Calcific neurocysticercosis and epileptogenesis

Efficiency of Cysticidal Therapy Impacted by the Host's Immune Response in Neurocysticercosis Patients

Neurocysticercosis (NCC) is a neurological condition caused by the presence of cysts of Taenia solium in the brain, which manifests with a range of clinical symptoms. The severity of NCC and its prognosis following anti-helminth drug (AHD) treatment are closely linked to peripheral and local inflammation. The study aimed to analyse the efficiency of cysticidal therapy impacted by the host's immune response in NCC patients. A total of 104 patients were screened in this study, and blood samples were collected from 30 patients. The follow-up samples within 3 to 6 months of treatment were collected. Patients were categorised as Responder (R) and Non-Responder (NR). Cytokines IL-6, IL-10, IFN-γ and TNF-α were estimated using ELISA kits in PBMC cells. T0 is the time point before the AHD treatment begins, and T1 is between 3 to 6 months after the treatment starts. The responder patients showed significantly lower IL-10 and IL-6 levels in the supernatants at T0 as compared to T1, while in non-responder patients, IL-10 and IL-6 levels were higher at T0 as compared to T1. The IFN-γ and TNF-α levels were found to be higher in the supernatants at T0 as compared to T1 in both the responder and non-responder patients. These observations imply that these cytokines might have an impact on the efficacy of AHD treatment in NCC patients.

Computed tomography of the head with and without contrast in imaging focal and unknown epilepsy - A prospective observational study

PURPOSE

Brain imaging is needed when investigating epilepsy. Imaging options available include MRI and CT scan which may be non-contrast (NCCT) or contrast-enhanced (CECT). The specific clinical question and probable epilepsy substrate in the epidemiological context and socioeconomic milieu are important in determining the choice of imaging. In patients with well-controlled focal or unknown epilepsy who are unlikely to be surgical candidates, is CECT essential or can NCCT be an acceptable choice?

METHODS

A prospective observational study was conducted at a tertiary care centre in India. Consecutive patients with focal or unknown epilepsy who were relatively well-controlled on medical treatment underwent NCCT followed by CECT brain. Three neuroradiologists independently reported the images. Proportion of abnormalities missed on NCCT and picked only on CECT were determined. How often abnormalities picked on CECT changed patient management was also analysed.

RESULTS

Two hundred and nineteen patients with focal (87 %) or unknown (13 %) epilepsy underwent NCCT followed by CECT brain. Most had epilepsy for >3 months and an annual seizure frequency of 2-10 seizures. There was a nearly perfect inter-observer agreement between 3 neuroradiologists in reporting the NCCT and CECT as 'normal' or 'abnormal' with kappa (κ) values of 0.9 and 1.0 respectively. The sensitivity of NCCT compared to CECT in detecting an abnormality was 97 % (CI 92.6 - 99.5 %) and the specificity was 99 % (CI 94.9 - 99.9 %). There was no significant difference in the proportion of NCCTs and CECTs found abnormal (50.22 % vs 51.14 %, p = 0.91). A solitary calcified granuloma was the most common abnormality reported on NCCT as well as CECT, 21.0 % and 19.1 % respectively. New findings picked on CECT alone, did not change management in any patient.

CONCLUSION

When imaging focal or unknown epilepsy, an NCCT performs as well as a CECT, especially in regions where calcified lesions contribute a significant etiological burden. The role of imaging in epilepsy varies between patients and a universal recommendation of an MRI or a CECT in all patients is neither cost-efficient nor evidence-based. In drug responsive focal or unknown epilepsy of longstanding duration, CT scans are either normal or have calcified lesions that are easily picked on NCCT.

Management of calcified cysticerci in the brain parenchyma: treating the dead parasite

INTRODUCTION

Calcifications are the end stage of many parenchymal brain cysticerci and may occur either spontaneously or as the result of treatment with cysticidal drugs. These lesions, traditionally considered inert and asymptomatic, have been associated with several complications that seem to be mostly related to brain damage and inflammation ensuing as the result of the exposure of the host's immune system to parasitic antigens trapped within calcifications.

AREAS COVERED

This review, based on the search of different electronic databases up to May 2024, focuses on the reported correlates and complications of calcified cysticerci (chronic headaches, seizures/epilepsy, hippocampal atrophy/sclerosis, gliomas), and the different interventions developed for their prevention and treatment. Common analgesics, non-steroidal anti-inflammatory drugs, corticosteroids, and antiseizure medications have been used with success but, with the exception of the latter, these drugs offer temporary relief of symptoms and support for their use is based on level 3 evidence.

EXPERT OPINION

Several strategies may reduce the severity of clinical consequences of calcified cysticerci. Probably, the most relevant intervention would be the prevention of their occurrence or reduction in their size. In this view, the use of bisphosphonates appears as a potential option that needs to be tested in humans.

Serum Proteomic Predictors of Calcification of Solitary Cysticercus Granuloma

Solitary cysticercus granulomas (SCG), prevalent among Indian patients with new-onset seizures, either resolve completely or transform into calcified granulomas. This study aimed to identify serum proteins through liquid chromatography-tandem mass spectrometry that could predict calcification of SCGs in 20 patients with SCG with at least 6-months of follow-up. At a median follow-up of 14 months, the SCG had calcified (n = 5), resolved (n = 11), or persisted (n = 4). Two serum proteins, ECM1 and MST1, were present in significantly higher serum concentrations, and AZGP1 in significantly lower concentration in subjects with calcifying SCGs than in those with lesions that resolved or persisted. On multivariate analysis, only ECM1 (odds ratio: 1.7, 95% CI: 0-2.8) and MST1 (odds ratio: 3.3, 95% CI: 0-4.1) were independent predictors of calcification of SCG. Combining elevated levels of serum ECM1 and MST1 had a sensitivity of 100% and specificity of 100% in differentiating granulomas that calcified from those that resolved/persisted. Increased expression of serum ECM1 and MST1 in patients with SCG might predict calcification.

Large (≥3-Millimeter) Parenchymal Brain Calcified Cysticerci Are More Often Associated with Hippocampal Atrophy than Smaller Ones in Seizure-Free Individuals with a Single Lesion

Calcified cysticerci are often associated with hippocampal atrophy (HA). While most studies suggest that repetitive seizures cause HA in these patients, others have demonstrated that HA may also occur in persons without epilepsy. Little is known about mechanisms triggering HA in seizure-free individuals with calcified cysticerci. Here, we aimed to assess whether the size of the calcification is associated with HA. Using a population-based design, we selected apparently seizure-free individuals with a single calcified cysticercus in whom interictal paroxysmal activity and other causes of HA have been discarded. A total of 55 individuals (mean age, 58.3 ± 13 years, 62% women) fulfilled inclusion criteria. Unadjusted and multivariate models were fitted to assess the association between the size of the calcification dichotomized into <3 mm and ≥3 mm (exposure) and the presence of HA (outcome). Sixteen participants (29%) had HA, which was asymmetric in eight (50%) cases. Hippocampal atrophy was noted in 11/20 (55%) participants with large calcifications and in 5/35 (14%) with small calcifications (P = 0.001). A multivariate logistic regression model showed a significant association between the presence of large calcifications and HA, after adjustment for relevant confounders (odds ratio: 7.78; 95% CI: 1.72-35.1). Participants with calcifications ≥3 mm in diameter were 7.8 times more likely to have HA than those with smaller ones. Study results open avenues of research for the use of agents to prevent HA progression.

