AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

Neurocysticercosis (NCC) is infection of the human CNS with the pork tapeworm, Taenia solium. NCC has gained increased recognition in the last 2 decades because of the development of MRI and CT scanning, increased immigration of people to the developed world from areas in which the parasite is endemic, and the increasing availability of CT scanning and MRI in countries where infection is endemic.

The 2 separate clinical syndromes of infection with T solium include intestinal tapeworm infection and NCC. NCC is further divided into parenchymal and extraparenchymal disease. Parenchymal disease results from infection with cysticerci within the brain parenchyma. Extraparenchymal disease develops when cysticerci are found in the cerebrospinal fluid (CSF) of the ventricles, cisterns, and subarachnoid space or within the eyes or spinal cord.

Pathophysiology

When humans ingest undercooked pork containing cysticerci of T solium, the scolex evaginates from the cyst and develops into an intestinal tapeworm. The tapeworm reaches a length of up to 10 meters and has hundreds of proglottids. Mature proglottids contain approximately 50,000 eggs. Free eggs or whole proglottids are released periodically into the stool of the carrier. They can survive in the environment for many months.

When pigs ingest the proglottids or eggs, the eggs hatch, penetrate the pigs' intestinal wall, and spread to skeletal muscle, especially the neck, tongue, and trunk. There, the larvae mature into encysted cysticerci over 2-3 months. The cysticerci suppress the host inflammatory response and survive in tissues for months to years. The life cycle is completed when humans ingest inadequately cooked pork containing viable cysticerci.

Human NCC results when a person ingests food contaminated with T solium eggs. The cystic larval stage normally found in the pig develops in the human host and spreads to the skeletal muscle and brain. In this situation, the human is a dead-end intermediate host.

The cysticercus is able to survive in the human brain by disarming host defenses. It secretes prostaglandins and other compounds that inhibit complement activation and cytokine production, resulting in only minimal host inflammation around the viable cysticercus.

Over a period of years, the parasite may lose its ability to control the host defenses. Consequently, an inflammatory response leads to degeneration of the cysticercus. When this inflammatory response occurs in the CNS parenchyma, patients develop the seizures typical of parenchymal NCC. As the degeneration continues, the parasite becomes encased in a granuloma, which either resolves or leads to scarring and calcification. Rarely, patients with numerous parenchymal cysticerci may develop diffuse cerebral edema, termed cysticercal encephalitis.

Approximately 10-20% of patients with NCC present with extraparenchymal disease, often with concomitant parenchymal disease. Subarachnoid NCC may form in the gyri of the cerebral convexities or in the fissures of the brain, especially the sylvian fissures. These forms of NCC are associated with parenchymal inflammation and resemble parenchymal disease in manifestations and pathogenesis. In severe cases, cysticerci in the sylvian fissures may enlarge to several centimeters in diameter and cause mass effects. Cysticerci can form in the ventricles of the brain, where they can cause hydrocephalus by blocking the outflow of CSF. Obstructive hydrocephalus also may be caused by associated ependymitis. If cysticerci form in the basal cisterns, they can cause basilar arachnoiditis. Arachnoiditis may result in communicating hydrocephalus or vasculitis. Involvement of the arteries may lead to lacunar infarctions or, occasionally, large vessel strokes.

Cysticerci may be located in the spinal subarachnoid space and the spinal cord medulla. Medullary cysticerci may cause cord compression or other symptoms related to their location. Ocular cysticercosis is generally intravitreal or subretinal. Skeletal muscle cysticerci are common but usually cause only minor local symptoms unless they are present in overwhelming numbers. Subcutaneous cysticerci manifest as painless, palpable, cystic lesions. CNS parenchymal cysticerci may be present in patients with suspected extraparenchymal or extra-CNS disease.

