Childhood neurocysticercosis--epidemiology, diagnosis and course

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.

Clinical manifestations associated with neurocysticercosis: a systematic review

BACKGROUND

The clinical manifestations of neurocysticercosis (NCC) are poorly understood. This systematic review aims to estimate the frequencies of different manifestations, complications and disabilities associated with NCC.

METHODS

A systematic search of the literature published from January 1, 1990, to June 1, 2008, in 24 different electronic databases and 8 languages was conducted. Meta-analyses were conducted when appropriate.

RESULTS

A total of 1569 documents were identified, and 21 included in the analysis. Among patients seen in neurology clinics, seizures/epilepsy were the most common manifestations (78.8%, 95%CI: 65.1%-89.7%) followed by headaches (37.9%, 95%CI: 23.3%-53.7%), focal deficits (16.0%, 95%CI: 9.7%-23.6%) and signs of increased intracranial pressure (11.7%, 95%CI: 6.0%-18.9%). All other manifestations occurred in less than 10% of symptomatic NCC patients. Only four studies reported on the mortality rate of NCC.

CONCLUSIONS

NCC is a pleomorphic disease linked to a range of manifestations. Although definitions of manifestations were very rarely provided, and varied from study to study, the proportion of NCC cases with seizures/epilepsy and the proportion of headaches were consistent across studies. These estimates are only applicable to patients who are ill enough to seek care in neurology clinics and likely over estimate the frequency of manifestations among all NCC cases.

Neurocysticercosis: clinical, radiologic, and inflammatory differences between children and adults

BACKGROUND

Human neurocysticercosis (NC) is caused by Taenia solium larvae lodged in the central nervous system. NC is clinically heterogeneous, ranging from asymptomatic infection to severely incapacitating and even fatal presentations. Although NC affects adults and children, age-related factors have not been thoroughly studied.

METHODS

We describe and compare the clinical, radiologic, and inflammatory features of pediatric and adult Mexican NC cases. Two hundred six NC cases (92 pediatric and 114 adult) diagnosed by computed tomography or magnetic resonance imaging were included.

RESULTS

Seizures were more frequent in children (80.4% versus 56.1%), and intracranial hypertension and headaches were more frequent in adults (27.2% versus 15.2% and 35.1% versus 21.7%, respectively). Different causes underlie the different distribution of seizures and intracranial hypertension in the 2 patient groups. In pediatric NC patients, single colloidal parenchymal cysts were the most common radiologic findings compared with adults in whom multiple viable parasites in the basal subarachnoidal cisterns or in the ventricles were seen. Cerebrospinal fluid inflammation was greater in adults than in children (P = 0.02).

CONCLUSIONS

This study documents significant age-related radiologic, clinical, and inflammatory differences in Mexican NC patients. Possible causes and relevance of these age-associated findings are discussed.

Neurocysticercosis in children: clinical characteristics and outcome

A study was undertaken on 176 children with neurocysticercosis to determine the clinical behaviour and long-term outcome of cases. The children were followed up prospectively in the paediatric neurology clinic for 6 years. Diagnosis was based primarily on CT scans. All the CT lesions were parenchymal and mostly single (87%) with ring enhancement and peri-lesional oedema. Partial seizure was the predominant presenting seizure type. About 65% of cases had recurrences at varying intervals during treatment. Albendazole therapy given to some cases did not appear to have any beneficial effect on seizure control. Repeat CTs done at varying intervals after the first seizures showed disappearance of the lesions in about 50% of cases. The majority of lesions disappeared without the use of albendazole. Recurrence of seizures after withdrawal of anti-epileptic medication was observed in 19% of the cases. Parenchymal neurocysticercosis in children commonly presents with partial seizures and ring lesions on CT. The disease can be managed well by anti-epileptic medication alone and the prognosis is good.

Interrelationship between radiologic findings and prognosis of epilepsy in children with neurocysticercosis

INTRODUCTION

Epileptic manifestations of Neurocysticercosis (NC) appear to depend on number and localization of the cysts. The objective of this study was to investigate the relationship between CT findings, number of parasites and the evolutive stage of the cysts, and the prognosis of epilepsy in children with NC.

METHOD

We studied 28 patients with the parenchymal form of NC, considering: epilepsy duration; seizure frequency before and after AED treatment; seizure control; number of AED and recurrence after AED withdrawal. Clinical information was crossed with the number of lesions and disease activity in univariate comparison.

RESULTS

The analysis of the clinical data in relation to the number of lesions and disease activity showed no statistical difference among the variables (p>0.05).

