The role of 3D volumetric MR sequences in diagnosing intraventricular neurocysticercosis: preliminar results

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.

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.

Neurocysticercosis in Children

Neurocysticercosis is one of the most common parasitic infections in the central nervous system in children. The usual clinical manifestation is new-onset focal seizure. However, there are other multiple clinical manifestations, such as increased intracranial pressure, meningoencephalitis, spinal cord syndrome, and blindness. The diagnosis needs high index of suspicion with clinical history, physical examination, neuroimaging, and immunologic studies. Recent advances in neuroimaging and serology facilitate the accurate diagnosis. Management of neurocysticercosis should focus on critical symptoms first, such as the use of antiepileptic drugs and medical or surgical therapy for increased intracranial pressure.

Added value of 3D-DRIVE and SWI Magnetic Resonance Imaging Sequences in Intraventricular Neurocysticercosis (IVNCC): An Institutional Experience from Northeast India

Background:

Prompt diagnosis and early treatment institution are important in intraventricular neurocysticercosis (IVNCC) as compared to the parenchymal or racemose form because it is associated with a poorer patient prognosis. Intraventricular neurocysticercosis is often missed on CT scan or conventional cranial magnetic resonance imaging because of similar density or signal intensity of cysticercus lesion with cerebrospinal fluid.Thestudy aims to evaluate the added value of 3D-DRIVE and SWI MRI sequences in isolated intraventricular cysticercosis with acute neurological presentation.

Methods and Materials:

This retrospective study was carried out on diagnosed 10 patients with isolated intraventricular neurocysticercosis (IVNCC) presented to a tertiary care hospital with an acute onset of symptoms or acute neurological deficit between June 2019 to May 2021. Relevant neurological examination, CSF analysis, a serological test of neurocysticercosis and MRI scan of the brain were performed.

Result:

Tenpatients of isolated intraventricular neurocysticercosis (3 males and 7 females) having 3 pediatric and 7 adults were included in this study sample.The common neurological complications of the isolated intraventricular neurocysticercosis in this study are observed as obstructive hydrocephalus in 8(80%) patients and ependymitis in 7(70%) patients. IVNCC with distinctly visualized scolex (visibility score 2) identified in 2(20%) patients in T2WI, 8 (80%) patients in 3D-DRIVE and 3(30%) patients in SWI sequences. The cyst wall of IVNCC was distinctly visualized (visibility score 2) in 1(10%) patient in T2WI, 8(80%) patients in 3D-DRIVE and 6(60%) patients in SWI sequence.

Conclusion:

Heavily T2-weighted steady-state and SWI sequences should be added to routine MRI sequences that helps to identify IVNCC and should be used in patients with unexplained hydrocephalus, especially in endemic regions of Neurocysticercosis.

A case of racemose and intraventricular neurocysticercosis in an unusual location

Racemose and intraventricular neurocysticercosis are uncommon types of neurocysticercosis, resulting in a multiloculated, grape-like cluster appearance in the cerebrospinal fluid (CSF) spaces. A male patient presented with symptoms of raised intracranial pressure and demonstrated racemose neurocysticercosis at an atypical location involving the region of the crus of the fornix at the level of the body of lateral ventricles on magnetic resonance imaging. Associated intraventricular neurocysticercosis was seen in the atrium of the left lateral ventricle and fourth ventricle.

A Case Report of Hydrocephalus in a US Military Recruit

We present a case of chronic non-communicating hydrocephalus (NCH) in a US military recruit. Non-communicating hydrocephalus is a pathologic obstruction of cerebrospinal fluid (CSF) resulting in enlargement of the ventricles and elevated intracranial pressure. The patient is an 18-year-old male recruit who was evaluated in the Naval Medical Center emergency room for left hip pain and incidentally was found to have profound ventriculomegaly on head imaging. The diagnosis and evaluation of hydrocephalus is greatly dependent on clinical history and supported by radiographic imaging. Based on these factors, one can determine if the hydrocephalus is either acute or chronic and communicating or non-communicating.

Taenia solium Cysticercosis and Its Impact in Neurological Disease

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

Next-generation sequencing of cerebrospinal fluid for the diagnosis of neurocysticercosis

OBJECTIVE

Neurocysticercosis (NCC) is the most common parasitic disease of the human central nervous system (CNS). However, a diagnosis of NCC may be hard to make if the specific clinical and routine neuroimaging manifestations are lacking, which hinders physicians from considering further immunodiagnostic tests.

