MR imaging of neurocysticercosis

Racemose neurocysticercosis: a case series

Neurocysticercosis (NCC) is a common parasitic condition of the central nervous system in certain parts of the world. The racemose variety of NCC is distinct from the commonly seen parenchymal form. It frequently infiltrates the basal cisterns and Sylvian fissures. Imaging plays a vital role in the diagnosis; however, as their signal intensity is similar to cerebrospinal fluid and due to the absence of enhancement in most cases, imaging diagnosis is often difficult on the conventional MRI sequences. Here, we present five cases of racemose NCC to emphasize the importance of a heavily T2-weighted sequence (Fast Imaging Employing Steady-state Acquisition) sequence in the diagnosing this entity.

Spinal Taenia solium cysticercosis in Mexican and Indian patients: a comparison of 30-year experience in two neurological referral centers and review of literature

OBJECTIVE

To present a retrospective study from patients with spinal cysticercosis (SC), diagnosed within the last 30 years in Mexican and Indian neurological referral centers.

METHODS

This is a retrospective and comparative study of the clinical and radiological profile between Mexican and Indian patients with spinal neurocysticercosis during a 30-year period and a review of the literature during the same period.

RESULTS

Twenty-seven SC patients were included: 19 from Mexico and 8 from India. SC presented predominantly with motor symptoms (21/27 patients): paraparesis and paraplegia were the most common signs; one-third of patients presented sphincter dysfunction. Imaging studies showed that parasites in vesicular stage were more frequent in patients from Mexico, while degenerative stages predominated in India. Association of subarachnoid cysticerci and hydrocephalus was observed only in Mexican patients.

CONCLUSIONS

Despite the limitations of this study, the collected information supports the existence of differences in the clinical and radiological traits of SC patients between Asian and Latin-American hospitals. The possible biological factors that may underlie these differences are discussed.

Prospective quantitative imaging study by magnetisation transfer for appearance of perilesional gliosis in solitary cerebral cysticercal lesion

This study aimed to detect perilesional gliosis around solitary cerebral cysticerci (SCC) by magnetisation transfer imaging (MTI), to compare its incidence between patients administered and not administered albendazole. We prospectively randomised patients with SCC and new-onset seizures to treatment with albendazole plus antiepileptics (treatment), or antiepileptics only (control), and performed MRI scans at zero, three, six, 12 and 24 months. Data were analysed for lesion characteristics, perilesional MT hyperintensity and MT ratios, calculated from the lesion and perilesional area. Eighty-one patients' data were analysed (M-41, F-40; ages 6-52 years). About 13% scolices appeared hyperintense on MTI at baseline. T1-isointense cyst walls and perilesional area showed MT hyperintensity in 30 - 41.4%; this proportion increased over time. Persistently visible SCC and stage of degeneration at enrolment did not predict development of MT hyperintensity. MT ratios (range - 98.75 to 49.79) increased over time and differed significantly from normal parenchyma. No difference in MT ratios was noted between treatment and control groups. Qualitative perilesional MT hyperintensity was more often seen in control group. Perilesional gliosis is present in >20% of SCC at six months, and continues to appear on later scans. Gliosis is independent of lesion persistence and stage of degeneration. Pre- and post-contrast MT imaging is equally useful in detection of gliosis. MT ratios from the lesion and perilesional parenchyma are significantly lower than from normal brain tissue at all stages of degeneration, but increase as degeneration occurs and healing progresses. Albendazole therapy does not affect the formation of perilesional gliosis.

Recurrent primary spinal subarachnoid neurocysticercosis

STUDY DESIGN

Case description.

OBJECTIVE

To describe a patient with a recurrent primary spinal subarachnoid neurocysticercosis (NCC) that was successfully treated with surgical decompression and medical therapy at our center.

SUMMARY OF BACKGROUND DATA

Spinal subarachnoid NCC is thought to be the secondary result from larval migration through the ventricular system into the spinal subarachnoid space. However, this entity can develop as a primary infection through blood stream or direct larval migration. It can result in high recurrence and severe neurologic morbidity if it is not treated in an appropriate manner.

METHODS

A 50-year-old woman with treatment history of spinal NCC presented with back pain and radicular pain. The lumbar magnetic resonance imaging showed a cystic lesion with septation and slight rim enhancement after gadolinium administration at the L4-S1 area. We performed surgical removal of this lesion and postoperative medical therapy for complete eradication of the parasite.