Frequency

United States

Approximately 1000 cases are seen per year. Most occur among Latin American immigrants. Less frequently, infection occurs among immigrants from other areas, including Asia and Africa. A small number of cases occur among people born in the United States who have traveled to areas in which the infection is endemic. These travelers are often the children of immigrants. Locally acquired infection is rare and is associated with contact with a tapeworm carrier. All tapeworm carriers acquire infection from areas of endemic disease.

International

An estimated 50-100 million people are infected. Areas of endemic disease include Latin America, India, China, Southeast Asia, and sub-Saharan Africa. Studies from Latin America and India have noted adult-onset seizures in approximately 2% of the population, with as many as one half due to NCC. In Latin America, the seroprevalence rate ranges from 4.9-24%. In India, the estimated prevalence is similar. Rural China and Korea have lower infection rates.

Mortality/Morbidity

• NCC is estimated to cause as many as 50% of adult-onset seizure cases in developing countries in which the parasite is endemic.
• Although some patients die from status epilepticus in areas with poor access to medical care, mortality from parenchymal disease is rare. With modern medical and surgical care, mortality from extraparenchymal disease is also unusual.
• However, hydrocephalus is potentially life threatening without aggressive surgical management. Even with shunting procedures, subarachnoid cysticercosis is associated with a high 10-year fatality rate.

Race

Immigrants from countries in which the parasite is endemic are more likely to be infected. While these immigrants are predominantly Hispanic or, to a lesser degree, Asian, prevalence rates appear to be related more to exposure than to genetic predisposition.

Sex

Cysticercal encephalitis, a severe form of cysticercosis, is more common in females. No other sex predisposition has been noted.

Age

Patients are typically aged 10-40 years. However, cases have been described in every age group, from the newborn period to advanced age.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

Generally, patients present with a history of exposure to an area in which the parasite is endemic and an adolescent- or adult-onset seizure disorder. Symptoms of hydrocephalus should raise concerns about extraparenchymal disease.

• Parenchymal CNS disease
• • Seizures may be focal, focal with secondary generalization, or generalized.
  • Headaches are common and may be migrainelike or tension-type.
  • Neurocognitive deficits may include learning disabilities, depression, and, perhaps, psychosis.
• Extraparenchymal disease
• • Most patients present with headaches or symptoms of hydrocephalus.
  • Symptoms of increased intracranial pressure (ICP) may include headache, nausea or vomiting, altered mental status, dizziness, and decreased visual acuity due to papilledema.
  • Patients with numerous cysticerci in the basilar cisterns may present with communicating hydrocephalus, meningismus (without fever), symptoms of lacunar infarcts from small vessel vasculitis, or symptoms of large vessel infarcts from cysticercal erosion into major arteries or severe inflammation of those arteries.
  • Patients with spinal cysticerci typically present with radicular symptoms, but rarely with motor or sensory deficits traceable to a spinal level.
  • Patients with ocular cysticerci report visual changes.

Physical

Parenchymal and extraparenchymal disease both can cause elevated ICP. Signs include hyperreflexia, papilledema (a late sign), and the Cushing reflex (a preterminal event).

• Parenchymal disease
• • Physical examination findings are usually normal.
  • Patients who have had seizures may have typical manifestations of the postictal state, with somnolence, an altered level of consciousness, and poor memory.
  • Focal neurologic deficits are unusual and suggest alternative diagnoses, such as tuberculoma, tumor, or, rarely, extraparenchymal NCC.
• Extraparenchymal disease
• • Ocular cysticerci are visible upon ophthalmologic examination.
  • Rare spinal cysticerci manifest as sensory or motor deficits or back tenderness.
  • Patients with NCC of the cisterns may present with lacunar infarcts or large vessel infarction with associated upper motor neuron signs.
  • Subcutaneous cysts may be palpable as fluid-filled nodules that resemble sebaceous cysts.

