Infectious Diseases
AIDS
Although not a neurological disease per se, AIDS is included here because of its wide-ranging relevance to neurological practice and the multiple infections that can be associated with nervous system manifestations (Tables 1–3).
From: Current Clinical Neurology: Diagnostic Criteria in Neurology Edited by: A. J. Lerner © Humana Press Inc., Totowa, NJ
147
Table 1
Case Definition of AIDS-Defining Illnesses
The AIDS case definition includes a confirmed diagnosis of HIV-1 infection and one or more of the following AIDS-defining illnesses, diagnosed presumptively or definitively according to the criteria listed below:
Candidiasis of the bronchi, trachea, or lungs
Gross inspection by endoscopy or at autopsy or by microscopy (histology or cytology) on a specimen obtained directly from the tissues affected (including scrapings from the mucosal surface) not from a culture.
Candidiasis, esophageal Definitive diagnosis:
Same as is for candidiasis of the bronchi, trachea, or lungs.
Presumptive diagnosis:
Recent onset of retrosternal pain on swallowing and oral candidiasis diagnosed by the gross appearance of white patches or plaques on an erythematous base or by the microscopic appearance of fungal mycelial filaments in an uncultured specimen scraped from the oral mucosa.
Cervical cancer, invasive Histological evidence of cancer.
Coccidiomycosis, disseminated or extrapulmonary
Microscopy (histology or cytology), culture, or detection of antigen in a specimen obtained directly from the affected tissues or a fluid from those tissues.
Cryptococcosis, extrapulmonary
Microscopy (histology or cytology), culture, or detection of antigen in a specimen obtained directly from the affected tissues or a fluid from those tissues.
Cryptosporidiosis, more than 1 month’s duration
Microscopy (histology or cytology), culture, or detection of antigen in a specimen obtained directly from the affected tissues or a fluid from those tissues.
Cytomegalovirus disease, other than liver, spleen, or nodes
Microscopy (histology or cytology), culture, or detection of antigen in a specimen obtained directly from the affected tissues or a fluid from those tissues.
Cytomegalovirus retinitis with loss of vision Definitive diagnosis:
As for cytomegalovirus disease, other than liver, spleen, or lymph nodes.
(Continued)
Table 1 (Continued) Presumptive diagnosis:
A characteristic appearance on serial ophthalmoscopic examinations, for example discrete patches of retinal whitening with distinct borders, spreading in a centrifugal manner along the paths of blood vessels, progressing over several months, and frequently associated with retinal vasculitis, hemorrhage, and necrosis.
Resolution of active disease leaves retinal scarring and atrophy with retinal pigment epithelial mottling.
Encephalopathy, HIV-related
Clinical findings of disabling cognitive or motor dysfunction interfering with occupation or activities of daily living, progressing over weeks to months, in the absence of a concurrent illness or condition other than HIV infection that could explain the findings. Methods to rule out such concurrent illness and conditions must include cerebrospinal fluid examination and either brain imaging (computed tomography or magnetic resonance) or autopsy.
Herpes simplex: chronic ulcer(s) of more than 1 month’s duration, bronchitis, pneumonitis, or esophagitis Microscopy (histology or cytology), culture, or detection of antigen in a specimen obtained directly from the affected tissues or a fluid from those tissues.
Histoplasmosis, disseminated or extrapulmonary
Microscopy (histology or cytology), culture, or detection of antigen in a specimen obtained directly from the affected tissues or a fluid from those tissues.
Isosporiasis, chronic intestinal, of more than 1 month’s duration
Microscopy (histology or cytology), culture, or detection of antigen in a specimen obtained directly from the affected tissues or a fluid from those tissues.
Kaposi’s sarcoma Definitive diagnosis:
Microscopy (histology or cytology).
Presumptive diagnosis:
A characteristic gross appearance of an erythematous or violaceous plaque-like lesion on skin or mucous membrane.
aLymphoma, Burkitt’s
Microscopy (histology or cytology).
Lymphoma, immunoblastic Microscopy (histology or cytology).
Lymphoma, primary, of brain Microscopy (histology or cytology).
