Neurocysticercosis

Transcriptomic analysis of subarachnoid cysts of Taenia solium reveals mechanisms for uncontrolled proliferation and adaptations to the microenvironment

Subarachnoid neurocysticercosis (SANCC) is caused by an abnormally transformed form of the metacestode or larval form of the tapeworm Taenia solium. In contrast to vesicular parenchymal and ventricular located cysts that contain a viable scolex and are anlage of the adult tapeworm, the subarachnoid cyst proliferates to form aberrant membranous cystic masses within the subarachnoid spaces that cause mass effects and acute and chronic arachnoiditis. How subarachnoid cyst proliferates and interacts with the human host is poorly understood, but parasite stem cells (germinative cells) likely participate. RNA-seq analysis of the subarachnoid cyst bladder wall compared to the bladder wall and scolex of the vesicular cyst revealed that the subarachnoid form exhibits activation of signaling pathways that promote proliferation and increased lipid metabolism. These adaptions allow growth in a nutrient-limited cerebral spinal fluid. In addition, we identified therapeutic drug targets that would inhibit growth of the parasite, potentially increase effectiveness of treatment, and shorten its duration.

Complex neurocysticercosis lesions on imaging: Explained through correlative histomorphology

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Isolated neurocysticercosis of the spine presenting with low back pain and cauda equina syndrome: a case report

INTRODUCTION

Cysticercosis, caused by Cysticercus cellulosae, is one of the common parasitic diseases that can affect the central nervous system (neurocysticercosis, NCC). Isolated involvement of cysticercosis of the spine, without the involvement of the brain, has been very rarely reported.

CASE PRESENTATION

This report presented a case, who was presenting with low back pain with radiation and cauda equina syndrome (CES). On MRI, the patient was found to have a subarachnoid cystic lesion at the level of lumbosacral vertebrae. Under neurosurgery, the patient underwent L5/S1 laminectomy, decompression, and excision of the cyst. On histopathological examination, the patient was diagnosed of having Cysticercosis. Immediately after surgery, the patient had neurological deterioration. However, at the end of 1 year, the patient had significant improvement both neurologically and functionally.

DISCUSSION

Spinal NCC should be considered in the differential diagnosis for a patient, who presents with a cystic lesion in the spinal subarachnoid space. Surgical exploration and excision of the cysts should be conducted not only to establish the diagnosis but also to decompress the cord and peripheral nerves.

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.

Seizures Related to Neurocysticercosis and Cocaine Use

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

Subarachnoid neurocysticercosis: emerging concepts and treatment

PURPOSE OF REVIEW

Subarachnoid neurocysticercosis (SUBNCC) is caused by a morphologically unique proliferative form of Taenia solium involving the subarachnoid spaces. Prolonged therapy based upon the pathophysiology of SUBNCC and long-term follow-up have shed light on the course of disease and led to highly improved outcomes.

RECENT FINDINGS

SUBNCC has a prolonged incubation period of between 10 and 25 years characterized by cyst proliferation and growth and invasion of contiguous spaces leading to mass effect (Stage 1). With induction of the host-immune responses, cysts degenerate leading to a predominately inflammatory arachnoiditis (Stage 2) causing hydrocephalus, infarcts, and other inflammatory based neurological manifestations. Inactive disease (Stage 3) may occur naturally but mostly is a result of successful treatment, which generally requires prolonged intensive anthelminthic and antiinflammatory treatments. Cerebral spinal fluid cestode antigen or cestode DNA falling to nondetectable levels predicts effective treatment. Prolonged treatment with extended follow-up has resulted in moderate disability and no mortality. Repeated short intensive 8-14-day courses of treatment are also used, but long-term outcomes and safety using this strategy are not reported.

SUMMARY

SUBNCC gives rise to a chronic arachnoiditis. Its unique ability to proliferate and induce inflammatory responses requires long-term anthelmintic and antiinflammatory medications.

Thinking Outside Malaria: A Rare Case of Disseminated Cysticercosis With Cardiopulmonary Involvement From Urban Tanzania

Dissemination of the cysticerci throughout the body with cardiopulmonary involvement represents a very rare occurrence and an uncommon form of cysticercosis manifestation. We report a rare case of a 48-year-old African male from urban Tanzania who was, at first, referred to our radiology department for a coronary computed tomography angiography (CCTA), but incidentally on further evaluation of the patient revealed a history of recurrent convulsions, loss of consciousness, a single episode of temporary loss of vision and recent skin nodules. The value of a full clinical and radiological evaluation of the patient presenting with adult-onset seizures cannot be overemphasized for the diagnosis of this disease. Management of disseminated cysticercosis is complex and, therefore, should be tailored to fit the individual cases and focus on clinical manifestations.

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.

