Asymptomatic Neurocysticercosis Research Articles

Neurocysticercosis: The duration of its preclinical phase relies on the parasite location.

Neurocysticercosis (NC) is a heterogeneous disease particularly in terms of response to treatment and prognosis. Parasite localization is one of the main factors involved in this heterogeneity. In this study we aim to determine whether differences in the duration of the preclinical phase associated with parasite location, could contribute to said heterogeneity. Ninety-nine patients were included, 24 with parasites in the parenchyma (PAR), 56 in the subarachnoid (SA) space and 19 in the ventricular system (IV). A questionnaire designed to assess exposure to classic NC risk factors 5, 10, 15, 20 and more than 20 years prior to diagnosis was applied. The results were compared between the three groups. Also, asymptomatic relatives of patients who had shared their living conditions in childhood or more recently were included and underwent brain scan and blood testing for specific antibodies. Over the course of their lives, exposure to risk factors decreased significantly for all patients, although the decrease was more evident in patients with parasites in the SA space (p < 0.001) compared to patients with PAR (p = 0.011) or IV cysts (p = 0.020). Five years prior to diagnosis, exposure to risk factors was significantly higher in patients with PAR or IV NC than in patients with SA NC (p = 0.04). Furthermore, individuals in close contact with PAR or IV patients in the years preceding diagnosis were more likely to have asymptomatic NC, specific antibodies in sera, particularly IgM, compared to individuals in close contact with SA patients during the same period. All these findings are highly suggestive of the possibility of a more recent infection of patients affected by parenchymal and ventricular NC than of patients with subarachnoid NC. Consequently, subarachnoid disease could be considered a chronic disease, which, probably contributes to the severity of the disease as well as the minimal response to medical treatment.

Radiological screening for neurocysticercosis in asymptomatic siblings of children with neurocysticercosis: An observational cohort study

Introduction: Neurocysticercosis (NCC) is the most common helminthic infection of the central nervous system and a leading cause of acquired epilepsy worldwide. Tuberculosis (TB) is transmitted through droplet infection to index pediatric case from only sputum acid-fast bacilli -positive patients while NCC in an index child can result from fecal–oral route from other family members who are Taenia carriers or through autoinfection as well. Objective: Similar to universal practice of TB screening of asymptomatic family members with chest X-ray which poses radiation hazard, radiation-free radiological screening by magnetic resonance imaging (MRI) brain of asymptomatic siblings of children with NCC was carried out in the present study in addition to evaluation of family members for taeniasis. Methods: Siblings (between 1 and 18 years of age) of children attending the pediatric NCC clinic at a tertiary care hospital in Chandigarh, India, with clinically suspected and radiologically confirmed the diagnosis of NCC, were enrolled. Contrast-enhanced MRI brain was obtained free of cost to detect the presence of asymptomatic NCC in siblings enrolled in the study. Stool analysis of family members of children with NCC was carried out to detect Taenia solium carriers. Results: Of 39 enrolled asymptomatic siblings, 4 (10.3%) children were detected to have solitary intraparenchymal NCC lesion. Of the aforementioned four siblings, 3 (75%) had viable lesions, while 1 (25%) had calcified lesion. Only 2 (1.7%) of 118 stool samples of family members tested were positive for T. solium eggs. Conclusions: The results from the present study suggest clustering of NCC cases in the family and that majority of children with NCC may continue to remain asymptomatic. Targeted family screening for NCC in asymptomatic family members of children with NCC may prove more cost effective than routine mass screening. Based on the results of this study, targeted deworming of community food handlers and caution in conducting routine deworming of children are suggested.

High Prevalence of Asymptomatic Neurocysticercosis in an Endemic Rural Community in Peru.

BackgroundNeurocysticercosis is a common helminthic infection of the central nervous system and an important cause of adult-onset epilepsy in endemic countries. However, few studies have examined associations between neurologic symptoms, serology and radiographic findings on a community-level.MethodologyWe conducted a population-based study of resident’s ≥2 years old in a highly endemic village in Peru (pop. 454). We applied a 14 -question neurologic screening tool and evaluated serum for antibodies against Taenia solium cysticercosis using enzyme-linked immunoelectrotransfer blot (LLGP-EITB). We invited all residents ≥18 years old to have non-contrast computerized tomography (CT) of the head.Principal findingsOf the 385 residents who provided serum samples, 142 (36.9%) were seropositive. Of the 256 residents who underwent CT scan, 48 (18.8%) had brain calcifications consistent with NCC; 8/48 (17.0%) reported a history of headache and/or seizures. Exposure to T. solium is very common in this endemic community where 1 out of 5 residents had brain calcifications. However, the vast majority of people with calcifications were asymptomatic.ConclusionThis study reports a high prevalence of NCC infection in an endemic community in Peru and confirms that a large proportion of apparently asymptomatic residents have brain calcifications that could provoke seizures in the future.

