Cognitive impairment and dementia in neurocysticercosis: a cross-sectional controlled study

Impaired spatial working memory and reduced hippocampal neuronal density in a rat model of neurocysticercosis

Neurocysticercosis (NCC) is the most common parasitic disease affecting the nervous system and is a leading cause of acquired epilepsy worldwide, as well as cognitive impairment, especially affecting memory. The aim of this study was to evaluate the effect of NCC on spatial working memory and its correlation with hippocampal neuronal density, in a rat model of NCC. This experimental study was conducted on female (n = 60) and male (n = 73) Holtzman rats. NCC was induced by intracranial inoculation of T. solium oncospheres in 14 day-old-rats. Spatial working memory was assessed using the T-maze test at 3, 6, 9, and 12 months post-inoculation, and sensorimotor evaluation was performed at 12 months post-inoculation. Hippocampal neuronal density was evaluated by immunostaining of NeuN-positive cells of the CA1 region. Of the rats inoculated with T. solium oncospheres, 87.2% (82/94) developed NCC. The study showed a significant decline in spatial working memory over a 1-year follow-up period in rats experimentally infected with NCC. Males showed an early decline that started at 3 months, while females demonstrated it at 9 months. Additionally, a decrease in neuronal density was observed in the hippocampus of NCC-infected rats, with a more significant reduction in rats with cysts in the hippocampus than in rats with cysts in other brain areas and control rats. This rat model of NCC provides valuable support for the relationship between neurocysticercosis and spatial working memory deficits. Further investigations are required to determine the mechanisms involved in cognitive impairment and establish the basis for future treatments.

From the immune system to mood disorders especially induced by Toxoplasma gondii: CD4+ T cell as a bridge

Toxoplasma gondii (T. gondii), a ubiquitous and obligatory intracellular protozoa, not only alters peripheral immune status, but crosses the blood-brain barrier to trigger brain parenchymal injury and central neuroinflammation to establish latent cerebral infection in humans and other vertebrates. Recent findings underscore the strong correlation between alterations in the peripheral and central immune environment and mood disorders. Th17 and Th1 cells are important pro-inflammatory cells that can drive the pathology of mood disorders by promoting neuroinflammation. As opposed to Th17 and Th1, regulatory T cells have inhibitory inflammatory and neuroprotective functions that can ameliorate mood disorders. T. gondii induces neuroinflammation, which can be mediated by CD4+ T cells (such as Tregs, Th17, Th1, and Th2). Though the pathophysiology and treatment of mood disorder have been currently studied, emerging evidence points to unique role of CD4+ T cells in mood disorder, especially those caused by T. gondii infection. In this review, we explore some recent studies that extend our understanding of the relationship between mood disorders and T. gondii.

Neurocysticercosis Infection: A Case Report

Neurocysticercosis is a condition affecting a significant number of people around the world. The etiology of this condition is a helminth parasite Taenia solium, which has a cycle eventually affecting the human host. This condition follows a cycle of human-to-human fecal-oral route and pigs as an intermediate host with transmission to humans. Infected humans can get dissemination of the larva through circulation and spread throughout the body. In this case, the neural tissue was affected. This article will review the neurocysticercosis condition, pathophysiology, mode of transmission, treatment, and complications.

Update on the diagnosis and management of neurocysticercosis

ABSTRACT Background: Neurocysticercosis (NCC) is a serious public health problem in several developing countries, including those in Latin America, Asia, and Africa. NCC is considered to be the main cause of late-onset epilepsy in endemic areas. Objective: This review summarizes recent advances in diagnosis and therapy of NCC. Methods: Relevant articles and books were reviewed and used as a source of information for this review. Results: The diagnosis of NCC is based upon neuroimaging studies (MRI and computed tomography) and laboratory analysis of the cerebrospinal fluid (CSF). Praziquantel and albendazole are considered parasiticidal drugs against NCC, but there is an intense debate over the value and safety of these drugs. Conclusion: Given the relative scarcity of clinical trials, more comparative interventional studies, especially randomized controlled trials in long-term clinical evolution, are required in order to clarify the controversy over the validity of parasitic therapy in patients with NCC.

CystiHuman: A model of human neurocysticercosis

INTRODUCTION

The Taenia solium tapeworm is responsible for cysticercosis, a neglected tropical disease presenting as larvae in the body of a host following taenia egg ingestion. Neurocysticercosis (NCC), the name of the disease when it affects the human central nervous system, is a major cause of epilepsy in developing countries, and can also cause intracranial hypertension, hydrocephalus and death. Simulation models can help identify the most cost-effective interventions before their implementation. Modelling NCC should enable the comparison of a broad range of interventions, from treatment of human taeniasis (presence of an adult taenia worm in the human intestine) to NCC mitigation. It also allows a focus on the actual impact of the disease, rather than using proxies as is the case for other models.

