A proposal for classification of neurocysticercosis

Incident Breakthrough Seizures, Serum Matrix Metalloproteinase-9 and Perfusion Magnetic Resonance Imaging Parameters in a Cohort of Children and Adolescents With Neurocysticercosis: A Longitudinal Observational Study

BACKGROUND

The current study estimated incident breakthrough seizures, serum matrix metalloproteinase-9 (MMP-9), and perfusion magnetic resonance imaging (MRI) parameters in five- to 18-year-olds with neurocysticercosis (NCC) from colloidal or vesicular through calcified stages over at least 24 months' follow-up.

METHODS

Single, colloidal, or vesicular parenchymal NCC cases were treated with albendazole and steroids and followed at a tertiary care north Indian hospital. Serum MMP-9 was estimated in colloidal or vesicular treatment-naive state and in a subset of calcified cases at six-month follow-up. The same subset of calcified cases also underwent perfusion MRI of the brain at six-month follow-up.

RESULTS

Among 70 cases, 70% calcified at six-month follow-up. Over a median follow-up of 30 months, the incidence of breakthrough seizures was 48.6% (61.2% in calcified and 19.2% in resolved, P = 0.001; 32.9% early [within six months] and 15.7% late [beyond six months], P = 0.02). Serum MMP-9 levels were higher in colloidal and vesicular compared with calcified stage (242.5 vs 159.8 ng/mL, P = 0.007); however, there was no significant association with breakthrough seizures and/or calcification in follow-up. In a subgroup of calcified cases (n = 31), the median relative cerebral blood volume on perfusion MRI in and around the lesion was lower in those with seizures (n = 12) than in those without (n = 19) (10.7 vs 25.2 mL/100 g, P = 0.05).

CONCLUSIONS

In post-treatment colloidal or vesicular NCC, incident breakthrough seizures decrease beyond six months. In calcified NCC with remote breakthrough seizures, significant perilesional hypoperfusion is seen compared with those without seizures.

High prevalence of neurocysticercosis among patients with epilepsy in a tertiary care hospital of Assam, India

Background:

Neurocysticercosis (NCC) is a parasitic disease of the central nervous system, which is caused by the metacestode of the pork tapeworm, Taenia solium. The present unicentric, hospital-based, cross-sectional study was undertaken to assess the contribution of NCC as a cause of active epilepsy among patients attending a tertiary health care center in Assam, India.

Materials and Methods:

Over a period of 2 years, 152 active epilepsy patients were investigated based on clinical, epidemiological, neuroimaging (contrast-enhanced computerized tomography), and immunological techniques to establish the diagnosis of NCC. A precoded questionnaire was administered to patients and/or guardians to collect detailed medical history.

Results:

Ninety-three cases (61.2%) fulfilled either definitive or probable diagnostic criteria for NCC. Anti-cysticercus immunoglobulin G antibodies were detected by ELISA and enzyme electro-immune transfer blot in 69 (45.4%) active epilepsy patients. Seroprevalence was higher in males, 46.6% (54/116); than in females, 41.7% (15/36), and increased significantly with age; peaking in the 20–39 years age group (36/76; χ² = 5.64; P = 0.02). Among the seropositive cases, 54 (78.3%) were diagnosed with NCC. A significantly higher number of seropositive individuals were diagnosed with NCC in the 20–39 years age group as compared to the 40 years and above age group (χ² = 6.28; P = 0.01). The association between seropositivity for NCC, and the number of lesions in the brain was statistically significant (χ² = −8.33; P = 0.003).

Conclusions:

This study indicates that NCC is a major cause of active epilepsy in Assam. A high prevalence of pediatric NCC is also a major concern.

Predictors of Seizure Recurrence in Solitary Calcified Neurocysticercosis in Relation to Computed Tomography Scan: Prospective Observational Study

Background and Purpose

Solitary calcified neurocysticercosis (NCC) on the computed tomography (CT) scan of brain in patients of epilepsy is common finding in endemic regions. Factors causing seizures in such cases are debatable. Immature calcification may be the causative factor for seizure recurrence. Thus, we aimed to study predictors of seizure recurrence specific to morphological characteristics on CT scan.

Methods

Patients with solitary calcified NCC on CT scan brain and active seizures were prospectively included. The protocol included clinical evaluation, contrast-enhanced CT scan of the brain, and electroencephalogram (EEG) at baseline and 9th month of 1-year follow-up in all patients. Seizure recurrence after 1 week of enrolment was recorded.

Results

One hundred twenty patients with a mean age of 23.33±12.81 years were included with a final follow-up of 109 patients and 35 patients had seizure recurrence. On univariate analysis, seizure frequency of more than 1 episode/month (45.7% vs. 25.7%, p=0.037; odds ratio [OR], 2.06; 95% confidence interval [CI], 1.05–5.68), perilesional edema on CT head (45% vs. 10.8%, p<0.001; OR, 6.95; 95% CI, 2.58–18.7), lower density (HU) of lesion on CT head (139.85±76.54 vs. 204.67±135.9 HU p=0.009) and abnormal EEG at presentation (p<0.001; OR, 18.25; 95% CI, 2.15–155.13) were significantly associated with seizure recurrence. On multivariate analysis, presence of perilesional edema on CT head (p=0.001; OR, 6.854; 95% CI, 2.26–20.77), density of lesion on CT (HU) (p=0.036; OR, 0.995; 95% CI, 0.99–1) and abnormal EEG (p=0.029; OR, 12.125; 95% CI, 1.29–113.74) were independently associated with seizure recurrence.

Conclusions

The presence of perilesional edema, HU of calcification on CT brain, and abnormal EEG suggest an increased risk of seizure recurrence in patients of epilepsy with solitary calcified NCC.

Neurocysticercosis in a Japanese woman with lung cancer who repeatedly visited endemic countries

Background

Taenia solium, present in most developing countries, infects many individuals and may result in their death. Neurocysticercosis (NCC) develops after invasion of the brain by parasitic larvae. It is the most common parasitic disease of the human central nervous system. On imaging scans it can be similar to brain tumors. We report a patient with a metastatic brain tumor and NCC. The co-presence of NCC was diagnosed based on specific neuroimaging- and epidemiologic findings.