RESULTS

The histopathology was diagnostic for a cysticercal cyst. Adjuvant medical therapy with albendazole was administered for 30 days after surgery. The patient remained symptom-free for 1 year after surgery without any evidence of recurrence.

CONCLUSION

We report a rare case of recurrent primary spinal subarachnoid NCC at L4-S1 area. In cases of primary spinal subarachnoid NCC can be treated by adequate combined approach with surgery and medical therapy. Spinal subarachnoid NCC should be added to the differential diagnosis of primary spinal intradural cysts, because this lesion can occur primarily.

Imaging of acoustic neuromas. 1992

Diagnosis of acoustic neuromas has been simplified considerably by computed tomography (CT) and magnetic resonance imaging (MRI). Either enhanced method will visualize almost every acoustic neuroma. MRI is more sensitive inside the internal auditory canal. Currently, a gadolinium-enhanced MRI scan is considered an accurate indicator of whether or not an individual has an acoustic neuroma, although there have been false-positive enhanced MRI scans recently reported.

Neurocysticercosis and human immunodeficiency virus infection: a case report

Ecuador is considered a holoendemic high-risk area for the transmission of cysticercosis. Moreover, the progression of human immunodeficiency virus (HIV) occurs worldwide. We present a case of simultaneous diagnosis of cysticercosis and HIV infection in a 22-year-old Ecuadorian immigrant. We would postulate that with the increasing HIV incidence in endemic areas of cysticercosis, the simultaneous diagnosis of both diseases is an event to be expected.

Neurocysticercosis: a review

BACKGROUND

In North America, the largest number of neurosurgical cases stemming from parasitic infections involves the larval form of Taenia solium, the infectious organism causing neurocysticercosis. This infection of the central nervous system (CNS) is most commonly seen in areas with significant immigrant populations and can often present particular challenges to treating physicians.

METHODS

A review of the literature was performed, highlighting the epidemiology, parasitology, and clinical manifestations of neurocysticercosis. Particular attention was paid to 4 locations of neurocysticercosis lesions: parenchymal, subarachnoid/cisternal, intraventricular, and spinal.

RESULTS

Both medical and surgical interventions may be necessary for adequate treatment of neurocysticercosis, depending on various factors, including location of lesion.

CONCLUSIONS

A review of neurocysticercosis, with particular attention paid to location of disease involvement in the CNS, provides important information to the clinical management of this disease.

Diagnosis of intraventricular cysticercosis by magnetic resonance imaging: Improved detection with three-dimensional spoiled gradient recalled echo sequences

Neurocysticercosis (NCC) is caused when the cysticercus larvae of Taenia solium infect the central nervous system. The larvae usually land in the parenchymal tissue, but quite rarely can lodge in the ventricles and cisterns of the brain. Unlike parenchymal NCC, it is not easy to demonstrate the cysticercus cysts within the cerebrospinal fluid spaces. Computed tomography and even conventional MR sequences can fail to detect such cysts. However, obtaining three-dimensional spoiled gradient recalled echo imaging sequences can help in improving the detection of intraventricular NCC, as is borne out by a case described in the present report. The use of such special MR sequences is therefore strongly advocated in suspected cases of intraventricular NCC.

Thoracic intramedullary cysticercosis--two case reports

A 36-year-old male and a 20-year-old male presented with intramedullary cysticercosis in the thoracic spinal cord. Magnetic resonance imaging clearly identified the cysts. Surgery was performed to decompress the spinal cord, as both patients had progressive and severe worsening of their neurological condition. Intramedullary cysticercosis can be treated successfully by surgery and/or medical therapy.

Intraventricular neurocysticercosis mimicking colloid cyst. Case report

The authors recently encountered a unique case of anterior third ventricular neurocysticercosis in which the cyst exhibited an unusually high signal on T1-weighted magnetic resonance imaging. The lesion's signal intensity and location made differentiation from colloid cyst difficult. Intraventricular neurocysticercosis should be included in the differential diagnosis of a colloid cyst.

Imaging features and surgery-related outcomes in intraventricular neurocysticercosis

Object

Neurocysticercosis (NCC) is the most common parasitic infection of the central nervous system, and its prevalence is continuing to increase in the United States. The diagnosis of intraventricular NCC (IVNCC) may be difficult, and surgery frequently fails to resolve symptoms. A retrospective review of magnetic resonance (MR) imaging characteristics and surgery-related outcomes may improve management strategies of this disease.

