Imaging of Neurocysticercosis

Neurocysticercosis-Induced Monoparesis: A Case Report of a Rare Neurological Manifestation

Neurocysticercosis (NCC), a disease caused by the larval form of the pork tapeworm Taenia solium, is a common cause of acquired epilepsy globally, especially in areas with poor sanitation. While seizures and headaches are common manifestations, cases of NCC leading to monoparesis are exceedingly rare. Here, we describe a distinctive case of a 42-year-old male who developed sudden weakness and spasms in his left hand without prior injury or other systemic symptoms. Magnetic resonance imaging (MRI) of the brain revealed a single cystic lesion in the right frontoparietal lobe indicative of NCC, which was the cause of his pure motor monoparesis (PMM), without any sensory loss. Treatment with dexamethasone and albendazole substantially improved his motor abilities, highlighting the necessity of considering NCC in differential diagnoses for monoparesis, particularly in endemic areas. This case adds a unique perspective to the clinical spectrum of NCC, highlighting the critical role of prompt and accurate diagnosis followed by appropriate treatment in achieving favorable outcomes.

Taenia martis Neurocysticercosis-Like Lesion in Child, Associated with Local Source, the Netherlands

A neurocysticercosis-like lesion in an 11-year-old boy in the Netherlands was determined to be caused by the zoonotic Taenia martis tapeworm. Subsequent testing revealed that 15% of wild martens tested in that region were infected with T. martis tapeworms with 100% genetic similarity; thus, the infection source was most likely local.

Overview of the Current Knowledge and Conventional MRI Characteristics of Peri- and Para-Vascular Spaces

Brain spaces around (perivascular spaces) and alongside (paravascular or Virchow-Robin spaces) vessels have gained significant attention in recent years due to the advancements of in vivo imaging tools and to their crucial role in maintaining brain health, contributing to the anatomic foundation of the glymphatic system. In fact, it is widely accepted that peri- and para-vascular spaces function as waste clearance pathways for the brain for materials such as ß-amyloid by allowing exchange between cerebrospinal fluid and interstitial fluid. Visible brain spaces on magnetic resonance imaging are often a normal finding, but they have also been associated with a wide range of neurological and systemic conditions, suggesting their potential as early indicators of intracranial pressure and neurofluid imbalance. Nonetheless, several aspects of these spaces are still controversial. This article offers an overview of the current knowledge and magnetic resonance imaging characteristics of peri- and para-vascular spaces, which can help in daily clinical practice image description and interpretation. This paper is organized into different sections, including the microscopic anatomy of peri- and para-vascular spaces, their associations with pathological and physiological events, and their differential diagnosis.

Racemose neurocysticercosis: a case series

Neurocysticercosis (NCC) is a common parasitic condition of the central nervous system in certain parts of the world. The racemose variety of NCC is distinct from the commonly seen parenchymal form. It frequently infiltrates the basal cisterns and Sylvian fissures. Imaging plays a vital role in the diagnosis; however, as their signal intensity is similar to cerebrospinal fluid and due to the absence of enhancement in most cases, imaging diagnosis is often difficult on the conventional MRI sequences. Here, we present five cases of racemose NCC to emphasize the importance of a heavily T2-weighted sequence (Fast Imaging Employing Steady-state Acquisition) sequence in the diagnosing this entity.

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.

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.

Neuroimaging in Adults and Children With Epilepsy

OBJECTIVE

This article discusses the fundamental importance of optimal epilepsy imaging using the International League Against Epilepsy-endorsed Harmonized Neuroimaging of Epilepsy Structural Sequences (HARNESS) protocol and the use of multimodality imaging in the evaluation of patients with drug-resistant epilepsy. It outlines a methodical approach to evaluating these images, particularly in the context of clinical information.

LATEST DEVELOPMENTS

Epilepsy imaging is rapidly evolving, and a high-resolution epilepsy protocol MRI is essential in evaluating newly diagnosed, chronic, and drug-resistant epilepsy. The article reviews the spectrum of relevant MRI findings in epilepsy and their clinical significance. Integrating multimodality imaging is a powerful tool in the presurgical evaluation of epilepsy, particularly in "MRI-negative" cases. For example, correlation of clinical phenomenology, video-EEG with positron emission tomography (PET), ictal subtraction single-photon emission computerized tomography (SPECT), magnetoencephalography (MEG), functional MRI, and advanced neuroimaging such as MRI texture analysis and voxel-based morphometry enhances the identification of subtle cortical lesions such as focal cortical dysplasias to optimize epilepsy localization and selection of optimal surgical candidates.