Case presentation

A 36-year-old non-smoking Japanese woman with a history of non-small-cell lung cancer had undergone resection of the lower lobe followed by cytotoxic chemotherapy 2 years before apparently suffering recurrence. A positron emission computed tomography (PET) scan incidentally revealed multiple intracranial cold spots exhibiting differences in their shape and size. On brain magnetic resonance imaging (MRI) scans we observed many different patterns of peripheral edema and gadolinium-enhancing effects. As she had often visited Latin America and Southeast Asia and had eaten raw pork and Kimchi, we suspected that the brain lesions were due to NCC rather than metastatic brain tumors. However, serum immunoblotting assay and DNA analysis were negative for T. solium. Rather than performing resection, we administered albendazole (ABZ) and dexamethasone because her earlier cytotoxic chemotherapy had elicited severe pancytopenia. Except for a single large lesion in the left frontal lobe, this treatment resulted in a significant reduction in the size of these lesions and a decrease in perilesional edema. She underwent resection of the residual lesion 10 months later. Histology revealed it to be a metastatic tumor. Polymerase chain reaction (PCR) assay for NCC was negative. In the course of 11-months follow-up there has been no recurrence.

Conclusion

This is the first presentation of NCC in a Japanese woman with a metastatic brain tumor. NCC was incidentally discovered on PET scans and, based on her travel history and epidemiological findings; it was diagnosed and successfully treated with ABZ. NCC is endemic in most developing countries and as visits to such countries have increased, NCC must be ruled out in patients with multiple cystic nodular brain lesions.

Geographic Distribution of the Prevalence of Neurocysticercosis in the Municipality of Piedade, São Paulo

Background:

Neurocysticercosis is a globally occurring parasitosis that affects the central nervous system. The main clinical manifestation is seizures.The aim of this study was to analyze the geographic distribution of patients with seizures attending the Emergency Unit of the Piedade municipality, SP, with a diagnosis of neurocysticercosis, and to compare the association of its prevalence with age, basic sanitation and food hygiene habits between rural and urban areas.

Methods:

One hundred thirty-six patients with seizures were evaluated. The Epidemiological data of all subjects will be described.

Results:

The diagnosis of neurocysticercosis was confirmed in 24 patients, corresponding to a prevalence of 17.65%. The presence of an open sewer predominated in the rural area, while the consumption of unwashed fruits, presence of elderly people and geographic distribution were similar in the two areas.

Conclusions:

Urgent measures to raise awareness about the disease and preventive actions should be taken by world authorities.

Neurocysticercosis in patients with active epilepsy in the tea garden community of Assam, Northeast India

Neurocysticercosis is a significant cause of epilepsy in the tropics. The present cross-sectional survey was conducted in the socioeconomically backward tea garden community of Assam to gauge the prevalence of neurocysticercosis in patients with active epilepsy and to determine the associated risk factors. In a door to door survey, a total of 1028 individuals from every fifth household of the study Teagarden were enrolled to identify self-reported seizure cases, followed by a neurological examination to confirm the diagnosis of active epilepsy. Patients with active epilepsy underwent clinical, epidemiological, neuroimaging (contrast-enhanced computerized tomography) and immunological evaluations to establish the diagnosis of neurocysticercosis. Clinically confirmed 53 (5.16%) active epilepsy were identified; 45 agreed to further assessment for neurocysticercosis and 19 (42.2%) cases fulfilled either definitive or probable diagnostic criteria for neurocysticercosis. Patients with epilepsy due to neurocysticercosis were more likely to suffer from taeniasis (20.0% vs 0.0%), rear pigs (57.9% vs 15.4%) or have pigs in their neighbourhood (78.9% vs 53.8%) relative to epileptic patients without neurocysticercosis. Rearing pigs (aOR 14.35, 95% CI: 3.98–51.75) or having pigs in the neighbourhood (aOR 12.34, 95% CI: 2.53–60.31) were independent risk factors of neurocysticercosis. In this community, the prevalence of taeniasis (adult worm infection) was 6.6% based on microscopy. The study reports a high prevalence of active epilepsy in the tea garden community of Assam and neurocysticercosis as its primary cause. The high prevalence of taeniasis is also a significant concern.

A prospective cohort study to assess the frequency and risk factors for calcification in single lesion parenchymal neurocysticercosis

BACKGROUND

Calcified neurocysticercosis (NCC) predisposes patients to an enduring state of epilepsy. The predictors for calcification in parenchymal neurocysticercosis are not well defined.

METHOD

In this prospective cohort study, consecutive children with single-lesion parenchymal NCC were enrolled and followed up for one year. All patients were investigated with brain 3 T-MRI and electroimmunotransfer blot (EITB). Clinical follow-ups were performed every 3 months. Radiology was repeated at the 6-month and one-year follow-ups. The proportion of calcified lesions at one year and the predictors of calcification were studied.

RESULT

During the study period from June 2013 to December 2015, 93 children with single lesion parenchymal NCC were enrolled. At presentation, 90 % of the lesions were in the colloidal stage, and 71 % of the lesions had moderate to severe perilesional oedema. All children had 6 months of follow-up, and 86 (92.5 %) had one year of follow-up. Seizure recurrence was present in 13 (14 %) children. Follow-up radiology at one year showed lesion resolution in 51 (59 %) lesions and calcification in 28 (32.5 %) lesions. Children with calcified lesions during follow-up had a higher odds of seizure recurrences {OR, 95 % CI 3.6(2.3-5.6)}. The presence at baseline of diffusion restriction {OR, 95% CI 2.9 (1.01-8.8)}, scolex or wall calcification in the T2 Star weighted angiography MRI images {OR, 95% CI 3.7 (1.7-8.2)} and >10 mm size of the lesion {OR, 95 % CI 2.4 (1.2-5.01)} predicted lesion calcification.

CONCLUSION

Children with calcification of the parenchymal NCC lesions have a higher risk for seizure recurrence during follow-up. The presence of diffusion restriction, calcified nidus in the colloidal nodular stage, and >10 mm size of the lesion at baseline predicted calcification of the lesion during follow-up.

A longitudinal analysis of albendazole treatment effect on neurocysticercosis cyst evolution using multistate models

BACKGROUND

In neurocysticercosis, the larval form of the pork tapeworm Taenia solium appears to evolve through three phases-active, degenerative and sometimes calcification-before disappearance. The antihelmintic drug, albendazole, has been shown to hasten the resolution of active cysts in neurocysticercosis. Little is known about the time cysts take to progress through each phase, with or without treatment.

METHODS

We reconfigured brain imaging data from patient level to cyst level for 117 patients in a randomized clinical trial of albendazole in which images were taken at baseline, 1, 6, 12 and 24 mo. Applying a multistate model, we modelled the hazard of a cyst evolving to subsequent cyst phases before the next imaging (vs no change). We examined the impact of albendazole treatment overall and by patient and cyst characteristics on the hazard.

RESULTS

Albendazole accelerated the evolution from the active to degenerative phase (HR=2.7, 95% CI 1.3 to 6.5) and from the degenerative phase to disappearance (HR=1.9, 95% CI 1.1 to 3.9). Albendazole's impact was stronger for patients who were male, did not have calcified cysts at baseline and who had multiple cysts in different locations.

