Pediatric neurocysticercosis: current challenges and future prospects

Development and validation of a predictive model assessing the risk of seizure recurrence in children with neurocysticercosis

INTRODUCTION

Neurocysticercosis (NCC) is a significant factor contributing to the incidence of seizures in developing countries. While numerous studies have investigated the recurrence of seizures in NCC, their reliability is often limited.

METHODS

We assessed the socio-demographic, clinical, and neuroimaging details of 161 children with seizures caused by NCC. We monitored them for seizure recurrence over a 6-month follow-up period. We divided the children into two groups: those with seizure recurrence and those without. Subsequently, we identified predictive factors associated with seizure recurrence through univariate analysis, followed by multivariate binary logistic regression. We evaluated the prognostic model for discrimination and calibration and then internally validated it using the bootstrap method.

RESULTS

A total of 23 children experienced breakthrough seizures. In multivariate analysis, the presence of epileptiform abnormalities in electroencephalogram (EEG), more than 5 NCC lesions, the presence of perilesional edema greater than 2 cm in maximum dimension, and a cluster of seizures before presentation were significantly associated with seizure recurrence (p < 0.05). These factors were included in the final NEPC (Number of NCC lesions, Epileptiform EEG abnormality, Perilesional edema, and Cluster of seizures) score. The final model exhibited good discrimination (AUC = 89.1 %; 95 % CI=80.5-95.3 %, p < 0.001) and calibration (p = 0.54). A score of 4 appeared to be the optimal threshold for discriminating between individuals with and without seizure recurrence, with sensitivity and specificity values of 85 % and 87 %, respectively. Interrater reliability was very strong between two pediatric neurologists and strong between a pediatric neurologist and a pediatric neurology trainee resident (k = 0.92 and 0.86, respectively).

CONCLUSION

The NEPC score demonstrates good sensitivity and specificity in predicting seizure recurrence in pediatric children with NCC.

Global research on cysticercosis and neurocysticercosis: A bibliometric analysis

Background

Cysticercosis is a parasitic infection caused by the larval stage Taenia solium. As a neglected tropical disease that is also difficult to diagnose, cysticercosis constitutes an important public health and research challenge. To characterize the development of research on cysticercosis and neurocysticercosis, considering the level of scientific evidence provided and the contribution of different countries to research, according to their endemic nature and their income level.

Methods

Indexed publications on cysticercosis and neurocysticercosis were retrieved from the MEDLINE database, and the evolution of scientific production and the topic areas addressed in the body of research were analyzed.

Results

A total of 7,860 papers published between 1928 and 2021 were analyzed. The volume of annual publications increased over time, standing at over 200 documents/year since 2010. Case studies constitute the main study design (27.4% of the documents with available information, n = 2,155), with fewer studies that provide the highest levels of scientific evidence, such as clinical studies (1.9%, n = 149) or systematic reviews (0.8%, n = 63). The most productive journals belong to the Parasitology and Tropical Medicine categories. Although the USA is the most productive country (n = 2,292), countries where Tenia solium is endemic, such as India (n = 1,749), Brazil (n = 941) and Peru (n = 898) also stand out, as does Mexico (n = 1,414). However, other endemic countries in Latin America and sub-Saharan Africa show little participation in the research. The level of international collaboration by country is very uneven, with some countries presenting very low values, such as India (9.9% of documents in international collaboration) or Brazil (18.7%); while there is evidence of intense international collaboration in countries like Peru (91.3%), Tanzania (88.2%) or Kenya (93.1%). Research output has coalesced in three thematic clusters: basic research in animals; parasitism, animal health, and zoonoses; and the diagnosis and therapeutic approach in diseases associated with cysticercosis and neurocysticercosis.

Conclusions

The generation of knowledge on cysticercosis presents different features from other areas of research, such as the outstanding contribution of only some endemic countries; and the relevance of comprehensive approaches to research (animal and human health). Studies that provide higher levels of scientific evidence should be promoted, as should research in endemic areas.