METHODS

This agent-based model is the first model that simulates human NCC and associated pathologies. It uses the output of another model, CystiAgent, which simulates the evolution of pig cysticercosis and human taeniasis, adding human and cyst agents, including a model of cyst location and stage, human symptoms, and treatment. CystiHuman also accounts for delays in the appearance of NCC-related symptoms. It comprises three modules detailing cyst development, seizure probability and timing, and intracranial hypertension/hydrocephalus, respectively. It has been implemented in Java MASON and calibrated in three endemic villages in Peru, then applied to another village (Rica Playa) to compare simulation results with field data in that village.

RESULTS AND DISCUSSION

Despite limitations in available field data, parameter values found through calibration are plausible and simulated outcomes in Rica Playa are close to actual values for NCC prevalence and the way it increases with age and cases with single lesions. Initial simulations further suggest that short-term interventions followed by a rapid increase in taeniasis prevalence back to original levels may have limited impacts on NCC prevalence.

Galectins - Important players of the immune response to CNS parasitic infection

Galectins are a family of proteins that bind β-galactosides and play key roles in a variety of cellular processes including host defense and entry of parasites into the host cells. They have been well studied in hosts but less so in parasites. As both host and parasite galectins are highly upregulated proteins following infection, galectins are an area of increasing interest and their role in immune modulation has only recently become clear. Correlation of CNS parasitic diseases with mental disorders as a result of direct or indirect interaction has been observed. Therefore, galectins produced by the parasite should be taken into consideration as potential therapeutic agents.

Psychiatric Disorders of Neurocysticercosis: Narrative Review

Neurocysticercosis, the most common type of neuroparasitosis, is a condition in which the central nervous system (CNS) is infested with the pork tapeworm Taenia solium cysticercosis' larvae. Neurocysticercosis is the most widespread parasitic CNS disease worldwide, affecting more than 50 million individuals. As neurocysticercosis is prevalent in developing countries, the growing number of migrants and travelers increases prevalence in developed countries. Possible neuropsychiatric manifestations are depression, cognitive dysfunction, dementia, and visual hallucinations. Depending on the cysts' location in the CNS, focal neurology or psychiatric symptoms manifest. The diagnosis of neurocysticercosis is based on neuroimaging and serology. The correlation between specific symptoms and the cyst's location might help better understand psychiatric disorders' pathophysiology. Nonetheless, the exact prevalence of neurocysticercosis is seldom reported in patients with psychiatric disorders, which may be due to the lack of imaging availability in developing countries with a high prevalence.

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.

Multiple Causes of Dementia as Engineered Senescence

All traumas—cranial, cardiovascular, hormone, viral, bacterial, fungi, parasites, misfolded protein, genetic, behavior, environmental and medication—affect the brain. This paper itemizes studies showing the many different causes of dementia including Alzheimer’s disease. Causes interact with each other, act sequentially by preparing the optimal conditions for its successor, initiate other diseases, allow for other traumas to accumulate and degrade protective features of the brain. Since such age-related cognitive impairment is not exclusively a human attribute there might be support for an evolutionary theory of dementia. Relying on theories of antagonistic pleiotropy and polymorphism, the brain has been designed to sequester trauma. Because of increased longevity, the short-term tactic of sequestering trauma becomes a long-term liability. We are engineered to sequester these insults until a tipping point is reached. Dementia is an evolutionary trade-off for longevity. We cannot cure dementia without understanding the overall biology of aging.

Neurocysticercosis Among Zambian Children and Adolescents With Human Immunodeficiency Virus: A Geographic Information Systems Approach

BACKGROUND

Neurocysticercosis is the most common parasitic infection of the brain and a leading cause of epilepsy in resource-limited settings. Although neurocysticercosis and human immunodeficiency virus coinfections have commonly been reported, there are few data on how they interact. As part of an observational study of human immunodeficiency virus and cognition in Lusaka, Zambia, we identified a cluster of subjects with neurocysticercosis. We hypothesized that the neighborhood of residence may be an important factor driving clustering of neurocysticercosis and used a geographic information systems approach to investigate this association.

METHODS

A total of 34 subjects with human immunodeficiency virus and 13 subjects without human immunodeficiency virus (aged eight to 17 years) enrolled in the HIV-Associated Neurocognitive Disorders in Zambia study, had magnetic resonance imaging of the brain performed, and were evaluated for neurocysticercosis. Quantitative geographic information systems was utilized to investigate the relationship between neighborhood of residence, HIV, and neurocysticercosis.