Natural History of Treated Subarachnoid Neurocysticercosis

Subarachnoid neurocysticercosis (SUBNCC) is usually caused by an aberrant proliferative form of Taenia solium causing mass effect and arachnoiditis. Thirty of 34 SUBNCC patients were treated with extended cysticidal and anti-inflammatory regimens and followed up a median of 4.2 years posttreatment (range: 15 for ≥ 4 years, 20 ≥ 2 years, 26 > 1 year, and 3 < 1 year). The median ages at the time of first symptom, diagnosis, and enrollment were 29.7, 35.6, and 37.9 years, respectively; 58.8% were male and 82.4% were Hispanic. The median time from immigration to symptoms (minimum incubation) was 10 years and the estimated true incubation period considerably greater. Fifty percent also had other forms of NCC. Common complications were hydrocephalus (56%), shunt placement (41%), infarcts (18%), and symptomatic spinal disease (15%). Thirty patients (88.2%) required prolonged treatment with albendazole (88.2%, median 0.55 year) and/or praziquantel (61.8%; median 0.96 year), corticosteroids (88.2%, median 1.09 years), methotrexate (50%, median 1.37 years), and etanercept (34.2%, median 0.81 year), which led to sustained inactive disease in 29/30 (96.7%) patients. Three were treated successfully for recurrences and one has continuing infection. Normalization of cerebral spinal fluid parameters and cestode antigen levels guided treatment decisions. All 15 patients with undetectable cestode antigen values have sustained inactive disease. There were no deaths and moderate morbidity posttreatment. Corticosteroid-related side effects were common, avascular necrosis of joints being the most serious (8/33, 24.2%). Prolonged cysticidal treatment and effective control of inflammation led to good clinical outcomes and sustained inactive disease which is likely curative.

The rolling cyst: migrating intraventricular neurocysticercosis-a case-based update

BACKGROUND

Neurocysticercosis is the most frequent parasitic disease of the central nervous system, and its incidence in the developed countries is increasing due to immigration and travels from endemic areas. The intraventricular location has been found to involve up to 61.3% of the patients; moreover, only 22 cases of migrating intraventricular cyst have been reported so far. Despite the rarity of the condition in western countries, its occurrence generates some concerns and the aim of this paper is to update the information concerning pathogenesis, clinical presentation, diagnosis and management of this entity.

METHODS AND RESULTS

All the pertinent literature was analysed, focused on the cases of migrating intraventricular neurocysticercosis and its peculiar features. An illustrative case regarding a 14-year-old girl is also presented.

CONCLUSIONS

Migrating intraventricular neurocysticercosis is a pathognomonic entity usually presenting with hydrocephalus, and its treatment is mainly surgical, preferring an endoscopic approach. When the resection of the intraventricular cyst is not performed, an accurate follow-up is mandatory to detect clinical changes due to a recurrent hydrocephalus or to the effect of the dying cyst on the surrounding area. In case of permanent shunt placement, the cysticidal and steroid treatment is recommended to reduce the risk of shunt failure.

Infections in the immunocompromised child

Prevention and management of opportunistic infections in children is particularly relevant in an era demonstrating an increased prevalence of immunocompromising conditions. The presence of an unusual organism which results in serious infection in a child should therefore always raise the consideration of immune compromise. The more common opportunistic infections have become easier to recognize in recent times due to improved awareness and more refined diagnostic testing. Targeted treatment is usually followed by long-term prophylactic medication. The impact of these conditions on patient outcome is of clear significance and certainly warrants further discussion.

Controversies in the treatment of seizures associated with neurocysticercosis

Seizures are the commonest manifestation of brain parenchymal cysticercosis. In terms of pathophysiological basis and prognostic significance of the seizures, a distinction might be applied between viable cysts, solitary cysticercus granuloma and calcific cysticerci. A number of uncertainties shroud the management of seizures in people with neurocysticercosis (NCC). Although antihelminthic treatment is effective in eliminating viable cysts and possibly cysticercus granulomas, its effect on seizure outcome remains uncertain. Corticosteroids and combinations of antihelminthic and corticosteroid treatments reduce the incidence of seizures in the short term at least. Although antiepileptic drugs (AEDs) are routinely employed in the treatment of seizures associated with NCC, there is no clear consensus regarding the choice and optimal duration of AED treatment. Long-term AED treatment is warranted in people with calcific residue following involution of brain parenchymal cysticercosis. This article is part of a Special Issue entitled "Neurocysticercosis and Epilepsy".

Reliability of Diagnostic Criteria for Neurocysticercosis for Patients with Ventricular Cystic Lesions or Granulomas: A systematic review

Intraventricular neurocysticercosis (NCC) is a severe form of NCC requiring prompt diagnosis and treatment. We aimed to assess the reliability of the most recent version of diagnostic criteria for this form of NCC. Two systematic literature reviews were performed; one included case reports of patients with intraventricular cysticercosis and the other included case reports of patients with intraventricular cystic lesions or granulomas caused by infections other than NCC. All assessed cases were categorized according to the last revision of the long-standing Del Brutto's set of diagnostic criteria to determine its sensitivity, specificity, and predictive value for this form of NCC. The search disclosed 128 patients with intraventricular NCC and 41 with other infections. The set of diagnostic criteria classified as definitive NCC 93 cases with intraventricular NCC (sensitivity 72.7%, 95% CI, 63.9-79.9%), as well as four cases with other infections (specificity 90.2%, 95% CI, 75.9-96.8%). The positive and negative predictive values of the criteria were 0.96 (95% CI, 0.89-0.99) and 0.51 (95% CI, 0.39-0.63), respectively. The revised Del Brutto's set of diagnostic criteria for NCC is acceptably sensitive and highly specific for diagnosing patients with the ventricular form of the disease.