Association between Taenia solium infection and HIV/AIDS in northern Tanzania: a matched cross sectional-study.

BackgroundThe frequency of Taenia solium, a zoonotic helminth, is increasing in many countries of sub-Saharan Africa, where the prevalence of the human immunodeficiency virus (HIV) is also high. However, little is known about how these two infections interact. The aim of this study was to compare the proportion of HIV positive (+) and negative (−) individuals who are infected with Taenia solium (TSOL) and who present with clinical and neurological manifestations of cysticercosis (CC).MethodsIn northern Tanzania, 170 HIV+ individuals and 170 HIV– controls matched for gender, age and village of origin were recruited. HIV staging and serological tests for TSOL antibodies (Ab) and antigen (Ag) were performed. Neurocysticercosis (NCC) was determined by computed tomography (CT) using standard diagnostic criteria. Neurological manifestations were confirmed by a standard neurological examination. In addition, demographic, clinical and neuroimaging data were collected. Further, CD4+ cell counts as well as information on highly active antiretroviral treatment (HAART) were noted.ResultsNo significant differences between HIV+ and HIV– individuals regarding the sero-prevalence of taeniosis-Ab (0.6% vs 1.2%), CC-Ab (2.4% vs 2.4%) and CC-Ag (0.6% vs 0.0%) were detected. A total of six NCC cases (3 HIV+ and 3 HIV–) were detected in the group of matched participants. Two individuals (1 HIV+ and 1 HIV–) presented with headaches as the main symptom for NCC, and four with asymptomatic NCC. Among the HIV+ group, TSOL was not associated with CD4+ cell counts, HAART duration or HIV stage.ConclusionsThis study found lower prevalence of taeniosis, CC and NCC than had been reported in the region to date. This low level of infection may have resulted in an inability to find cross-sectional associations between HIV status and TSOL infection or NCC. Larger sample sizes will be required in future studies conducted in that area to conclude if HIV influences the way NCC manifests itself.Electronic supplementary materialThe online version of this article (doi:10.1186/s40249-016-0209-7) contains supplementary material, which is available to authorized users.

Human Glutathione S-Transferase Enzyme Gene Polymorphisms and Their Association With Neurocysticercosis.

Neurocysticercosis (NCC), caused by cysticerci of Taenia solium is the most common helminthic infection of the central nervous system. Some individuals harboring different stages of cysticerci in the brain remain asymptomatic, while others with similar cysticerci lesions develop symptoms and the reasons remain largely unknown. Inflammatory response to antigens of dying parasite is said to be responsible for symptomatic disease. Reactive oxygen species (ROS) that are generated in inflammatory conditions can damage cellular macromolecules such as lipids, DNA, and proteins. The glutathione S-transferases (GSTs) are critical for the protection of cells from ROS. A total of 250 individuals were included in the study: symptomatic NCC = 75, asymptomatic NCC = 75, and healthy controls = 100. The individuals carrying the deletions of GSTM1 and GSTT1 were at risk for NCC (OR = 2.99, 95%CI = 1.31-6.82, p = 0.0073 and OR = 1.94, 95%CI = 0.98-3.82, p = 0.0550 respectively). Further, the individuals with these deletions were more likely to develop symptomatic disease (OR = 5.08, 95% CI = 2.12-12.18, p = 0.0001 for GSTM1 and OR = 3.25, 95%CI = 1.55-6.82, p = 0.0018 for GSTT1). Genetic variants of GSTM3 and GSTP1 were not associated with NCC. The total GST activity and levels of GSTM1, GSTT1, and GSTM3 were significantly higher in asymptomatic subjects than in symptomatic and healthy controls. Lower GST activity was observed in individuals with GSTM1 and GSTT1 deletions. The present study suggests that the individuals with GSTM1 and GSTT1 deletions are at higher risk to develop symptomatic disease. The higher GST activity and levels of GSTM1, GSTT1, and GSTM3 are likely to play role in maintaining asymptomatic condition.

