Treatment of neurocysticercosis: current status and future research needs

Differential in vitro effects of insulin on Taenia crassiceps and Taenia solium cysticerci

Hormones play a significant role in murine cysticercosis (Taenia crassiceps), and increase the frequency of porcine cysticercosis caused by Taenia solium. In the present study, we report the in vitro effect of insulin on the larval stages of T. crassiceps (ORF strain) and T. solium. In vitro exposure of T. crassiceps cysticerci to insulin was found to stimulate this parasite's reproduction twofold with respect to control values, while the same treatment had no effect on T. solium cysticerci. Moreover, normal female mice (BALB/cAnN) infected with T. crassiceps cysticerci previously exposed to insulin presented larger parasite loads than mice inoculated with vehicle-treated cysticerci. To determine the possible molecular mechanisms by which insulin affects T. crassiceps, the insulin receptor was amplified by means of reverse transcriptase-polymerase chain reaction (RT-PCR). Interestingly, both T. crassiceps and T. solium expressed the insulin receptor, although insulin had effects only on T. crassiceps. These results demonstrate that insulin has a dichotomistic effect; it acts directly only on T. crassiceps cysticerci reproduction, possibly through its binding to a specific insulin receptor synthesized by the parasite. Thus, insulin may be recognized by T. crassiceps cysticercus cells as a mitogenic factor, and contribute to parasite proliferation inside the host, as well as to the female mouse susceptibility to T.crassiceps. This phenomenon has not been reported for cysticercosis caused by T. solium, which could, in part, be related to the poor effect of insulin upon the human parasite.

Neurocysticercosis in children

Neurocysticercosis (NCC) is a common cause of seizures and neurologic disease. Although there may be variable presentations depending on the stage and location of cysts in the nervous system, most children (> 80%) present with seizures particularly partial seizures. About a third of cases have headache and vomiting. Diagnosis is made by either CT or MRI. Single enhancing lesions are the commonest visualization of a scolex confirms the diagnosis. Some cases have multiple cysts with a characteristic starry-sky appearance. Management involves use of anticonvulsants for seizures and steroids for cerebral edema. The use of cysticidal therapy continues to be debated. Controlled studies have shown that cysticidal therapy helps in increased and faster resolution of CT lesions. Improvement in long-term seizure control has not yet been proven. Children with single lesions have a good outcome and seizure recurrence rate is low. Children with multiple lesions have recurrent seizures. Extraparenchymal NCC has a guarded prognosis but it is rare in children. In endemic areas NCC must be considered in the differential diagnosis of seizures and various other neurological disorders.

The Nepalese shepherd

Neurocysticercosis is one of the most common causes of seizures in the developing world. Due to the high volumes of immigration from South America and Asia, American physicians are increasingly encountering this condition. This case report attempts to present a brief overview of some of the difficulties associated with the treatment of patients with a high disease burden.

Neuropsychiatric aspects of infectious diseases

Among the critically ill, infectious diseases can play a significant role in the etiology of neuropsychiatric disturbances. All critical care physicians are familiar with delirium as a secondary complication of systemic infection. This article focuses on key infectious diseases that commonly and directly produce neuropsychiatric symptoms, including direct infection of the central nervous system.

Treatment of neurocysticercosis: is it beneficial?

Neurocysticercosis is the most common parasitic disease of the CNS. Intracranial neurocysticercosis is classified into cerebral parenchymal and extraparenchymal forms (subarachnoidal and intraventricular). Current medical therapy for parenchymal and extraparenchymal neurocysticercosis invovles the use of anticysticercal drugs. Albendazole and praziquantel are two commonly used drugs. Most experts prefer to always use oral or parenteral corticosteroids along with anticysticercal drugs. The role of anticysticercal drugs in the treatment of parenchymal neurocysticercosis has always been a subject of intense controversy. Whether therapy with anticysticercal drugs results in improved seizure-related prognosis remains a major concern. A recent meta-analysis evaluating six controlled trials suggests that treatment with anticysticercal drugs results in better resolution of colloidal and vesicular cysticerci; in patients taking anticysticercal drugs, there was a lower risk of seizure reccurence in patients with colloidal cysticerci and a significant reduction in the rate of generalized seizures in patients with vesicular cysticerci. However, the findings of the study by Carpio et al. have revived the controversy regarding this treatment. These authors noted that the effect of a single dose of albendazole is, at best, only modest. Only a minority of patients with parenchymal neurocysticercosis benefitted and became cyst free and there was a lack of effectiveness toward the associated seizure disorders. No response was seen in patients with degenerative parenchymal or extraparenchymal forms of neurocysticercosis. Carpio et al. suggest that there is a need for further studies that employ different approaches, such as the use of high initial doses of albendazole, the use of two anticysticercal drugs or repeated prolonged courses of albendazole.