Revised diagnostic criteria for neurocysticercosis

BACKGROUND

A unified set of criteria for neurocysticercosis (NCC) has helped to standardize its diagnosis in different settings.

METHODS

Cysticercosis experts were convened to update current diagnostic criteria for NCC according to two principles: neuroimaging studies are essential for diagnosis, and all other information provides indirect evidence favoring the diagnosis. Recent diagnostic advances were incorporated to this revised set.

RESULTS

This revised set is structured in absolute, neuroimaging and clinical/exposure criteria. Absolute criteria include: histological confirmation of parasites, evidence of subretinal cysts, and demonstration of the scolex within a cyst. Neuroimaging criteria are categorized as major (cystic lesions without scolex, enhancing lesions, multilobulated cysts, and calcifications), confirmative (resolution of cysts after cysticidal drug therapy, spontaneous resolution of single enhancing lesions, and migrating ventricular cysts on sequential neuroimaging studies) and minor (hydrocephalus and leptomeningeal enhancement). Clinical/exposure criteria include: detection of anticysticercal antibodies or cysticercal antigens by well-standardized tests, systemic cysticercosis, evidence of a household Taenia carrier, suggestive clinical manifestations, and residency in endemic areas. Besides patients having absolute criteria, definitive diagnosis can be made in those having two major neuroimaging criteria (or one major plus one confirmative criteria) plus exposure. For patients presenting with one major and one minor neuroimaging criteria plus exposure, definitive diagnosis of NCC requires the exclusion of confounding pathologies. Probable diagnosis is reserved for individuals presenting with one neuroimaging criteria plus strong evidence of exposure.

CONCLUSIONS

This revised set of diagnostic criteria provides simpler definitions and may facilitate its more uniform and widespread applicability in different scenarios.

Rapid increase in cystic volume of an anaplastic astrocytoma misdiagnosed as neurocysticercosis: A case report

Reports describing a rapid increase in the cystic volume of anaplastic astrocytoma (AA) in a short time frame are rare. The present study reports the case of a 68-year-old male who was admitted to the No. 9 People's Hospital, Shanghai Jiaotong University School of Medicine (Shanghai, China), with a small cystic brain lesion and positive immunological testing for cysticercosis. Head magnetic resonance imaging (MRI) showed a cystic lesion, 6 mm in diameter, in the left frontal lobe. Neurocysticercosis was suspected and the patient was treated with a clinical trial of albendazole and steroids. A period of 25 days later, the patient's condition had deteriorated, and MRI revealed a cystic lesion in the left frontal lobe; thereafter, the cystic lesion was removed and a diagnosis of AA was established. The tumor was soft, ivory white and gelatinous due to myxoid degeneration. In this case, tumor-related angiogenesis and microvascular extravasation (blood-brain barrier disruption) may have been the main cause of the rapid increase in the cystic volume in such a short time frame. The similarity of the glioma and cysticercus antigens may have been the cause of the positive reactions in the cystic fluid. The present study reports the rare occurrence of a rapid increase of cystic volume and potential diagnostic difficulties.

Cerebral Cysticercosis by Taenia Crassiceps in a Domestic Cat

Cerebral cysticercosis by Taenia crassiceps was diagnosed in an adult female domestic shorthair cat. The animal was euthanized 6 weeks after the initial presentation with signs of vomiting, lethargy, and ataxia. The disease took an intermittent relapsing course with the neurological signs progressing eventually to recumbancy and coma. At necropsy, numerous cysticerci were found in the dilated left lateral ventricle and the adjacent brain parenchyma. The cysticerci were identified as metacestodes of T. crassiceps larvae based on size and morphology of the cysts; shape, number, and size of the rostellar hooks; and mode of proliferation, including endogenous and exogenous budding. Cerebral cysticercosis by T. crassiceps is rare in atypical intermediate hosts and has not been described in cats.

Update on Cysticercosis Epileptogenesis: the Role of the Hippocampus

Neurocysticercosis (NCC) is the most common helminthic infection of the nervous system and a frequent cause of reactive seizures and epilepsy worldwide. In many cases, multiple episodes of focal seizures related to an identifiable parenchymal brain cyst (and likely attributable to local damage) continue for years after the cyst resolves. However, cases where seizure semiology, interictal EEG abnormalities, and parasites location do not correlate raise concerns about the causal relationship between NCC and either reactive seizures or epilepsy, as well as the epileptogenic potential of parasites. Neurosurgical series of patients with intractable epilepsy and cross-sectional population-based studies have shown a robust association between NCC and hippocampal sclerosis (HS), which might contribute to the above-referred inconsistencies. Current information does not allow to define whether in patients with NCC, HS could result from recurrent seizure activity from a local or distant focus or from chronic recurrent inflammation. In either case, HS may become the pathological substrate of subsequent mesial temporal lobe epilepsy (MTLE). Longitudinal clinical- and population-based cohort studies are needed to evaluate the causal relationship between NCC and HS and to characterize this association with the occurrence of MTLE. If a cause-and-effect relationship between NCC and HS is demonstrated, NCC patients could be assessed to examine neuronal mechanisms of hippocampal epileptogenesis in comparison with animal models, to identify biomarkers of hippocampal epileptogenesis, and to develop novel interventions to prevent epilepsy in NCC and perhaps in other forms of acquired epilepsy.

