Spectrum of cognitive impairment in neurocysticercosis: differences according to disease phase

Report of three patients with extensive neurocysticercosis in rural southern Tanzania: neurological, serological and neuroradiological findings

BACKGROUND

Neurocysticercosis (NCC) is common in eastern Africa, but disease presentation varies considerably. Most patients have single or few NCC-typical lesions in their brain but some present with a large number of lesions. We present three patients with positive antibody-based serology for Taenia solium cysticercosis screened at the Vwawa district hospital, Mbozi district, southern Tanzania, in whom extensive NCC was confirmed by neuroimaging.

CASE PRESENTATIONS

Patient 1 was a 55-year-old female from the tribe Malila smallholder farmer who has had four generalized tonic-clonic epileptic seizures over a period of 11 years and one episode of transient left hemiparesis one year before seizure onset. The patient also reported monthly to weekly episodes of severe, progressive, unilateral headache. The computed tomography (CT) scan of the brain showed 25 NCC lesions of which 15 were in the vesicular stage. Patient 2 was a 30-year-old male from tribe Nyha mechanic who reported monthly episodes of moderate to severe, progressive, bilateral headache, but no epileptic seizures. The CT scan showed 63 NCC lesions of which 50 were in the vesicular stage. Patient 3 was a 54-year-old female from the tribe Malila smallholder farmer who suffered from frequent generalized tonic-clonic epileptic seizures with potential signs of focal seizure onset. She also reported weekly to daily episodes of severe, progressive, unilateral headache. The CT scan showed 29 NCC lesions of which 28 were in the vesicular stage.

CONCLUSIONS

Clinical presentation of NCC with multiple brain lesions varies considerably ranging from few epileptic seizures and severe headache to severe epilepsy with frequent epileptic seizures. Individuals with neurological signs/symptoms that may be due to NCC, based for example on epidemiological criteria or serological evidence of cysticercosis, are recommended to undergo neuroimaging before anthelminthic treatment is considered.

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.

Comparison of Long-Term Outcomes Between 7 Days and 28 Days Albendazole Monotherapy in the Treatment of Single-Lesion Neurocysticercosis in Children

OBJECTIVES

The objective was to compare the long-term clinical, radiological, and cognitive outcomes in children with single-lesion neurocysticercosis who received 7 or 28 days of albendazole therapy.

METHODOLOGY

This observational study conducted over 1 year included (1) consecutive children with single-lesion neurocysticercosis who received 7 or 28 days of albendazole therapy in the acute state and (2) completed follow-up for at least 5 years. Seizure recurrence, resolution of lesions, cognition (Malin's Intelligence Scale for Indian Children), behavior, and school performance (National Initiative for Children Healthcare Quality Vanderbilt Assessment Scale) were assessed.

RESULTS

Group A (albendazole for 7 days) comprised 55 children, and group B (albendazole for 28 days) included 48 children. The mean age at the time of diagnosis of neurocysticercosis was 6.6 ± 1.8 years; the mean age at the time of assessment for the study was 13.2 ± 1.2 years. Focal-onset seizures were the most common clinical presentation (58.3%). The majority of lesions were ring-shaped (92.3%) or colloidal (58.2%), with perilesional edema (89.3%). In the long-term follow-up, radiological resolution of the lesions was comparable in both groups. Complete resolution was seen in 52.7% receiving 7 days and 54.2% receiving 28 days albendazole. Seizures recurred in 20% receiving 7 days and 20.8% receiving 28 days albendazole. Overall, a low intelligence quotient (IQ < 70) was seen in 55.3% cases, "somewhat problematic" school performance in 12%, and behavioral abnormalities were present in 20% of the cases. The results were comparable between the 2 groups.

CONCLUSION

Seizure control, radiological resolution of lesion, school performance, cognitive and behavioral outcomes in the long term are comparable in children with single-lesion neurocysticercosis who have received albendazole cysticidal therapy for 7 days and 28 days. Recurrence of seizure is seen with both regimens in the long term, necessitating regular follow-up and discussion regarding the risk of recurrence before a withdrawal of anticonvulsant therapy.