CONCLUSIONS

This research provides a better understanding of where in the cyst trajectory albendazole has the greatest impact.

A multistate joint model for interval-censored event-history data subject to within-unit clustering and informative missingness, with application to neurocysticercosis research

We propose a multistate joint model to analyze interval-censored event-history data subject to within-unit clustering and nonignorable missing data. The model is motivated by a study of the neurocysticercosis (NC) cyst evolution at the cyst-level, taking into account the multiple cysts phases with intermittent missing data and loss to follow-up, as well as the intra-brain clustering of observations made on a predefined data collection schedule. Of particular interest in this study is the description of the process leading to cyst resolution, and whether this process varies by antiparasitic treatment. The model uses shared random effects to account for within-brain correlation and to explain the hidden heterogeneity governing the missing data mechanism. We developed a likelihood-based method using a Monte Carlo EM algorithm for the inference. The practical utility of the methods is illustrated using data from a randomized controlled trial on the effect of antiparasitic treatment with albendazole on NC cysts among patients from six hospitals in Ecuador. Simulation results demonstrate that the proposed methods perform well in the finite sample and misspecified models that ignore the data complexities could lead to substantial biases.

Zoonotic and vector-borne parasites and epilepsy in low-income and middle-income countries

Zoonotic and vector-borne parasites are important preventable risk factors for epilepsy. Three parasitic infections - cerebral malaria, Taenia solium cysticercosis and onchocerciasis - have an established association with epilepsy. Parasitoses are widely prevalent in low-income and middle-income countries, which are home to 80% of the people with epilepsy in the world. Once a parasitic infection has taken hold in the brain, therapeutic measures do not seem to influence the development of epilepsy in the long term. Consequently, strategies to control, eliminate and eradicate parasites represent the most feasible way to reduce the epilepsy burden at present. The elucidation of immune mechanisms underpinning the parasitic infections, some of which are parasite-specific, opens up new therapeutic possibilities. In this Review, we explore the pathophysiological basis of the link between parasitic infections and epilepsy, and we consider preventive and therapeutic approaches to reduce the burden of epilepsy attributable to parasitic disorders. We conclude that a concerted approach involving medical, veterinary, parasitological and ecological experts, backed by robust political support and sustainable funding, is the key to reducing this burden.

Inactive Calcified Cysts In Neurocysticercosis: Is This Actually The Case?

Neurocysticercosis is a worldwide disease that is extensively neglected. Its real gravity is not disclosed to people. Knowledge for the population in all countries must be done urgently.

Microsurgical Treatment of Epilepsy with Parenchymal Neurocysticercosis

Parenchymal neurocysticercosis is the most common form of neurocysticercosis in the central nervous system (CNS), which mainly causes epilepsy and usually responses well to routine medications. However, there are appreciable cases of relapses refractory to medical treatment. We investigated microsurgical treatment of epilepsy with parenchymal neurocysticercosis. Nine cases of epilepsy caused by parenchymal neurocysticercosis from 2002 to 2018 were analyzed retrospectively. Cysts in 7 cases were completely removed. No case died of operation and no new dysfunction of the nervous system was observed after surgery. Among the other 9 cases, 8 cases became seizure-free or controlled by medicine according to the postoperative follow-up for 6 months to 9 years. One case was lost for follow-up. It was suggested that epilepsy with parenchymal neurocysticercosis can usually be controlled after routine medications. However, surgery is still indicated in some cases and careful microsurgery is associated with satisfactory clinical outcomes in appropriately selected cases.

Exploring the complex associations over time among albendazole treatment, cyst evolution, and seizure outcomes in neurocysticercosis

OBJECTIVE

To develop a causal model for the occurrence of neurocysticercosis (NC)-related seizures and test hypotheses generated from the model.

METHODS

We used data from a randomized controlled trial comparing albendazole with placebo among patients newly diagnosed with NC. Based on our causal model, we explored the associations among albendazole treatment, NC cyst evolution, and seizure outcomes over 24 months of follow-up using generalized linear mixed effect models.

RESULTS

We included 153 participants, of whom 51% received albendazole. The association between seizure outcomes and treatment over time demonstrated lack of linearity and heterogeneity, requiring the inclusion of time-treatment interaction terms for valid modeling. Participants in the albendazole group had fewer seizures overall and of partial onset at all time points compared with the placebo group, but the difference increased over the first few months following treatment, then decreased over time. Generalized seizures exhibited a more complex association; those in the albendazole group had fewer seizures compared with those in the placebo group for the first few months after treatment, and then the association reversed and those in the placebo arm had fewer seizures. Adjusting for the number of NC cysts in each phase resulted in an attenuation of the strength of association between albendazole and seizure outcomes, consistent with mediation. Among participants in whom all cysts had disappeared (n = 21), none continued to have seizures.

SIGNIFICANCE

Albendazole treatment is associated with a possible reduction in focal seizures in the short term (3-6 months), perhaps by hastening the resolution of the cysts. However, the effect is not discernible over the long term, because most cysts either calcify or resolve completely, regardless of whether treated with albendazole. The stage of evolution of the cysticercus is an important consideration in the evaluation of albendazole effect on seizure outcome.

Intermittent perilesional edema and contrast enhancement in epilepsy with calcified neurocysticercosis may help to identify the seizure focus

Neurocysticercosis is a frequent cause of seizures in endemic countries. It is caused by the larvae of the tapeworm Taenia solium. The larvae once hosted in the cerebral parenchyma evolve into viable cysts, called the vesicular stage (with little or no inflammatory reaction), and may remain at this stage for years, or may enter in an inflammatory-degenerative process (colloidal phase) that ends with calcified nodules. Edema and MRI contrast enhancement associated with these calcifications have been described, suggesting that it may be associated with seizures. However, most of these reports were either cross-sectional case-control series or case reports with a single time point MRI. Therefore, the clinical significance of recurring perilesional edema and contrast enhancement around calcified lesions is still uncertain. Here, we describe repeated MRIs of a patient with calcified neurocysticercosis over 4 years. The seizures were associated with edema and contrast enhancement that disappeared in the seizure-free periods, occurring only around one calcified nodule that coincided with the EEG findings and seizure semiology, although he had three additional calcifications. These findings support the association between pericalcification contrast enhancement and edema with recent seizures. This MRI finding may be a marker to define the epileptogenic focus in epilepsies with calcified neurocysticercosis.

Infections in the immunocompromised child

Prevention and management of opportunistic infections in children is particularly relevant in an era demonstrating an increased prevalence of immunocompromising conditions. The presence of an unusual organism which results in serious infection in a child should therefore always raise the consideration of immune compromise. The more common opportunistic infections have become easier to recognize in recent times due to improved awareness and more refined diagnostic testing. Targeted treatment is usually followed by long-term prophylactic medication. The impact of these conditions on patient outcome is of clear significance and certainly warrants further discussion.