RESULTS

Three of 34 subjects with human immunodeficiency virus (8.82%) and one of 13 controls were found to have neurocysticercosis. Geographic cluster analysis demonstrated that all subjects with neurocysticercosis were clustered in two adjacent neighborhoods (Chawama and Kanyama) with lower rates of piped water (Chawama: 22.8%, Kanyama: 26.7%) and flush toilets (Chawama: 14.0%, Kanyama: 14.0%) than the surrounding neighborhoods.

CONCLUSION

We describe a cluster of patients with both neurocysticercosis and human immunodeficiency virus in Lusaka. Cases of neurocysticercosis clustered in neighborhoods with low rates of piped water and limited access to flush toilets. Geographic information systems may be a useful approach for studying the relationship between human immunodeficiency virus and neurocysticercosis. Larger studies are necessary to further investigate this association.

The effect of albendazole treatment on non-seizure outcomes in patients with symptomatic neurocysticercosis

Background

There is little information about the impact of anthelminthic treatment on clinical symptoms other than seizures in neurocysticercosis (NC). We investigated the effect of albendazole on non-seizure symptoms experienced by patients with NC.

Methods

Data are from a randomized controlled trial comparing albendazole plus prednisone with placebo plus prednisone for treatment of NC among 173 patients with active or transitional NC cysts and new-onset symptoms. We performed negative binomial regression to examine the number of follow-up visits when a symptom was reported, logistic regression to examine the probability of experiencing the symptom and Cox proportional hazards models to examine the time to first reporting the symptom.

Results

Eighty-five percent of patients reported at least one non-seizure symptom at baseline. Those treated with albendazole had significantly lower odds of memory loss and/or confusion during months 1-24 (odds ratio [OR] 0.42, p=0.037) and significantly increased odds of anxiety and/or depression during months 1-12 (OR 1.87, p=0.049). No treatment difference existed in experiencing symptoms in general or in experiencing headaches, limb weakness or gait disturbances, vomiting, nausea and/or stomach pain or visual disturbances over the follow-up period.

Conclusions

While the prevalence of non-seizure symptoms was high, albendazole treatment was associated with only two significant differences in the non-seizure symptoms over follow-up. Further research is needed to identify strategies to reduce the long-term symptom burden in patients with NC.

The Association between Calcified Neurocysticercosis and Cognitive Performance: A Case-Control Study Nested to a Population-Based Cohort

Mechanisms implicated in the association between neurocysticercosis (NCC) and cognitive impairment remain unknown. Atahualpa residents aged ≥ 40 years with calcified NCC were identified as case patients and paired 1:1 to age- and gender-matched controls. The selection process generated 79 pairs. Cognitive performance was measured by the Montreal Cognitive Assessment (MoCA). A conditional logistic regression model revealed no differences in MoCA scores across case patients and controls, after adjusting for education, epilepsy, depression, and hippocampal atrophy. The single covariate remaining significant was hippocampal atrophy. When participants were stratified according to this covariate, linear models showed lower MoCA scores among case patients (but not controls) with hippocampal atrophy. In a fully adjusted linear regression model, age remained as the single covariate explaining cognitive impairment among NCC patients. This study demonstrates an association between hippocampal atrophy and poor cognitive performance among patients with calcified NCC, most likely attributable to the effect of age.

Cognitive and Behavioral Profile of Treatment-Naïve Children Aged 6-14 Years with Neurocysticercosis from North India

Background:

Neurocysticercosis (NCC) produces a progressive organic brain damage by altering brain function with alterations in memory, difficulties in learning, and behavioral changes. The present study was designed to compare the cognitive and behavioral profile of school-going children aged 6–14 years with newly diagnosed NCC with their age-matched controls.

Materials and Methods:

A descriptive cross-sectional study was conducted among children aged 6–14 years with newly (<7 days) diagnosed NCC. Age- and gender-matched typically developing children with minor illness attending outpatient facility served as control. Intelligence and behavioral assessment were performed using Malin's Intelligence Scale for Indian Children and Childhood Behavior Checklist (CBCL) (school age version CBCL/6–18). CBCL T-scores were computed and scores < 60 were considered as normal, 60–63 as borderline, and > 63 as clinical range.

Results:

A total of 35 cases and 35 controls were enrolled. Baseline demographic characteristics were comparable between the two groups. Verbal intelligence quotient (IQ) scores were comparable between the cases (96.14 [10.23]) and controls (100.17 [10.89]) (P = 0.11). The behavioral assessment revealed normal T-scores (<60) in both the groups.