Neurocysticercosis Prevalence and Characteristics in Communities of Sinda District in Zambia: A Cross-Sectional Study

BACKGROUND

This study aimed at describing the epidemiology of (neuro)cysticercosis as well as its clinical and radiological characteristics in a Taenia solium endemic district of Zambia.

METHODS

This was part of a cross-sectional community-based study conducted in Sinda district to evaluate an antibody-detecting T. solium point-of-care (TS POC) test for taeniosis and (neuro)cysticercosis. All TS POC cysticercosis positive (CC+) participants and a subset of the TS POC cysticercosis negative (CC-) received a clinical evaluation and cerebral computed tomography (CT) examination for neurocysticercosis (NCC) diagnosis and staging.

RESULTS

Of the 1249 participants with a valid TS POC test result, 177 (14%) were TS POC CC+ . Cysticercosis sero-prevalence was estimated to be 20.1% (95% confidence intervals [CI] 14.6-27.0%). In total, 233 participants received a CT examination (151 TS POC CC+ , 82 TS POC CC-). Typical NCC lesions were present in 35/151 (23%) TS POC CC+ , and in 10/82 (12%) TS POC CC- participants. NCC prevalence was 13.5% (95% CI 8.4-21.1%) in the study population and 38.0% (95% CI 5.2-87.4%) among people reporting epileptic seizures. Participants with NCC were more likely to experience epileptic seizures (OR = 3.98, 95% CI 1.34-11.78, p = 0.01) than those without NCC, although only 7/45 (16%) people with NCC ever experienced epileptic seizures. The number of lesions did not differ by TS POC CC status (median: 3 [IQR 1-6] versus 2.5 [IQR 1-5.3], p = 0.64). Eight (23%) of the 35 TS POC CC+ participants with NCC had active stage lesions; in contrast none of the TS POC CC- participants was diagnosed with active NCC.

CONCLUSION

NCC is common in communities in the Eastern province of Zambia, but a large proportion of people remain asymptomatic.

Unmasking a Hidden Culprit: Neurocysticercosis, an Overlooked Cause of Acquired Epilepsy

Neurocysticercosis (NCC) is a common parasitic brain infestation caused by the ingestion of Taenia solium eggs, predominantly in developing countries. In this report, we presented the case of a 44-year-old woman who exhibited stroke symptoms and had a decade-long history of recurrent headaches and epilepsy. At presentation, a non-contrast computed tomography scan of the brain was performed and revealed hypodense oval lesions and calcified cysts in both cerebral hemispheres, strongly indicative of NCC. The patient responded positively to treatment with dexamethasone, albendazole, and carbamazepine. This case study underscores the importance of neuroimaging in investigating patients with neurological conditions like epilepsy, especially in developing countries. Early diagnosis and effective treatment are crucial in preventing and controlling NCC, reducing its impact on public health.

Coexistence of Lung Cancer and Neurocysticercosis: A Rare Case

Lung cancer with brain metastasis has a high morbidity and mortality worldwide. Neurocysticercosis is a parasitic infection commonly found in regions with poor sanitation. We present a case with the coexistence of lung cancer and neurocysticercosis. A 57-year-old Caucasian female, with a history of secondhand smoke exposure, presented with a cough. Further evaluation revealed a lesion in the right upper lobe of the lung on a CT scan, a frontal lobe lesion on brain MRI, and hypermetabolic lymph nodes on a PET scan. Biopsies confirmed invasive moderately differentiated adenocarcinoma, indicating stage 4 lung cancer with a solitary brain metastasis. The patient underwent stereotactic radiosurgery for the brain lesion and subsequently received chemoradiation therapy. Upon completion of therapy, the patient showed improvement in both lung and brain lesions. Durvalumab maintenance therapy was initiated. However, a follow-up MRI of the brain revealed a new lesion in the right lateral ventricle. Stereotactic radiosurgery was performed to target this lesion. Five months later, a repeat MRI showed growth of the brain lesion. Given the atypical image finding, a biopsy of the right lateral ventricle lesion was performed, revealing an unexpected diagnosis of calcified parenchymal neurocysticercosis. The patient was referred to an infectious disease specialist who started the patient on dexamethasone without antiparasitic treatment. The co-occurrence of metastatic lung cancer to the brain and neurocysticercosis presents significant diagnostic and therapeutic complexities. Despite stereotactic radiosurgery, the patient's neurologic symptoms failed to improve, and subsequent radiographic assessments yielded inconclusive results. Consequently, a brain biopsy was performed, deviating from the usual practice in cancer management, revealing the unexpected presence of neurocysticercosis. This unforeseen diagnosis underscores the critical significance of contemplating alternative etiologies in patients exhibiting atypical clinical manifestations, particularly in regions devoid of prevalent parasitic infections. This case highlights the challenges in identifying and managing complex cases involving lung cancer and neurocysticercosis, where treatment decisions must balance the need for oncologic control and the management of parasitic infection.

Calcified cerebral toxoplasmosis associated with recurrent perilesional edema causing neurological manifestations in an HIV-infected individual: case report with a decade-long follow-up

Four cases of people living with HIV/AIDS (PLWHA) with calcified cerebral toxoplasmosis associated with perilesional edema causing a single episode of neurological manifestations have recently been reported. Here, we describe the first detailed description of perilesional edema associated with calcified cerebral toxoplasmosis causing three episodes of neurological manifestations in a PLWHA, including seizures in two of them. These recurrences occurred over approximately a decade. Throughout this period, the patient showed immunological and virological control of the HIV infection, while using antiretroviral therapy regularly. This case broadens the spectrum of an emerging presentation of calcified cerebral toxoplasmosis, mimicking a well-described finding of neurocysticercosis in immunocompetent hosts.

Current Role of Surgery in the Treatment of Neurocysticercosis

Neurocysticercosis (NCC) is a common parasitic disease of the central nervous system (CNS) in low- and middle-income countries. The infection is pleomorphic, caused by the larval form of the cestode, Taenia solium, and part of the heterogeneity of its clinical presentations is associated with the localization of the parasite within the CNS. Changes in the current epidemiological trends of NCC indicate that extra-parenchymal NCC is proportionally becoming more frequent. Extraparenchymal NCC is commonly accompanied by raised intracranial hypertension due to hydrocephalus, which is an emergency requiring cyst extirpation by surgical intervention to relieve the symptoms. Although less frequent, parenchymal cysts may also reach giant sizes requiring urgent surgical treatment. Finally, there is an advancement in the comprehension of the association between NCC and epilepsy-and patients with drug-resistant seizures are candidates for surgical treatment. In this narrative review, we summarize the present state of knowledge to update the current trends in the role of surgery in the treatment of NCC.

Does ensuring optimum vitamin D levels result in early resolution of neurocysticercosis?

BACKGROUND

Neurocysticercosis is a leading cause of acquired epilepsy. Calcified granulomas are known to cause seizure recurrence. Researchers have reported that vitamin D deficiency is associated with brain calcification and reduction in calcification occurs with vitamin D receptor agonist calcitriol through upregulation of SLC20A2. Based on these observations, a hypothesis was proposed that the occurrence of calcification could be reduced by optimizing vitamin D levels, resulting in early resolution of neurocysticercosis.