Geographic Distribution of the Prevalence of Neurocysticercosis in the Municipality of Piedade, São Paulo

Background:

Neurocysticercosis is a globally occurring parasitosis that affects the central nervous system. The main clinical manifestation is seizures.The aim of this study was to analyze the geographic distribution of patients with seizures attending the Emergency Unit of the Piedade municipality, SP, with a diagnosis of neurocysticercosis, and to compare the association of its prevalence with age, basic sanitation and food hygiene habits between rural and urban areas.

Methods:

One hundred thirty-six patients with seizures were evaluated. The Epidemiological data of all subjects will be described.

Results:

The diagnosis of neurocysticercosis was confirmed in 24 patients, corresponding to a prevalence of 17.65%. The presence of an open sewer predominated in the rural area, while the consumption of unwashed fruits, presence of elderly people and geographic distribution were similar in the two areas.

Conclusions:

Urgent measures to raise awareness about the disease and preventive actions should be taken by world authorities.

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.

Inactive Calcified Cysts In Neurocysticercosis: Is This Actually The Case?

Neurocysticercosis is a worldwide disease that is extensively neglected. Its real gravity is not disclosed to people. Knowledge for the population in all countries must be done urgently.

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.

Structural Equation Modeling (SEM) of Cysticercosis in School-Aged Children in Tibetan Rural Farming Areas of Western China: Implications for Intervention Planning

Neurocysticercosis (NCC) significantly contributes to morbidity in developing countries. We recently published a study of prevalence and risk factors in school-aged children in three mountainous areas in Sichuan province of western China. Using structural equation modeling (SEM) on data from that study to guide intervention planning, here we examine risk factors grouped into three broad interventional categories: sociodemographics, human behavior, and sources of pork and pig husbandry. Because neuroimaging is not easily available, using SEM allows for the use of multiple observed variables (serological tests and symptoms) to represent probable NCC cases. Data collected from 2608 students was included in this analysis. Within this group, seroprevalence of cysticercosis IgG antibodies was 5.4%. SEM results showed that sociodemographic factors (β = 0.33, p < 0.05), sources of pork and pig husbandry (β = 0.26, p < 0.001), and behavioral factors (β = 0.33, p < 0.05) were all directly related to probable NCC in school-aged children. Sociodemographic factors affected probable NCC indirectly via sources of pork and pig husbandry factors (β = 0.07, p < 0.001) and behavioral variables (β = 0.07, p < 0.001). Both sociodemographic factors (β = 0.07, p < 0.05) and sources of pork and pig husbandry factors (β = 0.10, p < 0.01) affected probable NCC indirectly via behavioral variables. Because behavioral variables not only had a large direct effect but also served as a critical bridge to strengthen the effect of sociodemographics and sources of pork and pig husbandry on probable NCC, our findings suggest that interventions targeting behavioral factors may be the most effective in reducing disease.

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.

Overview of Taenia solium cysticercosis in West Africa

Human and porcine cysticercosis is endemic in West Africa, where epilepsy is relatively common, but rarely reported due to fear of stigmatization. Neurocysticercosis, caused by Taenia solium, tends to affect the poor in developing countries and control is hampered by inadequate infrastructure and financial resources coupled with lack of adequate information about its significance and distribution. The risk factors for human cysticercosis are closely associated with the characteristics of smallholder or backyard pig farming systems prevalent in this region. Poverty, ignorance and lack of political will militate against successful eradication, while tools for effective diagnosis, prevention and treatment, including vaccines for pigs, are not yet available in many countries. Cysticercosis was targeted for control by The World Health Organization global plan for 2008-2015; however, measures for control are yet to be undertaken in a coordinated manner in West Africa. Diagnostic tools, including neuroimaging facilities, should be strategically situated and made accessible to rural populations in West Africa. Community education in combination with a multipronged approach consisting of vaccination of pigs using TSOL18 vaccine and treatment with oxfendazole along with mass chemotherapy of humans with praziquantel could eliminate taeniasis and should be considered. In-depth and extensive epidemiological studies are required in West Africa in order to fully elucidate the prevalence of T. solium and to support more coordinated and effective control of human and porcine cysticercosis.

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.

Prevalence and risk factors for Taenia solium cysticercosis in school-aged children: A school based study in western Sichuan, People's Republic of China

Background

Taenia solium cysticercosis affects millions of impoverished people worldwide and can cause neurocysticercosis, an infection of the central nervous system which is potentially fatal. Children may represent an especially vulnerable population to neurocysticercosis, due to the risk of cognitive impairment during formative school years. While previous epidemiologic studies have suggested high prevalence in rural China, the prevalence in children as well as risk factors and impact of disease in low-resource areas remain poorly characterized.