Conclusions:

The study revealed comparable IQ and normal behavioral profile of treatment-naïve children with recently diagnosed NCC to their age-matched peers. Further studies with larger sample size and longitudinal study design are required to evaluate the role of NCC on cognition and behavior in Indian children.

Long-term Cognitive Outcome of Children With Parenchymal Neurocysticercosis: A Prospective Observation Study

To study the cognitive profile and scholastic performance of children with parenchymal neurocysticercosis. A total of 500 children with a diagnosis of neurocysticercosis and epilepsy registered in our pediatric neurocysticercosis clinic between January 1996 and December 2002 were enrolled. Patients were evaluated for their scholastic performance using their school grades. Cognitive assessment was done using Parental interview and the "Draw-a-Man" test. Poor scholastic performance was seen in 22.2% (111) children. Draw-a-Man test was done in 148 children; 18.2% (27/148) had scores equivalent to IQ <70. Intermittent headache, behavior problems, and poor memory were reported in 40% (201) children. Multiple lesions, lower socioeconomic status, and calcified lesions on follow-up were associated with academic underachievement ( P < .05). About a fourth of children with neurocysticercosis had cognitive impairment during follow-up. This was mostly seen in children from lower socioeconomic status and in those with multiple-lesion neurocysticercosis.

Cognitive impairment and quality of life of people with epilepsy and neurocysticercosis in Zambia

Cognitive impairment and quality of life (Qol) are important to assess the burden of epilepsy and neurocysticercosis (NCC), which are common but neglected in Sub-Saharan Africa (SSA). The aims of this study were to assess cognitive performance and Qol of people with epilepsy (PWE) in Zambia and to explore differences in PWE with and without NCC. In this community based, cross-sectional case-control-study, 47 PWE and 50 healthy controls completed five neuropsychological tests (Mini Mental State Examination (MMSE), Digit Span, Selective Reminding Test (SRT), Spatial Recall Test (SPART), Test Battery of Attentional Performance (TAP)) and a World Health Organization (WHO) questionnaire of Qol. Comparisons were made between PWE (n=47) and healthy controls (n=50) and between PWE with NCC (n=28) and without NCC (n=19), respectively, using Analysis of Covariance (ANCOVA) and Linear Models (LMs) while correcting for confounders such as age, sex, and schooling years, and adjusting for multiplicity. Working memory, spatial memory, verbal memory, verbal learning, orientation, speech and language reception, visuoconstructive ability, and attentional performance were significantly reduced in PWE compared with healthy controls (ANCOVA and LM, p<0.05). Quality of life of PWE was significantly lower in three domains (psychological, social, environmental) and in overall Qol compared with healthy controls (ANCOVA, p<0.05). There were no significant differences between PWE with NCC and PWE without NCC detected by ANCOVA. Using LM, significant differences between the groups were detected in four tests, indicating worse performance of PWE without NCC in MMSE, Digit Span, SPART, and lower physical Qol. Epilepsy was found to be associated with cognitive impairment and reduced Qol. People with epilepsy due to NCC had similar cognitive impairment and Qol compared with PWE due to other causes. Further studies should investigate the role of different conditions of NCC and the role of seizures on cognition and Qol.

Evaluating Healthcare Claims for Neurocysticercosis by Using All-Payer All-Claims Data, Oregon, 2010-2013

To characterize the frequency of neurocysticercosis, associated diagnostic codes, and place of infection, we searched Oregon's All Payer All-Claims dataset for 2010-2013. Twice as many cases were found by searching inpatient and outpatient data than by inpatient data alone. Studies relying exclusively on inpatient data underestimate frequency and miss less severe disease.

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.

Neuropsychiatric disorders in patients with neurocysticercosis

INTRODUCTION

The purpose of this study was to explore the presence of neuropsychiatric disorders in patients with neurocysticercosis (NCC).

METHOD

Patients with untreated NCC (n = 45) and healthy controls (n = 45) underwent psychiatric and neuropsychological assessments.

RESULTS

The majority of patients in the NCC group (64.4%) had at least 1 psychiatric diagnosis, compared with a minority in the control group (31.1%). The frequency of neurocognitive disorders, and particularly dementia (major neurocognitive disorder), was significantly higher in the group of patients with NCC.

DISCUSSION

This study confirms the relationship between NCC and cognitive disorders.

Pathogenesis of Taenia solium taeniasis and cysticercosis

Taenia solium infections (taeniasis/cysticercosis) are a major scourge to most developing countries. Neurocysticercosis, the infection of the human nervous system by the cystic larvae of this parasite, has a protean array of clinical manifestations varying from entirely asymptomatic infections to aggressive, lethal courses. The diversity of clinical manifestations reflects a series of contributing factors which include the number, size and location of the invading parasites, and particularly the inflammatory response of the host. This manuscript reviews the different presentations of T. solium infections in the human host with a focus on the mechanisms or processes responsible for their clinical expression.