ESSENTIAL POINTS

The neurologist has a unique role in understanding the clinical history and seizure phenomenology, which are the cornerstones of neuroanatomic localization. When integrated with advanced neuroimaging, the clinical context has a profound impact on identifying subtle MRI lesions or finding the "epileptogenic" lesion when multiple lesions are present. Patients with an identified lesion on MRI have a 2.5-fold improved chance of achieving seizure freedom with epilepsy surgery compared with those without a lesion. This clinical-radiographic integration is essential to accurate classification, localization, determination of long-term prognosis for seizure control, and identification of candidates for epilepsy surgery to reduce seizure burden or attain seizure freedom.

Case report and review of literature: Isolated intramedullary spinal neurocysticercosis

Background

Cases of isolated intramedullary spinal neurocysticercosis are extremely rare. Only 25 cases have been reported before 2022. Due to its rarity, the diagnosis of spinal neurocysticercosis may be missed.

Case presentation

We describe a 37-year-old female patient who developed back pain and lower extremity weakness and was found to have an intramedullary thoracic spine cystic lesion. She was taken to the operating room for resection of the lesion. Pathology revealed a larval cyst wall consistent with neurocysticercosis. The patient was started on albendazole and dexamethasone. Her exam improved post-operatively, and she was able to ambulate with minimal difficulty at the time of follow up.

Conclusion

The case provides insights on the diagnosis and treatment of isolated intramedullary spinal neurocysticercosis. Review of the literature suggests that combined surgical and medical intervention results in significant improvement in the patient's neurological exam, and decreases morbidity associated with the disease. We propose a treatment paradigm for this rare manifestation of neurocysticercosis.

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: an update on diagnosis, treatment, and prevention

Neurocysticercosis (NCC) is an important cause of neurological disease worldwide, including imported cases in nonendemic countries.

PURPOSE OF REVIEW

The purpose of this review is to update information on diagnosis, management, and prevention of neurocysticercosis.

RECENT FINDINGS

WHO and Infectious Diseases Society of America/American Society of Tropical Medicine and Hygiene guidelines emphasize the importance of corticosteroids and antiparasitic drugs for viable parenchymal disease and single enhancing lesions. Subarachnoid NCC is associated with a high fatality rate unless optimally treated. Advances in subarachnoid NCC include use of prolonged antiparasitic and anti-inflammatory courses and the increasing use of antigen-detection and quantitative PCR assays in diagnosis and follow-up. Emerging data support the safety and efficacy of minimally invasive surgery in ventricular cases. Calcified neurocysticercosis continues to be associated with a high burden of disease. Field studies are demonstrating the feasibility of eradication using a combination of mass chemotherapy for human tapeworms and vaccination/treatment of porcine cysticercosis.

SUMMARY

NCC remains an important and challenging cause of neurological disease with significant morbidity despite advances in treatment and prevention.

Neuroimaging of Epilepsy

PURPOSE OF REVIEW

This article provides an overview of imaging modalities, important imaging pathologies, and the role each imaging modality can play in the diagnosis, evaluation, and treatment of epilepsy, including epilepsy surgery.

RECENT FINDINGS

The Harmonized Neuroimaging of Epilepsy Structural Sequences (HARNESS-MRI) protocol was proposed to standardize MRI imaging for all patients with seizures. The role of 7-Tesla MRI in finding previously occult epileptogenic lesions is under investigation, and the technique is increasingly used. Developing MRI postprocessing techniques can increase the sensitivity of MRI. Improvements in functional imaging techniques such as EEG-functional MRI (fMRI) and magnetic source imaging provide complementary methods of identifying seizure foci. New epileptogenic pathologies such as multinodular and vacuolating neuronal tumors (MVNT) are being discovered, and the importance of others, such as encephaloceles, is better appreciated.