Controversies in the treatment of seizures associated with neurocysticercosis

Seizures are the commonest manifestation of brain parenchymal cysticercosis. In terms of pathophysiological basis and prognostic significance of the seizures, a distinction might be applied between viable cysts, solitary cysticercus granuloma and calcific cysticerci. A number of uncertainties shroud the management of seizures in people with neurocysticercosis (NCC). Although antihelminthic treatment is effective in eliminating viable cysts and possibly cysticercus granulomas, its effect on seizure outcome remains uncertain. Corticosteroids and combinations of antihelminthic and corticosteroid treatments reduce the incidence of seizures in the short term at least. Although antiepileptic drugs (AEDs) are routinely employed in the treatment of seizures associated with NCC, there is no clear consensus regarding the choice and optimal duration of AED treatment. Long-term AED treatment is warranted in people with calcific residue following involution of brain parenchymal cysticercosis. This article is part of a Special Issue entitled "Neurocysticercosis and Epilepsy".

A Stratified Analysis of Clinical Manifestations and Different Diagnostic Methods of Neurocysticercosis-Suspected Tamilian Population Residing in and Around Puducherry

INTRODUCTION

Human beings are accidental hosts for Cysticercus cellulosae showing varied clinical manifestations based on the site harbored by the parasitic cyst because of which disease profile remains unexplored at large. Besides this, diagnosis of the disease with a single conventional method is problematic due to lack of specificity and sensitivity.

AIM

To assess the varied clinical manifestations and stratify based on imaging and serological methods for diagnosis of Neurocysticercosis (NCC) in our study population.

MATERIALS AND METHODS

A hospital-based study was carried out at Jawaharlal Institute of Post-Graduate Medical Education and Research (JIPMER), the tertiary care centre caters patients from Puducherry and surrounding regions of Tamil Nadu. This is a cross-sectional analysis of clinically and radiologically suspected cases of NCC (n=119) for a period of three years (2012 to 2015). The collection of detailed clinical history and imaging findings (MRI or CT) along with the lifestyle parameters was done after obtaining informed consent. Enzyme-Linked Immune-Electro Transfer Blot (EITB) was carried out for the samples collected from study subjects.

RESULTS

Based on dietary and environmental factors non-vegetarians, pork eaters, raw vegetable consumers and open-field defecation showed significant seropositivity. The clinical manifestations like seizures, blurring of vision and chronic headache with nausea followed by neck pain, cognitive deficits and movement disorder have higher seropositivity respectively. Generalized seizures were found to be more than focal seizures. While comparing the imaging and serological tests for NCC diagnosis, the positivity rate was 46.2% considering positive by both methods; but 18.5% of sero-positive cases were imaging negative, and 16% of the sero-negative cases were imaging positive. The study showed a predominance of multiple cysts (62%) in cases with cystic lesions.

CONCLUSION

This study is first of its kind in associating varied and less commonly explored clinical manifestations with two different diagnostic measures in practice and its importance among our study settings. These manifestations must be considered as strong disease entities of NCC, which has to be suggested for differential diagnosis, and cannot be left ignored. Combinatorial diagnostic methods like serology and imaging techniques should be followed in diagnosis and assessing the disease burden.

Inflammation Caused by Praziquantel Treatment Depends on the Location of the Taenia solium Cysticercus in Porcine Neurocysticercosis

Background

Neurocysticercosis (NCC), infection of the central nervous system by Taenia solium cysticerci, is a pleomorphic disease. Inflammation around cysticerci is the major cause of disease but is variably present. One factor modulating the inflammatory responses may be the location and characteristics of the brain tissue adjacent to cysticerci. We analyzed and compared the inflammatory responses to cysticerci located in the parenchyma to those in the meninges or cysticerci partially in contact with both the parenchyma and the meninges (corticomeningeal).

Methodology/Principal Findings

Histological specimens of brain cysticerci (n = 196) from 11 pigs naturally infected with Taenia solium cysticerci were used. Four pigs were sacrificed after 2 days and four after 5 days of a single dose of praziquantel; 3 pigs did not receive treatment. All pigs were intravenously injected with Evans Blue to assess disruption of the blood-brain barrier. The degree of inflammation was estimated by use of a histological score (ISC) based on the extent of the inflammation in the pericystic areas as assessed in an image composed of several photomicrographs taken at 40X amplification. Parenchymal cysticerci provoked a significantly greater level of pericystic inflammation (higher ISC) after antiparasitic treatment compared to meningeal and corticomeningeal cysticerci. ISC of meningeal cysticerci was not significantly affected by treatment. In corticomeningeal cysticerci, the increase in ISC score was correlated to the extent of the cysticercus adjacent to the brain parenchyma. Disruption of the blood-brain barrier was associated with treatment only in parenchymal tissue.

Significance

Inflammatory response to cysticerci located in the meninges was significantly decreased compared to parenchymal cysticerci. The suboptimal inflammatory response to cysticidal drugs may be the reason subarachnoid NCC is generally refractory to treatment compared to parenchymal NCC.

The cystic larvae of the pork tapeworm Taenia solium may affect the human brain causing neurocysticercosis (NCC), a very frequent cause of neurological symptoms in developing countries. The clinical expression and response to treatment of human NCC are related to the location of cysticerci inside (intraparenchymal) or outside the brain parenchyma (extraparenchymal NCC). We used a naturally infected pig model to assess the characteristics of inflammation around brain cysticerci of parenchymal, meningeal and mixed locations. There were no major differences in inflammation without treatment. After antiparasitic treatment with praziquantel, inflammation around parenchymal brain cysticerci increased in comparison to meningeal located cysticerci. Cysticerci partially surrounded by both brain parenchyma and meninges showed increased inflammation in relation to the extent of the cysticercus in the brain parenchyma. The location of cysticerci within the brain is a factor that determines the extent and degree of the immune response following anticysticidal treatment. Similar changes may occur in treated human infections. Our work could contribute to explain the differences in response to antiparasitic treatment in different forms of human neurocysticercosis.