PATIENTS AND METHODS

Seven patients presented with fever, headache, nausea, cognitive decline, confusion, or progressive leg weakness. There were no pathogens found in the cerebrospinal fluid (CSF); patients were clinically suspected of meningoencephalitis or cerebrovascular disease. To clearly determine the etiology, next generation sequencing (NGS) of the CSF was used to detect pathogens in these seven patients.

RESULTS

Taenia solium DNA sequences were detected in the seven patients, but not in the non-template controls (NTCs) or the other patients with clinically suspected CNS infections. Based on the patients' medical data and the diagnostic criteria for NCC, seven patients were diagnosed with probable NCC. The unique reads aligning to Taenia solium ranged from 6 to 261064, with genomic coverage ranging from 0.0003% to 14.8079%. The number of unique reads and genomic coverage dropped in three of the seven patients after antiparasitic treatment, consistent with the relief of symptoms.

CONCLUSION

This study showed that NGS of the CSF might be an auxiliary diagnostic method for NCC patients. Larger studies are required.

Atypical radiological presentation of multiple cystic brain metastases from lung cancer simulating neurocysticercosis

Brain metastases (BMs) are usually characterised by vasogenic oedema and mass effect, but cystic appearance can rarely occur, mimicking parasitosis, such as neurocysticercosis (NCC). A woman in her mid-50s was admitted for dizziness and upper left extremity paresis. Neuroimaging showed multiple cystic lesions consistent with multiple stages of NCC evolution, and empiric albendazole was started, without any clinical improvement. A whole-body CT revealed a pulmonary lesion in the right superior lobe. Pathological analysis from brain specimen demonstrated a clear cell lung carcinoma. The patient gradually worsened and died 4 months after the diagnosis. In conclusion, multiple cystic BMs are an atypical presentation on neuroimaging; in these cases, a meticulous diagnostic workup should be performed, looking for the possible site of malignancy. Even when it is not possible to perform a biopsy from the primitive lesion, as reported in this case, a brain biopsy should be considered.

Active neurocysticercosis at the Hospital for Tropical Diseases, London: a clinical case series

Background

Neurocysticercosis is the commonest infectious cause of epilepsy in endemic countries, and accounts for a greater number of cases worldwide than any other single pathology. Infection is associated with long-term exposure in low-income countries, although acquisition after travel has been recognized. The standard of care in the UK is inpatient treatment with anti-helminthic drugs and steroids.

Methods

The authors reviewed all cases of neurocysticercosis managed at the Hospital for Tropical Diseases in London, England, between 2001 and 2015. Active disease was defined as evidence of either viable cysts or involuting cysts with associated parenchymal inflammation.

Results

Of 26 active cases, 65.4% were migrants from nine different countries; 34.6% were UK-born travellers who had visited 19 countries across South and Central America, sub-Saharan Africa, South and South-east Asia; India was the commonest country of exposure in both groups. Only 73.1% presented with seizures; two diagnoses were made through brain imaging of patients with peripheral cysticerci; 53.8% had a single cyst. Migrants were more likely to be seropositive than travellers (p=0.033). Only two patients had seizures during admission, one of whom had multiple seizures prior to diagnosis.

Conclusions

Neurocysticercosis presents in a non-endemic setting in both migrants and travellers. Travellers are less likely to be sero-positive. Not all cases of neurocysticercosis present with seizures. Outpatient management could be considered for selected patients.

Extraparenchymal neurocysticercosis: Demographic, clinicoradiological, and inflammatory features

Background

Extraparenchymal neurocysticercosis (ExPNCC), an infection caused by Taenia solium cysticerci that mainly occurs in the ventricular compartment (Ve) or the basal subarachnoid space (SAb), is more severe but less frequent and much less studied than parenchymal neurocysticercosis (ParNCC). Demographic, clinical, radiological, and lumbar cerebrospinal fluid features of patients affected by ExPNCC are herein described and compared with those of ParNCC patients.

Methodology and principal findings

429 patients with a confirmed diagnosis of neurocysticercosis, attending the Instituto Nacional de Neurología y Neurocirugía, a tertiary reference center in Mexico City, from 2000 through 2014, were included. Demographic information, signs and symptoms, radiological patterns, and lumbar cerebrospinal fluid (CSF) laboratory values were retrieved from medical records for all patients. Data were statistically analyzed to assess potential differences depending on cyst location and to determine the effects of age and sex on the disease presentation. In total, 238 ExPNCC and 191 ParNCC patients were included. With respect to parenchymal cysts, extraparenchymal parasites were diagnosed at an older age (P = 0.002), chiefly caused intracranial hypertension (P < 0.0001), were more frequently multiple and vesicular (P < 0.0001), and CSF from these patients showed higher protein concentration and cell count (P < 0.0001). SAb patients were diagnosed at an older age than Ve patients, and showed more frequently seizures, vesicular cysticerci, and higher CSF cellularity. Gender and age modulated some traits of the disease.

