Neurocysticercosis--retrospective study of autopsy reports, a 17-year experience

Neurocysticercosis: diagnosis via metagenomic next-generation sequencing

A 68-year-old Brazilian woman had 3 months of progressive fatigue, difficulty walking and 18 kg weight loss. On examination, there was gait apraxia and executive dysfunction. MR scan of brain showed communicating hydrocephalus and a cerebrospinal fluid showed 105 white cells/µL (≤5), predominantly lymphocytes, protein of 1.35 g/L (0.15-0.45) and the glucose content of 0.06 mmol/L (3.3-4.4). We suspected an infective cause and used of metagenomic next-generation sequencing to diagnose neurocysticercosis. This case highlights the challenge of diagnosing chronic meningitis and the relevance of genetic approaches in diagnosing neurological infections.

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

OBJECTIVES

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

METHODS

We conducted a systematic search of published and unpublished data on patients diagnosed with NCC in Europe (2000-2019) and extracted demographic, clinical and radiological information on each case, if available.

RESULTS

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

CONCLUSIONS

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

What Causes Seizures in Neurocysticercosis?

Neurocysticercosis (NCC) is the most prevalent parasitic infection of the central nervous system. It is caused by the presence of larvae of the cestode Taenia solium in the brain. The most common symptom of NCC is seizures, and it is widely considered the world’s leading cause of preventable epilepsy. Despite the prevalence and impact of NCC, a thorough, mechanistic understanding of seizure generation is still lacking. In this review, we address the question “What causes seizures in NCC?” by summarizing and discussing the major theories that seek to explain the seizurogenic and epileptogenic processes in this disorder. In addition, we highlight the potential for recent advances in disease modeling to help accelerate progress in this area.

Neurocysticercosis in Latin America: Current epidemiological situation based on official statistics from four countries

Background

Neurocysticercosis (NC) is one of the major parasitic diseases affecting the central nervous system and is endemic in much of Asia, sub-Saharan Africa, and Latin America. Its epidemiology is difficult to assess, although official registries are available in Brazil, Colombia, Ecuador, and Mexico.

Methodology/Principal findings

Using official statistics, we assessed trends in NC hospitalization rates during 1998–2019 in Brazil and Ecuador, during 2004–2019 in Mexico, and during 2009–2019 in Colombia. We also assessed the trend in NC mortality in Brazil (1998–2019), the trend in hospitalizations for NC in a Mexican tertiary-level hospital (Instituto Nacional de Neurología y Neurocirugía [INNN]; 1995–2019), and in Mexican primary care ambulatory clinics (1995–2019). Associations between NC hospitalization rates and the human development index (HDI) were also examined.

In Brazil, Ecuador, and Mexico, statistically significant decreases in NC hospitalization rates were observed. In Mexico, a significant increase in the age of patients at INNN was observed, suggesting a decreasing incidence of recent infection. Conversely, a significant increase in NC hospitalization rate was observed in Colombia. HDI was not significantly associated with NC hospitalization rates when adjusting for time.

Conclusions

The downward trends in NC cases in Brazil, Ecuador, and Mexico are encouraging, especially in the context of the PAHO/WHO plan of action to eliminate neglected tropical diseases from the region. On the other hand, in Colombia, the increased NC hospitalization rate is concerning and needs further evaluation so that the authorities can take specific measures. These results should encourage health authorities in other endemic countries to establish a system of official registries to identify where the need for a control program is most urgent. However, it is also important to remember that NC persists, although less frequently in some Latin American countries, and efforts to achieve its control must continue.

The present work shows the current trends in the frequency of neurocysticercosis hospitalizations in four endemic Latin American countries. Neurocysticercosis is a parasitic disease of the central nervous system that has been historically linked to poverty and poor sanitation. It is one of the neglected tropical diseases included in the PAHO/WHO action plan for their elimination. We compiled official data available from Brazil, Colombia, Ecuador, and Mexico. Our results show a clear and significant reduction in the disease burden in 3 of the 4 countries included. On the other hand, in Colombia, an increase in incidence was observed. These mixed results are of great relevance. They allow us to be optimistic about the possibility of eliminating this disease in some countries, but also allow us to consider why the disease does not seem to be controlled in other countries and direct public health measures aimed at eliminating this parasite in the countries that need it most.