SUMMARY

Brain imaging is a critical component of the diagnosis and evaluation of patients with epilepsy. Structural imaging modalities such as MRI and CT allow for the identification of a wide variety of potentially epileptogenic lesions. For patients with drug-resistant epilepsy under consideration for resective surgery, both structural and functional neuroimaging may be needed for focus identification and surgical planning for preservation of neurologic function.

Seizures Related to Neurocysticercosis and Cocaine Use

Neurocysticercosis (NCC) is an infection of the central nervous system with Taenia solium cysts that most commonly results in seizures. In stable patients without recent symptoms, these seizures may be provoked by seizure threshold-lowering drugs such as cocaine. This case details a 38-year-old male with a past medical history of epilepsy presenting with seizures due to comorbid NCC and cocaine use. This case was complicated by the lack of available information regarding the patient’s past medical history and medication use. We highlight the importance of obtaining a full work-up, including brain imaging, to provide optimal treatment for patients with seizures despite a history of drug use.

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.

Advanced magnetic resonance imaging and spectroscopy in a case of neurocysticercosis from North America

Neurocysticercosis (NCC) is a parasitic infection caused by Cysticercus cellulosae, the metacestode of pork tapeworm (Taenia solium). NCC is one of the most common public health problems worldwide. We present a patient harboring a bilobed ring-enhancing lesion with a presumed diagnosis of brain metastasis, who returned to the USA after traveling to an endemic region. The diagnosis of NCC was established based on a characteristic resonance of succinate on proton magnetic resonance spectroscopy. Also, higher mean diffusivity and lower fractional anisotropy along with relative cerebral blood volume were observed from the lesion compared to contralateral normal brain regions. Multiparametric analysis may improve the differential diagnosis of ring-enhancing intracranial lesions such as NCC.

Subarachnoid Neurocysticercosis Presenting as a New-Onset Seizure in an Immigrant From Guatemala

Subarachnoid involvement is a rare but severe form of neurocysticercosis (NCC), leading to serious complications if not recognized and treated appropriately. Imaging of the brain usually involves computed tomography and/or magnetic resonance image (MRI) of the brain, both of which can lead to a diagnosis of NCC. We present a 20-year-old female with no significant past medical history presenting with a new-onset seizure whose clinical treatment was significantly altered when subarachnoid involvement was identified. This case highlights the importance of brain MRI in recognizing subarachnoid disease, an important subset of NCC disease presentation.

The returned traveler with neurologic manifestations: could my patient have a parasite?

PURPOSE OF REVIEW

The present review focuses on parasitic infections of the central nervous system (CNS) that can affect the international traveler.

RECENT FINDINGS

The epidemiology of imported parasitic infections is changing and clinicians are treating increasing numbers of returned travelers with parasitic infections in the CNS with which they are not familiar.

SUMMARY

The epidemiology, life cycle, clinical manifestations, diagnosis, and treatment of parasites that affect the CNS will be discussed.

Current Diagnostic Criteria for Neurocysticercosis

Neurocysticercosis (NCC) causes significant neurological morbidity around the world, and is the most common preventable factor for epilepsy in adults. It is endemic in most developing countries, and also diagnosed with some frequency in industrialized countries because of travel and migration. The clinical manifestations of NCC are extremely variable and may include almost any neurological symptom, depending on the number of lesions, location, size and evolutive stage of the infecting parasitic larvae and the immune response of the host. Thus, the diagnosis of NCC relies mostly on neuroimaging and immunological tests. Despite being a disease with a known etiology, the lack of specificity of clinical manifestations and auxiliary examinations makes its diagnosis difficult. In an attempt for developing a standard diagnosis approach, a chart of diagnostic criteria for NCC was initially published in 1996, and revised in 2001 and 2017. This chart of diagnostic criteria systematized the diagnosis of NCC and became widely used worldwide. This manuscript describes the structure of the chart, the principles behind the changes for each revision, as well as the context of its use and potential for improvement.

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.