Conclusions

This study evidenced clear clinical, radiological, and inflammatory differences between ExPNCC and ParNCC, and between SAb and Ve patients, and demonstrated that parasite location determines different pathological entities.

Neurocysticercosis (NCC) is caused by the establishment of Taenia solium larvae in the human central nervous system. While NCC diagnosis, treatment, and prevention have clearly improved in the last 40 years, the disease still causes significant morbidity and mortality in endemic regions of Latin America, Asia, and Africa. Herein we described demographic, clinical, radiological, and cerebrospinal fluid features of a large series of NCC patients, and evaluated the relevance of parasite location on disease presentation. 191 patients with parenchymal parasites, 125 patients with extraparenchymal cysts, and 113 patients lodging parasites in both locations were included. Our results clearly demonstrated that differences in parasite location actually determines distinct diseases, with wide variations in severity. This is particularly evident when comparing parenchymal with extraparenchymal patients and ventricular with subarachnoid patients. Gender and age also modulate some characteristics of the disease. In conclusion, parasite location is one of the most important features of the disease, which must be considered when approaching an NCC patient.

Update on the Diagnosis and Management of Neurocysticercosis

Neurocysticercosis is an important cause of seizures worldwide and is endemic in most of Latin America, Sub-Saharan Africa, Southeast Asia, India, and China. Neurocysticercosis has profoundly different disease manifestations varying from asymptomatic presentation to life-threatening hydrocephalus. Clinical manifestations, pathogenesis, diagnostic methods, and optimal treatment vary with the location, number of lesions, and host response. Diagnosis is based on a combination of clinical presentation, neuroimaging findings, history of exposure, and serologic testing. Initial therapy should be focused on symptom management including seizure control and management of increased intracranial pressure. Emerging data are demonstrating that the optimal management approach varies with stage. Single enhancing or cystic lesions should be treated with albendazole and steroids. Patients with more than two cystic lesions should be treated with combination therapy with albendazole and praziquantel, whereas patients with hydrocephalus benefit from surgical management, especially with minimally invasive approaches.

New diagnostic criteria for neurocysticercosis: Reliability and validity

Objective

The diagnosis of neurocysticercosis (NCC) remains problematic because of the heterogeneity of its clinical, immunological, and imaging characteristics. Our aim was to develop and assess a new set of diagnostic criteria for NCC, which might allow for the accurate detection of, and differentiation between, parenchymal and extraparenchymal disease.

Methods

A group of Latin American NCC experts developed by consensus a new set of diagnostic criteria for NCC. A multicenter, retrospective study was then conducted to validate it. The reference standard for diagnosis of active NCC was the disappearance or reduction of cysts after anthelmintic treatment. In total, three pairs of independent neurologists blinded to the diagnosis evaluated 93 cases (with NCC) and 93 controls (without NCC) using the new diagnostic criteria. Mixed‐effects logistic regression models were used to estimate sensitivity and specificity.

Results

Inter‐rater reliability (kappa) of diagnosis among evaluators was 0.60. For diagnosis of NCC versus no NCC, the new criteria had a sensitivity of 93.2% and specificity of 81.4%. For parenchymal NCC, the new criteria had a sensitivity of 89.8% and specificity of 80.7% and for extraparenchymal NCC, the new criteria had a sensitivity of 65.9% and specificity of 94.9%.

Interpretation

These criteria have acceptable reliability and validity and could be a new tool for clinicians and researchers. An advantage of the new criteria is that they consider parasite location (ie, parenchymal or extraparenchymal), which is an important factor determining the clinical, immunological, and radiological presentation of the disease, and importantly, its treatment and prognosis. Ann Neurol 2016;80:434–442

Natural course of typical and atypical parenchymal solitary cysticercus granuloma of the brain: a 3-year prospective clinico-radiological study

OBJECTIVE

To evaluate the role of advanced magnetic resonance (MR) sequences (fast imaging employing steady-state acquisition (FIESTA), T2 star-weighted angiography (SWAN) and spoiled gradient recalled echo (SPGR)) in patients with single small enhancing computed tomography lesions and scolex demonstration in typical and atypical parenchymal neurocysticercosis.

METHODS

In this study, 59 patients of new-onset seizures with single small enhancing computed tomography lesions of the brain were included. Along with routine MR sequences, advanced MR sequences, like SWAN, FIESTA, and pre and post-contrast SPGR, were performed. Follow-up MR studies focussing on the morphology of the lesions and demonstration of scolex were performed 6 monthly for 3 years.