Magnetic resonance imaging of infectious meningitis and ventriculitis in adults

Magnetic resonance imaging findings of meningitis are usually nonspecific with respect to the causative pathogen because the brain response to these insults is similar in most cases. In this article, we will use a few representative cases to describe the characteristic magnetic resonance findings of meningitis and its complications, including ventriculitis.

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.

Induced neurocysticercosis in rhesus monkeys (Macaca mulatta) produces clinical signs and lesions similar to natural disease in man

Neurocysticercosis is a serious endemic zoonosis resulting in increased cases of seizure and epilepsy in humans. The genesis of clinical manifestations of the disease through experimental animal models is poorly exploited. The monkeys may prove useful for the purpose due to their behavior and cognitive responses mimicking man. In this study, neurocysticercosis was induced in two rhesus monkeys each with 12,000 and 6,000 eggs, whereas three monkeys were given placebo. The monkeys given higher dose developed hyperexcitability, epileptic seizures, muscular tremors, digital cramps at 10 DPI, and finally paralysis of limbs, followed by death on 67 DPI, whereas the monkeys given lower dose showed delayed and milder clinical signs. On necropsy, all the infected monkeys showed numerous cysticerci in the brain. Histopathologically, heavily infected monkeys revealed liquefactive necrosis and formation of irregular cystic cavities lined by atrophied parenchymal septa with remnants of neuropil of the cerebrum. In contrast, the monkeys infected with lower dose showed formation of typical foreign body granulomas characterized by central liquefaction surrounded by chronic inflammatory response. It was concluded that the inflammatory and immune response exerted by the host against cysticerci, in turn, led to histopathological lesions and the resultant clinical signs thereof.

Neurocysticercosis: an update

Neurocysticercosis (NCC) is the most common helminthic disease of the nervous system in humans and a major cause of acquired epilepsy worldwide. The presentation of the disease is dependent on both the immunological response of the host against the parasite as well as the location of the encysted organisms within the central nervous system (CNS). The principles of management utilized for intraparenchymal disease cannot be applied to extraparenchymal NCC. An advance in management of intraparenchymal NCC, the most common form encountered by physicians, is the use of both albendazole and praziquantel as a treatment strategy. Patients with subarachnoid NCC (SANCC) require months of treatment with both an antiparasitic agent and steroids to avoid complications such as hydrocephalus and vascular events during treatment. The determinants of successful treatment in SANCC have not been established, but response to therapy can be determined by evaluating several endpoints related to disease evolution including radiographic changes, serum antigen, and CSF antigen. Intraventricular NCC is primarily a surgical disease and data supports minimally invasive endoscopic removal of cysts in many of these patients. NCC is increasingly recognized in non-endemic countries due to increased immigration making it important for physicians to become familiar with the management of this disease.

Neurocysticercosis

Neurocysticercosis, the most common helminthic infection of the nervous system, is a major cause of acquired epilepsy worldwide. The disease occurs when humans become intermediate hosts of the tapeworm Taenia solium after ingesting its eggs by contagion from an asymptomatic Taenia carrier. Within the nervous system, parasites may locate in brain parenchyma, subarachnoid space, ventricular system, or spinal cord, causing several pathological changes that are responsible for the clinical pleomorphism of the disease. Seizures are the most common clinical manifestation, but a sizable proportion of patients develop focal deficits, intracranial hypertension, or cognitive decline. Preoperative diagnosis of neurocysticercosis is possible after proper integration of data from neuroimaging studies and immunological tests. Cysticidal drugs (albendazole and praziquantel) have changed the prognosis of most patients with neurocysticercosis. The use of these drugs has shown to reduce the parasite load within the central nervous system and to improve the clinical prognosis of the disease in many cases. Future studies should focus on disease eradication through the implementation of control programs against all the interrelated steps in the life cycle of T solium, including human carriers of the adult tapeworm, infected pigs, and eggs in the environment.

Distribution and histopathological changes induced by cysts of Taenia solium in the brain of pigs from Tanzania

Neurocysticercosis (NCC) caused by Taenia solium cysts is a frequent but neglected parasitic disease of the central nervous system (CNS) worldwide. The aim of this study was to describe anatomical locations of cysts in the CNS and the corresponding inflammation. A total of 17 naturally infected pigs were used to evaluate the distribution of cysts and, of these, seven were used to evaluate the corresponding inflammation further, through histopathology. Clinical signs in the pigs included dullness, sluggishness, somnolence, apathy and loss of consciousness. Cysts were distributed in all cerebral lobes, i.e. 39.7% in the frontal lobe, 20.3% in the parietal lobe, 20.0% in the occipital lobe and 19.7% in the temporal lobe, and only 0.4% in the cerebellum. No cysts were found in the spinal cord. Cysts were localized as follows: 47.9% in the dorsal subarachnoid, 46.9% in the parenchyma, 4.4% in the subarachnoid base and 0.9% in the ventricles. The results of the histopathology revealed lesions in an early inflammatory stage, i.e. stage I, in all anatomical locations except for two, which showed more of an inflammatory reaction, stage III, in one pig. It was concluded that clinical signs in pigs were neither pathognomonic nor consistent. These signs, therefore, cannot be used as a reliable indicator of porcine NCC. Furthermore, T. solium cysts were found to be in abundance in all cerebral lobes, and only a few were found in the cerebellum. Regarding the inflammatory response, no significant differences were found in the location and total number of cysts. Thus, further studies are needed to explain the determinants of cyst distribution in the CNS and assess in detail clinical signs associated with porcine NCC.