Neurocysticercosis: Current Perspectives on Diagnosis and Management

Porcine cysticercosis, human taeniasis, and (neuro)cysticercosis are endemic in many low- and middle-income countries (LMIC) where they present a significant health burden to affected communities. Neurocysticercosis (NCC) is one of the leading causes of human epilepsy in many hyperendemic regions in Latin America, Asia, and sub-Saharan Africa. The World Health Organization (WHO) reports an estimated 2.5-8.3 million cases of NCC annually with a disability-adjusted life year (DALY) burden of 2.8 million, but as for all neglected tropical diseases (NTDs), these values are likely to be underestimated. Diagnosis of NCC is complex and most accurately diagnosed using clinical neuroimaging that is unavailable in most hyperendemic regions in LMIC. On January 28, 2021, WHO will launch its road map for the NTDs' "Ending the neglect to attain the Sustainable Development Goals: a road map for neglected tropical diseases 2021-2030." Taeniasis/cysticercosis is targeted for control success considered as steady increase in the number of countries with intensified control in hyperendemic areas [increasing from 2 (3%) in 2020 to 4 (6%) in 2023, to 9 (14%) by 2025, and to 17 (27%) by 2030]. Cross-cutting targets that include 100% access to at least basic water supply, sanitation, and hygiene in areas endemic for NTDs and 75% integrated treatment coverage for preventative chemotherapy will additionally impact on the taeniasis/cysticercosis/NCC complex. With no vaccine available for humans, prevention of infection depends on communication to the public of the life cycle of a complex zoonosis to promote behavior change, underpinned by practical control measures including treatment of human taeniasis and (neuro)cysticercosis with albendazole and praziquantel [widely used as part of the mass drug administration (MDA) deworming programs], surgery where appropriate, and effective vaccination and deworming for pigs supported by meat inspection. Here, we review recent advances in tools and implementation for Taenia solium taeniasis/(neuro)cysticercosis (TSTC) control and milestones on the onward path to elimination.

Inflammation in neurocysticercosis: clinical relevance and impact on treatment decisions

INTRODUCTION

Neurocysticercosis is caused by the localization of Taenia solium larvae in the central nervous system. The disease remains endemic in most countries of Latin America, Asia and Africa. While major improvements have been made in its diagnosis and treatment, uncertainties persist regarding the clinical implications and treatment of the inflammatory reaction associated with the disease.

AREAS COVERED

In this review, based on PubMed searches, the authors describe the characteristics of the immune-inflammatory response in patients with neurocysticercosis, its clinical implications and the treatment currently administered. The dual role of inflammation (participating in both, the death of the parasite, and the precipitation of serious complications) is discussed. New therapeutic strategies of potential interest are presented.

EXPERT OPINION

Inflammatory reaction is the main pathogenic mechanism associated to neurocysticercosis. Its management is mainly based on corticosteroids administration. This strategy had improved prognostic of patients as it allows for the control of most of the inflammatory complications. On the other side, it might be involved in the persistence of parasites in some patients, despite cysticidal treatment, due to its immunosuppressive properties. New strategies are needed to improve therapeutical management, particularly in the severest presentations.

Approach to an Intracranial Mass in Patients With HIV

PURPOSE OF REVIEW

Space-occupying lesions represent a diagnostic challenge among people with the human immunodeficiency virus, acquired immunodeficiency syndrome (HIV/AIDS). To determine the best diagnostic approach to the wide array of possible etiologies and provide a thorough interpretation of neuroimaging in order to narrow a hierarchical differential diagnosis among these patients. Given that there is no pathognomonic neuroimaging pattern in this clinical setting, we searched results from brain biopsies to best determine the etiology of commonly found lesions.

RECENT FINDINGS

Multimodal brain MRI and MRI spectroscopy (MRS) often provide the most valuable information in the study of focal masses among people with HIV/AIDS. Brain biopsy appears safe and provides high diagnostic yields in these patients. Among patients with HIV/AIDS who present with space-occupying intracranial lesions, brain MRI and MRS are useful tests. However, in cases of diagnostic uncertainty, brain biopsy is a safe procedure and should be performed. The role of metabolic studies like ²⁰¹Th-SPECT or PET is useful in the detection of primary central nervous system lymphoma.

Neurocysticercosis-related seizures in the post-partum period: two cases and a review of the literature

Neurocysticercosis, the infection of the CNS with larval cysts of Taenia solium, is a leading cause of seizures in low-income countries. The clinical presentation of neurocysticercosis is variable and depends on the number, size, and location of cysticerci, and on the immune response of the host. In most patients, the affected site is the brain parenchyma, where cysts can precipitate seizures. Neurocysticercosis has seldom been described in pregnant women. In this Grand Round, we report two cases of pregnant women who immigrated to Italy from Bolivia and Ecuador, and who developed seizures in the early post-partum period, due to calcified parenchymal neurocysticercosis lesions. We discuss the complex interactions between neurocysticercosis and the immune system in pregnancy and the post-partum period. Building on this scenario, we propose practices for the management of neurocysticercosis in pregnancy and the post-partum period, highlighting important gaps in the literature that should be addressed.