Association of ICAM-1 K469E polymorphism with neurocysticercosis

Neurocysticercosis (NCC), a central nervous system (CNS) disease is caused by the larval stage of Taenia solium. The disease is heterogeneous in clinical presentation; some infected individuals develop symptoms and others may remain symptom free. Impaired blood brain barrier allows recruitment of immune cells in the CNS during infection and soluble intercellular adhesion molecule-1 (sICAM-1) plays an important role in the recruitment of immune cells. We studied ICAM-1 K469E polymorphism among symptomatic and asymptomatic NCC patients. The study revealed that individuals with variant (EE) genotype were more susceptible to symptomatic NCC and also had an elevated level of sICAM-1.

Asymptomatic neurocysticercosis over 15 years between transitory ischemic attack as initial and epilepsy as second manifestation

Asymptomatic neurocysticercosis over 15 years between transitory ischemic attack as initial and epilepsy as second manifestation

Association of MMP-2 and MMP-9 with clinical outcome of neurocysticercosis

Matrix metalloproteinases (MMPs) are the major endopeptidases involved in proteolysis of blood brain barrier (BBB) during central nervous system (CNS) infections. The present study detected serum levels and activities of MMP-2 and MMP-9 in patients with neurocysticercosis (NCC) and their association with symptomatic disease. In total, 68 individuals with NCC (36 symptomatic patients with active seizures and 32 asymptomatic individuals) and 37 healthy controls were enrolled for the study. Serum MMP-2 and MMP-9 levels and their activities were measured by ELISA and gel zymography respectively. Mean serum MMP-2 levels (ng/ml) were higher both in asymptomatic and symptomatic NCC cases compared to healthy controls. However, significantly higher levels of serum MMP-9 (ng/ml) were detected only in symptomatic NCC patients compared to asymptomatic NCC cases and healthy controls. Levels of both MMPs positively correlated with symptomatic NCC. Serum MMP-2 activities were significantly higher in symptomatic and asymptomatic NCC compared to healthy controls whereas serum MMP-9 activity was significantly associated with symptomatic NCC compared to healthy controls and asymptomatic NCC. In conclusion, the elevated level of MMP-9 in serum appears to play an important role in the development of symptoms i.e. active seizures in patients with NCC. However, further studies are needed to elucidate its precise role in disease pathogenesis.

An epidemiological study of asymptomatic neurocysticercosis in a pig farming community in northern India

Neurocysticercosis (NCC) is the most frequent parasitic infection of the central nervous system caused by the larvae of Taenia solium. The prevalence of NCC is obscured due to variations in the methods used for epidemiological studies and often asymptomatic manifestation. The present study was conducted on 595 apparently healthy individuals belonging to the pig farming community of northern India to estimate the prevalence of asymptomatic NCC and to evaluate risk factors based on questionnaires. Diagnosis of NCC was based on neuroimaging, immunological and epidemiological criteria. Asymptomatic NCC was detected in 90 (15.1%) of 595 individuals. The evaluation of risk factors showed that age >15 years (P=0.001), intake of raw vegetables (P=0.025) and undercooked pork (P=0.005), lack of safe drinking water (P=0.003), inadequate drainage system (P=0.049), no separate place for pigs (P≤0.001), NCC related active epilepsy in the family (P≤0.001) were significantly associated with asymptomatic NCC. The present study shows high prevalence of asymptomatic NCC in pig farming community of northern India. Further, asymptomatic NCC is associated with most variables of poor socio-economic parameters.