Causes

• Infection of the CNS with T solium and associated host inflammation

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Other Problems to be Considered

Tuberculoma
CNS tumor
Idiopathic epilepsy
Scar from old disseminated tuberculosis
Scar from old disseminated histoplasmosis
Scar from other old granulomatous disease
Scar from old trauma

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Lab Studies

• Signs and symptoms are nonspecific. Furthermore, most patients do not present with definitive evidence of infection. Del Brutto and colleagues have proposed criteria for diagnosis, which were most recently modified in 2001.
• Absolute criteria include the following:
• • Histologic demonstration of the parasite from biopsy of a brain or spinal cord lesion
  • Direct visualization of subretinal parasites by funduscopic examination
  • Cystic lesions showing the scolex on CT scans or MRIs
• Major criteria include the following:
• • Lesions highly suggestive of NCC on neuroimaging studies (CT scan or MRI showing cystic lesions without scolex, enhancing lesions, or typical parenchymal brain calcifications)
  • Serum anticysticercal antibodies demonstrated by immunoblot assay
  • Resolution of intracranial cystic lesions after therapy with albendazole or praziquantel
  • Spontaneous resolution of small, single, enhancing lesions (single ring-enhancing lesions <20 mm in diameter in patients with seizures, normal neurological examination findings, and no evidence of active systemic disease)
• Minor criteria include the following:
• • Lesions compatible with NCC on neuroimaging studies
  • Clinical manifestations suggestive of NCC (eg, epilepsy, focal neurologic signs, intracranial hypertension, dementia)
  • Positive findings from CSF enzyme-linked immunosorbent assay for detection of anticysticercal antibodies or cysticercal antigens
  • Cysticercosis outside the CNS
• Epidemiologic criteria include the following:
• • Evidence of a household contact with T solium infection
  • Individuals coming from or living in an area where cysticercosis is endemic
  • Household contact with an individual infected with T solium
• The diagnostic categories that follow pertain to the criteria outlined in the model developed by Del Brutto et al.
• • Definite neurocysticercosis (1 of the following)
  • • One absolute criterion
    • Two major criteria plus 1 minor criterion and 1 epidemiologic criterion
  • Probable neurocysticercosis (1 of the following)
  • • One major criterion plus 2 minor criteria
    • One major criterion plus 1 minor criterion plus 1 epidemiologic criterion
    • Three minor criteria plus 1 epidemiologic criterion
• Findings from routine laboratory studies are not specific. The white blood cell count is not usually elevated, and most patients do not have eosinophilia.
• Serologic studies can be helpful in diagnosis.
• • Serum anticysticercal antibodies can be demonstrated by an enzyme-linked immunoblot transfer blot (EITB) assay. The assay is highly specific for exposure to T solium. Sensitivity is high with multiple lesions or extraparenchymal infection, but may be as low as 28% in patients with a single parenchymal lesion. EITB assay findings may revert to negative after the cysticercus dies and are often negative in patients with only calcified lesions.
  • Enzyme-linked immunosorbent assays that use unfractionated antigen are fraught with problems regarding sensitivity and specificity, and they are reliably diagnostic only when performed on CSF.
  • An assay using monoclonal antibody HP10 to detect parasite secretory/excretory antigens performed well in CSF samples, with results similar to those from the EITB assay.
• Stool examination for ova and parasites can occasionally identify patients with intestinal taenia.
• • Because eggs are shed intermittently, most tapeworm carriers cannot be detected with a single stool test.
  • Furthermore, egg morphology is the same for T solium and Taenia saginata.
  • Antigen detection tests for stool and serologic tests for tapeworms are being studied; none is available for use in clinical practice.
  • Identifying tapeworm carriers does not usually help in diagnosing NCC, but it may be useful in detecting the source of infection in cases among US residents who have not traveled.

