Computed tomography and magnetic resonance imaging of neurocysticercosis

Triggered: Discovery of Neurocysticercosis Following Self-Administered Albendazole

A 25-year-old man with no medical history presented with a seizure one month after taking a self-administered dose of albendazole. Magnetic resonance imaging (MRI) of the brain revealed multiple ring-enhancing lesions, and the workup confirmed neurocysticercosis (NCC). Treatment with antiparasitics was delayed due to concern for worsening symptoms from the presence of cysts in the midbrain and hippocampus. The balance between treating NCC and limiting cerebral inflammation is delicate and relies on judgment from a multispecialty clinical team. In this case, corticosteroids and antiepileptics alone prevented additional seizures but failed to reduce the overall inflammation of cysts and the progression of the disease. Evidence of new cysts on MRI at week 13 from the onset of symptoms was evidence of an acute, evolving infectious process. Treatment with albendazole and praziquantel was initiated at 13 weeks from the onset of symptoms, and by 31 weeks, nearly all cysts had resolved with minimal residual inflammation.

Prevalence, Response to Cysticidal Therapy, and Risk Factors for Persistent Seizure in Indian Children with Neurocysticercosis

Background. Neurocysticercosis (NCC) is the commonest cause of childhood acquired epilepsy in developing countries. The use of cysticidal therapy in NCC, except "single lesion NCC," is still debated in view of its doubtful usefulness and potential adverse effects. Methods. Children presenting with first episode of seizure or acute focal neurological deficit without fever were screened for NCC and received appropriate therapy (followup done for 1 year to look for the response and side effects). Results. The prevalence of NCC was 4.5%. Most common presenting feature was generalized seizure and commonest imaging finding was single small enhancing lesion in the parietal lobe. Abnormal EEG and CSF abnormalities were found in almost half of the children. The response to therapy was very good with infrequent recurrence of seizure and adverse effects of therapy were encountered rarely. No risk factors for persistent seizure could be identified. Conclusion. Present study shows that the response to cysticidal therapy is very good in NCC as seizure recurrence was observed in only 5%, 4.2%, and 4.2% of cases at 3-month, 6-month, and 1-year followup. Adverse effects of therapy were observed in 20% of cases during therapy but they were mild and self-limiting.

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.

Intraventricular and subarachnoid racemose cysticercosis

Cysticercosis is endemic in India. Neurocysticercosis most commonly affects the brain parenchyma, which presents as focal lesions with the surrounding edema which later calcify. Rarely, it may affect the ventricular system and subarachnoid spaces and this form is known as racemose cysticercosis. We present magnetic resonance findings in a case of racemose cysticercosis.

Accuracy of serological testing for the diagnosis of prevalent neurocysticercosis in outpatients with epilepsy, Eastern Cape Province, South Africa

BACKGROUND

Few studies have estimated prevalence of neurocysticercosis (NCC) among persons with epilepsy in sub-Saharan Africa. While the limitations of serological testing in identification of NCC are well known, the characteristics of persons who are misdiagnosed based on serology have not been explored. The first objective of this pilot study was to estimate the prevalence of NCC in epilepsy outpatients from an area of South Africa endemic for cysticercosis. The second objective was to estimate the accuracy of serological testing in detecting NCC in these outpatients and characterize sources of disagreement between serology and neuroimaging.

METHODOLOGY/PRINCIPAL FINDINGS

All out-patients aged 5 or older attending the epilepsy clinic of St. Elizabeth's Hospital in Lusikisiki, Eastern Cape Province, between July 2004 and April 2005 were invited to participate. Epidemiological data were collected by local study staff using a standardized questionnaire. Blood samples were tested by ELISA for antibody and antigen for Taenia solium. Four randomly chosen, consenting participants were transported each week to Mthatha for brain CT scan. The proportion of persons with epilepsy attending St. Elizabeth clinic with CT-confirmed NCC was 37% (95% CI: 27%-48%). Using CT as the gold standard, the sensitivity and specificity of antibody testing for identifying NCC were 54.5% (36.4%-71.9%) and 69.2% (52.4%-83.0%), respectively. Sensitivity improved to 78.6% (49.2%-95.3%) for those with active lesions. Sensitivity and specificity of antigen testing were considerably poorer. Compared to false negatives, true positives more often had active lesions. False positives were more likely to keep pigs and to have seizure onset within the past year than were true negatives.

CONCLUSIONS/SIGNIFICANCE

The prevalence of NCC in South African outpatients with epilepsy is similar to that observed in other countries where cysticercosis is prevalent. Errors in classification of NCC using serology alone may reflect the natural history of NCC.

Intrathecal synthesis of specific immunoglobulin G antibodies in neurocysticercosis: evaluation of antibody concentrations by enzyme-linked immunosorbent assay using a whole cysticercal extract and cyst vesicular fluid as antigens

The demonstration of intrathecal antibody production has proven useful for showing the involvement of the central nervous system (CNS) in several diseases. In the present study, the intrathecal synthesis of cysticercus-specific immunoglobulin G (IgG) antibodies was investigated in 30 patients with neurocysticercosis based on calculation of the specific IgG antibody index (AI(IgG)). An AI(IgG) > or =1.5 was considered to be indicative of intrathecal antibody production. Antibody concentrations in serum and cerebrospinal fluid samples were evaluated using an enzyme-linked immunosorbent assay with 2 antigen preparations from Taenia solium cysticerci, namely, a whole cysticercal extract (TsoW) and the vesicular fluid of the parasite (TsoVF). Intrathecal, cysticercus-specific IgG antibody synthesis was observed in 21 (70%) and 23 (76.6%) patients using the TsoW and TsoVF antigens, respectively. The detection of the intrathecal synthesis of specific antibodies may be a potentially useful tool in establishing the involvement of CNS in cysticercosis.