METHODOLOGY

A case-control (retrospective and prospective) study on 60 children with solitary intraparenchymal neurocysticercosis, 20 new cases prior to starting cysticidal therapy and other 40 resolved cases was carried out. Among new cases, children deficient in vitamin D were given megadose of vitamin D and vitamin D levels were rechecked after 30 days. Children having normal vitamin D were taken as cases and the deficient ones were taken as controls. Standard treatment for neurocysticercosis was given. Three monthly MRI scans were done. Outcome was evaluated as resolution/persistence of neurocysticercosis at 3, 6, 9 and 12 months.

STATISTICS AND RESULTS

Pearson chi square/Fisher's exact test was used along with Kaplan Meier and log rank test. Of 60 patients, at 6 months 3 cases and 4 controls (p value 0.43), at 9 months 2 cases and 6 controls (p value 0.037) and at 12 months 3 cases and 6 controls (p value 0.029) had complete resolution of NCC.

CONCLUSION

The results do not show that adequate vitamin D levels result in early resolution of neurocysticercosis.

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.

Epilepsy Due to Solitary Calcified Cysticercus Granuloma

The calcified stage of the neurocysticercosis (NCC) is the common cause of acquired epilepsy in low and middle income countries in people aged > 20 years. Approximately 30% of adult onset seizures and epilepsy are attributable to NCC. In India and some of the Latin American countries, epilepsy due to solitary calcified NCC is the common adult onset epilepsy. The current evidence suggests that the calcified cysticercus granuloma is probably the epileptogenic focus. The mechanisms involved in the epileptogenic process are not well understood; Focal-onset seizures with or without impaired awareness are the common seizure type. Focal-onset seizure can evolve to bilateral tonic-clonic seizure. Seizure outcome with anti-seizure medication, most often with monotherapy, is very good. The seizure disorders associated with various stages of NCC can be preventable.

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.

Clinical characteristics and management of neurocysticercosis patients: a retrospective assessment of case reports from Europe

OBJECTIVES

Neurocysticercosis (NCC) is a parasitic disease caused by the larval stage of the tapeworm Taenia solium. NCC mainly occurs in Africa, Latin America and South-East Asia and can cause a variety of clinical signs/symptoms. Although it is a rare disease in Europe, it should nonetheless be considered as a differential diagnosis. The aim of this study was to describe clinical characteristics and management of patients with NCC diagnosed and treated in Europe.

METHODS

We conducted a systematic search of published and unpublished data on patients diagnosed with NCC in Europe (2000-2019) and extracted demographic, clinical and radiological information on each case, if available.

RESULTS

Out of 293 identified NCC cases, 59% of patients presented initially with epileptic seizures (21% focal onset); 52% presented with headache and 54% had other neurological signs/symptoms. The majority of patients had a travel or migration history (76%), mostly from/to Latin America (38%), Africa (32%) or Asia (30%). Treatment varied largely depending on cyst location and number. The outcome was favorable in 90% of the cases.

CONCLUSIONS

Management of NCC in Europe varied considerably but often had a good outcome. Travel and migration to and from areas endemic for T. solium will likely result in continued low prevalence of NCC in Europe. Therefore, training and guidance of clinicians is recommended for optimal patient management.

Complex neurocysticercosis lesions on imaging: Explained through correlative histomorphology

OBJECTIVES

Neurocysticercosis, the commonest neuro-parasite, sometimes presents as complex ring enhancing lesion causing diagnostic dilemma. We aim to establish radio-histo-morphological equivalents of early events in degeneration of the parasite to explain such imaging phenotypes.

METHODS

We compared patterns of degeneration in 23 randomly selected complex NCC on MRI with histo-morphology in 30 cysts obtained from an unrelated post mortem brain.

RESULTS

The anatomy of the parasite and the degenerative patterns of the scolex (hydropic changes, calcification, evagination, and fragmentation) and the cyst wall (undulation, accessory loculi, and frank disruption) were well demonstrated on both. The intact scolex remarkably resembled head of intestinal Taenia. The complex lesions were conglomeration of multiple communicating cysts with a single parent cyst and multiple daughter cysts. The parent cysts contained a solitary variably degenerated scolex, had thicker walls and associated chronic inflammation. The remaining cysts of the lesion complex contained no scolex, had poorly organized walls, turbid contents, and florid perilesional enhancement with leakage of contrast. Three lesions assumed a multi-cystic pseudo-tumorous pattern, of which two resolved into solitary calcific remnants on follow up.

CONCLUSION

Complex lesion in NCC result from degeneration of solitary parasite with perilesional gliosis, surrounded by multiple non-larval daughter cysts inciting acute intra and perilesional inflammation due to enhanced antigenic challenge. Possibly, attempted abortive asexual reproduction by the cellulose cyst as a preterminal event results in a "limited Racemose like transition." Correct interpretation has diagnostic and therapeutic implications as active lesions and their fibrocalcific residue may have greater epileptogenic potential.

Human Neurocysticercosis: An Overview

Human cysticercosis is caused by ingestion of T. solium eggs from taenia carriers. Neurocysticercosis (NCC), defined as the infection of the CNS and the meninges by the larval stage of Taenia solium, is the most common helminthic infection of the CNS worldwide. Parasites may lodge in brain parenchyma, subarachnoid space, ventricular system, or spinal cord, causing pathological changes that account for the pleomorphism of this disease. Seizures/epilepsy are the most common clinical manifestation, but other patients present with headache, focal deficits, intracranial hypertension, or cognitive decline. Accurate diagnosis of NCC is possible after interpretation of clinical data together with findings of neuroimaging studies and results of immunological tests. However, neuroimaging studies are fundamental for diagnosis because immunological test and clinical manifestations only provide circumstantial evidence of NCC. The introduction of cysticidal drugs changed the prognosis of most NCC patients. These drugs have been shown to reduce the burden of infection and to improve the clinical course of the disease in many patients. Efforts should be directed to eradicate the disease through the implementation of control programs against all the steps in the life cycle of T. solium, including carriers of the adult tapeworm, infected pigs, and eggs in the environment.

Neurocysticercosis research in Mexico: A bibliometric analysis of the Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez

Neurocysticercosis (NCC) is the most common neglected parasitic disease of the central nervous system and leads to many economic and health issues in endemic and non-endemic countries. A bibliometric analysis would shed light on the evolution and development of research in this field, and this is the first study on NCC research. Our institution in Mexico City, the Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez (INNN), has set some milestones in the management of neurocysticercosis and has a decade-long experience and such an analysis in an endemic country like Mexico will be beneficial. We tracked the scientific output in Scopus, from its foundation to March 2021. The studied variables were article type, number of citations, area (clinical/experimental), chronological profile, and preferred journals. In the period from 1964 to 2021, from a total of 3,166 articles from the institution, 232 papers are related to neurocysticercosis with a total of 7,155 citations. The trending topics in the clinical area are pharmacology and pathology in the experimental papers. The number of articles has steadily increased, but NCC is currently a neglected topic that needs further research to better address the disease burden and allow its eradication.

Comparative Efficacy and Safety of Lacosamide and Oxcarbazepine for Seizure Control in Children with Newly Diagnosed Solitary Neurocysticercosis

BACKGROUND

In newly diagnosed neurocysticercosis (NCC) with seizures, the choice of anti-seizure medication (ASM) seems to be arbitrary due to a lack of comparative studies. Although oxcarbazepine (OXC) is often considered efficacious for focal seizures in NCC, due to adverse effects, newer ASMs like levetiracetam (LCM) and lacosamide are also being explored.