Imaging Studies

• Neuroimaging with contrast-enhanced CT scanning or MRI is the mainstay of diagnosis.
• • MRI is better for detecting extraparenchymal disease and visualizing the scolex within the cysticercus.
  • CT scanning is better for detecting intracerebral calcifications.
  • Both modalities can detect hydrocephalus and active intraparenchymal lesions.
• With MRI or CT scanning, the following 4 stages of parenchymal disease can be differentiated:
• • The initial invasion appears as focal areas of edema or enhancement.
  • Viable cysts appear as 0.5- to 2-cm cystic lesions without associated edema. The image density of the cyst fluid is similar to that of CSF. The cyst wall is thin, isodense with brain parenchyma, and not visible.
  • Early degenerating cysts appear as cystic lesions with associated edema, and cysts that degenerate later lose their cystic fluid and appear similar to a granuloma, with associated edema.
  • The residual phase appears as calcified nodules that are 0.2-1 cm in diameter. No live cysticerci are present at this stage, although parasite antigen may still be present. This phase represents inactive disease.
• Extraparenchymal disease imaging may involve the following:
• • Ventricular, cisternal, and subarachnoid cysticerci have thin walls and may be isodense with CSF, so that hydrocephalus is the only visible abnormality on the CT scan.
  • The cyst wall is usually visible on an MRI.
  • Alternatively, cysts within the subarachnoid space may be better detected by using CT scanning with metrizamide contrast within the subarachnoid space or by using myelography.
  • Advanced MRI techniques such as fluid-attentuated inversion recovery have improved the diagnostic accuracy of ventricular and subarachnoid NCC by increasing the CSF signal after 100% oxygen administration.
  • Soft tissue radiographs may reveal typical cigar-shaped calcifications within the muscles, which correspond to scarring from prior muscular cysticerci. These are highly suggestive of exposure.

Other Tests

• EEGs are frequently obtained in seizure patients.
• • No pattern is diagnostic for NCC.
  • Focal abnormalities may be present in persons with active disease.
  • Seizures may also be caused by inactive disease (calcified nodules of the residual phase), but, in these cases, the EEG does not usually reveal focal abnormalities.

Procedures

• Lumbar puncture
• • Usually, this procedure is needed only to exclude other diagnoses.
  • CSF is often abnormal and may reveal mildly elevated protein levels and mildly depressed glucose levels. Findings are never diagnostic.
  • Pleocytosis with lymphocytic, neutrophilic, or eosinophilic predominance may be demonstrated, especially with subarachnoid infection.
• Biopsy
• • Biopsy specimens may be taken from subcutaneous nodules.
  • Biopsy of CNS lesions is rarely necessary.

Histologic Findings

Occasionally, CNS lesions are mistakenly identified as tumors and are diagnosed only at surgery. Upon gross examination, the cysticerci appear as 5- to 10-mm semiopaque cysts with a 1- to 2-mm mural nodule containing the scolex.

Histopathologic examination reveals a superficial tegument layer covered with microtriches, a cellular layer below that containing the cell nuclei and musculature, and a loose reticular layer characterized by canaliculi. When the parasites are viable, little surrounding inflammation is observed. Degenerating parasites, on the other hand, are invaded with an inflammatory infiltrate including lymphocytes, macrophages, plasma cells, neutrophils, and eosinophils.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical Care

• Symptomatic therapy is the mainstay of treatment.
• • Anticonvulsants are prescribed for patients with seizures.
  • CSF diversion is instituted for patients with obstructive hydrocephalus.
  • Corticosteroids are used for patients with cerebral edema or vasculitis.
• Parenchymal disease should be treated medically.
• • The primary focus is symptomatic therapy for seizures.
  • A postictal patient should initially receive supportive care that includes a safe environment.
  • Anticonvulsants should be administered early but may be tapered when seizures are controlled if findings from neuroimaging studies revert to normal (see Medication).
  • If significant intracranial edema is demonstrated, corticosteroids should be administered prior to considering antiparasitic therapy. Some authorities recommend routine use of corticosteroids in all cases of active NCC.
  • If viable cysticerci are suspected, antiparasitic drugs (ie, praziquantel and albendazole) may be used to hasten the death of the parasite. However, the decision to use antiparasitic therapy should be individualized to each patient.
  • A recent prospective randomized study compared the use of antiparasitic agents with placebo in patients with active parenchymal lesions. Results showed no significant difference in the number of subjects with recurrent seizures. However, the number of generalized seizures was significantly reduced with the combination of steroids and antiparasitic drugs. The beneficial effect was seen in a subgroup of subjects with numerous recurrent seizures.
  • Patients with only calcifications (ie, residual phase) with or without edema do not need antiparasitic therapy.
  • Patients with cerebral edema or uncontrolled hydrocephalus should not be treated with antiparasitic therapy until these conditions are resolved.
  • Patients with multiple cysticerci, especially in the basilar cisterns, or with giant cysticerci of the sylvian fissures, should receive both corticosteroids and antiparasitic therapy.
  • Generally, ventricular disease should be treated surgically, preferably using an endoscopic approach, but if the surgery is being performed only to place a shunt and not to remove the cysts, then antiparasitic therapy should be administered after the shunting procedure.