Distribution and histopathological changes induced by cysts ofTaenia soliumin the brain of pigs from Tanzania

Neurocysticercosis (NCC) caused byTaenia soliumcysts is a frequent but neglected parasitic disease of the central nervous system (CNS) worldwide. The aim of this study was to describe anatomical locations of cysts in the CNS and the corresponding inflammation. A total of 17 naturally infected pigs were used to evaluate the distribution of cysts and, of these, seven were used to evaluate the corresponding inflammation further, through histopathology. Clinical signs in the pigs included dullness, sluggishness, somnolence, apathy and loss of consciousness. Cysts were distributed in all cerebral lobes, i.e. 39.7% in the frontal lobe, 20.3% in the parietal lobe, 20.0% in the occipital lobe and 19.7% in the temporal lobe, and only 0.4% in the cerebellum. No cysts were found in the spinal cord. Cysts were localized as follows: 47.9% in the dorsal subarachnoid, 46.9% in the parenchyma, 4.4% in the subarachnoid base and 0.9% in the ventricles. The results of the histopathology revealed lesions in an early inflammatory stage, i.e. stage I, in all anatomical locations except for two, which showed more of an inflammatory reaction, stage III, in one pig. It was concluded that clinical signs in pigs were neither pathognomonic nor consistent. These signs, therefore, cannot be used as a reliable indicator of porcine NCC. Furthermore,T. soliumcysts were found to be in abundance in all cerebral lobes, and only a few were found in the cerebellum. Regarding the inflammatory response, no significant differences were found in the location and total number of cysts. Thus, further studies are needed to explain the determinants of cyst distribution in the CNS and assess in detail clinical signs associated with porcine NCC.

Magnetic resonance imaging in neurocysticercosis

Cysticercosis in one of the most common parasitic infections in the central nervous system. The complex and unpredictable nature of the host immune reaction against cysticercosis as well as the pleomorphism of your injuries make the disease neurocysticercosis interesting and fascinating to study. Imaging studies play an important role in the diagnosis of this disease. Advanced imaging techniques have improved detection and visualization of scolex cysts extraparenchymal spaces.

Therapy for neurocysticercosis

Therapy for neurocysticercosis has advanced during the last 20 years with the advent of albendazole (Zentel) and praziquantel (Cysticide). Albendazole is the current medication of choice for the treatment of neurocysticercosis and is recommended for symptomatic patients with multiple viable cysts in the brain parenchyma. Albendazole may also be useful in extraparenchymal cysticercosis, especially in the subarachnoid racemose form, when complete surgical resection of the cysts is usually impracticable. Currently, there is an intense debate over the value and safety of anticysticercal therapy. Causes for failure of anticysticercal therapy include high inter-individual variability in plasma concentration of albendazole sulfoxide and the complex interactions of several drugs with the albendazole metabolite. Furthermore, albendazole sulfoxide is an enantiomeric mixture of (+)- and (-)-albendazole sulfoxide with accumulation of the (+)-enantiomer in the cerebrospinal fluid. However, the question over which enantiomer is effective against cysticerci remains to be clarified.

Neurocysticercosis

Known as a disease of swine in ancient civilizations, cysticercosis is currently considered the most common helminthic infection of the nervous system, and a leading cause of acquired epilepsy worldwide. The disease occurs when humans become intermediate hosts of the tapeworm Taenia solium by ingesting its eggs from contaminated food or, most often, directly from a Taenia carrier by the fecal-oral route. Once in the human intestine, Taenia eggs evolve to oncospheres that, in turn, cross the intestinal wall and lodge in human tissues - especially the nervous system - where cysticerci develop. The brain is a hostile environment in which parasites attempt to escape the immune surveillance while the host is trying to drive out the infection. In some cases, cysticerci are destroyed by this immunological attack, while in others, parasites may live unchanged for years. Cysticerci may be located in brain parenchyma, subarachnoid space, ventricular system, or spinal cord, causing a myriad of pathologic changes that are the main changes responsible for the clinical pleomorphism of neurocysticercosis. Seizures are the most common clinical manifestation of the disease, but some patients present with focal deficits, intracranial hypertension, or cognitive decline. With the exception of cystic lesions showing the scolex as an eccentric nodule, neuroimaging findings of neurocysticercosis are nonspecific and may be seen in other diseases of the nervous system. Likewise, immune diagnostic tests have been faced with problems related to poor sensitivity or specificity. Accurate diagnosis is possible after interpretation of clinical data together with findings of neuroimaging studies and results of immunologic tests, in a proper epidemiologic scenario. The introduction of cysticidal drugs has changed the prognosis of neurocysticercosis. Praziquantel and albendazole have been shown to reduce the burden of infection in the brain (as seen on neuroimaging studies) and to improve the clinical course of the disease in most patients. Further efforts should be directed towards eradicating this disease through the implementation of control programs for all the interrelated steps in the life cycle of T. solium, including human carriers of the adult tapeworm, infected pigs, and eggs in the environment.