METHODS

This study was performed by case record review of children with newly diagnosed solitary viable parenchymal NCC aged 4-18years who received lacosamide and OXC at least for 12 weeks between August 2019 and April 2021, from a prospective registry of a tertiary care teaching hospital in north India. Seizure control, electroencephalographic abnormalities, resolution of inflammatory granulomas and adverse effects were compared between two arms at 12 and 24 weeks.

RESULTS

Total 31 (8.3 ± 4.7 years, 19 boys) and 72 (8.6 ± 4.2 years, 43 boys) completed at least 12 weeks follow-up in LCM and OXC groups, out of which 2 and 51 completed at least 24 weeks follow-up in LCM and OXC groups, respectively. The occurrence of breakthrough seizure was comparable in both arms at 12 and 24 weeks (1/31 and 2/22 in lacosamide group vs. 2/72 and 4/51 in OXC group, p = 0.66 and 0.59, respectively). Patients receiving OXC had more frequent treatment-emergent adverse events (p = 0.0001) and four patients required discontinuation due to severe adverse events (SAEs), while none in the lacosamide group had SAEs.

CONCLUSIONS

Lacosamide appears to be efficacious and safe for achieving seizure freedom in patients with solitary viable parenchymal neurocysticercosis.

Epileptogenesis in Common Parasitic Infections

Purpose of the review

Neurocysticercosis (NCC) has been well recognized as a leading cause of epilepsy. More recently, studies of other parasitic diseases such as cerebral malaria (CM) and onchocerciasis are yielding novel insights into the pathogenesis of parasite-associated epilepsy. We compare the clinical and electrophysiological findings in epilepsy associated with these highly prevalent parasites and discuss the mechanisms involved in epileptogenesis.

Recent Findings

Electrophysiological and imaging biomarkers continue to emerge, and individuals who are at-risk of developing parasite-associated epilepsies are being identified with greater reliability. While both Taenia solium and Plasmodium falciparum directly affect the brain parenchyma, Onchocerca volvulus is not known to invade the central nervous system. Thus, the causal association between O. volvulus and epilepsy remains controversial.

Summary

Both NCC and CM have a well-defined acute phase when the parasites directly or indirectly invade the brain parenchyma and lead to local inflammatory changes. This is followed by a chronic phase marked by recurrent seizures. However, these stages of epileptogenic process have not been identified in the case of O. volvulus.

The Interplay Between Brain Vascular Calcification and Microglia

Vascular calcifications are characterized by the ectopic deposition of calcium and phosphate in the vascular lumen or wall. They are a common finding in computed tomography scans or during autopsy and are often directly related to a pathological condition. While the pathogenesis and functional consequences of vascular calcifications have been intensively studied in some peripheral organs, vascular calcification, and its pathogenesis in the central nervous system is poorly characterized and understood. Here, we review the occurrence of vessel calcifications in the brain in the context of aging and various brain diseases. We discuss the pathomechanism of brain vascular calcification in primary familial brain calcification as an example of brain vessel calcification. A particular focus is the response of microglia to the vessel calcification in the brain and their role in the clearance of calcifications.

Neurocysticercosis in Children

Neurocysticercosis is one of the most common parasitic infections in the central nervous system in children. The usual clinical manifestation is new-onset focal seizure. However, there are other multiple clinical manifestations, such as increased intracranial pressure, meningoencephalitis, spinal cord syndrome, and blindness. The diagnosis needs high index of suspicion with clinical history, physical examination, neuroimaging, and immunologic studies. Recent advances in neuroimaging and serology facilitate the accurate diagnosis. Management of neurocysticercosis should focus on critical symptoms first, such as the use of antiepileptic drugs and medical or surgical therapy for increased intracranial pressure.

Evaluating the Association of Calcified Neurocysticercosis and Mesial Temporal Lobe Epilepsy With Hippocampal Sclerosis in a Large Cohort of Patients With Epilepsy

BACKGROUND

Neurocysticercosis (NCC) is a parasitic infection of the central nervous system that has been associated with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). However, this association has not been completely established.

OBJECTIVE

To evaluate the prevalence of calcified NCC (cNCC), its characteristics and a possible association between cNCC and MTLE-HS in a cohort of 731 patients with epilepsy.

METHODS

We review clinical, EEG and neuroimaging findings of 731 patients with epilepsy. From these, 659 had CT-scans and 441 patients had complete neuroimaging with CT-scans and MRI. In these patients, we review the prevalence and characteristic of epilepsy in cNCC and in MTLE-HS patients.

RESULTS

Forty-two (6.4%) of the 659 patients studied with CT-scans had cNCC. cNCC lesions were more frequent in women than in men (n = 33-78.6% vs. n = 09-21.4%, respectively; OR = 3.64;(95%CI = 1.71-7.69); p < 0.001). cNCC was more often in patients who developed epilepsy later in life, in older patients, in patients who had a longer history of epilepsy, and in those with a lower educational level. MTLE-HS was observed in 93 (21.1%) of 441 patients that had complete neuroimaging, and 25 (26.9%) of these 93 patients also had cNCC. Calcified NCC was observed in only 17 (4.9%) of the remaining 348 patients that had other types of epilepsy rather than MTLE-HS. Thus, in our cohort, cNCC was more frequently associated with MTLE-HS than with other forms of epilepsy, O.R. = 11.90;(95%CI = 6.10-23.26); p < 0.0001).

CONCLUSIONS

As expected, in some patients the epilepsy was directly related to cNCC lesional zone, although this was observed in a surprisingly lower number of patients. Also, cNCC lesions were observed in other forms of epilepsy, a finding that could occur only by chance, with epilepsy probably being not related to cNCC at all. In this cohort, cNCC was very commonly associated with MTLE-HS, an observation in agreement with the hypothesis that NCC can contribute to or directly cause MTLE-HS in many patients. Given the broad world prevalence of NCC and the relatively few studies in this field, our findings add more data suggesting a possible and intriguing frequent interplay between NCC and MTLE-HS, two of the most common causes of focal epilepsy worldwide.

Pathological Targets for Treating Temporal Lobe Epilepsy: Discoveries From Microscale to Macroscale

Temporal lobe epilepsy (TLE) is one of the most common and severe types of epilepsy, characterized by intractable, recurrent, and pharmacoresistant seizures. Histopathology of TLE is mostly investigated through observing hippocampal sclerosis (HS) in adults, which provides a robust means to analyze the related histopathological lesions. However, most pathological processes underlying the formation of these lesions remain elusive, as they are difficult to detect and observe. In recent years, significant efforts have been put in elucidating the pathophysiological pathways contributing to TLE epileptogenesis. In this review, we aimed to address the new and unrecognized neuropathological discoveries within the last 5 years, focusing on gene expression (miRNA and DNA methylation), neuronal peptides (neuropeptide Y), cellular metabolism (mitochondria and ion transport), cellular structure (microtubule and extracellular matrix), and tissue-level abnormalities (enlarged amygdala). Herein, we describe a range of biochemical mechanisms and their implication for epileptogenesis. Furthermore, we discuss their potential role as a target for TLE prevention and treatment. This review article summarizes the latest neuropathological discoveries at the molecular, cellular, and tissue levels involving both animal and patient studies, aiming to explore epileptogenesis and highlight new potential targets in the diagnosis and treatment of TLE.