Surgical Care

• Extraparenchymal disease was traditionally treated surgically because most symptoms are due to hydrocephalus.
• Surgical resection of ventricular NCC is associated with a low long-term risk of postoperative morbidity.
• Some studies suggest that endoscopic removal may be able to replace open surgery for removal of cysticerci in most cases.
• Ventriculoperitoneal (VP) shunting is now commonly used for the treatment of hydrocephalus. Case series have shown that the cysticerci are usually ruptured during removal, but no adverse consequences have been noted.
• • If VP shunting only is used, the rate of shunt failure approaches 75%.
  • The rate of shunt failure can be reduced by the use of antiparasitic drugs and corticosteroids.
  • Recent descriptions of valveless shunts noted lower rates of recurrent hydrocephalus, but these shunts were associated with a higher rate of inadequate drainage.
• Patients with inactive disease may present with hydrocephalus due to scar tissue in the cisterns or ventricular space, without evidence of cystic lesions.
• • VP shunting is necessary in these cases.
  • Antiparasitic drugs and corticosteroids are not needed because the cysticerci have already degenerated and shunt failure is rare.
• NCC of the basilar cisterns should be treated with corticosteroids, prolonged courses (eg, months) of antiparasitic drugs, and VP shunting if hydrocephalus is present.
• Giant subarachnoid cysticerci can cause significant mass effect as associated edema. The edema may respond to steroids, but the mass effect may remain.
• • Surgical drainage may be necessary.
  • Antiparasitic drugs may be beneficial, but only after steroids are given.
• Generally, ocular and spinal medullary cysticerci should be removed surgically.
• • However, cures of spinal medullary disease have been reported with medical treatment including corticosteroids and antiparasitic drugs.
  • Antiparasitic treatment in patients with retinal cysticerci may cause irreversible retinal damage.
• Spinal subarachnoid disease can often be treated medically.

Consultations

• Consultation with a neurosurgeon is essential for patients with hydrocephalus, significant mass effect, or extraparenchymal CNS disease.
• Consultation with a neurologist is needed if protracted or refractory seizures occur.
• Consultation with an infectious disease specialist is recommended if active disease is suspected.
• Patients with ocular NCC should undergo consultation with an ophthalmologist. At a minimum, a funduscopic examination should be performed before the initiation of antiparasitic drug therapy.

Activity

• Seizure precautions should be ordered for all patients who present with seizures. Many states in the United States do not allow patients with seizure disorders to drive. Physicians may be responsible for informing patients about these restrictions.
• Patients with hydrocephalus can have ataxia and may be at risk for falls.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Anticonvulsant and anti-inflammatory (steroid) medications are the basis of medical therapy for symptomatic patients. Antiparasitic drugs have not been shown to have a consistent long-term benefit in patients with parenchymal disease and seizures.

Drug Category: Anticonvulsants

Should be used in patients with seizures. Patients with parenchymal calcifications carry a high risk of seizure recurrence if anticonvulsants are tapered; therefore, these patients usually remain on anticonvulsants indefinitely. In contrast, patients with active cysticerci in whom lesions resolve without developing calcification should be treated with anticonvulsants until they are free from seizures for at least 1 y and results of neuroimaging studies show normalization. Anticonvulsants may then be tapered. Phenytoin, carbamazepine, and phenobarbital induce metabolism of praziquantel.