Neurotoxoplasmose e Neurocisticercose em Paciente com AIDS

Objetivo. Relatar um caso de coinfecção por neurotoxoplasmose e neurocisticercose em mulher acometida pela AIDS. Método. Relato de caso prospectivo, descritivo e contemporâneo de paciente do sexo feminino, 36 anos, com quadro clínico compatível com síndrome de hipertensão intracraniana. Os exames complementares diagnostica­ram neurotoxoplasmose e a sorologia anti-HIV foi positiva. Evolui, após semanas, com crises convulsivas e exames subsidiários de imagem demonstrando neurocisticercose. Resultados. As infecções oportunis­tas relacionadas à AIDS são frequentes. A neurotoxoplasmose é cau­sada pelo protozoário Toxoplasma gondii e principal causa de lesão intracraniana expansiva em pacientes com AIDS. A neurocisticercose, provocada por cisticercos (Cysticercus cellulosae ou C. racemosus), formas larvárias da Taenia solium, é bastante prevalente em nosso meio. Conclusão. Após suspeição clínico-radiológica de neurotoxo­plasmose, torna-se imperativo realização de teste anti-HIV, devido sua elevada frequência neste grupo de pacientes. Já a comorbidade neurocisticercose e AIDS é achado excepcional, resultado mais prova­velmente de mera coincidência, sem qualquer vínculo predisponente entre si.

Quantification of Amino Acid Neurotransmitters in Cerebrospinal Fluid of Patients with Neurocysticercosis

Background :

Neurocysticercosis is a parasitic disease that affects the central nervous system. Its main clinical manifestations are epileptic seizures. The objective of this study was to investigate the correlation between neurotransmitter concentrations in cerebrospinal fluid (CSF) and the different evolutive forms of neurocysticercosis with or without seizures.

Methods :

Neurotransmitter concentrations (Aspartate, Glutamate, GABA, Glutamine, Glycine, Taurine) were determined in CSF samples from 42 patients with neurocysticercosis divided into patients with the active cystic form (n = 24, 12 with and 12 without seizures) and patients with calcified form (n = 18, 12 with and 6 without seizures), and a control group consisting of 59 healthy subjects.

Results :

Alterations in amino acid concentration were observed in all patients with neurocysticercosis.

Conclusion :

We conclude that disturbances in amino acid metabolism accompany the presentation of neurocysticercosis. Replacement of the terms inactive cyst by reactive inactive cyst and calcification by reactive calcification is suggested.

Comparative Study of Paired Serum and Cerebrospinal Fluid Samples from Neurocysticercosis Patients for the Detection of Specific Antibody to Taenia solium Immunodiagnostic Antigen

Neurocysticercosis (NCC) is an important disease of the central nervous system caused by infection with Taenia solium metacestodes. In addition to the clinical findings and the imaging analysis, the results of immunological tests are informative for the diagnosis of NCC. To compare the usefulness of serum and cerebrospinal fluid (CSF) samples for antibody detection, paired serum and CSF samples from patients with NCC and other neurological diseases were examined by an enzyme-linked immunosorbent assay with low-molecular-weight antigens purified from T. solium cyst fluid in a blinded fashion. The sensitivity of both serum and CSF samples was 25.0% in inactive NCC cases (n = 4) and 90.9% in active NCC cases (n = 33), and the specificity of serum and CSF was 100% and 95.8%, respectively. When the serum and CSF samples were combined, the sensitivity in active NCC cases became 100%. There was no difference in test performance between serum and CSF samples. Based on these results, we recommend the detection of specific antibodies in serum for the diagnosis of active NCC because of the ease of collection. When the antibody test is negative, however, CSF should be used to confirm NCC and to rule out other medical disorders of the central nervous system. Antibody detection test using only serum or CSF has a limited diagnostic value and cannot be recommended for the diagnosis of suspected inactive NCC cases.

Neurocysticercosis: an update

Neurocysticercosis (NCC) is the most common helminthic disease of the nervous system in humans and a major cause of acquired epilepsy worldwide. The presentation of the disease is dependent on both the immunological response of the host against the parasite as well as the location of the encysted organisms within the central nervous system (CNS). The principles of management utilized for intraparenchymal disease cannot be applied to extraparenchymal NCC. An advance in management of intraparenchymal NCC, the most common form encountered by physicians, is the use of both albendazole and praziquantel as a treatment strategy. Patients with subarachnoid NCC (SANCC) require months of treatment with both an antiparasitic agent and steroids to avoid complications such as hydrocephalus and vascular events during treatment. The determinants of successful treatment in SANCC have not been established, but response to therapy can be determined by evaluating several endpoints related to disease evolution including radiographic changes, serum antigen, and CSF antigen. Intraventricular NCC is primarily a surgical disease and data supports minimally invasive endoscopic removal of cysts in many of these patients. NCC is increasingly recognized in non-endemic countries due to increased immigration making it important for physicians to become familiar with the management of this disease.

The relationship between neurocysticercosis and epilepsy: an endless debate

Neurocysticercosis (NC), or cerebral infection with Taenia solium, is an important public health problem worldwide. Among the neurological sequelae of NC, seizures have been described as the most common symptom. Acute symptomatic seizures often result from degeneration of a viable cyst; however, not all of these patients with acute or provoked seizures will develop epilepsy (i.e., recurrent unprovoked seizures). Because of the high prevalence of epilepsy and NC, a causal, as well as incidental relationship between the two may exist. The epileptogenicity of calcified cysts as well as the potential association between NC and hippocampal sclerosis necessitates future research. Antihelminthic treatment of NC results in disappearance of viable cysts in about one-third of patients with parenchymal disease, but a reduction in seizure recurrence has not been demonstrated in randomized controlled trials. Prevention is critical to reduce the burden of seizure and epilepsy related to NC.

Neurocysticercosis: relationship between the developmental stage of metacestode present and the titre of specific IgG in the cerebrospinal fluid

In double-blind, immunological assays, samples of cerebrospinal fluid (CSF) from 141 patients with neurocysticercosis (NCC) or other neurological disorders were tested for IgG reacting with the excretory/secretory (E/S) antigens of Taenia solium metacestodes. The results for the cases of NCC were then correlated with the developmental stage of the metacestodes present in each case, as assessed by computerized tomography and magnetic-resonance imaging. In the ELISA first used, the samples of CSF from most (88%) of the patients with the vesicular stage of NCC (some of whom also had the degenerate and/or calcified metacestodes) were found to contain the specific IgG. In electro-immunotransfer blot (EITB) assays, three of the E/S antigens, of 95, 49 and 29 kDA, were recognized by 86%-100% of the ELISA-positive CSF. When these three antigens were isolated and tested, as a pool, against all the CSF samples in double-blind ELISA, almost all (96.6%) of the CSF samples from patients with metacestodes at the vesicular stage were recognized. In the detection of individuals with vesicular metacestodes, the assay based on the three isolated antigens was significantly more sensitive than that based on the crude extract of E/S antigens (P < 0.05). In EITB assays based on the three antigens, the isolated proteins were again recognized by IgG in the CSF samples from those with vesicular metacestodes, but without the background 'noise' seen with the crude extract. In every assay employed, none of the CSF samples from NCC cases who only harboured degenerative and/or calcified metacestodes and none of those from patients who had other neurological disorders gave a positive result. The use in ELISA and EITB of antigens purified from crude extracts of metacestode E/S proteins could improve the immunodiagnosis of the vesicular stage of NCC, and allow better evaluation of NCC cases both pre- and post-treatment.