Neurocysticercosis

Cysticercosis is one of the most common parasitic diseases of the nervous system in humans, and constitutes a major public health problem for most of the developing world. The clinical manifestations of neurocysticercosis (NCC) largely depend on the the host immune response against the parasite. NCC diagnosis is based upon neuroimaging studies (computerized tomography, magnetic resonance imaging) and antibody/antigen detection in the serum and the cerebrospinal fluid. Anticysticercal therapy has been marked by an intense controversy. Randomized controlled trials evaluating the clinical benefit of treatment have yield conflicting data with some studies indicating a benefit and others failing to show a difference. Prevention strategies must rely on multiple approaches, tailoring each to the special features of the particular endemic area.

Diagnostic criteria for neurocysticercosis, revisited

Diagnosis of neurocysticercosis (NCC) can be a challenge. Clinical manifestations are non-specific, most neuroimaging findings are non-pathognomonic, and some serologic tests have low sensitivity or specificity. A set of diagnostic criteria was proposed in 2001 to avoid the over diagnosis of NCC that occurs in epidemiologic surveys, and to help clinicians evaluating patients with suspected NCC. The set included four stratified categories of criteria, including: (1) absolute: histological demonstration of cysticerci, cystic lesions showing the scolex on neuroimaging studies, and direct visualization of subretinal parasites by fundoscopic examination; (2) major: lesions highly suggestive of NCC on neuroimaging studies, positive serum enzyme-linked immunoelectrotransfer blot (EITB) for the detection of anticysticercal antibodies, resolution of intracranial cystic lesions after cysticidal drug therapy, and spontaneous resolution of single enhancing lesions; (3) minor: lesions compatible with NCC on neuroimaging studies, suggestive clinical manifestations, positive cerebrospinal fluid (CSF) ELISA for detection of anticysticercal antibodies or cysticercal antigens, and cysticercosis outside the nervous system; and (4) epidemiological: evidence of a household contact with Taenia solium infection, individuals coming from or living in cysticercosis endemic areas, and history of travel to disease-endemic areas. Interpretation of these criteria permits two degrees of diagnostic certainty: (1) definitive diagnosis, in patients who have one absolute criterion or in those who have two major plus one minor and one epidemiological criteria; and (2) probable diagnosis, in patients who have one major plus two minor criteria, in those who have one major plus one minor and one epidemiological criteria, and in those who have three minor plus one epidemiological criteria. After 10 years of usage, this set has been proved useful in both, field studies, and hospital settings. Recent advances in neuroimaging and immune diagnostic methods have enhanced its accuracy for the diagnosis of NCC.

Neurocysticercosis

PURPOSE OF REVIEW

Neurocysticercosis occurs when humans become intermediate hosts in the life cycle of Taenia solium by ingesting its eggs directly from a taenia carrier or, less often, by contaminated food. Within the nervous system, cysticerci may lodge in the brain parenchyma, subarachnoid space, ventricular system, or spinal cord, causing a number of pathologic changes that are responsible for the pleomorphism of neurocysticercosis. This article discusses the clinical manifestations, diagnosis, and treatment of neurocysticercosis.

RECENT FINDINGS

Formerly endemic in the developing world, mass immigration of people from disease-endemic to nonendemic areas has caused a recent increase in the prevalence of neurocysticercosis in developed countries, where this condition should no longer be considered exotic. Recent advances in neuroimaging and immune diagnostic methods, and the introduction of a set of diagnostic criteria, have enhanced the diagnostic accuracy for neurocysticercosis. Likewise, introduction of potent cysticidal drugs has radically changed its prognosis.

SUMMARY

Neurocysticercosis is the most common helminthic infection of the CNS and a major cause of acquired epilepsy worldwide. Diagnosis of neurocysticercosis is possible after interpretation of clinical data together with findings of neuroimaging studies and results of immunologic tests in a proper epidemiologic context. The use of cysticidal drugs reduces the burden of infection in the brain and improves the clinical course of most patients. Further efforts must be directed to eradicate the disease through the implementation of control programs against all interrelated steps in the life cycle of T. solium, including human carriers of the adult tapeworm, infected pigs, and eggs in the environment.

Evaluation of cysticercus-specific IgG (total and subclasses) and IgE antibody responses in cerebrospinal fluid samples from patients with neurocysticercosis showing intrathecal production of specific IgG antibodies

In the present study, an enzyme-linked immunosorbent assay (ELISA) standardized with vesicular fluid of Taenia solium cysticerci was used to screen for IgG (total and subclasses) and IgE antibodies in cerebrospinal fluid (CSF) samples from patients with neurocysticercosis showing intrathecal production of specific IgG antibodies and patients with other neurological disorders. The following results were obtained: IgG-ELISA: 100% sensitivity (median of the ELISA absorbances (MEA)=1.17) and 100% specificity; IgG1-ELISA: 72.7% sensitivity (MEA=0.49) and 100% specificity; IgG2-ELISA: 81.8% sensitivity (MEA=0.46) and 100% specificity; IgG3-ELISA: 63.6% sensitivity (MEA=0.12) and 100% specificity; IgG4-ELISA: 90.9% sensitivity (MEA=0.85) and 100% specificity; IgE-ELISA 93.8% sensitivity (MEA=0.60) and 100% specificity. There were no significant differences between the sensitivities and specificities in the detection of IgG-ELISA and IgE-ELISA, although in CSF samples from patients with neurocysticercosis the MEA of the IgG-ELISA was significantly higher than that of the IgE-ELISA. The sensitivity and MEA values of the IgG4-ELISA were higher than the corresponding values for the other IgG subclasses. Future studies should address the contribution of IgG4 and IgE antibodies to the physiopathology of neurocysticercosis.