Mycobacterium tuberculosis, any site, pulmonary or extrapulmonary Definitive diagnosis:
Isolation of M. tuberculosis, Mycobacterium bovis, or Mycobacterium africanum from a clinical specimen Presumptive diagnosis:
Demonstration of acid-fast bacilli in a clinical specimen or, when a culture is not available, in a
histopathological lesion in a person with signs or symptoms compatible with tuberculosis, or evidence of resolution of disease where treatment with two or more antituberculosis medications have been prescribed and follow-up has been instigated.
Mycobacterial disease (other or unidentified species), disseminated or extrapulmonary Definitive diagnosis:
Culture.
Presumptive diagnosis:
Microscopy of a specimen from stool or normally sterile body fluids, or tissue from a site other than lungs, skin, or cervical or hilar lymph nodes that shows acid-fast bacilli of a species not identified by culture.
Pneumocystis carinii pneumonia Definitive diagnosis:
Microscopy (histology or culture).
Presumptive diagnosis:
• A history of dyspnea on exertion or nonproductive cough of recent onset (within the past 3 months); and
• Chest X-ray evidence of diffuse bilateral interstitial infiltrates or evidence by gallium scan of diffuse bilateral pulmonary disease; and
• Arterial blood gas analysis showing arterial pO
2less than 70 mmHg, or low respiratory diffusing capacity (less than 80% of predicted values), or an increase in the alveolar–arterial oxygen tension gradient; and
• No evidence of bacterial pneumonia.
(Continued)
Table 1 (Continued)
Pneumonia, recurrent bacterial Definitive diagnosis:
Two or more episodes of acute pneumonia occurring within 12 months. Both episodes must have infection with a pathogen that typically causes pneumonia (other than P. carinii or M. tuberculosis) proven by culture or some other organism-specific diagnostic method and new (not present earlier) radiological evidence of pneumonia.
Presumptive diagnosis:
Two or more episodes occurring within 12 months of acute pneumonia (new symptoms, signs or X-ray evidence not present earlier), based on clinical or radiologic evidence.
Progressive multifocal leukoencephalopathy (see Table 4) Microscopy (histology or cytology).
Salmonella septicemia, recurrent
Culture-proven infection with Salmonella species.
Toxoplasmosis Definitive diagnosis:
Microscopy (histology or cytology).
Presumptive diagnosis:
Toxoplasmosis of the brain, based on observation of:
• Recent onset of a focal neurological abnormality consistent with intracranial disease or a reduced level of consciousness; and
• Evidence by brain imaging (computed tomography or magnetic resonance imaging) of a lesion having a mass effect or the radiographic appearance of which is enhanced by injection of contrast medium; and
• Serum antibody to Toxoplasma or successful response to therapy for toxoplasmosis.
Wasting syndrome because of HIV infection
• Profound involuntary weight loss of more than 10% of baseline body weight; and
• Chronic diarrhea (at least two loose stools per day for 30 days) or chronic weakness and documented fever (for at least 30 days, intermittent or constant) in the absence of a concurrent illness or condition other than HIV infection, such as tuberculosis, cancer, cryptosporidiosis, or other specific enteritis, that could explain the findings.
Bacterial infection affecting a child less than 13 years of age
Laboratory diagnosis of multiple or recurrent bacterial infections (any combination of at least two within 2 years) of the following types: septicemia, pneumonia, meningitis, bone or joint infection, abscess of an internal organ or body cavity (excluding otitis media or superficial skin or mucosal abscesses) caused by Haemophilus spp., Streptococcus pneumoniae or other pyogenic bacteria.
Lymphoid interstitial pneumonia and/or pulmonary lymphoid hyperplasia affecting a child younger than 13 years of age
Definitive diagnosis:
Microscopy (histology or cytology).
Presumptive diagnosis:
Lymphoid interstitial pneumonia—bilateral, reticulonodular, interstitial pulmonary infiltrates present on chest X-ray for 2 months or more, with no pathogen identified and no response to antibiotic treatment. Other causes of interstitial infiltrates should be excluded, such as tuberculosis, P. carinii pneumonia, cytomegalovirus infection, and other viral or parasitic infections.
a
A presumptive diagnosis of Kaposi’s sarcoma should not be made by clinicians who have only seen few cases.
(Adapted from AIDS and HIV surveillance case definition. MMWR 1999;48[RR13]:29–31.)