Metabolic Disorders among Children Presenting with Acute Encephalopathy

OBJECTIVE

To study the clinicoetiological profile of children presenting with acute noninfectious encephalopathy (NIE) and identify the proportion of children having inborn errors of metabolism (IEM).

METHOD

This descriptive cross sectional study was conducted in a tertiary care centre in Northern India. Consecutive children, aged more than 28 d and less than 12 y, with acute encephalopathy were enrolled after ruling out CNS infection. All children were evaluated on an internally validated structured proforma. A sequential pre-decided battery of tests was applied to determine the cause of encephalopathy. IEM suspects were subjected to TMS/GCMS followed by mutation analysis for confirmation.

RESULTS

Fifty children with noninfectious encephalopathy (NIE) were recruited and metabolic causes were detected in 9 of these children (18%), aged 3 to 42 mo, with female preponderance. The IEMs included lactic acidosis (4), glutaric aciduria (3), isovaleric academia (1), and hyperhomocysteinemia (1). History of previously affected siblings and consanguinity between the parents were important indicators of IEM. MS/MS and mutation analysis were the mainstay of diagnosis in these patients. IEMs contributed to the most common cause amongst cases of NIE.

CONCLUSION

IEMs constitute a significant proportion of NIE in India and a high index of suspicion is required to make the diagnosis.

Seizure Semiology, Location of Lesion on Neuroimaging, and Interictal Electroencephalographic (EEG) Abnormalities in Children With Single-Lesion Neurocysticercosis-Is There a Correlation?

BACKGROUND

Single-lesion neurocysticercosis provides a model of seizure genesis secondary to an acquired lesion. We aimed to study the correlation of seizure semiology with the location of the lesion and interictal electroencephalographic (EEG) abnormalities in children with single-lesion neurocysticercosis. Methods: Prospective, observational study in children with single-lesion neurocysticercosis and seizures. Seizure classification was done after an interview with the parent/onlooker and the child. Localization and lateralization of the lesion were done by neuroimaging. The EEG abnormalities were classified based on their morphology and location. Results: Ninety-two children (7.9 ± 2.4 years) were included. Focal-onset seizures were the commonest (n = 54; 58.6%) seizures. Majority of the lesions were located in the frontal (n = 43; 47%) and parietal cortex (n = 34; 37%). EEG showed focal slowing (n = 15; 53.6%) and epileptiform spikes/spike-wave complexes (n = 13; 46.4%). There was a perfect agreement of clinical semiology with imaging lateralization (K = 1.0) and moderate agreement with imaging localization (K = 0.4). There was no significant agreement of clinical localization with EEG slowing (K = 0.1) or sharps (K = 0). There was moderate agreement (K = 0.6) of EEG slowing and substantial agreement (K = 0.7) of EEG sharps with clinical lateralization. Focal EEG slowing had moderate (K = 0.5) agreement with imaging lateralization. Focal sharps/spikes had substantial (K = 0.7) agreement with imaging lateralization. The positive predictive value (PPV) of seizure semiology for lateralization and localization was 100% and 68%, respectively. PVV of focal sharps for lateralization and localization was 84% and 70%, respectively. PPV of focal slowing for lateralization and localization was 77% and 65%, respectively. Conclusion: Seizure semiology in single-lesion neurocysticercosis correlates very well with lateralization but not so well with localization of lesion on neuroimaging. Focal EEG abnormalities are seen in nearly one-third of children with single-lesion neurocysticercosis. EEG often predicts the side of the lesion but has poor localizing value.

Efficacy of Combination Therapy of Albendazole and Praziquantel vs Albendazole Monotherapy in Children With Persistent Neurocysticercosis: A Randomized Controlled Trial

AIM

To compare the efficacy of combined albendazole and praziquantel therapy vs albendazole monotherapy in a placebo-controlled, double-blinded, randomized trial in children with persisting neurocysticercosis.