A Clinical Prognostic Scoring System for Neurocysticercosis

Objectives  In patients with neurocysticercosis (NCC), an accurate risk prediction would allow a better therapeutic approach; however, there are currently no tools that can enhance the accuracy of risk prediction. We designed a prognostic scoring system to be used by neurologists and other physicians managing patients with NCC.

Materials and Methods  Using data from clinical records of patients from a third-level national reference center for neurological diseases, we assessed demographic, clinical, and tomographic variables among 293 patients diagnosed with NCC. Multivariable logistic regression analyses were used to develop a clinical prognostic scoring instrument. Patients with NCC were assessed for neurological impairment at 3 months after diagnosis.

Statistical Analysis  Score accuracy was assessed by receiver operating characteristic (ROC) curve analysis. The primary outcome was the presence of neurological impairment, resulting in disability according to self-report or caregiver reports; this outcome was assessed during follow-up visits at 3 ± 1 months after discharge.

Results  The most common symptoms at presentation were headache (67%) and seizure (63%). A six-item (total score from –4 to + 2) prognostic instrument was constructed on the basis of the presence of seizures/headache at presentation, a leukocyte count above 12x 109/dL, the presence of six to ten parasites, subarachnoid localization, and the use of anthelmintic drugs. Among 113 patients with negative scores, 79.6% developed neurological deficits. Among patients with scores of 1 to 2, 64.6% recovered completely, with an overall accuracy of prediction of 74.7% and area under the ROC curve = 0.722 (95% CI, 0.664–0.780, p < 0.0001).

Conclusions  The clinical prognostic scoring system for NCC described in this study is a new instrument for use in daily clinical practice. It is simple to administer, and it has a prognostic accuracy of 75%. Its use has the potential to improve the quality of care by guiding appropriate decision-making and early management of patients with NCC.

Epidemiology of central nervous system infectious diseases: a meta-analysis and systematic review with implications for neurosurgeons worldwide

OBJECTIVE

Central nervous system (CNS) infections cause significant morbidity and mortality and often require neurosurgical intervention for proper diagnosis and treatment. However, neither the international burden of CNS infection, nor the current capacity of the neurosurgical workforce to treat these diseases is well characterized. The objective of this study was to elucidate the global incidence of surgically relevant CNS infection, highlighting geographic areas for targeted improvement in neurosurgical capacity.

METHODS

A systematic literature review and meta-analysis were performed to capture studies published between 1990 and 2016. PubMed, EMBASE, and Cochrane databases were searched using variations of terms relating to CNS infection and epidemiology (incidence, prevalence, burden, case fatality, etc.). To deliver a geographic breakdown of disease, results were pooled using the random-effects model and stratified by WHO region and national income status for the different CNS infection types.

RESULTS

The search yielded 10,906 studies, 154 of which were used in the final qualitative analysis. A meta-analysis was performed to compute disease incidence by using data extracted from 71 of the 154 studies. The remaining 83 studies were excluded from the quantitative analysis because they did not report incidence. A total of 508,078 cases of CNS infections across all studies were included, with a total sample size of 130,681,681 individuals. Mean patient age was 35.8 years (range: newborn to 95 years), and the male/female ratio was 1:1.74. Among the 71 studies with incidence data, 39 were based in high-income countries, 25 in middle-income countries, and 7 in low-income countries. The pooled incidence of studied CNS infections was consistently highest in low-income countries, followed by middle- and then high-income countries. Regarding WHO regions, Africa had the highest pooled incidence of bacterial meningitis (65 cases/100,000 people), neurocysticercosis (650/100,000), and tuberculous spondylodiscitis (55/100,000), whereas Southeast Asia had the highest pooled incidence of intracranial abscess (49/100,000), and Europe had the highest pooled incidence of nontuberculous vertebral spondylodiscitis (5/100,000). Overall, few articles reported data on deaths associated with infection. The limited case fatality data revealed the highest case fatality for tuberculous meningitis/spondylodiscitis (21.1%) and the lowest for neurocysticercosis (5.5%). In all five disease categories, funnel plots assessing for publication bias were asymmetrical and suggested that the results may underestimate the incidence of disease.

CONCLUSIONS

This systematic review and meta-analysis approximates the global incidence of neurosurgically relevant infectious diseases. These results underscore the disproportionate burden of CNS infections in the developing world, where there is a tremendous demand to provide training and resources for high-quality neurosurgical care.