Methods

The authors report the presentations, neuroimaging characteristics, surgical management, and outcomes of 30 patients with IVNCC treated over a 10-year period (mean follow-up period 4 years). Cysts were located in the lateral ventricles (five cases), the third ventricle (five cases), and the fourth ventricle (21 cases). One patient had lesions in both the lateral and fourth ventricles. Presenting symptoms were related to hydrocephalus or mass effect from the lesions.

All patients underwent computerized tomography (CT) and MR imaging of the brain. Treatment consisted of shunt implantation or primary excision of an IVNCC lesion. Outcomes after operations and reoperations were evaluated in light of enhancement characteristics on MR imaging.

Computerized tomography scanning demonstrated IVNCC lesions in 10% of cases, and MR revealed lesions in 100% of cases. In patients in whom gadolinium (Gd) enhancement of IVNCC lesions was demonstrated on MR imaging, the surgery-related failure rate was higher and patients required reoperation, and in those in whom gadolinium enhancement was absent the surgery-related failure rate was lower (64 and 19%, respectively; p < 0.0002).

Conclusions

Magnetic resonance imaging is superior to CT scanning for detecting IVNCC lesions. The absence of pericystic Gd enhancement on MR imaging is an indication for excision of the lesions. If pericystic enhancement is present, shunt surgery should be performed, and craniotomy reserved for treatment of those patients with symptomatic lesions secondary to mass effect. A treatment algorithm based on patient symptoms, cyst location, and MR imaging Gd enhancement characteristics is proposed.

Spinal neurocysticercosis

Worldwide, cysticercosis is the most common parasitic infection of the central nervous system. In endemic regions, the incidence of neurocysticercosis (NCC) approaches 4% of the general population. The disease is predominantly intracranial, the authors of most series generally report the incidence of spinal NCC as only 1.5 to 3% of all cases. Although spinal NCC is relatively rare, it represents a distinct clinical entity that can have devastating consequences for the patient. Because of the limited size of the spinal canal, the mass effect of these lesions is poorly tolerated. Most spinal NCC occurs in the subarachnoid space where mass effect can cause spinal cord compression, although obstruction of cerebrospinal fluid pathways due to scarring of the subarachnoid space can also cause symptoms.

The authors treated six patients with spinal NCC. In five cases the lesions were located in the subarachnoid space, and in one the lesion was intramedullary. All patients with subarachnoid spinal NCC required excision of the symptomatic lesions; in two cases initial medical therapy had failed. The patient with intramedullary spinal NCC experienced mild symptoms and underwent steroid therapy. All patients experienced variably improved outcomes and were eventually ambulatory.

Medical therapy should be carefully considered in selected patients in whom symptoms are stable and nonprogressive. Surgical intervention is required when severe or progressive deficits occur to prevent permanent injury. In some patients recovery may be limited as a result of inflammatory injury to the spinal cord or arachnoidal adhesions.

Neurocysticercosis: updates on epidemiology, pathogenesis, diagnosis, and management

Neurocysticercosis is now recognized as a common cause of neurologic disease in developing countries and the United States. The pathogenesis and clinical manifestations vary with the site of infection and accompanying host response. Inactive infection should be treated symptomatically. Active parenchymal infection results from an inflammatory reaction to the degenerating cysticercus and will also respond to symptomatic treatment. Controlled trials have not demonstrated a clinical benefit for antiparasitic drugs. Ventricular neurocysticercosis often causes obstructive hydrocephalus. Surgical intervention, especially cerebrospinal fluid diversion, is the key to management of hydrocephalus. Shunt failure may be less frequent when patients are treated with prednisone and/or antiparasitic drugs. Subarachnoid cysticercosis is associated with arachnoiditis. The arachnoiditis may result in meningitis, vasculitis with stroke, or hydrocephalus. Patients should be treated with corticosteroids, antiparasitic drugs, and shunting if hydrocephalus is present.

Focal seizures with single small ring-enhancing lesion

An 8-year-old girl presented with simple partial seizures. The differential diagnosis and evaluation point out the fact that in most of the world, conditions considered rare in the United States are important diagnostic considerations.

