Childhood epilepsy due to neurocysticercosis: a comparative study

Neurocysticercosis-related Seizures: Imaging Biomarkers

Neurocysticercosis (NCC)-a parasitic CNS infection endemic to developing nations-has been called the leading global cause of acquired epilepsy yet remains understudied. It is currently unknown why a large proportion of patients develop recurrent seizures, often following the presentation of acute seizures. Furthermore, the presentation of NCC is heterogenous and the features that predispose to the development of an epileptogenic state remain uncertain. Perilesional factors (such as oedema and gliosis) have been implicated in NCC-related ictogenesis, but the effects of cystic factors, including lesion load and location, seem not to play a role in the development of habitual epilepsy. In addition, the cytotoxic consequences of the cyst's degenerative stages are varied and the majority of research, relying on retrospective data, lacks the necessary specificity to distinguish between acute symptomatic and unprovoked seizures. Previous research has established that epileptogenesis can be the consequence of abnormal network connectivity, and some imaging studies have suggested that a causative link may exist between NCC and aberrant network organisation. In wider epilepsy research, network approaches have been widely adopted; studies benefiting predominantly from the rich, multimodal data provided by advanced MRI methods are at the forefront of the field. Quantitative MRI approaches have the potential to elucidate the lesser-understood epileptogenic mechanisms of NCC. This review will summarise the current understanding of the relationship between NCC and epilepsy, with a focus on MRI methodologies. In addition, network neuroscience approaches with putative value will be highlighted, drawing from current imaging trends in epilepsy research.

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.

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 presentation of neurocysticercosis-related epilepsy

Neurocysticercosis (NCC) is the most common parasitic infection of the central nervous system and a major risk factor for seizures and epilepsy. Seizure types in NCC vary largely across studies and seizure semiology is poorly understood. We discuss here the studies regarding seizure types and seizure semiology in NCC, and examine the clinical presentation in patients with NCC and drug-resistant epilepsy. We also provide evidence of the role of MRI and EEG in the diagnosis of NCC-related epilepsy. Focal seizures are reported in 60-90% of patients with NCC-related epilepsy, and around 90% of all seizures registered prospectively are focal not evolving to bilateral tonic-clonic seizures. A great number of cases suggest that seizure semiology is topographically related to NCC lesions. Patients with hippocampal sclerosis and NCC have different clinical and neurophysiological characteristics than those with hippocampal sclerosis alone. Different MRI protocols have allowed to better differentiate NCC from other etiologies. Lesions' stages might account on the chances of finding an interictal epileptiform discharge. Studies pursuing the seizure onset in patients with NCC are lacking and they are specially needed to determine both whether the reported events of individual cases are seizures, and whether they are related to the NCC lesion or lesions. This article is part of a Special Issue entitled "Neurocysticercosis and Epilepsy".

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.

Neurocysticercosis in children

Neurocysticercosis (NCC) is a common cause of seizures and neurologic disease. Although there may be variable presentations depending on the stage and location of cysts in the nervous system, most children (> 80%) present with seizures particularly partial seizures. About a third of cases have headache and vomiting. Diagnosis is made by either CT or MRI. Single enhancing lesions are the commonest visualization of a scolex confirms the diagnosis. Some cases have multiple cysts with a characteristic starry-sky appearance. Management involves use of anticonvulsants for seizures and steroids for cerebral edema. The use of cysticidal therapy continues to be debated. Controlled studies have shown that cysticidal therapy helps in increased and faster resolution of CT lesions. Improvement in long-term seizure control has not yet been proven. Children with single lesions have a good outcome and seizure recurrence rate is low. Children with multiple lesions have recurrent seizures. Extraparenchymal NCC has a guarded prognosis but it is rare in children. In endemic areas NCC must be considered in the differential diagnosis of seizures and various other neurological disorders.