Taenia solium Taeniasis and Cysticercosis in Southeast Asia

Human taeniasis/cysticercosis caused by the pork tapeworm Taenia solium has been identified as a potentially eradicable disease by the International Task Force for Disease Eradication of the World Health Organization. In southeast Asia, T. solium taeniasis/cysticercosis is considered one of the major neglected tropical diseases afflicting the region. In the last few decades, a considerable effort has been invested toward establishing the epidemiology and burden of disease in several southeast Asian countries. Moreover, further evidence is emerging as to understanding the dynamics of disease transmission and cultural, political, and socioeconomic factors influencing the success of control and eradication efforts within the region. However, despite major collaborations by several champion groups, advances have been slow and little remains known about the complete epidemiology of taeniasis/cysticercosis and the barriers to programmatic success. This review article aims to address the above issues with a further focus on the challenges to control and eradicate taeniasis/cysticercosis within the southeast Asia region.

Cognitive Dysfunction and its Determinants in Patients with Neurocysticercosis

INTRODUCTION

Neurocysticercosis (NCC) is the most common parasitic infection of man. In addition to a headache, seizures, and focal deficits, this is associated with significant cognitive dysfunction. Many studies revealed that the number and location of lesions are not always responsible for cognitive dysfunction. Cholinesterase and pseudocholinesterase are found in the walls of the cysticercus which could contribute to cholinergic depletion and thus cognitive dysfunction.

PATIENTS AND METHODS

A total of 43 patients who presented with NCC were evaluated for cognitive deficits, as well as cholinesterase levels in cerebrospinal fluid (CSF) with control CSF from patients undergoing spinal anesthesia. Blood levels of interleukin-10 and tumor necrosis factor alpha were also estimated and correlated with cognitive deficits.

RESULTS

There is a mild increase in the acetylcholinesterase in CSF of patients compared to controls, but it did not correlate with cognitive deficits. There is an increase in interleukins to a significant level which correlates with vesicular stage of the organism and cognitive impairment. The number of lesions also correlated with cognitive impairment even though the location did not. The domains of cognitive deficits seen are sustained attention, category fluency, verbal working memory, planning, set shifting, verbal learning, visual memory, and construction.

DISCUSSION AND CONCLUSION

NCC is associated with multi-domain cognitive impairment correlates with vescicular stage, proinflammatory cytokines and number of lesions but not location, vesicular stage, and proinflammatory cytokines.

An Unusual Presentation of Neurocysticercosis: A Space-Occupying Lesion in the Fourth Ventricle Associated with Progressive Cognitive Decline

We communicate a case of a middle-aged Brazilian patient with an unusual presentation of fourth ventricular neurocysticercosis: occurrence of two intraventricular cysts at different locations in the brain within 2 years and cognitive decline as the only neurological symptom. Neurocysticercosis was confirmed by magnetic resonance imaging, serology, histology, and genetic analysis. Neurocysticercosis should be considered as a differential diagnosis in cases with atypical neurologic or psychiatric symptoms, atypical neuroimaging and travel history. Especially, fourth ventricular cysts carry the risk of obstructive hydrocephalus and brainstem compression and therefore should be extirpated completely. If complete removal of the cystic structures cannot be proven in cases with surgically treated neurocysticercosis, anthelminthic therapy and thorough follow-up examinations should be conducted.

Extraparenchymal (Racemose) Neurocysticercosis and Its Multitude Manifestations: A Comprehensive Review

Neurocysticercosis is an infection of the central nervous system caused by the larval form of the pork tapeworm Taenia solium. In the brain it occurs in two forms: parenchymal and extraparenchymal or racemose cysts. The clinical presentation of racemose cysts is pleomorphic, and is quite different from parenchymal cysticercosis. The clinical diagnosis of racemose cysts is quite challenging, with neuroimaging being the mainstay. However, the advent of newer brain imaging modalities has made a more accurate diagnosis possible. The primary focus of this article is racemose neurocysticercosis and its multitude manifestations, and includes a discussion of the newer diagnostic modalities and treatment options.