METHODS

Children with persistent neurocysticercosis were randomized into 3 groups-albendazole (n = 19), albendazole and praziquantel (n = 21), and placebo (n = 20)-for 30 days and followed up at 3 and 6 months for resolution and recurrence of seizures.

RESULTS

Mean age of children was 9.3 ± 2.9 years (range 3-14). At baseline, the majority of lesions were ring-enhancing (70%), colloidal (97%), with scolex (68%) and perilesional-edema (45%), and located in the parietal (58%) lobe. One case each in albendazole and placebo groups had a recurrence of seizure in the first month of treatment. The majority (62%) of children in the combination therapy group showed complete resolution of the persisting lesion at the end of 6 months compared to the albendazole alone group (26.3%, P = .02). Percentage reduction in the lesion's mean area at 6 months was highest in the combination group compared with other groups (P = .006). Rate of calcification was identical in all 3 groups (10%). None of the patients required interruption of therapy.

CONCLUSION

Our study demonstrates the safety and efficacy of albendazole and praziquantel in combination for complete radiologic resolution in children with persistent neurocysticercosis when compared with albendazole monotherapy or placebo. The combination therapy did not result in increased seizure recurrence or adverse drug reaction compared with albendazole monotherapy.

Comparison of Long-Term Outcomes Between 7 Days and 28 Days Albendazole Monotherapy in the Treatment of Single-Lesion Neurocysticercosis in Children

OBJECTIVES

The objective was to compare the long-term clinical, radiological, and cognitive outcomes in children with single-lesion neurocysticercosis who received 7 or 28 days of albendazole therapy.

METHODOLOGY

This observational study conducted over 1 year included (1) consecutive children with single-lesion neurocysticercosis who received 7 or 28 days of albendazole therapy in the acute state and (2) completed follow-up for at least 5 years. Seizure recurrence, resolution of lesions, cognition (Malin's Intelligence Scale for Indian Children), behavior, and school performance (National Initiative for Children Healthcare Quality Vanderbilt Assessment Scale) were assessed.

RESULTS

Group A (albendazole for 7 days) comprised 55 children, and group B (albendazole for 28 days) included 48 children. The mean age at the time of diagnosis of neurocysticercosis was 6.6 ± 1.8 years; the mean age at the time of assessment for the study was 13.2 ± 1.2 years. Focal-onset seizures were the most common clinical presentation (58.3%). The majority of lesions were ring-shaped (92.3%) or colloidal (58.2%), with perilesional edema (89.3%). In the long-term follow-up, radiological resolution of the lesions was comparable in both groups. Complete resolution was seen in 52.7% receiving 7 days and 54.2% receiving 28 days albendazole. Seizures recurred in 20% receiving 7 days and 20.8% receiving 28 days albendazole. Overall, a low intelligence quotient (IQ < 70) was seen in 55.3% cases, "somewhat problematic" school performance in 12%, and behavioral abnormalities were present in 20% of the cases. The results were comparable between the 2 groups.

CONCLUSION

Seizure control, radiological resolution of lesion, school performance, cognitive and behavioral outcomes in the long term are comparable in children with single-lesion neurocysticercosis who have received albendazole cysticidal therapy for 7 days and 28 days. Recurrence of seizure is seen with both regimens in the long term, necessitating regular follow-up and discussion regarding the risk of recurrence before a withdrawal of anticonvulsant therapy.

Neurocysticercosis in Epileptic Children: An Overlooked Condition in Mozambique, Challenges in Diagnosis, Management and Research Priorities