Methodology/Principal findings

Utilizing school based sampling, we conducted a cross-sectional study, administering a questionnaire and collecting blood for T. solium cysticercosis antibodies in 2867 fifth and sixth grade students across 27 schools in west Sichuan. We used mixed-effects logistic regression models controlling for school-level clustering to study associations between risk factors and to characterize factors influencing the administration of deworming medication. Overall prevalence of cysticercosis antibodies was 6%, but prevalence was significantly higher in three schools which all had prevalences of 15% or higher. Students from households owning pigs (adjusted odds ratio [OR] 1.81, 95% CI 1.08–3.03), from households reporting feeding their pigs human feces (adjusted OR 1.49, 95% CI 1.03–2.16), and self-reporting worms in their feces (adjusted OR 1.85, 95% CI 1.18–2.91) were more likely to have cysticercosis IgG antibodies. Students attending high prevalence schools were more likely to come from households allowing pigs to freely forage for food (OR 2.26, 95% CI 1.72–2.98) and lacking a toilet (OR 1.84, 95% CI 1.38–2.46). Children who were boarding at school were less likely to have received treatment for gastrointestinal worms (adjusted OR 0.58, 95% CI 0.42–0.80).

Conclusions/Significance

Our study indicates high prevalences of cysticercosis antibodies in young school aged children in rural China. While further studies to assess potential for school-based transmission are needed, school-based disease control may be an important intervention to ensure the health of vulnerable pediatric populations in T. solium endemic areas.

The zoonotic tapeworm, Taenia solium, affects millions of impoverished people worldwide and can cause neurocysticercosis (NCC), an infection of the central nervous system which is potentially fatal. Hypothetically, children may be a vulnerable population to infection as neurological problems and cognitive impairment caused by NCC during formative school years may lead to poor academic performance, contributing to drop-out rates and, eventually, propagating cycles of poverty. We carried out a school-based study of T. solium cysticerosis in primary school-aged children in rural western Sichuan. Our results indicate high levels of T. solium exposure in young school-aged children in rural China. While further studies to assess disease transmission within schools are needed, school-based disease control may be an important intervention to ensure the health of pediatric populations at risk for infection.

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.

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".

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.

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.

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.

Quantification of Amino Acid Neurotransmitters in Cerebrospinal Fluid of Patients with Neurocysticercosis

Background :

Neurocysticercosis is a parasitic disease that affects the central nervous system. Its main clinical manifestations are epileptic seizures. The objective of this study was to investigate the correlation between neurotransmitter concentrations in cerebrospinal fluid (CSF) and the different evolutive forms of neurocysticercosis with or without seizures.

Methods :

Neurotransmitter concentrations (Aspartate, Glutamate, GABA, Glutamine, Glycine, Taurine) were determined in CSF samples from 42 patients with neurocysticercosis divided into patients with the active cystic form (n = 24, 12 with and 12 without seizures) and patients with calcified form (n = 18, 12 with and 6 without seizures), and a control group consisting of 59 healthy subjects.

Results :

Alterations in amino acid concentration were observed in all patients with neurocysticercosis.

Conclusion :

We conclude that disturbances in amino acid metabolism accompany the presentation of neurocysticercosis. Replacement of the terms inactive cyst by reactive inactive cyst and calcification by reactive calcification is suggested.

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.

Clinical symptoms, diagnosis, and treatment of neurocysticercosis

The infection of the nervous system by the cystic larvae of Taenia solium (neurocysticercosis) is a frequent cause of seizure disorders. Neurocysticercosis is endemic or presumed to be endemic in many low-income countries. The lifecycle of the worm and the clinical manifestations of neurocysticercosis are well established, and CT and MRI have substantially improved knowledge of the disease course. Improvements in immunodiagnosis have further advanced comprehension of the pathophysiology of this disease. This knowledge has led to individualised treatment approaches that account for the involvement of parenchymal or extraparenchymal spaces, the number and form of parasites, and the extent of degeneration and associated inflammation. Clinical investigations are focused on development of effective treatments and reduction of side-effects induced by treatment, such as seizures, hydrocephalus, infarcts, and neuroinjury.

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.