fracture and skin infestation caused by Dermatobia hominis larvae. MRI performed revealed multiple subependymal and intraventricular lesions with concentric blooming artifacts and moderate hydrocephalus. Based on his previous history, intracerebral myiasis diagnosis was suggested. His mother denied any kind of diagnostic surgery or treatment. To the best of our knowledge, this is the first MRI report of a possible intracerebral myiasis, an exceedingly rare entity.

Transventricular, transaqueductal scope-in-scope endoscopic excision of fourth ventricular neurocysticercosis: a series of 13 cases and a review

OBJECT

Neurocysticercosis (NCC) is the most common parasitic infestation of the central nervous system worldwide. In patients presenting with acute hydrocephalus due to intraventricular NCC, surgery is the only option. Still, there is no consensus regarding the optimal surgical strategy, although neuroendoscopic excision is a promising method. However, the literature regarding the use of this modality in fourth ventricular NCC is scarce. The authors describe a series of patients with fourth ventricular NCC treated endoscopically.

METHODS

The clinical records of 13 patients with fourth ventricular NCC who had presented with hydrocephalus were retrospectively analyzed. A fourth ventricular cyst was completely excised in all patients by using a transventricular, transaqueductal "scope-in-scope" endoscopic technique. Twelve endoscopic third ventriculostomies and 1 septostomy had been performed.

RESULTS

Shunt placement was avoided in all patients. There were minimal peri- and postoperative complications. The mean duration of follow-up was 22.3 months (range 3-41 months). All patients had an improved clinical outcome. Follow-up neuroimaging revealed no residual lesion and a decreased ventricle size in all patients.

CONCLUSIONS

The present series of patients with fourth ventricular NCC is the largest in the existing English-language medical literature. Endoscopic fourth ventricular cysticercal cyst excision along with internal cerebrospinal fluid diversion via endoscopic third ventriculostomy is an effective alternative to open microneurosurgical procedures and avoids shunt placement and its related complications.

Detection of toxoplasmic lesions in mouse brain by USPIO-enhanced magnetic resonance imaging

The objective of this study was to examine the feasibility of detecting toxoplasmic brain lesions in a mouse model of cerebral toxoplasmosis by ultrasmall superparamagnetic particles of iron oxide (USPIO)-enhanced magnetic resonance imaging (MRI). Toxoplasmosis encephalitis was induced in Kunming mice by intracerebral injection of Toxoplasma gondii tachyzoites. T2- and T2*--weighted MRI was performed 1, 3, 4, 5 and 6 days after infection before USPIO injection; immediately after USPIO injection; and 24 h later. A comparison of USPIO enhancement and Gd-DTPA enhancement was made in three toxoplasmic mice 4 days after infection. Hematoxylin and eosin staining and Prussian blue staining were performed to detect inflammatory reactions and presence of iron in and around the toxoplasmic brain lesions. Nonenhanced T2-/T2*-weighted imaging detected few abnormalities in the brain up to 5 days. Most mice developed prominent hydrocephalus at 6 days. Gd-DTPA-enhanced imaging showed prominent enhancement of the cerebral ventricles but revealed only few space-occupying lesions in the parenchyma. USPIO-enhanced T2*-weighted imaging showed improved detection of toxoplasmic brain lesions that were invisible to nonenhanced T2-/T2*-weighted imaging and gadolinium-enhanced imaging. Most of the enhancing lesions showed nodular enhancement immediately after USPIO injection, some of which changed appearance 24 h later, having a ring enhancement at the outer rim. It can be concluded that USPIO enhancement of the toxoplasmic lesions may reflect blood-brain barrier impairment and/or inflammatory reactions associated with these lesions. USPIO-enhanced imaging may be used in combination with gadolinium-enhanced imaging to provide better characterization of toxoplasmic brain lesions and, potentially, improve the differential diagnosis of toxoplasmosis encephalitis.

Case of subcutaneous sparganosis: Use of imaging in definitive preoperative diagnosis

Herein, we report a rare case of subcutaneous sparganosis in a 60-year-old Japanese woman. She had a 2 cm x 2 cm elastic-hard, subcutaneous nodule, which was the larva of a tapeworm, and a surrounding granuloma in her internal thigh. It was thought that she became infected by drinking water contaminated with the worm. She was definitively diagnosed by enzyme-linked immunosorbent assay (ELISA). After excision of the lesion, the titer of ELISA showed clear decline; therefore, we could conclude that she had been completely freed from sparganosis. The magnetic resonance imaging (MRI) and ultrasound sonography of her subcutaneous nodule demonstrated the characteristic signs: a band-like structure in the MRI and a coiled linear hypoechoic body in a clear, oval mass in the ultrasound sonography.