Reversible dementia due to neurocysticercosis: Improvement of the racemose type with antihistamines

Infection of the human central nervous system (CNS) by the larvae of Taenia solium, termed neurocysticercosis (NCC), is endemic in most developing countries, where it is a major cause of acquired seizures and other neurological morbidity, including neuropsychiatric symptoms. However, despite its frequent manifestation, some findings, such as cognitive impairment and dementia, remain poorly understood. Less commonly, NCC may affect the ventricular system and subarachnoid spaces and this form is known as extraparenchymal neurocysticercosis. A particular presentation of the subarachnoid form is called racemose cysticercosis, which has a progressive pattern, frequently leads to hydrocephalus and can be life-threatening. Here we review a case of the racemose variety of cysticercosis, complicated by hydrocephalus and reversible dementia, with remission of symptoms after derivation and that remained stable with use of dexchlorpheniramine. We discuss the challenges in diagnosis, imaging findings, treatment and follow-up of this disease.

Cognitive and behaviour dysfunction of children with neurocysticercosis: a cross-sectional study

Eighty-three confirmed cases of neurocysticercosis diagnosed as per modified delBrutto criteria were enrolled in the study (Group-I) to observe cognitive and behavioural changes. Controls consisted of two groups: children with idiopathic generalized tonic-clonic seizure (Group-II) and normal children with non-specific cough (Group-III). Cases and controls were subjected to cognitive and behaviour assessment. There was significant difference in the intelligence quotient (IQ) of cases in domains of visual perception, immediate recall, analysis synthesis and reasoning, verbal ability, memory and spatial ability. In the age group of 6-18 years, cases had significantly more behaviour problems than control without seizure, in domains of anxious depressed, withdrawn depressed, somatic problems, social problems and rule-breaking behaviour. Neurocysticercosis causes decline in cognitive function and behaviours in older children, which should be recognized early for appropriate management and to avoid undue parental anxiety.

Rickettsiae, protozoa, and opisthokonta/metazoa

Rhizobiales (formerly named Rickettsiales) cause in rare instances meningitis and meningovasculitis, respectively. In case of history of exposure, infection by Rhizobiales needs to be considered since both diagnosis and therapy may be extremely difficult and pathogen-specific. The same applies to protozoa; in this chapter, Babesia species, free-living amoebae and Entamoeba histolytica infection, including severe meningitis and brain abscess, infection by Trypanosoma species (South American and African trypanosomiasis) are discussed with respect to history, epidemiology, clinical signs, and symptoms as well as differential diagnosis and therapy. Parasitic flatworms and roundworms, potentially able to invade the central nervous system, trematodes (flukes), cestodes (in particular, Cysticercus cellulosae), but also nematodes (in particular, Strongyloides spp. in the immunocompromised) are of worldwide importance. In contrast, filarial worms, Toxocara spp., Trichinella spp., Gnathostoma and Angiostrongylus spp. are seen only in certain geographically confined areas. Even more regionally confined are infestations of the central nervous system by metazoa, in particular, tongue worms (=arthropods) or larvae of flies (=maggots). The aim of this chapter is (1) to alert the neurologist to these infections, and (2) to enable the attending emergency neurologist to take a knowledgeable history, with an emphasis on epidemiology, clinical signs, and symptoms as well as therapeutic management possibilities.

Neurocysticercosis presenting as acute psychosis: a rare case report from rural India

Neurocysticercosis, caused by the larval stage of the tapeworm Taenia solium, is the most common parasitic infection of the central nervous system. Its clinical manifestations are varied, non specific and pleomorphic, depending on multiple factors. Seizures are the commonest presentation of neurocysticercosis. In this communication we describe an interesting case of multiple neurocysticercosis in a young presenting with psychiatric manifestations. He responded well to steroid and antipsychotic treatment. This case highlights an uncommon presentation of neurocysticercosis and significance of early recognizing this reversible cause will avoid delay in treatment.

Reversible dementia as a presenting manifestation of racemose neurocysticercosis

Racemose cysticercosis is a less frequent presentation of neurocysticercosis (NCC). It's presentation and management is quite different from cerebral parenchymal NCC. Diagnosis of racemose cysticercosis is based on the combination of clinical, epidemiologic, radiographic, and immunologic information. Compared with cysticercus cellulose, which most commonly presents as seizures, racemose NCC due to its extraaxial location presents with raised intracranial pressure and meningitis, and frequently requires neurosurgical intervention. Dementia as a sole presenting feature of NCC is rare. We report a case of racemose NCC with dementia as the presenting manifestation. The outcome of dementia patients with NCC seems favorable in most cases therefore a high index of suspicion for NCC should be kept especially in endemic areas.

Cognitive and surgical outcome in mesial temporal lobe epilepsy associated with hippocampal sclerosis plus neurocysticercosis: a cohort study

Background

Where neurocysticercosis (NCC) is endemic, chronic calcified neurocysticercosis (cNCC) can be observed in patients with mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS). Considering that both disorders cause recurrent seizures or cognitive impairment, we evaluated if temporal lobectomy is cognitively safe and effective for seizure control in MTLE-HS plus cNCC.