Pathology of CNS parasitic infections

Parasitic infections of the central nervous system (CNS) include two broad categories of infectious organisms: single-celled protozoa and multicellular metazoa. The protozoal infections include malaria, American trypanosomiasis, human African trypanosomiasis, toxoplasmosis, amebiasis, microsporidiasis, and leishmaniasis. The metazoal infections are grouped into flatworms, which include trematoda and cestoda, and roundworms or nematoda. Trematoda infections include schistosomiasis and paragonimiasis. Cestoda infections include cysticercosis, coenurosis, hydatidosis, and sparganosis. Nematoda infections include gnathostomiasis, angiostrongyliasis, toxocariasis, strongyloidiasis, filariasis, baylisascariasis, dracunculiasis, micronemiasis, and lagochilascariasis. The most common route of CNS invasion is through the blood. In some cases, the parasite invades the olfactory neuroepithelium in the nasal mucosa and penetrates the brain via the subarachnoid space or reaches the CNS through neural foramina of the skull base around the cranial nerves or vessels. The neuropathological changes vary greatly, depending on the type and size of the parasite, geographical strain variations in parasitic virulence, immune evasion by the parasite, and differences in host immune response. Congestion of the leptomeninges, cerebral edema, hemorrhage, thrombosis, vasculitis, necrosis, calcification, abscesses, meningeal and perivascular polymorphonuclear and mononuclear inflammatory infiltrate, microglial nodules, gliosis, granulomas, and fibrosis can be found affecting isolated or multiple regions of the CNS, or even diffusely spread. Some infections may be present as an expanding mass lesion. The parasites can be identified by conventional histology, immunohistochemistry, in situ hybridization, and PCR.

Neurocysticercosis, meningioma, and silent corticotroph pituitary adenoma in a 61-year-old woman

We report here the case of a 61-year-old woman who presented with hydrocephalus and cystic and solid lesions in sella turcica, suprasellar areas, and third ventricle. After ventriculoperitoneal shunt she developed cognitive changes and the cystic lesions enlarged. Magnetic resonance imaging (MRI) demonstrated multiple cysts and a solid lesion in the sella and around the anterior clinoid process. With diagnosis of neurocysticercosis she underwent craniotomy. Pathologic examination documented two different lesions: viable and dead cysticerci with inflaming infiltration and a left anterior clinoidal meningioma. At the second surgery, six weeks later via transnasal transsphenoidal approach a silent corticotroph pituitary adenoma was removed which was studied by histology, immunohistochemistry, and electron microscopy. To our knowledge, the occurrence of these three different lesions in the sellar area was not described before.

Prevalence of neurocysticercosis among people with epilepsy in rural areas of Burkina Faso

PURPOSE

To estimate the lifetime prevalence of neurocysticercosis (NCC)-associated epilepsy and the proportion of NCC among people with epilepsy in three Burkina Faso villages.

METHODS

Three villages were selected to represent three types of pig-rearing methods: (1) Batondo, where pigs are left to roam; (2) Pabré, where pigs are mostly tethered or penned; and (3) Nyonyogo, where the majority of residents are Muslim and few pigs are raised. In Batondo and Nyonyogo, all concessions (a group of several households) were included. Half of the concessions in Pabré were randomly chosen. All households of selected concessions were included, and one person per household was randomly selected for epilepsy screening and serologic testing for cysticercosis. Self-reported cases of epilepsy were also examined and confirmed cases included in analyses other than the estimate of NCC-associated epilepsy prevalence. Epilepsy was defined as ever having had more than one episode of unprovoked seizures. Individuals with medically confirmed epilepsy had a computerized tomography (CT) scan of the brain before and after contrast medium injection. The diagnosis of NCC was made using a modification of the criteria of Del Brutto et al.

KEY FINDINGS

Thirty-nine (4%) of 888 randomly selected villagers and 33 (94%) of 35 self-reported seizures cases were confirmed to have epilepsy by medical examination. Among the 68 participants with epilepsy who had a CT scan, 20 patients were diagnosed with definitive or probable NCC for a proportion of 46.9% (95% confidence interval [CI] 30.2-64.1) in Batondo and 45.5% (95% CI 19.0-74.1) in Pabré. No cases of NCC were identified in Nyonyogo.

SIGNIFICANCE

All the definitive and probable cases of NCC were from the two villages where pig breeding is common. Prevention policies intended to reduce the burden of epilepsy in this country should include measures designed to interrupt the life cycle of Taenia solium.