CONCLUSION

We conclude that the course of epilepsy due to NC in childhood cannot be based exclusively on the number or stage of the parasites.

Childhood epilepsy due to neurocysticercosis: a comparative study

PURPOSE

To assess the clinical profile of pediatric patients with epilepsy and neurocysticercosis (NC), and compare them with a group of pediatric patients with benign partial epilepsy to determine clinical differences, response to treatment, and prognosis.

METHODS

We studied 28 patients (16 girls) with probable or definitive diagnosis of NC and epilepsy and 32 patients (16 girls) with partial benign epilepsy (BE). All patients had normal neurologic examination. We compared NC and BE patients looking for differences in demographics (age at first seizure, gender, family history); clinical presentation (type, frequency, duration, and total number of seizures, duration of epilepsy, status epilepticus, cluster, and postictal deficit); treatment [duration, number of antiepileptic drugs (AEDs), maximal dose, drug association, number of seizure-free patients, time to obtain control and recurrence after medication discontinuation]; complementary examinations (the first and the last EEG).

RESULTS

The mean follow-up was 5.4 years for the 28 NC patients and 4.6 years for the 32 BE patients (p=0.98). We did not find statistical differences between NC and BE in gender, family history, types of seizures, frequency and length of seizures, previous status epilepticus, seizure clustering, and presence of postictal deficits. However, we found that NC compared with BE patients had significant longer AED treatment, more seizures after AED introduction, tried more AEDs and at maximal dose, and in 20%, required polytherapy. The recurrence rate in NC was 54.4% and this was not significantly associated with number of lesions and disease activity seen on CT scans or the presence of EEG abnormalities.

CONCLUSIONS

NC presents with a mild form of epilepsy in terms of seizure severity; however, it is more challenging in regard to drug management and has a less favorable long-term prognosis in terms of seizure remission. The number of lesions or disease activity seen on computed tomography (CT) as well as EEG abnormalities have no prognostic value in childhood epilepsy due to NC.

[Neurocysticercosis and Lennox-Gastaut syndrome: case report]

Report of a girl with the epileptic, hydrocephalic and encephalitic form of neurocysticercosis, diagnosed by cerebrospinal fluid and computed tomography exams, during her second year of life and an evolution with multiple types of seizures, prolonged periods of intracranial hypertension due to obstruction in the ventriculoperitoneal shunt, psychomotor regression and blindness until she was 10 years old, when the Lennox-Gastaut syndrome was diagnosed. Nowadays the patient is 16 years old and presents complex partial seizures with automatism not completely controlled with clobazan and oxcarbazepine, associated to left spastic hemiparesis, universal hyperreflexia, psychomotor agitation, self-mutilation, amaurosis and severe mental retardation. The association between neurocysticercosis and Lennox-Gastaut syndrome was first described in 1973 by Frochtengarten & Scarante in a Brazilian girl with a similar clinical picture.

Clinical aspects of neurocysticercosis in children

The purpose of this report was to evaluate the clinical aspects of neurocysticercosis in children from a Brazilian region. A retrospective study of 25 children with this neuroparasitosis was performed. The diagnosis was based on clinical, cerebrospinal fluid, and neuroimaging findings. The patients were predominantly male (72%), were 1 to 11 years of age (average = 8 years, 6 months), and most resided in urban areas (68%). The more frequent manifestations were epileptic seizures (72%), headache (60%), learning disability (24%), behavioral changes (12%), psychomotor involution (8%), and intracranial hypertension (4%). The neurologic examination was normal in 80% of the patients. Twenty-two children received only symptomatic drugs. Three patients underwent treatment with cysticidal drugs, one with praziquantel and two with albendazole, with complete remission of the signs in one patient (33%) and improvement in two others (67%). Of the 25 patients, 43.4% had remission and 47.8% had improvement. We emphasize the need to consider neurocysticercosis as a differential diagnosis in children coming from endemic areas and presenting with learning disabilities, behavioral changes, and psychomotor involution. The clinical aspects in most of the children from the Botucatu region suggest a spontaneous resolution of neurocysticercosis without the need for cysticidal treatment.