Immune response in symptomatic and asymptomatic neurocysticercosis

Innate immune system is crucial in the pathogenesis of neurocysticercosis (NCC) and helminth glycans can induce anti-inflammatory milieu via toll-like receptor 4 (TLR4) dependent mechanisms. The association of TLR4 and cytokines is yet to be explored in NCC. Therefore, the present study detected the serum levels of cytokines and soluble intercellular adhesion molecule (sICAM)-1 in asymptomatic and symptomatic NCC and their association with TLR4 expression. Sixty eight patients with NCC (asymptomatic, 36 and symptomatic, 32), and age and gender matched 37 healthy controls were enrolled to determine the levels of different pro- and anti-inflammatory cytokines, sICAM-1 in the serum by ELISA and expression of TLR4 in peripheral blood mononuclear cells (PBMCs) by flow cytometry. In asymptomatic NCC cases, the levels of IL-10 and IL-4 were significantly elevated compared to healthy controls and symptomatic NCC patients whereas the levels of IFN-γ, TNF-α, IL-17, IL-23 and sICAM-1 were higher in symptomatic NCC patients compared to healthy controls and asymptomatic NCC individuals. Frequency of TLR4 expressing PBMCs and CD14 positive cells were significantly higher in both groups of NCC. Although the number of TLR4 expressing cells was almost similar in both asymptomatic and symptomatic groups, the median fluorescence intensity was significantly higher in symptomatic group indicating that higher levels of TLR4 expression in symptomatic patients correlated with enhanced pro-inflammatory cytokine production.

Toll‐Like Receptor 4 Polymorphism and Its Association with Symptomatic Neurocysticercosis

Symptoms and signs of neurocysticercosis (NCC) are nonspecific and depend upon several factors, including the host immune response to the parasite. Toll-like receptors (TLRs) play an important role in innate immunity. Susceptibility of humans to NCC in relation to TLR polymorphism is unknown. The present study examines TLR4 polymorphism in human NCC and its role in symptomatic disease. A total of 140 patients with NCC (82 symptomatic [ie, with active epilepsy] and 58 asymptomatic) and 150 healthy control subjects were examined for TLR4 Asp299Gly and Thr399Ile polymorphisms by means of polymerase chain reaction and restriction fragment-length polymorphism. TLR4 Asp299Gly and Thr399Ile were significantly associated with the occurrence of NCC (P < .001 for Asp299Gly; P = .003 for Thr399Ile) and progression to symptomatic NCC, compared with control subjects (P < .001 for Asp299Gly; P < .001 for Thr399Ile) or asymptomatic NCC (P < .001 for Asp299Gly; P = .002 for Thr399Ile). Frequency of haplotype Gly/Thr (P <.001) was observed to be a risk factor for susceptibility to NCC. Gly and Ile carriers had a statistically significant association with NCC (P < .001 for Gly; P = .003 for Ile) and symptomatic NCC (P < .001 for Gly; P <or= .001 for Ile), compared with control subjects. Both carriers were also associated with symptomatic NCC (P < .001 for Gly; P < .004 for Ile), when compared with asymptomatic NCC.

Increased expression of ICAM-1 among symptomatic neurocysticercosis

Neurocysticercosis (NCC) is a common parasitic infection of the central nervous system (CNS) caused by larvae of Taenia solium. Most infected individuals remain asymptomatic while few develop symptoms i.e. seizures. Integrity or disruption of blood brain barrier plays an important role in CNS infection and inflammatory response. Therefore, we studied the induction of Th1 (TNF-α, IFN-γ, IL-1β and IL-2), Th2 (IL-4), IL-10 cytokines and adhesion molecule sICAM-1 in the lymphocytes isolated from symptomatic and asymptomatic NCC cases by stimulating them with Taenia solium cyst fluid antigens. The expression of TNF-α, IFN-γ, IL-1β and sICAM-1 was significantly higher only in symptomatic NCC cases. Our study highlights the role of adhesion molecules in the development of symptoms in NCC.

Asymptomatic neurocysticercosis in a patient with AIDS and cryptococcal meningitis

Asymptomatic neurocysticercosis in a patient with AIDS and cryptococcal meningitis

Neurocysticercosis--a review of 231 cases.

Two hundred thirty-one cases of neurocysticercosis are reviewed. Diagnosis was established by cerebral computed tomography during a seven-year period (1983-1989). One hundred and fourty-four (62%) presented with symptom-related disease (symptomatic neurocysticercosis and in 87 the diagnosis was incidental (asymptomatic neurocysticercosis). In symptomatic neurocysticercosis the parasitosis was considered inactive in 115 cases and active in 29. Seizures occurred in 135 patients (96% of the symptomatic neurocysticercosis). In the active form we also found: meningitis (n = 15), intracranial hypertension (n = 12), hydrocephalus (n = 10) and arteritis (n = 2). Treatment included praziquantel (n = 21), albendazole (n = 4), dexamethasone (n = 18) and surgery (n = 10).