HIV-1-Associated Progressive Multifocal Leukoencephalopathy
Progressive multifocal leukoencephalopathy is caused by the JC virus, which is found widely. It
occurs as a clinical infection in immunosuppressed individuals, for whom it is a recrudescent infec-
tion. The majority of cases of progressive multifocal leukoencephalopathy are now seen in patients
with AIDS, where it may be the presenting opportunistic infection; it affects up to 5% of patients with
AIDS. Giesen et al. proposed the criteria found in Table 4, but these diagnostic criteria have not been
widely tested, and are based on an empirical series.
Table 2
US Centers for Disease Control 1993 Classification System
for HIV Infection and Expanded AIDS Surveillance Cases Definition for Adolescents and Adults
CD4
+T-cell count
Clinical category >500 μL 200–499 μL <200 μL
(A) Asymptomatic, primary HIV, PGL A1 A2 A3
(B) Symptomatic, not (A) or (C) B1 B2 B3
(C) AIDS-defining conditions C1 C2 C3
PGL, persistent generalized lymphadenopathy.
(Adapted from AIDS and HIV surveillance case definition. MMWR 1999;48[RR13]:29–31.) Table 3
Revised Surveillance Case Definition for HIV Infection
This revised definition of HIV infection, which applies to any HIV (e.g., HIV-1 or HIV-2), is intended for public health surveillance only. It incorporates the reporting criteria for HIV infection and AIDS into a single case definition. The revised criteria for HIV infection update the definition of HIV infection implemented in 1993; the revised HIV criteria apply to AIDS-defining conditions for adults and children, which require laboratory evidence of HIV. This definition is not presented as a guide to clinical diagnosis or for other uses.
I. In adults, adolescents, or children aged greater than or equal to 18 months,
aa reportable case of HIV infection must meet at least one of the following criteria:
Laboratory criteria:
• Positive result on a screening test for HIV antibody (e.g., repeatedly reactive enzyme immunoassay), followed by a positive result on a confirmatory (sensitive and more specific) test for HIV antibody (e.g., Western blot or immunofluorescence antibody test); or
• Positive result or report of a detectable quantity on any of the following HIV virological (nonantibody) tests:
o HIV nucleic acid (DNA or RNA) detection (e.g., DNA polymerase chain reaction [PCR] or plasma HIV-1 RNA).
bo HIV p24 antigen test, including neutralization assay.
o HIV isolation (viral culture).
or
Clinical or other criteria (if the above laboratory criteria are not met):
• Diagnosis of HIV infection, based on the laboratory criteria above, that is documented in a medical record by a physician; or
• Conditions that meet criteria included in the case definition for AIDS.
II. In a child aged less than 18 months, a reportable case of HIV infection must meet at least one of the following criteria:
Laboratory criteria:
Definitive:
• Positive results on two separate specimens (excluding cord blood) using one or more of the following HIV virological (nonantibody) tests:
o HIV nucleic acid (DNA or RNA) detection.
o HIV p24 antigen test, including neutralization assay, in a child greater than or equal to 1 month of age.
o HIV isolation (viral culture).
or
Presumptive:
A child who does not meet the criteria for definitive HIV infection but who has:
• Positive results on only one specimen (excluding cord blood) using the above HIV virological tests and no subsequent negative HIV virological or negative HIV antibody tests
or
Clinical or other criteria (if the above definitive or presumptive laboratory criteria are not met):
• Diagnosis of HIV infection, based on the laboratory criteria above, that is documented in a medical record by a physician; or
• Conditions that meet criteria included in the 1987 pediatric surveillance case definition for AIDS.
Table 3 (Continued)
III. A child aged less than 18 months born to an HIV-infected mother will be categorized for surveillance purposes as “not infected with HIV” if the child does not meet the criteria for HIV infection but meets the following criteria:
Laboratory criteria:
Definitive:
• At least two negative HIV antibody tests from separate specimens obtained at age 6 months or older; or
• At least two negative HIV antibody tests from separate specimens obtained at age 6 months or older; or
• At least two negative HIV virological tests
afrom separate specimens, both of which were performed at greater than or equal to 1 month of age and one of which was performed at age 4 months or older
and
• No other laboratory or clinical evidence of HIV infection (i.e., has not had any positive virological tests, if performed, and has not had an AIDS-defining condition).