Clinical analysis of 52 cases of neurocysticercosis

We studied 52 cases of neurocysticercosis from January 1991 to December 2006 in order to increase our understanding of the diagnosis and treatment of the disease. The majority of patients were between 18 and 45 years old (78.8%). Men were more subject to the disease than women. The urban population was more at risk than the rural population. The treatment involved the use of mannitol, dexamethasone and oral administrations of albendazole or praziquantel. The effectiveness rate was 57.7% (30), the improvement rate was 28.8% (15), and the inefficacy rate was 14.0% (6). Neurocysticercosis was easy to misdiagnose. Praziquantel and albendazole are effective drugs for neurocysticercosis.

[Degenerating neurocysticercosis cysts: differential diagnosis with cerebral metastasis]

INTRODUCTION

Neurocysticercosis is the most common parasitic disease of the central nervous system. It has a worldwide distribution.

CASE REPORT

We report the case of a 70-year-old woman from Guadeloupe presenting gait abnormalities, impaired ideation, right hemiparesis in a context of weight loss, and fatigue. Blood analyses were normal with neither inflammatory syndrome nor blood hypereosinophilia. Brain computed tomography and magnetic resonance imaging showed hydrocephaly in relation with Sylvius' aqueduc stenosis, and diffuse contrast-enhancing lesions suggesting metastases. Because of clinical symptoms, the patient underwent ventriculostomy; the cerebral spinal fluid examination was normal. Then a frontal biopsy was performed. Histological examination was compatible with neurocysticercosis and confirmed by serology. The patient was successfully treated with albendazole and steroids.

CONCLUSION

Neurocysticercosis must be considered as a differential diagnosis of cerebral metastasis, especially in patients from endemic countries.

Inexpensive anti-cysticercosis vaccine: S3Pvac expressed in heat inactivated M13 filamentous phage proves effective against naturally acquired Taenia solium porcine cysticercosis

In search of reducing vaccine production costs', a recombinant M13 phage version of the anti-cysticercosis tripeptide vaccine (S3Pvac) was developed. The efficacy of S3Pvac-Phage vs. placebo was evaluated in a randomized trial that included 1,047 rural pigs in 16 villages of Central Mexico. Three to five months after vaccination 530 pigs were examined by tongue inspection. At 5-27 months of age, 331 pigs (197 vaccinated/134 controls) were inspected at necropsy. Vaccination reduced 70% the frequency of tongue cysticercosis and, based on necropsy, 54% of muscle-cysticercosis and by 87% the number of cysticerci.

The immune response in Taenia solium cysticercosis: protection and injury

This article reviews current knowledge on the innate and acquired immune responses in human Taenia solium neurocysticercosis, highlighting the conditions that appear to be favourable for the survival or destruction of the parasite and for the benefit or injury to its host.

Advances in the diagnosis and management of neurocysticercosis

Neurocysticercosis is the most common cause of late-onset epilepsy in developing countries. The larval stage of Taenia solium is the causative agent of the disease. Recent advances in neuroimaging and serologic diagnostic techniques have led to increased recognition of its importance, but its pathogenesis is just beginning to be clarified. Experts now agree that the clinical manifestations, pathogenic mechanisms and optimal treatment vary with the number of parasites, their location and the degree of host inflammation. Symptomatic therapy (i.e., antiepileptic medications and, when indicated, surgery) is critically important but there are also important roles for antiparasitic and anti-inflammatory drugs. Neurocysticercosis is a potentially eradicable disease but this is probably unlikely to be achieved in the short term.