RESULTS

The majority of patients (62.7%) were men with partial seizure as the most common manifestation. On SPGR, contrast lesions were identified as either 'typical' (42, 71.2%) or 'atypical' (17, 28.8%). In the typical lesion group, SWAN and FIESTA sequences detected scolex in 30 (71.4%) and 32 (76.2%), respectively. The combination of SPGR-contrast, FIESTA and SWAN sequences detected scolex in 35 (83.3%) patients compared to 19 (45.2%) by routine sequences (P < 0.001). In the atypical lesion group, SWAN and FIESTA sequences detected scolex in 15 (88.2%) and 16 (94.1%) patients, respectively. The combination of SPGR-contrast, FIESTA and SWAN sequences detected scolex in 16 (94.1%) patients compared to 10 (58.8%) by routine sequences (P < 0.001). Follow-up showed greater resolution with lesser calcification in the typical group compared to the atypical group.

CONCLUSION

This study provides an insight into the natural course of typical and atypical solitary cysticercus granuloma lesions, and the utility of SPGR-contrast, FIESTA and SWAN MR sequences in scolex demonstration and identification of atypical lesions.

Relevance of 3D magnetic resonance imaging sequences in diagnosing basal subarachnoid neurocysticercosis

Imagenological diagnosis of subarachnoid neurocysticercosis is usually difficult when classical magnetic resonance imaging (MRI) sequences are used. The purpose of this study was to evaluate the advantages of 3D MRI sequences (Fast Imaging Employing Steady-state Acquisition (FIESTA) and Spoiled Gradient Recalled Echo (SPGR)) with respect to classical sequences (Fluid Attenuation Inversion Recovery (FLAIR) and T1) in visualizing Taenia solium cyst in these locations. Forty-seven T. solium cysts located in the basal cisterns of the subarachnoid space were diagnosed in eighteen Mexican patients. A pre-treatment MRI was performed on all patients, and all four sequences (FIESTA, FLAIR, T1 SPGR, and T2) were evaluated independently by two neuroradiologists. The sensitivity of each sequence to detect the parasite membrane and scolex was evaluated, along with its capacity to detect differences in signal intensity between cerebrospinal fluid (CSF) and cysts. FIESTA sequences allowed the visualization of cyst membrane in 87.2% of the parasites evaluated, FLAIR in 38.3%, SPGR in 23.4%, and T2 in 17.0%. The superiority of FIESTA sequences over the other three imaging methods was statistically significant (P<0.001). Scolices were detected by FIESTA twice as much as the other sequences did, although this difference was not significant (P>0.05). Differences in signal intensity between CSF and parasite cysts were significant in FIESTA (P<0.0001), SPGR (P<0.0001), and FLAIR (P=0.005) sequences. For the first time, the usefulness of 3D MRI sequences to diagnose T. solium cysts located in the basal cisterns of the subarachnoid space was demonstrated. The routine use of these sequences could favor an earlier diagnosis and greatly improve the prognosis of patients affected by this severe form of the disease.

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.

Neurocysticercosis: HP10 antigen detection is useful for the follow-up of the severe patients

BACKGROUND

The most severe clinical form of neurocysticercosis (NC) occurs when cysticerci are located in the subarachnoid space at the base of the brain (SaB). The diagnosis, monitoring and treatment of NC-SaB, constitutes a severe clinical challenge. Herein we evaluate the potential of the HP10 antigen detection enzyme-linked immunosorbent assay (HP10 Ag-ELISA) in the long term follow-up of NC-SaB cases. Assay performance was compared with that of Magnetic Resonance Imaging (MRI). In addition, the robustness of the HP10 Ag-ELISA was evaluated independently at two different institutions.

METHODOLOGY/PRINCIPAL FINDINGS

A double-blind prospective cohort trial was conducted involving 38 NC-SaB cases and a total of 108 paired serum and cerebrospinal fluid (CSF) samples taken at intervals of 4 to 8 months for up to 43 months. At each medical visit, results of sera and CSF HP10 Ag-ELISA and MRI obtained at last visit were compared and their accuracy was evaluated retrospectively, considering radiological evolution between appointments. In the long-term follow-up study, HP10 Ag-ELISA had a better agreement than MRI with retrospective radiological evaluation. High reproducibility of HP10 Ag-ELISA between laboratories was also demonstrated.

CONCLUSIONS

Results reported in this study establish for the first time the usefulness of the comparatively low cost HP10 Ag-ELISA for long term follow-up of NC-SaB patients.

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.