From seizures to epilepsy and its substrates: neurocysticercosis

Neurocysticercosis (NCC) is the main risk factor for late-onset seizures in many Taenia solium endemic countries and is also increasingly recognized in high income countries, where it was once thought to have been eliminated. The course and outcome of NCC-associated seizures and epilepsy are poorly understood. Substrates underlying NCC-associated seizures and epilepsy are unknown. Another unknown is if there is an association between NCC and hippocampal sclerosis (HS) and if it leads to intractable epilepsy. We review evidence regarding the structural basis of seizures and epilepsy in NCC and its association with HS. There are only a limited number of prospective studies of NCC-associated seizures and epilepsy. From these, it can be inferred that the risk of seizure recurrence is high following a first seizure, even though seizures are well-controlled with antiepileptic drugs. The single most important risk factor for ongoing or recurrent seizures is the persistence of either degenerating or residual calcified cysticercus cysts in the brain parenchyma on follow-up imaging studies. Medically intractable epilepsy requiring surgical treatment appears to be rare in people with NCC. In few cases that have been operated, gliosis around the cysticerci is the principal pathologic finding. Reports of the association between NCC and HS might be categorized into those in which the calcified cysticercus is located within the hippocampus and those in which the calcified cysticercus is located remote from the hippocampus. The former are convincing cases of medically intractable epilepsy with good seizure control following hippocampal resection. In the remaining, it is unclear whether a dual pathology relationship exists between HS and the calcified cysticercus. Carefully planned, follow-up studies incorporating high-resolution and quantitative imaging are desirable in order to clarify the outcome, the structural basis of NCC-associated epilepsy, and also its association with HS.

Edema surrounding calcified intracranial cysticerci: clinical manifestations, natural history, and treatment

Calcified granulomas are the most common radiological finding in neurocysticercosis (10-20% of endemic populations). A small proportion serves as foci of seizure activity, which results in large numbers of persons with epilepsy. Calcified granulomas are not all the same. Some demonstrate blood-brain barrier dysfunction (magnetic resonance imaging enhancement) most likely due to the presence of inflammation, visualizable scolices, and/or gliosis. About half the patients with a recent history of seizures, positive serology, and only calcified lesions develop perilesional edema at the time of a seizure recurrence. The natural history, treatment, and pathophysiology of this phenomenon are not well studied. Episodes are usually associated with seizures or other neurological manifestations, resolve by 4-6 weeks, sometimes occur repeatedly, and usually involve a subset of the same calcifications. Treatment is supportive. Histopathological examination of one calcification associated with multiple perilesional edema episodes revealed significant inflammation and supports the concept that perilesional edema is inflammatory in nature. This most likely is due to host responses to released or newly recognized parasite antigen and/or upregulation of the host immune response. Immunosuppressive and anti-inflammatory agents may be useful in prevention and/or treatment of this phenomenon.

Prevalence of neurocysticercosis among people with epilepsy in rural areas of Burkina Faso

PURPOSE

To estimate the lifetime prevalence of neurocysticercosis (NCC)-associated epilepsy and the proportion of NCC among people with epilepsy in three Burkina Faso villages.

METHODS

Three villages were selected to represent three types of pig-rearing methods: (1) Batondo, where pigs are left to roam; (2) Pabré, where pigs are mostly tethered or penned; and (3) Nyonyogo, where the majority of residents are Muslim and few pigs are raised. In Batondo and Nyonyogo, all concessions (a group of several households) were included. Half of the concessions in Pabré were randomly chosen. All households of selected concessions were included, and one person per household was randomly selected for epilepsy screening and serologic testing for cysticercosis. Self-reported cases of epilepsy were also examined and confirmed cases included in analyses other than the estimate of NCC-associated epilepsy prevalence. Epilepsy was defined as ever having had more than one episode of unprovoked seizures. Individuals with medically confirmed epilepsy had a computerized tomography (CT) scan of the brain before and after contrast medium injection. The diagnosis of NCC was made using a modification of the criteria of Del Brutto et al.

KEY FINDINGS

Thirty-nine (4%) of 888 randomly selected villagers and 33 (94%) of 35 self-reported seizures cases were confirmed to have epilepsy by medical examination. Among the 68 participants with epilepsy who had a CT scan, 20 patients were diagnosed with definitive or probable NCC for a proportion of 46.9% (95% confidence interval [CI] 30.2-64.1) in Batondo and 45.5% (95% CI 19.0-74.1) in Pabré. No cases of NCC were identified in Nyonyogo.

SIGNIFICANCE

All the definitive and probable cases of NCC were from the two villages where pig breeding is common. Prevention policies intended to reduce the burden of epilepsy in this country should include measures designed to interrupt the life cycle of Taenia solium.

The association of living conditions and lifestyle factors with burden of cysts among neurocysticercosis patients in Ecuador

We used baseline data on 154 symptomatic neurocysticercosis (NCC) patients in Ecuador to identify predictors of the burden of cysts. We ran logistic regression models with the burden of cysts as the outcome, defined as the number of cysts in the brain (1 vs >1), and having cysts in all 3 phases of evolution (active, transitional and calcifications) vs <3. These two outcomes are thought to be indicators of exposure dose and/or repeated exposure over time. The predictors examined were: living in a rural area, living on a dirt road, living in an adobe or wood house (vs brick/cement), no running water in the house, no bathroom in the house, having a domestic employee cook in the home, eating most meals at restaurants or street vendors, working in a manual labour job. We found that the odds of having multiple NCC cysts was higher among those working in manual labour (OR=3.5, p=0.004), and those who ate most meals outside the home had higher odds of having cysts in all 3 phases (OR=5.0, p=0.007). Burden of cysts may be a useful outcome when looking to identify exposure risk factors in the absence of an uninfected control group.

Quantification of Fas protein in CSF of patients with neurocysticercosis

Neurocysticercosis is a parasitic disease that affects the central nervous system. The objective of this study was to investigate the correlation between neuronal death evaluated by the quantification of Fas apoptotic factor and the different evolutive forms of neurocysticercosis accompanied or not by epileptic seizures.

METHODS

Cerebrospinal fluid samples from 36 patients with a diagnosis of neurocysticercosis divided into the following groups: active cystic form (n=15), 9 patients with and 6 without seizures, and calcified form (=21), 9 with and 12 without seizures. Fourteen patients comprised the control group. Fas protein concentrations were determined by ELISA.