Taenia solium Cysticercosis and Its Impact in Neurological Disease

Taenia solium neurocysticercosis (NCC) is endemic in most of the world and contributes significantly to the burden of epilepsy and other neurological morbidity. Also present in developed countries because of immigration and travel, NCC is one of few diseases targeted for eradication. This paper reviews all aspects of its life cycle (taeniasis, porcine cysticercosis, human cysticercosis), with a focus on recent advances in its diagnosis, management, and control. Diagnosis of taeniasis is limited by poor availability of immunological or molecular assays. Diagnosis of NCC rests on neuroimaging findings, supported by serological assays. The treatment of NCC should be approached in the context of the particular type of infection (intra- or extraparenchymal; number, location, and stage of lesions) and has evolved toward combined symptomatic and antiparasitic management, with particular attention to modulating inflammation. Research on NCC and particularly the use of recently available genome data and animal models of infection should help to elucidate mechanisms of brain inflammation, damage, and epileptogenesis.

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.

Intramedullary Neurocysticercosis Mimicking Cord Tumor

Isolated spinal intramedullary involvement by neurocysticercosis is extremely rare. We report a case of a Hispanic female with right-sided weakness, magnetic resonance imaging showing cervical intramedullary lesion. Surgery was performed due to the progressive nature of symptoms. The cervical cord lesion was completely removed; pathology was consistent with degenerated cysticercosis. Progressive clinical improvement with physiotherapy was achieved. Although rare, especially in the absence of intracranial lesions, the diagnosis should be considered in appropriate patient population as it usually presents a peripherally enhancing cystic lesion.

A longitudinal analysis of albendazole treatment effect on neurocysticercosis cyst evolution using multistate models

BACKGROUND

In neurocysticercosis, the larval form of the pork tapeworm Taenia solium appears to evolve through three phases-active, degenerative and sometimes calcification-before disappearance. The antihelmintic drug, albendazole, has been shown to hasten the resolution of active cysts in neurocysticercosis. Little is known about the time cysts take to progress through each phase, with or without treatment.

METHODS

We reconfigured brain imaging data from patient level to cyst level for 117 patients in a randomized clinical trial of albendazole in which images were taken at baseline, 1, 6, 12 and 24 mo. Applying a multistate model, we modelled the hazard of a cyst evolving to subsequent cyst phases before the next imaging (vs no change). We examined the impact of albendazole treatment overall and by patient and cyst characteristics on the hazard.

RESULTS

Albendazole accelerated the evolution from the active to degenerative phase (HR=2.7, 95% CI 1.3 to 6.5) and from the degenerative phase to disappearance (HR=1.9, 95% CI 1.1 to 3.9). Albendazole's impact was stronger for patients who were male, did not have calcified cysts at baseline and who had multiple cysts in different locations.

CONCLUSIONS

This research provides a better understanding of where in the cyst trajectory albendazole has the greatest impact.

A Mistaken Diagnosis of Secondary Glioblastoma as Parasitosis

Background: Glioblastoma is a malignant brain tumor with poor prognosis requiring early diagnosis. Secondary glioblastoma refers to cases that progressed from low-grade glioma. Evidence shows that timely resection correlates with increased survival.

Case presentation: We describe a case of a patient with secondary glioblastoma who was mistakenly diagnosed with Angiostrongylus cantonensis infection until 7 years after disease onset. The patient presented with non-specific clinical manifestations at disease onset. A conventional magnetic resonance imaging (MRI) in the primary survey provided insufficient information, and thus failed to identify the malignancy. During follow-up, unfortunately, clinicians were misled by the patient's raw food diet, a positive serum parasite antibody and a result of low glucose metabolism on Fluorodeoxyglucose-positron emission tomography-computed tomography (FDG-PET-CT). The patient was diagnosed with parasitosis. However, his condition kept getting worse under antiparasitic treatment. Preoperative magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) failed to reverse the mistaken impression. Final diagnosis was confirmed until intraoperative and postoperative pathological findings indicated glioblastoma.