Incidence of Adult-Onset Epilepsy and the Contributory Role of Neurocysticercosis in a Five-Year, Population-Based, Prospective Study in Rural Ecuador

This prospective cohort study aimed to assess incidence and etiology of adult-onset epilepsy in previously seizure-free Atahualpa residents aged ≥ 20 years. Persons with adult-onset epilepsy occurring over 5 years were identified from annual door-to-door surveys and other overlapping sources. Those who emigrated or declined consent were excluded at the administrative censoring date of the last survey when these subjects were interviewed. Persons who died and those who developed incident epilepsy were censored at the time of these outcomes. Poisson regression models adjusted for demographics, education, alcohol intake, and the length of observation time, were used to estimate annual adult-onset epilepsy incidence rate ratio and cumulative incidence. Systematic neuroimaging screening was offered to participants to get insights on the etiology of epilepsy. Individuals enrolled in this cohort (N = 1,480) contributed to 6,811.6 years of follow-up. Seventeen developed incident adult-onset epilepsy, for an annual incident rate of 249.2 per 100,000 persons-year (95% CI: 130.7-367.7). Cumulative incidence was 1,245.9 per 100,000 persons (95% CI: 653.7-1,838.3) after a mean of 4.6 (SE: 0.06) years of follow-up. Six persons with incident epilepsy had neurocysticercosis (35%). Individuals with neurocysticercosis were six times more likely to develop adult-onset epilepsy than those without this disease (IRR: 6.01; 95% CI: 2.16-16.7), after adjusting for relevant covariates. The attributable fraction of incident adult-onset epilepsy due to neurocysticercosis was 30.9% (95% CI: 25.6-46.2%). This rural Ecuadorian population has a high incidence of adult-onset epilepsy, with neurocysticercosis being an important contributory cause.

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.

Frequency and Determinant Factors for Calcification in Neurocysticercosis

BACKGROUND

Neurocysticercosis is a major cause of acquired epilepsy. Larval cysts in the human brain eventually resolve and either disappear or leave a calcification that is associated with seizures. In this study, we assessed the proportion of calcification in parenchymal neurocysticercosis and risk factors associated with calcification.

METHODS

Data for 220 patients with parenchymal NCC from 3 trials of antiparasitic treatment were assessed to determine what proportion of the cysts that resolved 6 months after treatment ended up in a residual calcification at 1 year. Also, we evaluated the risk factors associated with calcification.

RESULTS

The overall proportion of calcification was 38% (188/497 cysts, from 147 patients). Predictors for calcification at the cyst level were cysts larger than 14 mm (risk ratio [RR], 1.34; 95% confidence interval [CI], 1.02-1.75) and cysts with edema at baseline (RR, 1.39; 95% CI, 1.05-1.85). At the patient level, having had more than 24 months with seizures (RR, 1.25; 95% CI, 1.08-1.46), mild antibody response (RR, 1.14; 95% CI, 1.002-1.27), increased dose albendazole regime (RR, 1.26; 95% CI, 1.14-1.39), lower doses of dexamethasone (RR, 1.36; 95% CI, 1.02-1.81), not receiving early antiparasitic retreatment (RR, 1.45; 95% CI, 1.08-1.93), or complete cure (RR, 1.48; 95% CI, 1.29-1.71) were associated with a increased risk of calcification.

CONCLUSIONS

Approximately 38% of parenchymal cysts calcify after antiparasitic treatment. Some factors associated with calcification are modifiable and may be considered to decrease or avoid calcification, potentially decreasing the risk for seizure relapses.

Chronic administration of cryptolepine nanoparticle formulation alleviates seizures in a neurocysticercosis model

Worldwide, neurocysticercosis remains an important cause of acquired epilepsy. We therefore seek to investigate the effectiveness of the nanoparticle formulation of cryptolepine in alleviating seizures in a neurocysticercosis model. A solid-lipid nanoparticle formulation of extracted cryptolepine was prepared. The parasites were maintained in T. crassiceps metacestode (ORF strain) - infected female BALB/c mice. Cryp (5 ​mg/kg), SLN-CRYP (5 ​mg/kg), ABZ (50 ​mg/kg) DXM (0.5 ​mg/kg), and PHE (30 ​mg/kg). were assessed for in vitro cysticidal, in vivo cysticidal and/or antiseizure activity in 70 mice that had developed seizures from infection with T. crassiceps. General pathologic processes were studied in the host tissue and inflammatory mediators were quantified from isolated mice brains. All treatments (CRYP, SLN-CRYP and ABZ) caused significantly reduced viability of T. crassiceps cysts. Treatment with SLN-CRYP significantly shrunk cysticerci and resolved ventricular expansion and deviation similar to albendazole on examination of encephala. SLN-CRYP inhibited hyperemia but was more effective against microgliosis, calcification, edema and meningitis. Mean seizure score was significantly reduced in models administered with SLN-CRYP (p ​< ​0.0001); as were frequency (p ​< ​0.0001) and duration (p ​< ​0.0001) of seizures. SLN-CRYP significantly reduced brain homogenate levels of IL-10 (p ​= ​0.0016) and IFN-γ (p ​< ​0.0001). Our study shows that the chronic administration of the nanoparticle formulation of cryptolepine is effective in alleviating seizures associated with neurocysticercosis in a mouse model.

Brain calcification because of neurocysticercosis: a vast field to be explored

PURPOSE OF REVIEW

Neurocysticercosis is the most common helminthic infection of the central nervous system caused by the larval stage of the pork tapeworm, Taenia solium. Endemic regions include Latin American countries, sub-Saharan Africa, and large regions of Asia, including the Indian subcontinent and is a global health problem. Seizures are the most common manifestation and approximately 30% of adult-onset seizures in endemic regions are attributable to NCC. Calcifications because of neurocysticercosis is the most common finding on imaging in endemic regions and are important seizure foci contributing to the burden of epilepsy.

RECENT FINDINGS

After treatment with antiparasitics for multiple viable parenchymal disease, approximately 38% of cysts that resolved after 6 months of therapy will result in residual calcifications, which represents a significant burden of residual disease. Calcified disease has been referred to as 'inactive disease', but there is accumulating evidence to suggest that calcified granulomas are actually dynamic and substantially contribute to the development and maintenance of seizures.

SUMMARY

Calcified parenchymal neurocysticercosis contributes significantly to the development and maintenance of seizures in endemic regions. Understanding the pathogenesis of the role of calcified NCC in seizure development and risk factors for development of calcifications after treatment is critical to decreasing the burden of symptomatic disease in endemic regions.

A 13th-century cystic echinococcosis from the cemetery of the monastery of Badia Pozzeveri (Lucca, Italy)

OBJECTIVE

To differentially diagnose a calcified formation recovered from a 13th century AD grave from the Tuscan monastery of Badia Pozzeveri, Lucca, Italy.

MATERIALS

A calcified formation from the thoraco-abdominal region of a skeleton buried in the monastery cemetery.

METHODS

Cone Beam Computed Tomography, Scanning Electron Microscope and Energy Dispersive X-Ray Spectroscopy.

RESULTS

A hollow, calcified ovoid formation was identified as typical of a hydatid cyst, permitting the diagnosis of cystic echinococcosis in a 35-45year-old female.