RESULTS

Only the group of patients with calcified cysts without seizures presented cerebrospinal fluid levels of Fas similar to those of the control group. Higher levels were observed for the other groups.

CONCLUSIONS

The present finding suggests high cerebrospinal fluid levels of soluble Fas protein, except for patients with calcified cysts without seizures. Significant differences were observed for the group with calcified cysts and seizures, suggesting greater neuronal damage in these patients. Replacement of the term inactive cyst with reactive inactive cyst is suggested.

Central nervous system infection

This article outlines a practical imaging approach to CNS infection and reviews 5 basic imaging patterns commonly seen: (1) extra-axial lesion, (2) ring-enhancing lesion, (3) temporal lobe lesion, (4) basal ganglia lesion, and (5) white matter abnormality. Opportunistic infections in the setting of HIV are also discussed within the context of these 5 basic imaging patterns. Characteristic imaging features in conjunction with clinical history are also highlighted in order to narrow the differential diagnosis or suggest a specific diagnosis in some cases.

Emergent neuroimaging of intracranial infection/inflammation

Infectious and inflammatory processes of the intracranial compartment often result in acute clinical presentations. The possible causes are legion. Clues to the diagnosis involve clinical presentation, laboratory analysis, and neuroimaging. This article reviews some of the salient factors in understanding intracranial infection/ inflammation, including pathophysiology and neuroimaging protocols/findings, and provides some examples and a few "pearls and pitfalls."

Seizure in people with newly diagnosed active or transitional neurocysticercosis

PURPOSE

The aim of this study is to describe seizure as a presenting symptom in individuals with recently diagnosed neurocysticercosis (NCC).

METHODS

Using logistic regression, we examined the probability of having seizures as a presenting symptom among those with active or transitional NCC by host age and gender, and by number of cysts, location of the cysts in the brain, and phase of evolution of the encysted parasite.

RESULTS

We found that the odds of having seizures as presenting symptom for those in the youngest age group (3-24 years old) were 12.9 times that of the oldest participants (age 55-82 years) (p=0.006). People with cysts in parenchymal locations had a significantly higher odds of seizures compared to those with all their cysts elsewhere (ventricles or subarachnoid) (OR=6.2, p=0.028); and the number of cysts was significantly associated with having seizures (OR=1.1, p=0.026). Host gender and cyst phase were not significantly associated with having seizures after adjusting for confounders and covariates.

CONCLUSION

Children, those with cysts in parenchymal locations, and those with a higher number of cysts appear to be more likely to experience seizure when they have NCC cysts in the active or transitional stage.

A systematic review of the frequency of neurocyticercosis with a focus on people with epilepsy

BACKGROUND

The objective of this study is to conduct a systematic review of studies reporting the frequency of neurocysticercosis (NCC) worldwide.

METHODS/PRINCIPAL FINDINGS

PubMed, Commonwealth Agricultural Bureau (CAB) abstracts and 23 international databases were systematically searched for articles published from January 1, 1990 to June 1, 2008. Articles were evaluated for inclusion by at least two researchers focusing on study design and methods. Data were extracted independently using standardized forms. A random-effects binomial model was used to estimate the proportion of NCC among people with epilepsy (PWE). Overall, 565 articles were retrieved and 290 (51%) selected for further analysis. After a second analytic phase, only 4.5% of articles, all of which used neuroimaging for the diagnosis of NCC, were reviewed. Only two studies, both from the US, estimated an incidence rate of NCC using hospital discharge data. The prevalence of NCC in a random sample of village residents was reported from one study where 9.1% of the population harboured brain lesions of NCC. The proportion of NCC among different study populations varied widely. However, the proportion of NCC in PWE was a lot more consistent. The pooled estimate for this population was 29.0% (95%CI: 22.9%-35.5%). These results were not sensitive to the inclusion or exclusion of any particular study.

CONCLUSION/SIGNIFICANCE

Only one study has estimated the prevalence of NCC in a random sample of all residents. Hence, the prevalence of NCC worldwide remains unknown. However, the pooled estimate for the proportion of NCC among PWE was very robust and could be used, in conjunction with estimates of the prevalence and incidence of epilepsy, to estimate this component of the burden of NCC in endemic areas. The previously recommended guidelines for the diagnostic process and for declaring NCC an international reportable disease would improve the knowledge on the global frequency of NCC.

The association of host age and gender with inflammation around neurocysticercosis cysts

The results of previous investigations indicate that age and gender may influence the strength of the human host's immune response to infection of the central nervous system with the larvae of Taenia solium. Most of the relevant research on such neurocysticercosis (NCC) has, however, been conducted on hospital-based samples in developing countries, where differential access to healthcare may bias the study results. Using data from 171 NCC patients participating in a treatment trial, the associations of patient age and gender with the presence of inflammation around NCC cysts (i.e. cysts in the transitional phase) have recently been explored, after controlling for measures of economic and geographical access to healthcare. Data on cysts were collected from computed-tomography or magnetic-resonance images taken at four time-points, from baseline to 12-months post-treatment. The odds of having transitional cysts were evaluated by logistic regression whereas Poisson regression was used to explore the numbers of transitional cysts, with generalised estimating equations (GEE) used to account for the multiple observations over time. After controlling for healthcare access, the odds of having transitional cysts were found to be 1.5-fold higher for the female patients than for the male, although this association was not statistically significant (P = 0.136). In the Poisson model, however, the number of transitional cysts was found to be 1.8-fold higher in the female patients than in the male, and this gender effect was not only statistically significant (P = 0.002) but also constant over time. The association of host age with transitional cysts was more complicated, with significant interaction between age and time. It therefore appears that there are significant gender and age differences in the local immune response to NCC, even after adjusting for differences in healthcare access.

Investigation of familial aggregation of seizures in neurocysticercosis patients

Regional differences in the clinical manifestations of human neurocysticercosis (NCC) may indicate a role of host genetics. We examined whether there is familial aggregation of seizures in first-degree relatives of NCC patients with seizure versus NCC patients without seizure as presenting symptom in a group of patients in Ecuador. The results of our analyses were null, and there was no trend toward familial aggregation of seizures in NCC patients.

Perilesional brain oedema and seizure activity in patients with calcified neurocysticercosis: a prospective cohort and nested case-control study

BACKGROUND

Cysticercosis due to Taenia solium is a cause of adult-acquired seizures and epilepsy even in patients with only calcified larval cysts. Transient perilesional brain oedema is seen around the calcified foci but its importance, association with seizures, incidence, and pathophysiology are unknown.

METHODS

110 patients with only calcified lesions and a history of seizures or severe headaches were followed prospectively in a cohort design to assess the incidence of seizure relapse. In a nested case-control substudy, perilesional oedema was assessed by MRI at the time of seizure in symptomatic patients and in matched asymptomatic controls taken from the study population.