Drug Category: Corticosteroids

Should be used acutely for patients with significant cerebral edema, mass effect, or vasculitis associated with NCC. High doses (approximately 1 mg/kg/d of prednisone) should be used. High-dose dexamethasone (30 mg/d) should be used initially to treat cysticercal encephalitis. If cerebral edema resolves, patients may be treated with antiparasitic drugs later. Long-term courses of corticosteroids should be used in patients with subarachnoid NCC with meningitis, stroke, or communicating hydrocephalus and should be tapered as soon as possible based on lumbar puncture and neuroimaging results. Long-term course of corticosteroids also may prevent shunt failure in patients with VP shunt and active disease. Patients with intramedullary spinal NCC should be treated with steroids until resolution of cord edema. Patients receiving long-term corticosteroids should be given calcium supplementation to help counterbalance osteoporotic effects of corticosteroids.

Drug Category: Antiparasitics

Praziquantel and albendazole are antiparasitic drugs used to treat NCC. Have been used for >20 y but data by which to judge their therapeutic role are still controversial. When praziquantel is administered with cimetidine to increase its bioavailability, praziquantel is probably as effective as albendazole in killing viable cysticerci.

Antiparasitic drugs are contraindicated in cysticercal encephalitis (characterized by diffuse cerebral edema), uncontrolled elevated ICP, ocular disease, and subarachnoid NCC in close proximity to blood vessels. In all of these cases, steroids should be administered early so that the inflammatory reaction is quelled. Antiparasitic drugs, which may cause release of more antigens and stimulate more inflammation, can then be considered on a case-by-case basis.

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Further Inpatient Care

• ICU monitoring is necessary for patients with uncontrolled seizures, elevated ICP, or severe extraparenchymal disease.
• If antiparasitic therapy is provided, patients should be hospitalized and monitored during the initial phase.
• • As cysticerci die, patients may experience worsening neurologic symptoms due to an increased inflammatory response.
  • Most symptoms associated with antiparasitic therapy develop within 3-5 days of beginning therapy.
  • Antiparasitic therapy may then be completed in an outpatient setting.

Further Outpatient Care

• In patients with seizures from NCC without calcification, perform imaging studies every 3-6 months. If calcification develops, lifelong anticonvulsant therapy is indicated, and further imaging studies can be performed as needed.
• If results of imaging studies show normalization and seizures are under control after 2 years of therapy, anticonvulsants may be tapered, and further imaging can be performed as needed.
• Patients with calcified lesions and a seizure disorder should be maintained on anticonvulsants indefinitely, and they should undergo imaging studies only as needed.
• Monitor anticonvulsant serum levels to prevent toxicity.

In/Out Patient Meds

• Discharge medications may include steroids, anticonvulsants, antiparasitics, and cimetidine.

Transfer

• Patients with extraparenchymal NCC should be treated at hospitals with active neurosurgical services because emergency procedures such as shunt placement or ventriculostomy may be required if patients develop worsening hydrocephalus.

Deterrence/Prevention

• Meat inspection has been effective at preventing transmission of tapeworms in developed countries but has been uniformly unsuccessful in developing countries.
• In areas of endemic cysticercosis, avoid undercooked pork to reduce the risk of intestinal infection.
• Be vigilant about avoiding potential fecal-oral transmission to reduce the risk of NCC while in endemic areas. Individuals traveling to such areas should be warned as follows:
• • Eat only fruits and vegetables that you have peeled yourself.
  • Thoroughly wash (with water from a clean source) all food prior to ingestion.
  • Wash hands carefully and often.
• Mass chemotherapy has been used to interrupt transmission in some areas of endemic infection, but disease usually returns within a few years.
• Vaccines for prevention of cysticercosis have proven effective for other Taenia species and are in development for T solium.