CONCLUSIONS

The study reveals the circulation of the parasite Echinococcus granulosus in the region of Lucca in late medieval Tuscany.

SIGNIFICANCE

This finding is the fourth case of cystic echinococcosis from an archaeological context in Italy and provides insight into environmental conditions that appear to have affected members of a community, irrespective of social status.

LIMITATIONS

Caution and the application of multiple analyses must be exercised in the differential diagnosis to discriminate among calcified formations.

SUGGESTIONS FOR FURTHER RESEARCH

Analysis of stable isotopes of the calcified formation, such as ¹⁵N and ¹³C, in order to compare them with isotopic values of the host individual and to further confirm the parasitic origin of the find.

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.

Unique Characteristics of Epilepsy Development in Neurocysticercosis

The parasitic helminth infection neurocysticercosis (NCC) is the most common cause of adult-acquired epilepsy in the world. Despite the serious consequences of epilepsy due to this infection, an in-depth review of the distinct characteristics of epilepsy due to neurocysticercosis has never been conducted. In this review, we evaluate the relationship between NCC and epilepsy and the unique characteristics of epilepsy caused by NCC. We also discuss recent advances in our understanding of NCC-related epilepsy, including the importance of anti-inflammatory therapies, the association between NCC and temporal lobe epilepsy, and the recent discovery of biomarkers of severe epilepsy development in individuals with NCC and seizures.

Host immune responses during Taenia solium Neurocysticercosis infection and treatment

Taenia solium cysticercosis and taeniasis (TSCT), caused by the tapeworm T. solium, is a foodborne and zoonotic disease classified since 2010 by WHO as a neglected tropical isease. It causes considerable impact on health and economy and is one of the leading causes of acquired epilepsy in most endemic countries of Latin America, Sub-Saharan Africa, and Asia. There is some evidence that the prevalence of TSCT in high-income countries has recently increased, mainly due to immigration from endemic areas. In regions endemic for TSCT, human cysticercosis can manifest clinically as neurocysticercosis (NCC), resulting in epileptic seizures and severe progressive headaches, amongst other neurological signs and/or symptoms. The development of these symptoms results from a complex interplay between anatomical cyst localization, environmental factors, parasite's infective potential, host genetics, and, especially, host immune responses. Treatment of individuals with active NCC (presence of viable cerebral cysts) with anthelmintic drugs together with steroids is usually effective and, in the majority, reduces the number and/or size of cerebral lesions as well as the neurological symptoms. However, in some cases, treatment may profoundly enhance anthelmintic inflammatory responses with ensuing symptoms, which, otherwise, would have remained silent as long as the cysts are viable. This intriguing silencing process is not yet fully understood but may involve active modulation of host responses by cyst-derived immunomodulatory components released directly into the surrounding brain tissue or by the induction of regulatory networks including regulatory T cells (Treg) or regulatory B cells (Breg). These processes might be disturbed once the cysts undergo treatment-induced apoptosis and necrosis or in a coinfection setting such as HIV. Herein, we review the current literature regarding the immunology and pathogenesis of NCC with a highlight on the mobilization of immune cells during human NCC and their interaction with viable and degenerating cysticerci. Moreover, the immunological parameters associated with NCC in people living with HIV/AIDS and treatments are discussed. Eventually, we propose open questions to understand the role of the immune system and its impact in this intriguing host-parasite crosstalk.

An Ambispective Cohort Study to Assess Seizure Recurrences in Children with Calcified Parenchymal Neurocysticercosis

Calcified neurocysticercosis (NCC), previously thought to be a dead end, is an important risk factor for seizure recurrences. We studied the pattern of seizure recurrences and associated radiological findings in children with calcified NCC. In this ambispective cohort study, we enrolled children (age 1-15 years) with calcified NCC attending the pediatric NCC clinic between January 2017 and December 2017. Retrospective data were collected from the hospital records, and all enrolled children were prospectively followed up till June 2018. The study group divided into two groups: 1) children first presenting with calcified granuloma and 2) children presented with ring-enhancing lesion (REL) and transformed into the calcified lesion during follow-up imaging. During the study period (January 2017-December 2017), 520 children with NCC were screened and 128 with calcified NCC were enrolled. The mean age was 10.8 ± 3.2 years, and 63% were boys. Among 128 children, 40 (31%) had calcified granuloma and 88 (69%) had REL transformed to calcified granuloma. Sixty-one (49%) children had seizure recurrence: 22 (58%) within calcified granuloma group and 39 (45%) within REL transformed to calcified granuloma group (P = 0.18). Seizure recurrence was associated with the presence of perilesional edema (PE) in 35 (57.4%) children on computed tomography scan. The median interval between two seizure recurrences was 30 (17-56) months, and the median antiepileptic drug-free interval was 17 (12-22) months. The total duration of continued seizures was 42 (26-58) months, slightly longer in children with REL transformed to calcified granuloma group (42, 95% CI: 18-66 months) in comparison to calcified granuloma group (35, 95% CI: 10-60 months, P = 0.32). To conclude, children with calcified NCC have seizure recurrences over a prolonged period. Seizure recurrences are intermittent and may be interspersed with a prolonged period of quiescence in between. The presence of PE and contrast enhancement around the lesion during seizure recurrence suggests lesion reactivation.

Taenia solium cysticercosis and taeniasis in urban settings: Epidemiological evidence from a health-center based study among people with epilepsy in Dar es Salaam, Tanzania

In Africa, urbanization is happening faster than ever before which results in new implications for transmission of infectious diseases. For the zoonotic parasite Taenia solium, a major cause of acquired epilepsy in endemic countries, the prevalence in urban settings is unknown. The present study investigated epidemiological, neurological, and radiological characteristics of T. solium cysticercosis and taeniasis (TSCT) in people with epilepsy (PWE) living in Dar es Salaam, Tanzania, one of the fastest growing cities worldwide. A total of 302 PWE were recruited from six health centers in the Kinondoni district of Dar es Salaam. Serological testing for T. solium cysticercosis-antigen (Ag) and -antibodies (Abs) and for T. solium taeniasis-Abs was performed in all PWE. In addition, clinical and radiological examinations that included cranial computed tomography (CT) were performed. With questionnaires, demographic data from study populations were collected, and factors associated with TSCT were assessed. Follow-up examinations were conducted in PWE with TSCT. T. solium cysticercosis-Ag was detected in three (0.99%; 95% CI: 0–2.11%), -Abs in eight (2.65%; 95% CI: 0.84–4.46%), and taeniasis-Abs in five (1.66%; 95% CI: 0.22–3.09%) of 302 PWE. Six PWE (1.99%; 95% CI: 0.41–3.56%) were diagnosed with neurocysticercosis (NCC). This study demonstrates the presence of TSCT in Dar es Salaam, however, NCC was only associated with a few cases of epilepsy. The small fraction of PWE with cysticercosis- and taeniasis-Abs may suggest that active transmission of T. solium plays only a minor role in Dar es Salaam. A sufficiently powered risk analysis was hampered by the small number of PWE with TSCT; therefore, further studies are required to determine the exact routes of infection and risk behavior of affected individuals.