Diagnostic importance of eosinophilic meningitis in HIV-positive and HIV-negative patients

The presence of eosinophils in the cerebrospinal fluid (CSF) should always be considered abnormal. This study aimed to evaluate the causes of eosinophils in the CSF of patients who are HIV positive and HIV negative. This is the first study of eosinophils in the CSF of patients who are HIV-positive. This was a retrospective study of CSF reports from 1996 to 2005, patients were selected based on the presence of eosinophils in the CSF. We analyzed 20,008 CSF reports; eosinophils were present in 5%. The median and interquartile range (IQR) of eosinophils was 2% (1%, 4%). Eosinophilic meningitis (CSF eosinophils ≥ 10%) was present in 12% of the samples. The main etiologies were infectious diseases as follows: neurocysticercosis, Cryptococcus sp. meningitis, and acute bacterial meningitis. In HIV-positive cases, all causes were by infectious disease, the main pathogen being Cryptococcus sp. The probability of neurocysticercosis in a patient from an endemic region who is HIV-negative and has CSF eosinophils more than 10% was five times higher compared to a person without eosinophilic meningitis. There was a weak positive correlation between CSF eosinophils and increased serum eosinophils. Among the HIV-negative cases, the most frequent non-infectious causes were cerebrovascular syndromes, of these hemorrhage (91.5%). In the HIV-positive group, there were no cases of non-infectious cerebral disease. CSF eosinophils are suggestive of disease. The causes must be investigated, considering the most prevalent infectious diseases in the region.

Target product profiles for the diagnosis of Taenia solium taeniasis, neurocysticercosis and porcine cysticercosis

Target Product Profiles (TPPs) are process tools providing product requirements to guide researchers, developers and manufacturers in their efforts to develop effective and useful products such as biologicals, drugs or diagnostics. During a WHO Stakeholders Meeting on Taenia solium diagnostics, several TPPs were initiated to address diagnostic needs for different stages in the parasite's transmission (taeniasis, human and porcine cysticercosis). Following the meeting, draft TPPs were completed and distributed for consultation to 100 people/organizations, including experts in parasitology, human and pig cysticercosis, diagnostic researchers and manufacturers, international organizations working with neglected or zoonotic diseases, Ministries of Health and Ministries of Livestock in some of the endemic countries, WHO regional offices and other interested parties. There were 53 respondents. All comments and feedback received were considered and discussions were held with different experts according to their area of expertise. The comments were consolidated and final TPPs are presented here. They are considered to be live documents which are likely to undergo review and updating in the future when new knowledge and technologies become available.

Reprint of "Neurocysticercosis-related mortality in Brazil, 2000-2011: Epidemiology of a neglected neurologic cause of death"

Neurocysticercosis (NCC) is an important cause of severe neurological disease mainly in low- and middle-income countries, but data on NCC mortality from endemic areas are scarce. Here we analysed the epidemiological patterns of NCC-related mortality in Brazil. We included all deaths recorded in Brazil between 2000 and 2011, in which NCC was mentioned on death certificates, either as underlying or as associated cause of death. NCC was identified in 1829/12,491,280 deaths (0.015%), 1130 (61.8%) as underlying cause, and 699 (38.2%) as associated cause. Overall age-adjusted mortality rate for the period was 0.97 deaths/1,000,000 inhabitants (95% confidence interval [CI]: 0.83-1.12). The highest NCC-related mortality rates were found in males, elderly, white race/colour and residents in endemic states/regions. Age-adjusted mortality rates at national level decreased significantly over time (annual percent change [APC]: -4.7; 95% CI: -6.0 to -3.3), with a decrease in the Southeast, South and Central-West regions, and a non-significant increasing trend in the North and Northeast regions. We identified spatial and spatiotemporal high-risk mortality clusters located mainly in NCC-endemic areas. Conditions related to the nervous system were the most commonly associated causes of death when NCC was mentioned as an underlying cause, and HIV/AIDS was the main underlying cause when NCC was an associated cause. NCC is a neglected and preventable cause of severe neurologic disease and death with high public health impact in Brazil. There is a clear need to strengthen nationwide epidemiological surveillance and control for the taeniasis/cysticercosis complex.