Neuroradiologic review of intracranial infection

The detection of intracranial infection continues to be a common reason for neuroradiologic examination. This review covers the neuroradiologic findings of the variety of common infections. It includes meningitis and its complications, as well as bacterial, viral, tuberculous, fungal, and parasitic diseases. Finally, a review of the common infections associated with AIDS is presented. With an increased ability to recognize such infections, radiologists should be able to supply their clinical colleagues with more specific diagnoses.

An occult cause of persistent nausea and vomiting

We report a patient with multiple negative evaluations during emergency department visits and inpatient admissions for unexplained, intermittent nausea, vomiting, and abdominal pain. The etiology of her symptoms was not revealed until her 13th hospital visit, when head magnetic resonance imaging suggested active neurocysticercosis. Central etiologies should be considered for intractable nausea and vomiting in neurologically intact patients even if head computed-assisted tomography scan is negative.

Psychiatric manifestations of neurocysticercosis: a study of 38 patients from a neurology clinic in Brazil

OBJECTIVE

To determine the frequency and features of psychiatric morbidity in a cross section of 38 outpatients with neurocysticercosis.

METHODS

Diagnosis of neurocysticercosis was established by CT, MRI, and CSF analysis. Psychiatric diagnoses were made by using the present state examination and the schedule for affective disorders and schizophrenia-lifetime version; cognitive state was assessed by mini mental state examination and Strub and Black's mental status examination.

RESULTS

Signs of psychiatric disease and cognitive decline were found in 65.8 and 87.5% of the cases respectively. Depression was the most frequent psychiatric diagnosis (52.6%) and 14.2% of the patients were psychotic. Active disease and intracranial hypertension were associated with higher psychiatric morbidity, and previous history of mood disorders was strongly related to current depression. Other variables, such as number and type of brain lesions, severity of neuropsychological deficits, epilepsy, and use of steroids did not correlate with mental disturbances in this sample.

CONCLUSIONS

Psychiatric abnormalities, particularly depression syndromes, are frequent in patients with neurocysticercosis. Although regarded as a rare cause of dementia, mild cognitive impairment may be a much more prevalent neuropsychological feature of patients with neurocysticercosis. The extent to which organic mechanisms related to brain lesions may underlie the mental changes is yet unclear, although the similar sex distribution of patients with and without depression, as well as the above mentioned correlations, provide further evidence of the part played by organic factors in the cause of these syndromes.

Comparative study of CT and MRI in patients with seizures and a solitary cerebral cysticercus granuloma

We hypothesized that when contrast-enhanced CT reveals a solitary cerebral cysticercus granuloma, MRI would not usually provide additional information that might assist in management. We retrospectively compared visualisation of solitary cysticercus granulomas on contrast-enhanced CT and MRI in 16 patients presenting with seizures; gadolinium (Gd) enhancement was used in 6 patients. The granuloma was delineated well on both CT and MRI in 15 patients; in one patient, in whom CT was performed with 10-mm slices, it was seen only on contrast-enhanced MRI, CT and unenhanced MRI revealing only the surrounding oedema. On CT the granuloma was seen best on thin (2-5 mm) contrast-enhanced sections (in 10 patients). On MRI, Gd-enhanced images showed the granuloma best, as a ring-enhancing lesion, in all 6 patients. In the other 10 patients, the granuloma was seen only on T2-weighted images in 8 and on both T1- and T2-weighted images in 2. On T2-weighted images a characteristic low-signal ring with a high-signal centre was seen in 12 patients. Sensitivity of the imaging techniques was: contrast-enhanced CT (5 and 10 mm slices) 93.8% (15/16); thin (2-5 mm) section contrast-enhanced CT 100% (6/6); unenhanced MRI 93.8% (15/16). MRI did not reveal additional granulomas or cysts in any patient. In patients strongly suspected to be harbouring this lesion, when 10-mm contrast-enhanced CT reveals only oedema, thin (2-5 mm) slice CT is a cost-effective alternative to MRI.

Retrobulbar optic nerve cysticercosis. Case report

The authors report a first case of intraoptic neurocysticercosis in a 12-year-old boy living on Reunion Island. Cysticercosis of the retrobulbar portion of the optic nerve is rare. Because of the patient's age and disturbances in both visual acuity and visual field, it was initially believed to be an optic nerve tumor. Computerized tomography scans and surgical aspects were confirmed by pathological findings. A conservative removal using en bloc orbitotomy showed good functional and aesthetic results.