Evaluation of Taenia solium and Taenia crassiceps cysticercal antigens for the serodiagnosis of neurocysticercosis

We evaluated the usefulness of seven cysticercal antigen extracts, four from Taenia solium cysticerci (whole parasite-TsoW, membrane-TsoMe, vesicular fluid-TsoVF and scolex-TsoSc) and three from T. crassiceps cysticerci (whole parasite-TcraW, membrane-TcraMe and vesicular fluid-TcraVF), for serodiagnosis of neurocysticercosis with an enzyme-linked immunosorbent assay (ELISA). Cysticercus-specific IgG were screened in serum samples from 23 patients with neurocysticercosis, 32 patients with other infections and 48 healthy persons. The best results were obtained with the TsoVF-ELISA (91.3% sensitivity; 96.2% specificity) and TcraVF-ELISA (91.3% sensitivity; 95% specificity). The ELISA done with whole parasite and membrane extracts from cysts of T. solium and T. crassiceps and the scolex extract from T. solium cysts showed a low performance in terms of sensitivity, ranging from 47.8% to 73.9%. None of the antigen preparations from T. solium and T. crassiceps cysticerci used in this study showed outstanding performance for the serodiagnosis of neurocysticercosis. However, considering the results obtained with the seven antigen preparations, vesicular fluid from T. solium and T. crassiceps cysticerci may be useful for detecting specific antibodies in sera from patients with neurocysticercosis.

Neurocysticercosis: evaluation with advanced magnetic resonance techniques and atypical forms

Neurocysticercosis (NCC) is the most common helminthic infection of the central nervous system, but its diagnosis remains difficult. The purpose of this article is to perform a critical analysis of the literature and show our experience in the evaluation of NCC. We discuss the advanced MR technique applications such as diffusion and perfusion-weighted imaging, spectroscopy, cisternography with FLAIR, and supplemental O2 and 3D-CISS. The typical manifestations of NCC are described; emphasis is given to the unusual presentations. The atypical forms of neurocysticercosis were divided into: intraventricular, subarachnoid, spinal, orbital, and intraparenchymatous. Special attention was also given to reactivation of previously calcified lesions and neurocysticercosis associated with mesial temporal sclerosis.

Parasitic worms of the central nervous system: an Australian perspective

The diagnosis and management of parasitic diseases of the central nervous system (CNS) is difficult, even for infectious diseases physicians and neurologists. Furthermore, few overviews of the spectrum of causative helminths and clinical syndromes have been published. In the present study, we review the seven most common parasitic diseases of the CNS: (i) cysticercosis, (ii) neuroschistosomiasis, (iii) paragonimiasis, (iv) angiostrongyliasis, (v) hydatid disease, (vi) sparganosis and (vii) gnathostomiasis. Major syndromes of parasitic disease of the CNS and their differential causes are discussed, including: (i) cystic lesions, (ii) enhancing granulomas (with and without creeping subcutaneous eruptions), (iii) eosinophilic meningoencephalitis and (iv) spinal cord disease. Specific risk factors that predispose to these infections are also discussed and particular attention is drawn to the situation in Australia.

Intramedullary spinal cysticercosis. Case report and review of the literature

Cysticercosis is the most common parasitic infection of the central nervous system. It infrequently affects the spine, but when it does, it can present with symptoms similar to other more common spinal diseases. The authors present a case of isolated intramedullary cysticercosis of the cervical spine and review the literature.

A rapid latex agglutination test for the detection of anti-cysticercus antibodies in cerebrospinal fluid (CSF)

Simple and rapid latex-based diagnostic tests have been used for detecting specific antigens or antibodies in several diseases. In this article, we present the preliminary results obtained with a latex agglutination test (LAT) for diagnosing neurocysticercosis by detection of antibodies in CSF. A total of 43 CSF samples were assayed by the LAT: 19 CSF samples from patients with neurocysticercosis and 24 CSF samples from patients with other neurologic disorders (neurosyphilis, n = 8; neurotoxoplasmosis, n = 3; viral meningitis, n = 4, chronic headache, n = 9). The LAT exhibited 89.5% sensitivity and 75% specificity. The use of LAT seems to be an additional approach for the screening of neurocysticercosis with advantage of simplicity and rapidity. Further studies could be performed using purified antigens and serum samples.

A quantitative enzyme-linked immunosorbent assay (ELISA) for the immunodiagnosis of neurocysticercosis using a purified fraction from Taenia solium cysticerci

A quantitative enzyme-linked immunosorbent assay (ELISA) for the immunodiagnosis of neurocysticercosis is described. The ELISA was standardized using a purified Taenia solium cysticerci fraction (PCF) obtained by ion exchange chromatography. The ELISA using PCF (PCF-ELISA) and a qualitative ELISA using a whole extract from T. solium cysticerci (WEC-ELISA) were used to screen for cysticercus-specific IgG antibodies in cerebrospinal fluid (CSF) samples from 57 patients with neurocysticercosis and 50 patients with other neurologic disorders. The sensitivity of both assays was 95%, whereas the specificities of PCF-ELISA and WEC-ELISA were 100% and 92%, respectively. The excellent sensitivity and specificity of the PCF-ELISA make this assay a potentially useful tool in screening for antibodies against T. solium cysticerci.