The association between seizures and deposition of collagen in the brain in porcine Taenia solium neurocysticercosis

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Pigs with seizures had larger amount of collagen compared to pigs without seizures.

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Collagen is likely to play a role in the pathogenesis of seizures in neurocysticercosis.

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Pigs can serve as a model for studying the pathogenesis of seizures in neurocysticercosis.

Neurocysticercosis caused by infection with Taenia solium is a significant cause of epilepsy and seizures in humans. The aim of this study was to assess the association between seizures and the deposition of collagen in brain tissue in pigs with T. solium neurocysticercosis. In total 78 brain tissue sections from seven pigs were examined histopathologically i.e. two pigs with epileptic seizures and T. solium cysts, four pigs without seizures but with cysts, and one non-infected control pig.

Pigs with epileptic seizures had a larger amount of collagen in their brain tissue, showing as large fibrotic scars and moderate amount of collagen deposited around cysts, compared to pigs without seizures and the negative control pig. Our results indicate that collagen is likely to play a considerable part in the pathogenesis of seizures in T. solium neurocysticercosis.

Neurocysticercosis-related mortality in Brazil, 2000-2011: Epidemiology of a neglected neurologic cause of death

Neurocysticercosis (NCC) is an important cause of severe neurological disease mainly in low- and middle-income countries, but data on NCC mortality from endemic areas are scarce. Here we analysed the epidemiological patterns of NCC-related mortality in Brazil. We included all deaths recorded in Brazil between 2000 and 2011, in which NCC was mentioned on death certificates, either as underlying or as associated cause of death. NCC was identified in 1829/12,491,280 deaths (0.015%), 1130 (61.8%) as underlying cause, and 699 (38.2%) as associated cause. Overall age-adjusted mortality rate for the period was 0.97 deaths/1,000,000 inhabitants (95% confidence interval [CI]: 0.83-1.12). The highest NCC-related mortality rates were found in males, elderly, white race/colour and residents in endemic states/regions. Age-adjusted mortality rates at national level decreased significantly over time (annual percent change [APC]: -4.7; 95% CI: -6.0 to -3.3), with a decrease in the Southeast, South and Central-West regions, and a non-significant increasing trend in the North and Northeast regions. We identified spatial and spatiotemporal high-risk mortality clusters located mainly in NCC-endemic areas. Conditions related to the nervous system were the most commonly associated causes of death when NCC was mentioned as an underlying cause, and HIV/AIDS was the main underlying cause when NCC was an associated cause. NCC is a neglected and preventable cause of severe neurologic disease and death with high public health impact in Brazil. There is a clear need to strengthen nationwide epidemiological surveillance and control for the taeniasis/cysticercosis complex.

Neurocysticercosis in sub-Saharan Africa: a review of prevalence, clinical characteristics, diagnosis, and management

Neurocysticercosis has been recognized as a major cause of secondary epilepsy worldwide. So far, most of the knowledge about the disease comes from Latin America and the Indian subcontinent. Unfortunately, in sub-Saharan Africa the condition was neglected for a long time, mainly owing to the lack of appropriate diagnostic tools. This review therefore focuses on the prevalence of neurocysticercosis in sub-Saharan Africa, the clinical picture with emphasis on epilepsy, as well as the diagnosis and treatment of neurocysticercosis and its related epilepsy/epileptic seizures in African resource-poor settings.

Surgical management and role of medical therapy in ruptured aneurysmal neurocysticercosis. A case report and review of the literature

We describe the case of an 80-year-old Hispanic male with an acute subarachnoid hemorrhage (SAH) due to an inflammatory middle cerebral artery (MCA) aneurysm rupture. Two years prior to this episode, the patient had undergone a resection of a left intracranial neurocysticercosis lesion. A current CT, CTA and MRI showed significant SAH, a left MCA aneurysm and a cystic lesion compatible with neurocysticercosis. Intraoperatively, this aneurysm was found to be adjacent to a neurocysticercosis cyst, a diagnosis confirmed by surgical pathology. Only a few cases of subarachnoid hemorrhage due to an inflammatory brain aneurysm have been reported. Due to the associated higher incidence of intraoperative rupture and difficulty clipping, our paper highlights the importance of considering an inflammatory origin in patients with a history of neurocysticercosis and subarachnoid hemorrhage. This is the oldest patient on record reported for this diagnosis and surgery.