Methods

Retrospective cohort study of neuropsychological profile and surgical outcome of 324 MTLE-HS patients submitted to temporal lobectomy, comparing the results according to the presence or absence of cNCC.

Findings

cNCC occurred in 126 (38.9%) of our MTLE-HS patients, a frequency higher than expected, more frequently in women than in men (O.R. = 1.66; 95% C.I. = 1.05–2.61; p = 0.03). Left-side (but not right side) surgery caused impairment in selected neuropsychological tests, but this impairment was not accentuated by the presence of cNCC. Ninety-four (74.6%) patients with MTLE-HS plus cNCC and 153 patients (77.3%) with MTLE-HS alone were Engel class I after surgery (O.R. = 1.16; 95% C.I. = 0.69–1.95; p = 0.58). However, the chances of Engel class IA were significantly lower in MTLE-HS plus cNCC than in patients with MTLE-HS alone (31.7% versus 48.5%; O.R. = 2.02; 95% C.I. = 1.27–3.23; p = 0.003). Patients with MTLE-HS plus cNCC showed higher rates of Engel class ID (15.1% versus 6.6%; O.R. = 2.50; 95% C.I. = 1.20–5.32; p = 0.012).

Interpretation

cNCC can be highly prevalent among MTLE-HS patients living in areas where neurocysticercosis is endemic, suggesting a cause-effect relationship between the two diseases. cNCC does not add further risk for cognitive decline after surgery in MTLE-HS patients. The rates of Engel class I outcome were very similar for the two groups; however, MTLE-HS plus cNCC patients achieved Engel IA status less frequently, and Engel ID status more frequently. Temporal lobectomy can be safely performed in most patients with MTLE-HS plus cNCC without affecting cognitive outcome. Long-term surgical seizure control in MTLE-HS plus cNCC is still satisfactory, as long as selected patients remain under medication.

Neurocysticercosis

Cysticercosis, an infection caused by the cystic larvae of the pork tapeworm Taenia solium, is one of the most frequent parasitic infections of the human nervous system (neurocysticercosis). It is endemic in most of Latin America, the sub-Saharan Africa, and vast parts of Asia, including the Indian subcontinent. It has also been increasingly diagnosed in developed countries because of migration of people from endemic zones and exposure in travelers. The life cycle involves the development of the adult tapeworm in the human small intestine (after ingesting infected pork with cysts) and larval infection in pig tissues (after ingesting human stools containing the eggs of the tapeworm). Humans get infected by the fecal-oral route, most often from a direct contact with an asymptomatic Taenia carrier. Most common clinical presentations are seizures (particularly late-onset seizures), chronic headaches, and intracranial hypertension. However, cysticerci can locate anywhere in the human nervous system, thus potentially causing almost any neurological syndrome and making clinical diagnosis a difficult task. Neuroimaging is the main diagnostic tool, and specific serology confirms the diagnosis and helps to define the diagnosis when images are unclear. Factors such as location (extraparenchymal versus intraparenchymal), number, size and evolutive stage of the parasites determine the clinical manifestations, therapeutic approach, and prognosis. Management includes symptomatic drugs (analgesics, antiepileptic drugs, anti-inflammatory agents) and in many cases cysticidal drugs, either albendazole or praziquantel. In recent years, efforts have focused on transmission control and potential elimination in endemic regions.

A rare case of gliomatosis cerebri presenting as dementia

Dementia with the onset before the age of 65 years is classified as early-onset dementia. Although uncommon, it has considerable impact on the lives of patients and care givers, alike. A substantial subset of patients may have underlying reversible causes. Yet, many, especially those of the very young may be initially misdiagnosed. A case of young woman with rapid mental decay is described here. She was finally diagnosed with gliomatosis cerebri (GC) involving only right frontal lobe. This atypical radiological feature of GC with primary presentation as memory loss needs special attention and clinicians should be aware of such conditions.

Frontotemporal dementia and neurocysticercosis: a case report

We report a case of a 67-year-old woman with frontotemporal dementia (FTD) and a history of neurocysticercosis. After her retirement she showed progressive behavioral changes and neuropsychiatric symptoms with relative preservation of cognitive functioning. During the next three years, the patient manifested progressive deterioration of verbal communication gradually evolving to mutism, a hallmark of cases of progressive nonfluent aphasia.

Cognitive changes and quality of life in neurocysticercosis: a longitudinal study

BACKGROUND

Few studies have focused on the cognitive morbidity of neurocysticercosis (NCC), one of the most common parasitic infections of the central nervous system. We longitudinally assessed the cognitive status and quality of life (QoL) of patients with incident symptomatic NCC cases and matched controls.