Conclusion: We ascribe the incorrect diagnosis to insufficient understanding on imaging manifestations of brain neoplasm as well as clinical features of parasitosis. Thus, we review the MRI, FDG-PET-CT, MRS, and DTI data of this case according to the timeline, refer to relevant studies, and point out the pitfalls. With a long course of slowly progressing, this was a rare case of secondary glioblastoma with the absence of isocitrate dehydrogenase 1 (IDH1) gene mutation.

Helminthic Infections of the Central Nervous System

PURPOSE OF REVIEW

This article discusses select helminthic parasitic infections that may affect the central nervous system and reviews the epidemiology, neurologic presentation, recommended diagnostic testing, and treatment approach to these infections.

RECENT FINDINGS

Emigration from and travel to areas endemic for helminthic infections that affect the nervous system has led to increased incidence of parasitic neurologic disease in developed countries, necessitating that neurologists be familiar with the diagnostic and therapeutic approach to these diseases. Evidence is emerging on the optimal treatment for neurocysticercosis, which varies based on the form of the disease in the nervous system.

SUMMARY

Parenchymal neurocysticercosis is a leading cause of acquired epilepsy worldwide, and extraparenchymal neurocysticercosis is responsible for many cases of hydrocephalus. Recognition of the different stages and locations of neurocysticercosis is essential for proper management. Similarly, schistosomiasis constitutes a major cause of myelopathy in endemic areas and requires prompt diagnosis and treatment to avoid permanent deficits.

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.

Estimating the association between being seropositive for cysticercosis and the prevalence of epilepsy and severe chronic headaches in 60 villages of rural Burkina Faso

Background

Individuals diagnosed with neurocysticercosis often present with epilepsy and sometimes with progressively worsening severe chronic headaches (WSCH). While cross-sectional associations between seropositivity to cysticercal antigens and epilepsy have been reported, few large scale studies have been conducted in West Africa and none have measured the association between seropositivity to cysticercal antigens and headaches. This study aimed at filling these knowledge gaps by estimating the strength of the cross-sectional association between seropositivity to cysticercal antigens and the prevalence of epilepsy and WSCH in 60 villages of Burkina Faso, West Africa.

Methodology/Principal findings

Baseline data from a cluster randomized controlled trial collected from January 2011 to February 2012 in 60 villages across three provinces in Burkina Faso were used. Between 78 and 80 individuals were screened for epilepsy and WSCH in each village, and those screened positive were confirmed by a physician. Seventy-five percent of all participants were asked to provide a blood sample to test for Taenia solium cysticercus circulating antigens. Hierarchical multivariable logistic models were used to measure the association between seropositivity to cysticercal antigens and epilepsy (lifetime and active) as well as WSCH. Among 3696 individuals who provided a blood sample, 145 were found to have epilepsy only, 140 WSCH only and 19 both. There were positive associations between seropositivity to cysticercal antigens and active epilepsy (prevalence odds ratio (POR): 2.40 (95%CI: 1.15–5.00)) and WSCH (POR: 2.59 (1.34–4.99)).

Conclusions/Significance

Our study is the first to demonstrate a cross-sectional association between seropositivity to cysticercal antigens and WSCH in a large community-based study conducted in West Africa. The measured cross-sectional association had a strength similar to the ones previously observed between seropositivity to cysticercal antigens and lifetime or active epilepsy. As a result, preventing new cysticercosis cases in communities may reduce the prevalence of these two important neurological disorders.

Taenia solium is a parasite that can be transmitted between humans and pigs in areas with poor sanitation and pig management practices. When this parasite infects the human brain, it can cause epilepsy or severe headaches. Our study aimed to measure the association between being seropositive to cysticercal antigens and having epilepsy (lifetime and active) or severe headaches in 60 villages of Burkina Faso. We found that active epilepsy and severe headaches were associated with seropositivity to cysticercal antigens. These results confirm prior studies which suggested an association between being seropositive for cysticercal antigens and these two neurological symptoms. Preventing cysticercosis could reduce new cases of these two neurological symptoms from occurring.