Neurocysticercosis and HIV infection: report of two cases and review

BACKGROUND

With the progression of acquired immunodeficiency virus (AIDS) and human immunodeficiency virus (HIV) infection to endemic areas of cysticercosis, the simultaneous diagnosis of both diseases is an expected event.

METHODS

Among 91 patients with AIDS or HIV infection studied from 1987 to 1993 at a neurologic reference center in Mexico City, 2 patients with AIDS and neurocysticercosis were found. Five previously reported cases were jointly reviewed.

RESULTS

The first patient presented with increased intracranial pressure of rapid progression. A single giant cyst was surgically excised and cysticercus was confirmed on histopathologic examination. The second patient had brain toxoplasmosis and concurrent neurocysticercosis as an incidental finding.

CONCLUSIONS

Neurocysticercosis in HIV infection/AIDS may appear as a life-threatening condition or as an incidental finding. All reported cases have been found in advanced stages of HIV infection. Management must be individualized depending on the clinical form of cysticercosis, stage of HIV infection, and coexisting opportunistic conditions. Surgery may be lifesaving and some patients apparently responded to cysticidal drugs.

Third ventricular cysticercal cyst mimicking a colloid cyst: case report

We describe a case of a 28-year-old Latino man who presented with signs and symptoms of raised intracranial pressure and radiographic evidence of a third ventricular cystic lesion. The cyst was removed via a transcallosal approach; the histology was noted to be a cysticercal lesion. The radiographic and histological features of this interesting case are discussed.

Nonneoplastic intracranial cysts and cystic lesions

This article reviews the gamut of cystic lesions, unrelated to neoplastic disease, that are found in the brain, subarachnoid space, and ventricles. The utility of MRI in diagnosing these entities is shown.

Central American mesencephalopathy

A 31-year-old Hispanic laborer sought medical attention for a four-day history of posterior headaches and double vision. The headache spontaneously resolved, but the patient continued to experience vertical diplopia. The neuro-ophthalmic exam revealed minimal anisocoria and subtle deficits of vertical motion of the left eye. MRI scanning demonstrated a lesion within the midbrain on the left side. Lumbar puncture revealed cells consisting primarily of lymphocytes and eosinophils. Both serum and cerebrospinal fluid revealed glycoproteins indicative of a cysticercosis infection. The patient was treated with Praziquantel and steroids with improvement of his oculomotor function.

Brainstem cysticercosis simulating cystic tumor lesion. A case report

The authors report the case of a 37 year-old man with a solitary cysticercus cyst in the brainstem (pons) successfully removed through a suboccipital craniectomy. Surgery in neurocysticercosis has been indicated in patients with hydrocephalus and/or large cystic lesions. Cystic lesions in the brainstem and spinal cord may have indication for surgery for two reasons: (1) diagnosis; and (2) treatment. Aspects related to differential diagnosis and therapeutic alternatives are discussed.

Diagnosis and management of neurocysticercosis

Long endemic in developing countries, cysticercosis is surfacing in the United States. Diagnosis of CNS involvement has been aided by laboratory and radiologic advances. Anthelmintic agents add to treatment options.

Neurocysticercosis--a review of 231 cases

Two hundred thirty-one cases of neurocysticercosis are reviewed. Diagnosis was established by cerebral computed tomography during a seven-year period (1983-1989). One hundred and fourty-four (62%) presented with symptom-related disease (symptomatic neurocysticercosis and in 87 the diagnosis was incidental (asymptomatic neurocysticercosis). In symptomatic neurocysticercosis the parasitosis was considered inactive in 115 cases and active in 29. Seizures occurred in 135 patients (96% of the symptomatic neurocysticercosis). In the active form we also found: meningitis (n = 15), intracranial hypertension (n = 12), hydrocephalus (n = 10) and arteritis (n = 2). Treatment included praziquantel (n = 21), albendazole (n = 4), dexamethasone (n = 18) and surgery (n = 10).

Etiology and management of single small CT lesions in patients with seizures: understanding a controversy

Single, small (less than 1 cm) enhancing lesions are frequent findings on CT scans of Indian patients with seizures. These lesions have also been reported in patients from other parts of the world. They often resolve spontaneously and their etiology has been disputed for over a decade. Initially diagnosed in Indian patients as tuberculomas, a number of other etiologies have been suggested. More recently, based on biopsy data, we have shown that a majority of these lesions are caused by cysticercosis. This review traces the development of the controversy and reports the current understanding of their etiology. A logical approach to their management is also discussed.