Taenia solium cysticercosis and taeniasis is a zoonotic disease complex which affects thousands of people in sub-Saharan Africa. This parasite has a human-pig life cycle and has been considered a public health problem mainly in rural areas. As African towns and suburbs grow rapidly and disproportionally, adequate infrastructure such as sewage systems and clean water often lack while population density, trade, and travel increase. This may lead to the appearance of parasitic diseases formerly considered `rural´ in urban settings. In this study, we searched for evidence of T. solium infections in the Kinondoni district of Dar es Salaam, Tanzania. We focused on people with epilepsy (PWE) since epilepsy is one of the most common and severe disorders associated with T. solium neurocysticercosis and tested all of them serologically for T. solium cysticercosis and taeniasis. We further investigated neurological and radiological characteristics. Our findings show that in our study area in Dar es Salaam 2.65% of PWE had contracted T. solium infection at some stage. Neurocysticercosis, as confirmed by neuroimaging, was found only in 1.99% of PWE. This, in combination with the relatively small number of PWE detected with taeniasis antibodies (1.66%), points towards the fact that active transmission of T. solium seems to play only a minor role in this urban setting, suggesting that infections may mainly be contracted in rural areas. Further large-scale studies are required to investigate the infection pathways and risk behavior related to T. solium infections within urban areas of sub-Saharan Africa.

Neurocysticercosis and Hippocampal Atrophy: MRI Findings and the Evolution of Viable or Calcified Cysts in Patients With Neurocysticercosis

Neurocysticercosis (NC) is the most common parasitic infection of the central nervous system (CNS). Several studies have reported an association between NC and mesial temporal lobe epilepsy (MTLE). We intended to evaluate the frequency of hippocampal atrophy (HA), clinical evolution and imaging findings in patients with calcified neurocysticercotic lesions (CNLs). Methods: One hundred and eighty-one subjects (70 cases and 111 controls) were evaluated for the presence or absence of HA. We assessed the imaging findings, and the evolution of patients with NC treated or not with anthelmintics for NC. Results: Hippocampal volumes were different between cases and controls (p < 0.001). Seventy percent of the cases presented HA. 52.2% of the patients without a history of anthelmintic treatment for NC had reports of epileptic seizures. There was an association between non-treatment and the later occurrence of epileptic seizures (p = 0.006). There was an association between perilesional edema on MRI and the presence of uncontrolled epileptic seizures (p = 0.004). Conclusions: Hippocampal atrophy is frequent in patients with NCC. There was an association between no anthelmintic treatment in the acute phase of NC, perilesional edema, more pronounced hippocampal atrophy, and the occurrence of refractory seizures.

Parasites and epilepsy: Understanding the determinants of epileptogenesis

There is a large body of evidence suggesting that parasites could be a major preventable risk factor for epilepsy in low- and middle-income countries. We review potentially important substrates for epileptogenesis in parasitic diseases. Taenia solium is the most widely known parasite associated with epilepsy, and the risk seems determined mainly by the extent of cortical involvement and the evolution of the primary cortical lesion to gliosis or to a calcified granuloma. For most parasites, however, epileptogenesis is more complex, and other favorable host genetic factors and parasite-specific characteristics may be critical. In situations where cortical involvement by the parasite is either absent or minimal, parasite-induced epileptogenesis through an autoimmune process seems plausible. Further research to identify important markers of epileptogenesis in parasitic diseases will have huge implications for the development of trials to halt or delay onset of epilepsy.

Inflammation is a key risk factor for persistent seizures in neurocysticercosis

Objective

We conducted a retrospective, case-control study of neurocysticercosis patients to ascertain early markers that identify subjects likely to develop treatment-resistant seizures.

Methods

Clinical histories and imaging studies from 38 neurocysticercosis patients who had been followed for 18 months after treatment were evaluated. Both pairwise and multifactorial analyses were conducted to identify factors associated with continued seizures.

Results

Eleven of 38 patients continued to have seizures during the follow-up period. On univariate analysis, the number of neurocysticercosis lesions, number of bands on the baseline neurocysticercosis western blot, edema volumes on follow-up MRI scans, edema volume changes between baseline and follow-up images, and proportion of calcified lesions with perilesional edema were all significantly increased in subjects who had persistent seizures during the 18-month follow-up period. On multivariate analyses using recursive partition and random forest algorithms, variables associated with persistent seizures included: the number of total and calcified lesions, presence of perilesional edema, the rate of change in the lesion and edema volumes from baseline to follow-up, and the number of bands on the neurocysticercosis western blot.

Interpretation

Measures of both inflammation and disease burden are key risk factors for persistent seizures despite anticonvulsant treatments in patients with neurocysticercosis. Inflammation is therefore a potentially modifiable risk factor for the frequently seen severe seizure disorders in patients with neurocysticercosis.

TNF-α blockade suppresses pericystic inflammation following anthelmintic treatment in porcine neurocysticercosis

Background

Neurocysticercosis (NCC) is an infection of the brain with the larval cyst of the tapeworm, Taenia solium. Cysticidal treatment induces parasite killing resulting in a post inflammatory response and seizures, which generally requires corticosteroid treatment to control inflammation. The nature of this response and how to best control it is unclear. We investigated the anti-inflammatory effects of pretreatment with etanercept (ETN), an anti-tumor necrosis factor agent, or dexamethasone (DEX), a high potency corticosteroid, on the post treatment inflammatory response in naturally infected pigs with neurocysticercosis after a single dose of the cysticidal drug praziquantel (PZQ).

Methodology/Principal findings

We followed the methods from a previously developed treatment model of NCC in naturally infected swine. The four study groups of infected pigs included 3 groups treated with PZQ on day 0: PZQ-treated alone (100 mg/kg PO; n = 9), pretreated with dexamethasone (DEX, 0.2 mg/kg IM administered on days -1, +1 and +3; n = 6), and pretreated with etanercept (ETN, 25 mg IM per animal on days -7 and 0; n = 6). The fourth group remained untreated (n = 3). As measured by quantitative RT-PCR, ETN pretreatment depressed transcription of a wide range of proinflammatory, regulatory and matrix protease encoding genes at 120 hr post PZQ treatment in capsules of cysts that demonstrated extravasated Evans Blue (EB) (a measure of blood brain barrier dysfunction) compared to animals not receiving ETN. Transcription was significantly depressed for the proinflammatory genes tumor necrosis factor (TNF)-α, and interferon (IFN)-γ; the inflammation regulating genes cytotoxic T-lymphocyte-associated protein (CTLA)4, interleukin (IL)-13 and transforming growth factor (TGF)-β; the tissue remodeling genes matrix metalloprotease (MMP)1 and 9, tissue inhibitors of metalloproteases (TIMP)1 and 2, and the genes regulating endothelial function vascular endothelial growth factor (VEGF)1, angiopoietin (Ang)1, Ang 2, and platelet endothelial cell adhesion molecule (PECAM)-1. In contrast, transcription was only modestly decreased in the DEX pretreated pigs compared to PZQ alone, and only for TNF-α, IL-6, IFN-γ, TGF-β and Ang1. IL-10 was not affected by either ETN or DEX pretreatments. The degree of inflammation, assessed by semi-quantitative inflammatory scores, was modestly decreased in both ETN and DEX pretreated animals compared to PZQ treated pigs whereas cyst damage scores were moderately decreased only in cysts from DEX pretreated pigs. However, the proportion of cysts with EB extravasation was not significantly changed in ETN and DEX pretreated groups.