Influence of gender on cardiac and encephalic inflammation in the elderly with cysticercosis: a case control study

Background. The present study explores the influence of the host's age and gender upon the inflammatory infiltrate. We aimed to quantify the inflammatory infiltrate caused by cysticercosis, which is related to aging, in the heart and in the encephalon. Methods. 75 autopsy protocols with cysticercosis diagnosis from department of pathology at a university hospital from 1970 to 2008 were reviewed. Two groups were formed: elderly with cysticercosis and nonelderly with cysticercosis. We used KS-300 (Kontron-Zeiss) software for morphometric analysis of the inflammation. Results. The elderly had an average of 3.1 ± 2.5 cysticerci, whereas the non-elderly had 2.7 ± 3.8 parasites. The non-elderly group with cysticercosis had significantly more inflammation, both cardiac and encephalic, than the elderly group. The elderly females with cysticercosis had more cardiac and encephalic inflammation. Conclusions. In this study, we showed that the non-elderly had significantly more cardiac and encephalic inflammation than the elderly, and that such inflammatory infiltrate decreases with age and depends upon the evolutionary stage of the cysticercus. Furthermore, there are differences concerning gender in the intensity of the inflammatory response due to cysticerci in the heart and brain parenchyma during senescence. Even during this period, women continue to have a more intense response to the parasitosis.

Epidemiology of central nervous system infection

In cases of central nervous system infection, it is crucial for the neuroradiologist to provide an accurate differential diagnosis of the possible pathogens involved so that treating physicians can be aided in the choice of empiric therapy. This approach requires the radiologist to be aware of local epidemiology and have knowledge of infectious agents that are endemic to their area of practice. This article reviews and discusses the changing epidemiology of pathogens most often observed in meningitis, brain abscess, epidural abscess, postoperative infections, and human immunodeficiency virus infection.

Correlation between the clinico radiological heterogeneity and the immune-inflammatory profiles in pediatric patients with neurocysticercosis from a tertiary referral centre

INTRODUCTION

Neurocysticercosis (NCC) is the leading cause of epilepsy in developing world. Cysticercal lesions develop in brain depending upon a combination of host immune-inflammatory response, mainly mediated by cytokines produced by cysticercal antigens.

AIM AND OBJECTIVES

To correlate between MRI findings and levels of Th1/Th2 cytokines present in sera of children clinically suspected of NCC with generalized or partial seizure.

MATERIAL AND METHODS

Fifty children presenting with history of seizures and/or mass effects and/or hydrocephalous, with a diagnosis of NCC based on the clinical and radiological profile were included. Antibody (IgM) for NCC and Th1/Th2 cytokine response (TNF-α, IL-2/and IL-6) detection was done on sera from all the patients following manufacturer's instructions.

RESULTS

Out of 50 cases, 10 presented with acute symptoms of NCC with an immunological response of a predominance of pro-inflammatory cytokines (IL-2: 8, TNF-α: 2). High IL-6 was found in 40 children indicating an active lesion with chronic granulomas suggestive of parasitic destruction and persisting presentation with seizures. However, the levels of IL-6 differed with values lower in patients with inactive (calcified lesions) forms of NCC. A significant proportion (43 of 50 cases) had negative serology, probably because of the waning of antibody response months or years after the parasites die.

CONCLUSION

Parasite maintains equilibrium with host immune response in early infection, a mild Th1 response is provoked; but later this equilibrium is disturbed toward Th2 response that leads to parasite destruction. Number or stage of the parasites along with immunegenetic aspects may explain the pleomorphic and unpredictable course of NCC.

Reduced diffusion in neurocysticercosis: circumstances of appearance and possible natural history implications

BACKGROUND AND PURPOSE

Few studies discuss DWI findings in patients with NCC, and their conclusions are variable and contradictory. The aim of our study was to describe DWI findings of a cohort of patients with NCC, emphasizing the frequency of reduced diffusion.

MATERIALS AND METHODS

This retrospective study included 48 patients with NCC. Two neuroradiologists analyzed MR images regarding location, number, and stage of NCC lesions. On the basis of visual analysis, they defined, by consensus, the presence of high signal within NCC lesions on DWI and measured their ADC values when feasible.

RESULTS

The total number of lesions was 342: parenchymal (263), subarachnoid (65), and intraventricular (14); 83 were DWI hyperintense. The first pattern was a small eccentric hyperintense dot/curvilinear structure on DWI (representing the scolex) noted in intraparenchymal lesions in vesicular (41 lesions, 29%) and colloidal vesicular (18 lesions, 19%) stages, in 14 (22%) subarachnoid lesions, and 2 (14%) intraventricular lesions; rADC calculations were hampered by the intrinsic small dimensions of this finding. The second pattern was the presence of total/subtotal DWI hyperintensity in intraparenchymal lesions, 5 in the colloidal vesicular stage (5%) and 1 in the granular nodular phase (3%). Two subarachnoid lesions also showed the same presentation; in this second pattern, reduced diffusion was present in different degrees, measured by rADC calculations.

CONCLUSIONS

DWI may identify the scolex, increasing diagnostic confidence for NCC. Total/subtotal DWI hyperintensity, related to the stage of the lesion, though uncommon, allows including NCC as a consideration in the differential diagnosis of lesions with reduced diffusion and ring enhancement.