Previous studies suggest that neurocysticercosis (NCC), the most common cause of acute symptomatic seizures (ASS), epilepsy and other neuropsychiatric disorders, typically presents with a solitary lesion and focal seizures in children from places where cysticercosis is endemic. We report a series of 3 patients, aged 7 to 11 years, with a history of epilepsy and or recurrent headache referred from Mocuba to the Quaternary Central Hospital in Quelimane, Zambeze Province, Mozambique, an area endemic for cysticercosis. Clinical history and examination, blood chemistry and hemogram screening, serological testing for Cysticercus antigens and antibodies detection, and a computerized tomography (CT) scan, were performed. NCC was confirmed in all 3 patients, based on criteria defined by Del Bruto. Two confirmed cases tested positive for antigen (Ag) by enzyme-linked immunosorbent assay (ELISA) with CT lesions in different stages of parasite evolution. Headache/encephalopathy was present in all patients. This case series of children with epilepsy confirms for the first time the presence of NCC in children from Zambezia province, an east-central region of Mozambique. Further, NCC should be included in the differential diagnosis of children with ASS, epilepsy and other neuropsychiatric disorders. Future studies should be targeted to the identification of biomarkers to support the diagnosis of NCC, given the limited availability of imaging tools and limited value of serological assays for the diagnosis and management of NCC.

Pediatric Neurocysticercosis

Neurocysticercosis is the most common helminth infection of nervous system in humans caused by the encysted larvae of Taenia solium. It is a major cause of epilepsy in tropical areas and the most common cause of focal-onset seizures in North Indian children. Children with neurocysticercosis have pleomorphic manifestations depending on the location, number and viability of the cysts and host response. In endemic areas, neurocysticercosis should be clinically suspected in any child with recent-onset seizures, headache or focal motor deficits where there is no other suggestion of an underlying neurological disorder. Diagnosis of neurocysticercosis is essentially based on neuroimaging; visualization of a scolex is diagnostic. Management includes use of cysticidal drugs usually albendazole, which seems to be effective for lesion resolution and seizure remission, use of steroids and anti-epileptic drugs. Single lesions portend good prognosis with resolution of lesions in >60% of the cases within 6 mo and good seizure control. Prognosis is guarded in cysticercus encephalitis, racemose and extraparenchymal neurocysticercosis.

Pediatric neurocysticercosis

BACKGROUND

Neurocysticercosis (NCC) is an infestation of the nervous system caused by encysted larvae of Taenia solium. NCC is an important acquired cause of epilepsy and other neurological manifestations especially in endemic areas. NCC in children has pleomorphic manifestations depending on the location, number, viability of the cysts, and host response. Even with advancing knowledge of the disease manifestations, many aspects related to diagnosis and treatment, particularly in children, still remain controversial and pose challenges to clinical practice. There is no gold standard test to diagnose NCC and the management recommendations are still emerging. This review provides an overview of diagnosis of NCC in children and its management with special focus on current challenges and future prospects.

DISCUSSION

In developing countries, NCC is important not only because of its frequency but also because of high morbidity and mortality rates associated, especially in cases in which it progresses to increased intracranial pressure. Because of its pleomorphic presentation, NCC should be considered in the differential diagnosis of a number of neurological conditions. Treatment with cysticidal therapy leads to reduction in seizure frequency and a faster resolution of lesions.

CONCLUSIONS

We have summarized the current approaches to diagnosis and treatment of NCC, recent advances in understanding the biology of NCC, and how one can take advantage of these new insights to formulate the next generation of clinical trials.

Neurocysticercosis in Children with Seizures: A Cross-Sectional Study

Background

Neurocysticercosis (NCC), a common cause of seizures in children from low and middle income countries (LMICs), if not diagnosed and treated early enough may lead to considerable morbidity and mortality. There is a lack of data on the prevalence of NCC and its clinical characteristics among those with seizure in South-Western Nepal.

Aims and Objectives

To study the prevalence and clinical characteristics of NCC in children with seizures.

Material and Methods

All children admitted to Universal College of Medical Sciences, a tertiary hospital in South-Western Nepal with seizures during 2014–16, were tested for NCC. NCC was diagnosed by neuroimaging [computerized tomography (CT) scan or magnetic resonance imaging (MRI)]. We used logistic regression to test the association between NCC with participants' characteristics and clinical symptoms.