METHODOLOGY/PRINCIPAL FINDINGS

The setting of the study was the Sabogal Hospital and Cysticercosis Unit, Department of Transmissible Diseases, National Institute of Neurological Sciences, Lima, Peru. The design was a longitudinal study of new onset NCC cases and controls. Participants included a total of 14 patients with recently diagnosed NCC along with 14 healthy neighborhood controls and 7 recently diagnosed epilepsy controls. A standardized neuropsychological battery was performed at baseline and at 6 months on NCC cases and controls. A brain MRI was performed in patients with NCC at baseline and 6 months. Neuropsychological results were compared between NCC cases and controls at both time points. At baseline, patients with NCC had lower scores on attention tasks (p<0.04) compared with epilepsy controls but no significant differences compared to healthy controls. Six months after receiving anti-parasitic treatment, the NCC group significantly improved on tasks involving psychomotor speed (p<0.02). QoL at baseline suggested impaired mental function and social function in both the NCC and epilepsy group compared with healthy controls. QoL gains in social function (p=0.006) were noted at 6 months in patients with NCC.

CONCLUSIONS/SIGNIFICANCE

Newly diagnosed patients with NCC in this sample had mild cognitive deficits and more marked decreases in quality of life at baseline compared with controls. Improvements were found in both cognitive status and quality of life in patients with NCC after treatment.

Medical management of neurocysticercosis

INTRODUCTION

Neurocysticercosis (NCC) is considered to be the most common cause of acquired epilepsy worldwide. Formerly restricted to palliative measures, therapy for NCC has advanced with the advent of two drugs that are considered to be effective: praziquantel (PZQ) and albendazole (ALB).

AREAS COVERED

All available articles regarding research related to the treatment of NCC were searched. Relevant articles were then reviewed and used as sources of information for this review.

EXPERT OPINION

Anticysticercal therapy has been marked by intense controversy. Recent descriptions of spontaneous resolution of parenchymal cysticercosis with benign evolution, risks of complications and reports of no long-term benefits have reinforced the debate over the usefulness and safety of anticysticercal therapy. High interindividual variability and complex pharmacological interactions will require the close monitoring of plasma concentrations of ALB and PZQ metabolites in future trials. Given the relative scarcity of clinical trials, more comparative interventional studies - especially randomized controlled trials in long-term clinical evolution - are required to clarify the controversy over the validity of parasitic therapy in patients with NCC.

Cysticercosis of the central nervous system: how should it be managed?

PURPOSE OF REVIEW

Taenia solium neurocysticercosis (NCC) has been long recognized as an important cause of neurological morbidity in most of the world. Unwarranted generalization of diagnostic and treatment recommendations made it difficult to assess individual prognosis and responses for each type of NCC. Understanding of the main clinical presentations (dependent on number, location, size, and stage of parasites, as well as on the immune response of the host) allows a better view of treatment options and expected outcomes.

RECENT FINDINGS

Current treatment options are still limited and involve symptomatic agents, antiparasitic agents, or surgery. The importance of adequate symptomatic management, the potential for improved antiparasitic treatment regimes, in particular combination therapy, and the increasingly important role of minimally invasive neurosurgery are also reviewed in this article.

SUMMARY

Treatment decisions in NCC should be individualized in relation to the type of NCC. Initial measures should focus on the symptomatic management before considering antiparasitic therapy when appropriate. Appropriate patient categorization, new antiparasitic regimes, and minimally invasive surgery are improving the prognosis of patients with NCC.

Diagnosis and treatment of neurocysticercosis

Neurocysticercosis is a parasitic disease caused by the larval (cystic) form of the pork cestode tapeworm, Taenia solium, and is a major cause of acquired seizures and epilepsy worldwide. Development of sensitive and specific diagnostic methods, particularly CT and MRI, has revolutionized our knowledge of the burden of cysticercosis infection and disease, and has led to the development of effective antihelminthic treatments for neurocysticercosis. The importance of calcified granulomas with perilesional edema as foci of seizures and epilepsy in populations where neurocysticercosis is endemic is newly recognized, and indicates that treatment with anti-inflammatory agents could have a role in controlling or preventing epilepsy in these patients. Importantly, neurocysticercosis is one of the few diseases that could potentially be controlled or eliminated-an accomplishment that would prevent millions of cases of epilepsy. This Review examines the rationale for treatment of neurocysticercosis and highlights the essential role of inflammation in the pathogenesis of disease, the exacerbation of symptoms that occurs as a result of antihelminthic treatment, and the limitations of current antihelminthic and anti-inflammatory treatments.