Solitary Brain Mass in a Patient with Seizures: An Unexpected Infectious Etiology

Neurocysticercosis is a parasitosis caused by the larval stage of the pork tapeworm Taenia solium. The diagnosis is challenging as morphology on neuroimaging can be inconclusive and serology is frequently negative. We describe the case of a 24-year old Hispanic man who presented with seizures and loss of consciousness. Magnetic resonance imaging (MRI) showed a cystic mass in right frontal lobe. Work-up that included body computed tomography (CT) scan and Western blot serology for Echinococcus and cysticercosis was unrevealing. He underwent craniotomy with resection of the mass. Histopathology showed fragments of Taenia solium. He was treated with albendazole for 14 days. No further seizures were noted at 6-month follow-up.

Repeated Peritoneal Catheter Blockage Caused by Neurocysticercosis Following Ventriculoperitoneal Shunt Placement for Hydrocephalus

Cerebral cysticercosis is common, but the possibility for repeated occurrence of peritoneal catheter blockage caused by neurocysticercosis (NCC) after two revisions following ventriculoperitoneal shunt placement for hydrocephalus is unusual. Herein, we describe one rare case in which peritoneal catheter revision was performed two times unsuccessfully. Endoscopic cysternostomy rather than peritoneal catheter adjustment was performed successfully, and histopathological examination of excised cystic samples confirmed NCC in our hospital. The present case highlights the need for awareness of NCC as a possible etiology of hydrocephalus, especially in developing countries. Uncommon findings in both lateral ventricles following low-field magnetic resonance imaging scans as well as the rarity of this infection involved in unusual location play important roles in misdiagnosis and incorrect treatment for hydrocephalus; thus, endoscopic cysternostomy, rather than multiple shunt adjustment of the peritoneal end, is recommended in the selected patient. To the best of our knowledge, this is the first report describing the misdiagnosis and inappropriate treatment of hydrocephalus caused by cerebral cysticercosis in China.

Reciprocal contribution of clinical studies and the HP10 antigen ELISA for the diagnosis of extraparenchymal neurocysticercosis

To evaluate diagnosis of active neurocysticercosis, paired cerebral spinal fluid (CSF) and serum samples from 24 neurocysticercosis (NCC) patients and 17 control neurological patients were assayed in the HP10 Taenia antigen (Ag) ELISA. The CSF samples were also tested with an HP10 Lateral Flow Assay (LFA). The HP10 Ag was detected by ELISA in the CSF of 5/5 patients with Definitive extraparenchymal NCC, and in 4/5 of the corresponding sera. In the Definitive parenchymal group, on the other hand, the HP10 Ag was absent in 2/3 CSF (with a very low value in the one positive sample) and all the corresponding serum samples. Samples of CSF from 4/7 patients in the Probable parenchymal group, were also significantly HP10 Ag positive, suggesting the presence of extraparenchymal cysts not identified by the imaging studies. With the possible exception of one patient, the corresponding serum samples of the Probable parenchymal NCC group, were all HP10 Ag negative. Samples of CSF from 9 NCC patients diagnosed with Mixed parenchymal and extraparenchymal NCC were all significantly HP10 Ag positive, confirming the presence of extraparenchymal cysts, with only 7/9 of the corresponding serum samples being HP10 positive. Thus detection of the HP10 Ag indicates extraparenchymal and not parenchymal cyst localization and is more sensitive with CSF than serum. Three neurological patients clinically diagnosed as subarachnoid cyst, hydrocephalus and tuberculoma, respectively, were clearly positive for HP10 Ag. Of these, two were confirmed as NCC by subsequent imaging; the third died prior to further examination. Thus, a total of 8 patients had their clinical diagnosis questioned. Finally, there was good agreement between the HP10 Ag ELISA and LFA with CSF samples giving an optical density ≥0.4 in the ELISA assay. In conclusion, the HP10 Ag assay should provide a valuable and reciprocal tool in the clinical diagnosis and follow up of extraparenchymal NCC.

Imaging for Adults With Seizures and Epilepsy

PURPOSE OF REVIEW

This article discusses structural and functional neuroimaging findings in patients with seizures and epilepsy. The indications for neuroimaging in these patients and the potential diagnostic utility of these studies are presented.