Clinical spectrum of 500 children with neurocysticercosis and response to albendazole therapy

Neurocysticercosis is a major cause of neurologic illness worldwide. Its manifestations are variable, and somewhat different when it occurs in children. Controversy exists regarding anticysticercal therapy. The clinical, laboratory, and radiographic features of 500 consecutive children with neurocysticercosis were studied; the children were then followed prospectively and their response to albendazole therapy was analyzed. Diagnosis of neurocysticercosis was based primarily on neuroimaging. Computed tomographic (CT) scans, neurocysticercosis serology, chest radiographs, and Mantoux tests were done in all children, and magnetic resonance imaging scans in 10%. All children with multiple lesions, and some randomly allocated children with single, small, enhancing CT lesions received albendazole. CT scans were repeated after 3 to 6 months. There were 272 boys and 228 girls, age range 1 6/12 to 12 6/12 years. Seizures were present in 94.8% of cases; 83.7% had focal seizures. Features of raised intracranial pressure were seen in 30% of patients and focal neurodeficit in 4%. Single lesions were seen in 76% of the children, with perilesional edema in 57.4%. Thirty-four children who had multiple cysts and received albendazole underwent serial CT evaluation. Four showed disappearance of lesions and 22 had reductions in the size or number, to give an overall improvement rate of 76%. Serial CT studies were available on 176 children with single lesions, 90 of whom received albendazole. Improvement (disappearance or reduction in the size of lesions) was observed in 91% (82 of 90) of albendazole-treated children versus 85% (73 of 86) of untreated children. This difference was not significant. No significant side-effects of albendazole were reported. These data indicate that partial seizures and single parenchymal cysts are the most frequent clinical and neuroradiographic manifestations of neurocysticercosis in children. Although albendazole therapy should be considered, especially in children with multiple lesions, many children with isolated neurocysticercosis will improve without antiparasitic therapy.

Neurocysticercosis and epilepsy in developing countries

Neurocysticercosis is a disease of poverty and underdevelopment. Little is known about the natural history of the infection in humans, but some of the mechanisms whereby the parasite remains silent and evades the host immune response are understood. Symptomatic neurocysticercosis usually results from host inflammatory response after parasite death, and the clinical manifestations can be diverse. There is no evidence that cysticidal treatment does more good than harm in addition to conventional antiepileptic treatment. Population control measures involving immunisation or mass treatment have not shown long term effectiveness.Epilepsy, similarly to neurocysticercosis, is a largely unrecognised but increasing burden on the welfare and economies of developing countries. The technology of drug treatment and psychosocial rehabilitation is well known but requires widespread and effective dissemination at low cost. There is little epidemiological data on risk factors for epilepsy in developing countries on which to base prevention strategies. The public health prioritisation of chronic disorders such as epilepsy remains a challenge for policy and practice in developing countries. For both neurocysticercosis and epilepsy, there is a dilemma about whether limited public resources would better be spent on general economic development, which would be expected to have a broad impact on the health and welfare of communities, or on specific programmes to help individual affected people with neurocysticercosis and epilepsy. Either approach requires detailed economic evaluation.

Neurocysticercosos in South-Central America and the Indian subcontinent. A comparative evaluation

Neurocysticercosis is an important public health problem in South-Central American and South Asia. A review of the differences in epidemiological and clinical attributes of cysticercosis and taeniasis in South Central America and India, respectively, is undertaken in the present communication. Intestinal taeniasis is hyperendemic in several American countries. In comparison, the prevalence of Taenia solium infestation is lower in India. The clinical manifestations in several American neurocysticercosis series comprise epilepsy, intracranial hypertension and meningeal-racemose cysticercosis, in roughly equal proportions. An overwhelming majority of the Indian subjects present with seizures. The commonest pathological substrate of the disorder in Indian patients is the solitary parenchymal degenerating cyst. The reasons for the predominance of solitary forms in India, and of multilesional forms in South Central America are discussed. The magnitude of Taenia solium infestation and the frequency of pork consumption in a given population appear to influence the quantum of cyst load in affected individuals.

Human cysticercosis: parasitology, pathology, clinical manifestations and available treatment

Human cysticercosis is a global health problem and neurocysticercosis a serious clinical syndrome. The diagnosis of neurocysticercosis can now be made with a high degree of accuracy by scrutiny of clinical signs and symptoms in combination with X-ray, computed tomography or magnetic resonance imaging, serological tests and laboratory examinations. Differential clinical diagnosis with tumor, and vascular and inflammatory conditions, may however, prove difficult in nonendemic areas. The management of cysticercosis has been radically changed by the advent of effective chemotherapy. Both the heterocyclic pyrazinoisoquinoline compound, praziquantel and the benzimidazole carbamate, albendazole, have now been extensively tested and successfully used for treatments of neurocysticercosis, usually in combination with corticosteroids. The definition of appropriate criteria and guidelines for the use of chemotherapy, may however, require further research. Surgical interventions continue to play an important role in certain clinical presentations. Recent advances in immunological research hold realistic promise for the development of a vaccine against Taenia solium.