Neuroimaging and pathological findings in a child with cerebral sparganosis

The authors report the case of a 6-year-old boy with cerebral sparganosis due to infection with a plerocercoid tapeworm larva of Spirometra mansoni. Magnetic resonance imaging revealed an area of irregular long T2 signal in the right frontal lobe. When compared with images obtained 2 years earlier, the lesion appeared to have migrated into the parietal lobe. During surgery for the removal of a granuloma, the parasite was discovered and excised. Following surgery, the patient's neurological deficits markedly improved. The authors review the pathological and imaging features of cerebral sparganosis.

Spinal hydatid disease, a rare but existent pathological entity: case report and review of the literature

Spinal hydatid disease is a not uncommon cause of spinal cord compression in endemic countries; however, involvement of the epidural space with sparing of the vertebral column is rare. Early diagnosis and surgical decompression with total removal of the hydatid lesion, when possible, is generally considered the standard of care for this disease. The authors describe a case of massive epidural hydatid disease without involvement of the vertebral column in a 62-year-old male patient, treated with a 2-stage surgical operation and administration of systemic albendazole. The literature is reviewed regarding the clinical features, diagnosis, treatment and prognosis of spinal echinococcosis.

Identification of immunodominant excretory–secretory cysteine proteases of adultParagonimus westermani by proteome analysis

Paragonimus westermani causes inflammatory lung disease in humans. The parasite excretes a host of biologically active molecules, which are thought to be involved in pathophysiological and immunological events during infection. Analyses of the 2-DE protein profiles of the excretory-secretory products (ESP) of adult P. westermani revealed approximately 147 protein spots, at least 15 of which were identified as cysteine proteases (CPs), at pHs between 4.5 and 8.5, and molecular weights (MWs) between 27 and 35 kDa. An additional three CPs (designated as PwCP-3, -8 and -11) were newly recognized by TOF/TOF MS. Their molecular biological information, which shared a high level sequence homology, was elucidated. The majority of the CPs reacted strongly with sera from paragonimiasis patients. When we observed the chronological changes in the antibody responses of the respective CPs against canine sera collected serially at 1, 3, 5, 7, 11 and 14 wk after experimental infection, these molecules exhibited a multiplicity of distinct immune recognition patterns. Our results clearly showed that P. westermani adult ESP were principally composed of excretory-secretory CPs, and that these CPs may exert effects not only on host tissue degradation and nutrient uptake, but also on the immune-regulating cells via synergistic and independent interactions.

MRI features of pediatric cerebral paragonimiasis in the active stage

We retrospectively reviewed the MR images of the brains of six children (age = 5-13 years) who had cerebral paragonimiasis in the early active stage. Diagnosis was based on a positive antibody test enzyme-linked immunosorbent assay (ELISA) for paragonimiasis in serum. The most common finding (in five patients) was irregular hemorrhage of various degrees. Moreover, in three cases some multiple irregular lesions with surrounding edema appeared to be conglomerated and aggregated. The rare appearance (in one patient) was a "tunnel sign," which showed the migrating track of the adult worm. In one patient with abscess and minimal hemorrhage, diffusion-weighted imaging (DWI) showed a heterogeneous high signal of lesions. Other findings included slight (one patient) or marked (one patient) irregular contrast enhancement, and large edematous areas surrounding small centers of hemorrhage (two patients). MR findings of conglomerated lesions with hemorrhage or tunnel sign may help to establish the diagnosis of active-stage cerebral paragonimiasis.

Neurocysticercosis: a review

BACKGROUND

In North America, the largest number of neurosurgical cases stemming from parasitic infections involves the larval form of Taenia solium, the infectious organism causing neurocysticercosis. This infection of the central nervous system (CNS) is most commonly seen in areas with significant immigrant populations and can often present particular challenges to treating physicians.

METHODS

A review of the literature was performed, highlighting the epidemiology, parasitology, and clinical manifestations of neurocysticercosis. Particular attention was paid to 4 locations of neurocysticercosis lesions: parenchymal, subarachnoid/cisternal, intraventricular, and spinal.

RESULTS

Both medical and surgical interventions may be necessary for adequate treatment of neurocysticercosis, depending on various factors, including location of lesion.

CONCLUSIONS

A review of neurocysticercosis, with particular attention paid to location of disease involvement in the CNS, provides important information to the clinical management of this disease.

Alteration of antibodies against the fifth-stage larvae and changes in brain magnetic resonance images in experimentally infected rabbits with Angiostrongylus cantonensis

Magnetic resonance (MR) imaging has been suggested to be helpful in delineating the lesions during the acute phase of angiostrongyliasis caused by Angiostrongylus cantonensis. In this study, antibody titers in serum samples of 3 rabbits were determined by enzyme-linked immunosorbent assay, and brain MR images were obtained from 6 rabbits. The antibody titer elevated rapidly in the first 4 wk postinfection (PI) before reaching a plateau. However, suspicious changes in brain MR images near the left lateral ventricle and hippocampus were found only in 1 rabbit on day 28 PI. These findings indicate that immunologic responses in the central nervous system at the early stage of angiostrongyliasis are not sufficient to be observed by image studies.