RECENT FINDINGS

Patients presenting with new seizures typically require urgent imaging to rule out a critical underlying cause. MRI is the structural neuroimaging procedure of choice in individuals with epilepsy. Specific epilepsy protocols should be considered to increase the diagnostic yield of neuroimaging in patients with structural lesions associated with focal or generalized seizures. Common epileptogenic pathologic processes include mesial temporal sclerosis, malformations of cortical development, focal encephalomacia, primary brain tumors, vascular malformations, and neurocysticercosis. Functional neuroimaging studies are usually restricted to the evaluation of patients with drug-resistant focal epilepsy who are being considered for surgical treatment.

SUMMARY

The role of neuroimaging in epilepsy depends on the appropriate clinical indication. In patients without known epilepsy presenting with acute seizures, structural imaging is essential to rule out an underlying etiology (eg, subdural hematoma) that may require a specific therapeutic intervention. In individuals with new or previously uninvestigated epilepsy, MRI serves multiple purposes, including identifying a causative focal lesion and helping to diagnose the epilepsy type. In a significant number of patients with epilepsy, the MRI results are normal or reveal indeterminate findings. For patients with drug-resistant focal epilepsy, functional neuroimaging techniques, such as fludeoxyglucose-positron emission tomography (FDG-PET), ictal single-photon emission computed tomography (SPECT), or functional MRI (fMRI), may assist in surgical planning, especially in patients with MRI-negative epilepsy, whose prognosis for a seizure-free outcome after surgery is worse than for patients with an epileptogenic lesion on structural MRI.

Neurocysticercosis in Bhutan: a cross-sectional study in people with epilepsy

BACKGROUND

We sought to provide an assessment of the burden of neurocysticercosis among people with epilepsy (PWE) in Bhutan and evaluate the yield of various tests for Taenia solium.

METHODS

PWE were enrolled at the National Referral Hospital in Thimphu (2014-2015). Serum was tested for anti-Taenia solium IgG using ELISA (Ab-ELISA), enzyme-linked immunoelectrotransfer blot (EITB), and parasite antigen. Results were compared to brain MRI. Participants were categorized as definite neurocysticercosis (MRI and EITB positive), probable neurocysticercosis (MRI or EITB positive), or without neurocysticercosis. Logistic regression models were constructed to explore clinicodemographic associations.

RESULTS

There were 12/205 (6%, 95% CI 2%, 9%) definite and 40/205 (20%, 95% CI 14%, 25%) probable neurocysticercosis cases. 25/205 (12%) with positive EITB did not have neurocysticercosis on MRI, and 15/205 (7%) participants with positive MRI had negative EITB. Participants with neurocysticercosis-suggestive lesions on MRI had an average of 1.2 cysts (parenchymal 26/27; nodular/calcified stage 21/27). In a multivariable analysis, present age (OR 1.05, 95% CI 1.01,1.09, p=0.025) was positively associated with (combined probable or definite) neurocysticercosis while mesial temporal sclerosis on MRI (OR 0.294, 95% CI 0.144, 0.598, p=0.001) was negatively associated.

CONCLUSIONS

Neurocysticercosis was associated with 6-25% of epilepsy in a Bhutanese cohort. Combining EITB and MRI would aid the diagnosis of neurocysticercosis among PWE since no test identified all cases.

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.

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".

Treatment of racemose neurocysticercosis

Background:

Neurocysticercosis (NCC) is a common parasitic infection of the central nervous system, caused by the tapeworm Taenia solium. It is endemic to certain parts of the world, including Central America, South America, Asia, and Africa. The racemose form, characterized by extraparenchymal location, increased morbidity and mortality, and large loculated cystic lesions, is rarely seen in industrialized countries, such as the United States. The management of racemose neurocysticercosis (RNCC) differs from that of the typical parenchymal variant. The ideal course of treatment is debated by experts, but typically includes either surgical intervention with subsequent medical therapy or medical therapy alone.

Case Description:

We present the case of a 34-year-old male diagnosed with RNCC and treated successfully with surgical cyst drainage, resection, and subsequent medical therapy.

Conclusion:

Currently, no standardized evidence-based protocol exists that dictate appropriate treatment for extraparenchymal or racemose NCC. We present a case of RNCC treated successfully with surgical and medical intervention. Further research encompassing well-designed clinical trials is necessary to delineate appropriate and standardized protocols for treatment of this disease.