Conclusions/Significance

Overall, TNF-α blockade using ETN treatment modulated expression of a large variety of genes that play a role in induction and control of inflammation and structural changes. In contrast the number of inflammatory cells was only moderately decreased suggesting weaker effects on cell migration into the inflammatory capsules surrounding cysts than on release of modulatory molecules. Taken together, these data suggest that TNF-α blockade may provide a viable strategy to manage post-treatment pericystic inflammation that follows antiparasitic therapy for neurocysticercosis.

Infection of the brain with larvae of the tapeworm Taenia solium is called neurocysticercosis (NCC), a disease with varied and serious neurological symptoms. Therapy requires antiparasitic drugs and corticosteroids to prevent seizures caused by treatment due to inflammation around dying parasites. The gene expression of the proinflammatory molecule tumor necrosis factor alpha (TNF-α) is increased in NCC. We treated three groups of naturally infected pigs with an antiparasitic drug: one group was also pretreated with an anti-TNF-α inhibitor, the second one with a corticosteroid, and the third was not pretreated. All pigs were infused with Evans blue dye (EB), which leaks where the blood brain barrier is damaged by inflammation around cysts. We compared the expression of several genes involved in inflammation, healing and fibrosis and regulation of vascular function in tissues surrounding cysts. In inflamed samples showing leaked EB, the inhibition of TNF-α suppressed nearly all the genes assessed, and this suppression was significantly stronger than the moderate decrease caused by corticosteroid pretreatment on most of the genes. On microscopic examination, the inflammation observed was slightly decreased with both pretreatments in relation to the group that was not pretreated. We believe that the inflammatory route that includes TNF-α should be further explored in the search for better management of inflammation directed to degenerating cysts.

Neurocysticercosis among People Living Near Pigs Heavily Infected with Cysticercosis in Rural Endemic Peru

Neurocysticercosis causes substantial neurologic morbidity in endemic regions around the world. In this cross-sectional study, we describe the frequency of neurocysticercosis among a presumed high-risk group of people in an endemic community in northern Peru. Participants who screened positive on a nine-question seizure survey were evaluated clinically to diagnose epilepsy using International League Against Epilepsy criteria. Those with epilepsy were offered a noncontrast computerized tomography (CT) of the head. We also tested sera from all participants using the lentil lectin-bound glycoprotein enzyme-linked immunoelectrotransfer blot (EITB) to detect anti-cysticercus antibodies and enzyme-linked immunosorbent assay (ELISA) B60/B158 to detect cysticercosis antigens. Participants with strongly positive ELISA (ratio ≥ 3) were offered a noncontrast magnetic resonance imaging (MRI) of the brain. We diagnosed 16 cases of epilepsy among 527 people screened (lifetime prevalence 30 per 1,000). Twelve with epilepsy accepted CT scan and five (41.7%) had parenchymal calcifications. None had viable cysts. Of the 514 who provided a blood sample, 241 (46.9%) were seropositive by EITB and 12 (2.9%) were strongly positive by ELISA (ratio ≥ 3). Eleven accepted MRI and eight (72.3%) had neurocysticercosis, including five with extraparenchymal cysts, five with parenchymal vesicular cysts, and two with parenchymal granulomas. These findings show that clinically relevant forms of neurocysticercosis and epilepsy can be found by applying screening interventions in communities endemic to Taenia solium. Longitudinal controlled studies are needed to better understand which subgroups are at highest risk and which are most likely to have improved prognosis as a result of screening.

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".

Understanding the association of neurocysticercosis and mesial temporal lobe epilepsy and its impact on the surgical treatment of patients with drug-resistant epilepsy

Mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS) is one of the most common types of focal epilepsies. This is an epileptic syndrome commonly associated with treatment-resistant seizures, being also the most prevalent form of drug-resistant epilepsy which is treated surgically in most epilepsy surgery centers. Neurocysticercosis (NCC) is one of the most common parasitic infections of the central nervous system, and one of the most common etiological agents of focal epilepsy, affecting millions of patients worldwide. Recently, researchers reported a curious association between MTLE-HS with NCC, but this association remains poorly understood. Some argue that calcified NCC lesions in MTLE-HS patients is only a coincidental finding, since both disorders are prevalent worldwide. However, others suppose there might exist a pathogenic relationship between both disorders and some even suspect that NCC, by acting as an initial precipitating injury (IPI), might cause hippocampal damage and, eventually, MTLE-HS. In this review, we discuss the various reports that examine this association, and suggest possible explanations for why calcified NCC lesions are also observed in patients with MTLE-HS. We also propose mechanisms by which NCC could lead to MTLE-HS. Finally, we discuss the implications of NCC for the treatment of pharmacologically-resistant focal epilepsies in patients with calcified NCC or in patients with MTLE-HS and calcified NCC lesions. We believe that investigations in the relationship between NCC and MTLE-HS might offer further insights into how NCC may trigger epilepsy, and into how MTLE-HS originates. Moreover, observations in patients with drug-resistant epilepsy with both NCC and hippocampal sclerosis may not only aid in the understanding and treatment of patients with MTLE-HS, but also of patients with other forms of dual pathologies aside from NCC. This article is part of a Special Issue titled Neurocysticercosis and Epilepsy.

Epilepsy surgery and neurocysticercosis: Assessing the role of the cysticercotic lesion in medically-refractory epilepsy

There is increasing evidence of the existence of refractoriness to treatment with antiepileptic medications in those with NCC-related epilepsy. We performed a systematic review with the objective to determine the role of a cysticercotic lesion in this group of patients. We sought those manuscripts, including case reports, describing patients with NCC-related medically-intractable epilepsy who underwent epilepsy surgery and were seizure-free a year after. Only 10 manuscripts fulfilled inclusion and exclusion criteria. Three different clinical presentations were identified: 1) the cysticercotic lesion was epileptogenic, 2) there was dual pathology, including the cysticercotic lesion, with the other lesion usually being hippocampal sclerosis, and 3) the cysticercotic lesion was not related to the epileptogenic focus. In the case of an epileptogenic cysticercotic lesion, the presence of gliosis appeared to be the culprit for epileptogenicity. More studies using large cohorts of patients might be able to confirm our findings. This article is part of a Special issue entitled "Neurocysticercosis and Epilepsy".

Infections of the Central Nervous System in Returning Travelers and Immigrants

PURPOSE OF REVIEW

This review highlights current knowledge in travel-related neuroinfectious diseases, providing insight on approaches to prevention, diagnosis, and treatment of infections of the central nervous system (CNS) in travelers and immigrants.

RECENT FINDINGS

Updates on travel vaccine recommendations including vaccine-specific interactions with immunosuppressive agents, advances in Zika virus and dengue virus vaccine development, new diagnostic criteria for neurocysticercosis, updates on treatment approaches for tuberculosis meningitis. Increasing rates of travel are leading to the spread of known infectious diseases and the emergence of new diseases in travel medicine. Among these infections, neuroinfectious diseases carry significant morbidity and mortality. To reduce the effect of travel-related illness, appropriate pre-travel measures and up-to-date diagnostic and treatment strategies are essential for optimal outcomes. This review highlights important travel information relevant to neuroinfectious diseases for several populations including immunocompetent, immunocompromised, pregnant, and infant/children travelers. It also outlines the travel risk, clinical presentation, diagnosis, and management of a select list of neuroinfectious diseases by region, including neurocysticercosis, Zika virus, tuberculosis meningitis, rabies, and tick-borne encephalitis.