Higher succinate than acetate levels differentiate cerebral degenerating cysticerci from anaerobic abscesses on in-vivo proton MR spectroscopy

We present three patients with large intraparenchymal isolated degenerating cysticerci in whom the diagnosis was primarily based on in-vivo proton MR spectroscopy, and subsequently confirmed histologically. We suggest that the presence of succinate alone or more succinate acetate indicates the presence of degenerating cysticerci and differentiates them from anaerobic brain abscesses, which show acetate alone or in higher concentration than succinate, even when the clinical and imaging features are similar.

Taenia solium: identification of specific antibody binding regions of metacestode 10-kDa protein

Taenia solium neurocysticercosis (NCC) represents one of the major public health problems associated with several neurological manifestations worldwide. We previously identified a recombinant 10-kDa protein of T. solium metacestode (CyDA) specific to active NCC. Immunoblottings with sera from active NCC patients and from animals experimentally infected with larval T. solium (pig), T. saginata (pig), T. asiatica (pig), and T. crassiceps (mouse) strongly recognized CyDA, while sera from patients infected only with adult worms did not. Mapping of antigenic sites using deletion mutants revealed that amino acids (aa) residues 30-34, Asn-Met-Thr-Val-Met (NMTVM), reacted only with sera from active stage T. solium cysticercosis cases. Recognition of CyDA aa 30-34 resided almost exclusively in the IgG4 isotype. Competitive immunoprecipitation with synthetic peptides confirmed the specificity of anti-sera for this penta-peptide. These results demonstrated that aa residues NMTVM in CyDA comprise the core sequence for an active stage NCC-related antigenic determinant. ligand binding protein, HLBP; Cyst fluid, CF; Pooled serum of 10 active NCC patients, serum-pool.

MR spectroscopy in neurocysticercosis

MR spectroscopy findings in a case of neurocysticercosis are presented. A combination of elevated lactate, alanine, succinate, and choline levels and reduced levels of N -acetylaspartate and creatine in a cystic intraaxial lesion in the brain helped in characterizing the lesion. To our knowledge, the short echo point resolved spectroscopic sequence (PRESS) spectrum of neurocysticercosis, as described in our case, has not been reported before.

Suspected protozoal myeloencephalitis in a two-month-old colt

A two-month-old Appaloosa colt developed neurological signs shortly after birth involving deficits affecting cranial nerves IV, VII, VIII, IX, X and XII, and possibly nerve VI. The most likely differential diagnoses were congenital anomalies, meningoencephalitides, trauma or nutritional causes. The foal was investigated by the analysis of cerebrospinal fluid (CSF), electromyelography (EMG), brain auditory evoked responses, magnetic resonance imaging (MRI), peripheral nerve biopsy, and Western blot analysis for the presence of intrathecal antibodies to Sarcocystis neurona, the causative agent of equine protozoal myeloencephalitis. Significantly abnormal EMG findings included spontaneous electrical activity of the tongue, suggesting denervation. The MRI was useful in ruling out masses, congenital anomalies and focal abscessation. The cytology of CSF revealed mild mononuclear reactivity. Western blot testing of CSF was positive, indicating the intrathecal presence of antibodies to S neurona. The foal was treated with pyrimethamine and trimethoprim-sulphadiazine for two months and returned to nearly normal neurologic status.

Spinal toxoplasmic arachnoiditis associated with osteoid formation: a rare presentation of toxoplasmosis

STUDY DESIGN

An extremely rare presentation of an isolated spinal toxoplasmic arachnoiditis is described.

OBJECTIVE

To draw attention to the fact that spinal arachnoid membranes may be a potential reservoir for Toxoplasma gondii.

SUMMARY OF BACKGROUND DATA

Central nervous system toxoplasmosis is a common manifestation in patients who are immunodeficient. Reports on the spinal toxoplasmosis are rare and focused on spinal cord involvement.

METHODS

An adult patient presented with symptoms of spastic paraparesis that had begun 13 years before admission. Thoracic spinal magnetic resonance imaging showed small lesions in posterior subarachnoid space at Th7-Th8. A Th7-Th8 laminectomy was performed. Intradural-extramedullary lesions were excised.

RESULTS

Clinical, immunologic, and pathologic examinations showed adhesive spinal arachnoiditis associated with osteoid formation caused by past toxoplasmic infection. There was no impairment of the immunologic defense system.

CONCLUSION

Where no causative factor is found in serious spinal adhesive arachnoiditis, the possibility of spinal toxoplasmosis should also be investigated.

Intradural-extramedullary spinal cysticercosis: MR imaging findings

A rare case with intradural-extramedullary cysticercosis is presented here. MR imaging with and without gd-DTPA were performed. There were multiple cysts in the basal cistern, cisterna magna, and cervical subarachnoid space which were isointense with cerebrospinal fluid both on T2- and T1-weighted images. Swelling and increased signal intensity in the cord parenchyma were detected on T2-weighted images. Gadolinium enhanced studies showed rim-shaped enhancement in the cysts and irregular, diffuse enhancement in the meninges.