Migrating intraventricular cysticercus during MRI

Stereotactic surgery for neurocysticercosis of the 4th ventricle: illustrative cases

BACKGROUND

Neurocysticercosis, caused by the larval stage of Taenia solium, affects the cerebral ventricles in 20–30% of cases and may lead to hydrocephalus and other neurological morbidity. Conventional treatment for cysts in the 4th ventricle includes open surgery (suboccipital approach) and neuroendoscopy, with the latter being the option of choice. Stereotactic surgery, minimally invasive, offers a good alternative for this type of deep lesion.

OBSERVATIONS

The authors report the cases of two women, 30 and 45 years old, who presented with headache, dizziness, and ataxia and were diagnosed with 4th ventricle cysticercosis. Magnetic resonance imaging (MRI) revealed dilated 4th ventricles (approximately 2.5 cm in both cases, with cystic images inside the ventricular cavity). Both patients were treated with stereotactic surgery via a suboccipital transcerebellar approach. Cyst material was extracted, and the diagnosis was confirmed by pathological examination. The surgeries had no complications and resulted in clinical improvement. Control MRI scans showed reduction of the volume of the ventricle without residual cysts.

LESSONS

Minimally invasive stereotactic surgery provided a safe alternative for 4th ventricle neurocysticercosis cysts, with more benefits than risks in comparison with conventional techniques.

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.

Fourth ventricle neurocysticercosis: A case report

Background:

Neurocysticercosis (NCC) is the most common helminthic disease of the nervous system in humans and it is caused by the larvae of the pork tapeworm, Taenia solium. We present a case of microsurgical removal of a fourth ventricle NCC cyst combined with an endoscopic third ventriculostomy (ETV) to treat hydrocephalus.

Case Description:

A 36-year-old woman presented to the emergency room with headache and decreased visual acuity over the last 4 months. A brain magnetic resonance imaging showed obstructive hydrocephalus apparently correlated to a mobile, cystic lesion of the fourth ventricle. In the same operative time, an ETV and a suboccipital craniotomy were performed in order to remove the lesion and to treat the hydrocephalus. The cyst was completely removed and pathologically identified as a T. solium cyst. The early postoperative course was uneventful and she was discharged asymptomatic and off anthelmintic medication. Five weeks later, the patient returned with hydrocephalus recurrence and was successfully retreated with an ETV. At 5-month follow-up, she remains asymptomatic and has no evidence of persistent disease or hydrocephalus recurrence.

Conclusion:

Intraventricular neurocysticercosis is, typically, a surgical disease. For cysts located on the fourth ventricle, a suboccipital craniotomy and a telovelar approach remains a valid option. Cyst removal does not necessarily resolve the hydrocephalus problem. ETV offers an option to the classic shunt placement approach and was shown to be effective even on hydrocephalus recurrence.

Transventricular Migration of Neurocysticercosis

BACKGROUND

The movements of a neurocysticercosis cyst within the ventricular cavity have been identified rarely.

CASE DESCRIPTION

A 22-year old male patient presented with the main symptom of diplopia for about a week. Findings of the neurologic examination revealed bilateral sixth cranial nerve weakness. Investigations during the period showed an intraventricular tumor that migrated from lateral ventricle to the third ventricle and subsequently to the fourth ventricle. The lesion was resected from the fourth ventricle and was identified to be a neurocysticercosis cyst.

CONCLUSIONS

Such an intraventricular migration of any kind of tumor has not been recorded in the literature.

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.

Migration of intraventricular neurocysticercus after ventriculostomy

Intraventricular neurocysticerci are an uncommon occurrence and are often difficult to diagnose. They are often a cause of obstructive hydrocephalus and inflammatory reactions, which can be life threatening. Intraventricular neurocysticerci are most common in the fourth ventricle and surgical decompression of obstructive hydrocephalus is an important step in their management. However, these cysticerci are also known to migrate within the ventricular system and may cause confusion during surgery. It thus becomes very important for radiologists and neurosurgeons to be aware of this phenomenon.

Detection of Taenia solium antigens and anti-T. solium antibodies in paired serum and cerebrospinal fluid samples from patients with intraparenchymal or extraparenchymal neurocysticercosis

BACKGROUND

Neurocysticercosis (NCC) is a frequent cause of epilepsy worldwide. Compared with the more common parenchymal brain cysts, extraparenchymal infections are difficult to manage and have a poor prognosis. Serological assays are used to detect circulating Taenia solium antigens or anti-T. solium antibodies in serum or cerebrospinal fluid (CSF) samples. There are no guidelines on whether to use serum or CSF specimens for a particular assay.

METHODS

We obtained paired serum and CSF samples from 91 patients with NCC (48 had intraparenchymal NCC, and 43 had extraparenchymal NCC) for detection of antibodies, using an enzyme-linked immunotransfer blot (EITB) assay, and antigens, using a monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA).

RESULTS

For the intraparenchymal NCC group, the EITB assay yielded more true-positive results for serum samples, and the ELISA yielded slightly more true-positive results for CSF samples than for serum samples, but none of these differences were statistically significant. Most patients with calcified NCC were antibody positive but antigen negative. For extraparenchymal disease, all samples were antibody positive, and all but 2 were antigen positive, with most samples containing high antigen levels.

CONCLUSIONS

The sensitivity of antibody-detecting EITB assays is not increased through the use of CSF samples rather than serum samples. The antigen-detecting ELISA performed better for CSF samples than for serum samples, but for both specimen types it was less sensitive than the EITB assay. Active and inactive NCC are better differentiated from each other by the antigen-detecting ELISA, for both serum and CSF samples. High antigen levels suggest the presence of subarachnoid NCC.