FINDINGS

Between November, 1999, and December, 2006, 29 patients had an incident seizure during a median follow up of 32.33 (SD 19.99) months, with an estimated 5-year seizure incidence of 36% (95% CI 25% to 49%). 24 of 29 (83%) patients with seizure relapse had an MRI evaluation within 5 days of the event; perilesional oedema was seen in 12 patients (50%) compared with two (9%) of 23 asymptomatic matched controls.

INTERPRETATION

Perilesional oedema is common and associated with episodic seizure activity in patients with calcified neurocysticercosis. Our findings are probably representative of symptomatic patients in regions where T solium neurocysticercosis is endemic and suggest a unique and possibly preventable cause of seizures in this population.

Treatment of neurocysticercosis: is it beneficial?

Neurocysticercosis is the most common parasitic disease of the CNS. Intracranial neurocysticercosis is classified into cerebral parenchymal and extraparenchymal forms (subarachnoidal and intraventricular). Current medical therapy for parenchymal and extraparenchymal neurocysticercosis invovles the use of anticysticercal drugs. Albendazole and praziquantel are two commonly used drugs. Most experts prefer to always use oral or parenteral corticosteroids along with anticysticercal drugs. The role of anticysticercal drugs in the treatment of parenchymal neurocysticercosis has always been a subject of intense controversy. Whether therapy with anticysticercal drugs results in improved seizure-related prognosis remains a major concern. A recent meta-analysis evaluating six controlled trials suggests that treatment with anticysticercal drugs results in better resolution of colloidal and vesicular cysticerci; in patients taking anticysticercal drugs, there was a lower risk of seizure reccurence in patients with colloidal cysticerci and a significant reduction in the rate of generalized seizures in patients with vesicular cysticerci. However, the findings of the study by Carpio et al. have revived the controversy regarding this treatment. These authors noted that the effect of a single dose of albendazole is, at best, only modest. Only a minority of patients with parenchymal neurocysticercosis benefitted and became cyst free and there was a lack of effectiveness toward the associated seizure disorders. No response was seen in patients with degenerative parenchymal or extraparenchymal forms of neurocysticercosis. Carpio et al. suggest that there is a need for further studies that employ different approaches, such as the use of high initial doses of albendazole, the use of two anticysticercal drugs or repeated prolonged courses of albendazole.

WITHDRAWN: Drugs for treating neurocysticercosis (tapeworm infection of the brain)

BACKGROUND

Anthelminthic drugs may shrink brain cysts in neurocysticercosis, but can also cause severe adverse effects.

OBJECTIVES

The objective of this review was to assess the effects of drug treatment in human neurocysticercosis in relation to survival, cyst persistence, subsequent seizures and hydrocephalus.

SEARCH STRATEGY

We searched the Cochrane Infectious Diseases Group specialized trials register (September 2002), The Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2002), MEDLINE (1966 to September 2002), EMBASE (1980 to August 2002), LILACS (September 2002). We contacted researchers and experts in the field, and pharmaceutical companies.

SELECTION CRITERIA

Randomised or quasi-randomised trials comparing a cysticidal drug with a placebo or a control group receiving symptomatic therapy, in patients with neurocystercosis.

DATA COLLECTION AND ANALYSIS

Assessment of trial quality and data extraction was done independently by two reviewers.

MAIN RESULTS

Four studies involving 305 people met the inclusion criteria. None reported on withdrawal of anticonvulsant therapy, headache relief, disability or death as outcomes. A difference just approaching significance was detected between cysticidal therapy and placebo in relation to cyst persistence up to six months (relative risk 0.83, 95% confidence interval 0.70 to 0.99). Two trials reported on seizures after one to two years follow-up and found no difference (relative risk 0.95, 95% 0.59 to 1.51). There was no difference detected for hydrocephalus (relative risk 2.19, 95% confidence interval 0.29 to 16.55).

AUTHORS' CONCLUSIONS

There is insufficient evidence to assess whether cysticidal therapy in neurocysticerosis is associated with beneficial effects.

Epidemiologic classification of seizures associated with neurocysticercosis: observations from a sample of seizure disorders in neurologic care in India

AIMS

To determine the etiologic role of neurocysticercosis (NC) in a hospital-based sample of epilepsies divided according to International League Against Epilepsy (ILAE) epidemiological criteria and number of seizures prior to presentation.

METHODS

A sample comprising 1026 consecutive patients with either definite seizures or epilepsy attending a Neurology Outpatient Service was divided into four subgroups: single seizure (n = 314), incident epilepsy (n = 127), prevalent epilepsy (n = 398) and recurrent acute symptomatic seizures (RASS) (n = 175). The etiologic contribution of NC to each of the subgroups was examined with imaging studies.

RESULTS

Neurocysticercosis was diagnosed on imaging studies in 34.6% of patients with seizure disorder of any type, 59.2% of those with a single seizure, 23.7% of those with recurrent seizure disorder, 92.0% of those with RASS, none of cases of incident epilepsy and 2.0% with prevalent epilepsy. A diagnosis of NC was significantly associated with single seizures (P < 0.001).

CONCLUSIONS

Imaging abnormalities consistent with NC are frequently noted in persons presenting with a single seizure in neurologic care in NC-endemic countries like India. The probability of diagnosing NC diminishes with increasing numbers of seizures. Among samples of individuals with recurrent-unprovoked seizures, it is rare for imaging to demonstrate lesions of NC.

Serum and cerebrospinal fluid S100B concentrations in patients with neurocysticercosis

The clinical manifestations of neurocysticercosis (NC) are varied and depend on the number and location of cysts, as well as on the host immune response. Symptoms usually occur in NC when cysticerci enter a degenerative course associated with an inflammatory response. The expression of brain damage markers may be expected to increase during this phase. S100B is a calcium-binding protein produced and released predominantly by astrocytes that has been used as a marker of reactive gliosis and astrocytic death in many pathological conditions. The aim of the present study was to investigate the levels of S100B in patients in different phases of NC evolution. Cerebrospinal fluid and serum S100B concentrations were measured in 25 patients with NC: 14 patients with degenerative cysts (D), 8 patients with viable cysts (V) and 3 patients with inactive cysts. All NC patients, except 1, had five or less cysts. In most of them, symptoms had been present for at least 1 month before sample collection. Samples from 8 normal controls (C) were also assayed. The albumin quotient was used to estimate the blood-brain barrier permeability. There were no significant differences in serum (P = 0.5) or cerebrospinal fluid (P = 0.91) S100B levels among the V, D, and C groups. These findings suggest that parenchymal changes associated with a relatively small number of degenerating cysts probably have a negligible impact on glial tissue.