Causes of childhood epilepsy in Vietnam: cases in Bach Mai Hospital

BACKGROUND

Little is known about childhood epilepsy in Vietnam, and because the causes of symptomatic epilepsy could be the result of both rapid economic development and traditional Vietnamese lifestyle, the purpose of the present paper was to clarify the nature of childhood epilepsy in Vietnam.

METHOD

A classification of epilepsy using International League Against Epilepsy classification was made and an investigation of causes was carried out.

RESULTS

Of those 162 new patients diagnosed as having epilepsy in Bach Mai Hospital, Hanoi, Vietnam, from February 2002 to February 2004 (male 84, female 78), there were 58 cases of generalized epilepsy: 22 symptomatic and 36 idiopathic or cryptogenic. A total of 90 patients were diagnosed as having localization-related epilepsy: 53 as symptomatic and 37 as idiopathic or cryptogenic. A total of 14 cases were also considered as not epileptic after strict review of both the history and the examination data.

CONCLUSION

Concerning the causes, the following were noted: (i) the rate of infectious diseases and trauma as causes of epilepsy was considerably higher in Vietnam than in developed countries; (ii) certain infectious diseases could be prevented if vaccinations and public health knowledge were improved; and (iii) the number of trauma cases, mainly due to traffic accidents, would likely be reduced if the traffic system was improved.

Neurocysticercosis in children

Neurocysticercosis is a major cause of neurologic disease worldwide. The clinical presentations are pleomorphic depending on the stage and location of cysts in the nervous system. Most children (> 80%) present with seizures, particularly partial seizures; headache and vomiting are seen in about a third of cases. Diagnosis is made by either computed tomography (CT) or magnetic resonance imaging. Single enhancing lesions are the most common finding. Visualization of a scolex confirms the diagnosis. Some cases have multiple cysts; the "starry-sky" appearance in cases with innumerable cysts is characteristic. Most children require anticonvulsants. Corticosteroids are indicated in those with cerebral edema. The efficacy of cysticidal therapy continues to be debated. Controlled studies suggest that cysticidal therapy helps in increased and faster resolution of CT lesions, but there is no conclusive evidence that it improves long-term seizure control. The prognosis in cases with single lesions is good; seizure control is achieved with a single anticonvulsant, and the recurrence rate is low. Children with multiple lesions have recurrent seizures. Extraparenchymal neurocysticercosis is rare in children and carries a poor prognosis. Neurocysticercosis must be considered in the differential diagnosis of seizures and a wide variety of neurologic disorders, particularly in endemic areas.

Neurocysticercosis: an update

Taeniosis and cysticercosis, diseases caused by the parasitic tapeworm Taenia solium, are distributed worldwide where pigs are eaten and sanitation is poor, and also in the more developed countries as a result of increasing migration. Neurocysticercosis is the commonest parasitic disease of the human nervous system. Immunological assays detect positivity for human cysticercosis in 8-12% of people in some endemic regions, which indicates the presence of antibodies against the parasite but not necessarily active or central-nervous-system infection. The only reliable tool for diagnosis of neurocysticercosis is imaging by CT or MRI. The presence of viable cysts with a mural nodule, associated with degenerative cysts and calcifications, is typical. Classification of neurocysticercosis into active, transitional, and inactive forms gives a good clinical-imaging correlation and facilitates medical and surgical treatment. The main clinical manifestations of neurocysticercosis are seizures, headache, and focal neurological deficits, and it can have such sequelae as epilepsy, hydrocephalus, and dementia. Treatment should be individually fitted for each patient, with antiepileptic drugs, analgesics, corticosteroids, or a combination of these. Anthelmintic drugs (praziquantel and albendazole) are used routinely, but so far no controlled clinical trial has established specific indications or definitive doses of treatment. Parenchymal forms of neurocysticercosis have a good prognosis in terms of clinical remission. The most effective approach to taeniosis and cysticercosis is prevention, which should be a primary public-health focus for less developed countries.