Complications

• Parenchymal disease causes seizures but few long-term complications. However, studies suggest that childhood infection may be associated with learning disabilities and cognitive dysfunction.
• Extraparenchymal disease may cause elevated ICP, resulting in herniation and death.
• Vasculitis associated with cisternal NCC may cause strokes, communicating hydrocephalus, and death.

Prognosis

• Most patients with parenchymal cysticercosis either remain asymptomatic or develop a self-limited seizure disorder.
• Among those who develop intracerebral calcifications, most have recurrent seizures unless treated with anticonvulsants. If treated with anticonvulsants, the seizures are generally easily controlled.
• Ventricular NCC usually requires shunting.
• • Neurosurgery may be complicated by focal neurologic damage.
  • Shunt revisions are often needed unless patients are treated with corticosteroids or antiparasitic drugs. However, even with treatment, some still require subsequent revision.
  • Prior to the use of corticosteroids and antiparasitic drugs, subarachnoid disease was associated with a 90% 10-year fatality rate, even with shunting. With current management, fatalities appear to be rare.
• Good evidence indicates that once infected, patients are immune to reinfection.

Patient Education

• Seizure patients and their families should know proper seizure first aid.
• Patients who have had seizures should know about possible driving restrictions, which, in the United States, vary from state to state.
• Patients who have received a VP shunt should be educated about the signs and symptoms of elevated ICP (possible shunt failure) and meningitis (secondary infection of indwelling hardware).
• Family members should be queried about symptoms suggestive of tapeworms, such as passing proglottids. They should be treated if symptoms are present.

MISCELLANEOUS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

• Failure to consider the diagnosis and perform appropriate testing (primarily neuroimaging studies)
• • The symptoms of NCC are nonspecific, but imaging studies usually confirm the diagnosis.
  • The key to diagnosis is careful evaluation of patients who are at risk.
  • Diagnostic testing for patients with seizures who have not undergone studies previously should include neuroimaging studies (either CT scanning or MRI).
  • If patients have suggestive lesions, obtaining further history of exposure, serologic analyses, or imaging studies that show soft tissue calcifications can confirm the diagnosis.
• Failure to promptly initiate therapy for elevated ICP
• • Elevated ICP in NCC is an emergency, just as it is with other illnesses.
  • Patients usually present with headaches, but the headaches may not be significantly different from those due to a wide range of other causes.
  • Patients with headaches who also have symptoms of hydrocephalus require more emergent evaluation. These symptoms include nausea and vomiting, dizziness, visual changes, or abnormal neurologic examination findings.
  • Obstructive hydrocephalus usually requires emergency surgery.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

• Del Brutto OH, Rajshekhar V, White AC, et al. Proposed diagnostic criteria for neurocysticercosis. Neurology. Jul 24 2001;57(2):177-83. [Medline].
• García HH, Pretell EJ, Gilman RH, et al. A trial of antiparasitic treatment to reduce the rate of seizures due to cerebral cysticercosis. N Engl J Med. Jan 15 2004;350(3):249-58. [Medline].
• García HH, Evans CA, Nash TE, et al. Current consensus guidelines for treatment of neurocysticercosis. Clin Microbiol Rev. Oct 2002;15(4):747-56. [Medline].
• Singh G, Prabhakar S, eds. Taenia Solium Cysticercosis: From Basic to Clinical Science. New York, NY: CABI Publishers; 2002.
• White AC Jr. Neurocysticercosis: updates on epidemiology, pathogenesis, diagnosis, and management. Annu Rev Med. 2000;51:187-206. [Medline].
• White AC Jr, Robinson P, Kuhn R. Taenia solium cysticercosis: host-parasite interactions and the immune response. Chem Immunol. 1997;66:209-30. [Medline].
• White AC Jr. Neurocysticercosis: a major cause of neurological disease worldwide. Clin Infect Dis. Feb 1997;24(2):101-13; quiz 114-5. [Medline].

Article Last Updated: Jan 14, 2005