Results

Among 4962 in-patient children, 168 (104 boys and 64 girls) had seizures (138 with generalized tonic clonic seizures (GTCS) and 30 with focal seizures). 43% of children with seizures had CT scan confirmed NCC. The prevalence of NCC in the oldest children (13–16 years) was significantly greater (57.1% versus 15.6%) compared to the youngest (0–4 years) one (p < 0.001). Among 72 children with NCC, the proportions of children with vesicular, calcified, and colloidal stages were 76% (n = 35), 18% (n = 13), and 6% (n = 2), respectively. Children with focal seizures had 13% more NCC compared to those with GTCS but the result was statistically not significant. The adjusted odds of having NCC among 5–8 years, 9–12 years, and 13–16 years children were 6.6 (1.78–24.60), 11.06 (2.74–44.60), and 14.47 (3.13–66.96), respectively, compared to 0–4-year-old children. Reoccurrence of seizures within the first 3 months of taking antiepileptic drug in those with NCC was approximately 3 times higher compared to those without NCC (11% versus 4%, p = 0.084).

Conclusions

This study shows that NCC contributes significantly to higher prevalence of seizures in children in South-Western region of Nepal.

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.

K. G, Basnet S, Tiwari PK, Bahadur N, Mishra R. Time trend of neurocysticercosis in children with seizures in a tertiary hospital of western Nepal

Introduction

Neurocysticercosis is a common cause of seizure disorders in children of Western Nepal. The clinical presentation is variable. The incidence varies depending on the food habits and ethnicity of the population. The present study was undertaken with the objective of studying the mode of presentation, radiological findings and to determine the recent trend of the disease in children of Western Nepal.

Methods

Records from the Department of Pediatrics, Manipal Teaching Hospital, Pokhara, Nepal of children aged 0–17 years admitted from 2003 to 2015 and with the discharge diagnosis of seizure and neurocysticercosis (NCC) were reviewed. The diagnosis was primarily based on clinical features, neurological involvement and CT and MRI studies. Seizures due to other CNS pathologies were excluded. Patients with NCC were treated with Albendazole15mg/kg/day for 28 days with supportive treatments for seizures and raised intracranial pressure. Patients were followed up for one year after the completion of the treatment.

Results

There were 1355 cases of seizure disorders, out of which 229 (16.90%) were NCC. There were 99 (43.23%) in the age group 6–10 years followed by 91 (41.09%) in the age group of 11–15 years. Seizures were the most common presenting symptom in 88.65%, followed by raised ICP in 9.61%. Neuropsychiatric changes were noted in 38 cases (16.59%). CT scan findings revealed single lesion in 78.16% and multiple lesions in 21.83%. Poisson regression analysis showed statistically significant decline of year-wise incidence of NCC cases (p<0.05) from 2003 to 2015.

Conclusion

The decline in the incidence of NCC in recent years is most probably attributed to improved hygiene with the construction of household toilets to avoid open defecation and biannual deworming with Albendazole as a part of School Health and Nutrition Project.

Neurocysticercosis is a common parasitic infection of the central nervous system. It is caused by larval form of Taenia solium and it has been identified as a “Neglected Tropical Disease” endemic in south East Asia, including Nepal, by WHO. The clinical features in children are pleomorphic depending on the number, location and size of cysticerci. The parenchymatous lesions are presented as neurological symptoms like sudden onset seizures, encephalitis, raised intracranial pressure and neuropsychiatric symptoms. CT and MRI are the main diagnostic tools. Maximum incidence was found in school age children (6–15 years). Year wise review of percentage of NCC, revealed a declining trend from 20.83% in 2009 to 5.37% in 2014. The decline in the incidence of NCC noted in our study might be due to biannual deworming using Albendazole as a part of School Health and Nutrition Programme started by Ministry of Health Services, Nepal in 2008 and extended to all the districts of the country. In addition construction of household and school toilets to avoid open defecation, health education and hand washing facilities might have played a role. Large multicentre trials to evaluate role of biannual Albendazole to prevent cysticercosis is recommended.