or
Presumptive:
A child who does not meet the above criteria for definitive “not infected” status but who has:
• One negative enzyme immunoassay HIV antibody test performed at age 6 months or older and NO positive HIV virological tests, if performed; or
• One negative HIV virological test
aperformed at age 4 months or older and NO positive HIV virological tests, if performed; or
• One positive HIV virological test with at least two subsequent negative virological tests,
cat least one of which is at age 4 months or older; or negative HIV antibody test results, at least one of which is at age 6 months or older
and
• No other laboratory or clinical evidence of HIV infection (i.e., has not had any positive virological tests, if performed, and has not had an AIDS-defining condition)
or
Clinical or other criteria (if the above definitive or presumptive laboratory criteria are not met):
• Determined by a physician to be “not infected,” and a physician has noted the results of the preceding HIV diagnostic tests in the medical record
and
• NO other laboratory or clinical evidence of HIV infection (i.e., has not had any positive virological tests, if performed, and has not had an AIDS-defining condition).
IV. A child aged less than 18 months born to an HIV-infected mother will be categorized as having perinatal exposure to HIV infection if the child does not meet the criteria for HIV infection (II) or the criteria for
“not infected with HIV” (III).
Draft revised surveillance criteria for HIV infection were approved and recommended by the membership of the Council of State and Territorial Epidemiologists (CSTE) at the 1998 annual meeting. Draft versions of these criteria were previously reviewed by state HIV/AIDS surveillance staffs, Centers for Desease Control, CSTE, and laboratory experts.
In addition, the pediatric criteria were reviewed by an expert panel of consultants.
a
Children aged 18 months or older but younger than 13 years are categorized as “not infected with HIV” if they meet the criteria in III.
b
In adults, adolescents, and children infected by other than perinatal exposure, plasma viral RNA nucleic acid tests should NOT be used in lieu of licensed HIV screening tests (e.g., repeatedly reactive enzyme immunoassay).
In addition, a negative (i.e., undetectable) plasma HIV-1 RNA test result does not rule out the diagnosis of HIV infection.
c
HIV nucleic acid (DNA or RNA) detection tests are the virological methods of choice to exclude infection in children aged younger than 18 months. Although HIV culture can be used for this purpose, it is more com- plex and expensive to perform and is less well standardized than nucleic acid detection tests. The use of p24 anti- gen testing to exclude infection in children aged less than 18 months is not recommended because of its lack of sensitivity.
(Adapted from AIDS and HIV surveillance case definition. MMWR 1999;48[RR13]:29–31. Available from the web-
site of the Centers for Disease Control: http://www.cdc.gov/mmwr/preview/mmwrhtml/rr4813a2.htm.)
ARBOVIRAL ENCEPHALITIS OR MENINGITIS
Table 4
Features Suggestive of Diagnosis of HIV-1-Associated Progressive Multifocal Leukoencephalopathy
A. Rapid onset of neurological symptoms in HIV-1 infection.
B. Male gender.
C. Multifocal clinical deficits.
D. Magnetic resonance imaging findings of white matter.
1. Multifocal, asymmetric.
2. No mass effect.
3. No contrast enhancement.
4. No concomitant brain atrophy.
5. Location near white/grey junction.
E. Cerebrospinal fluid JC virus-positive by polymerase chain reaction.
F. Normal cerebrospinal fluid.
Cases fitting this clinical profile would meet diagnostic criteria for progressive multifocal leukoencephalopathy.
If more than one of five criteria are missing, a stereotactic brain biopsy is suggested.
(Adapted with permission from Giesen HJ, Neuen-Jacob E, Dorries K, Jablonowski H, Roick H, Arendt G.
Diagnsotic criteria and clinical procedures in HIV-1-associated progressive multifocal leukoencephalopathy. J Neurol Sci 1997;147:63–72, and from Elsevier.)
Table 5
2001 Case Definition of Arboviral Infection From the Center for Disease Control (Includes California Serogroup, Eastern Equine, St. Louis, Western Equine, West Nile, Powassan Encephalitides/Meningitides)
Clinical description
Arboviral infections may be asymptomatic or may result in illnesses of variable severity sometimes associated with central nervous system (CNS) involvement. When the CNS is affected, clinical syndromes ranging from febrile headache to aseptic meningitis to encephalitis may occur, and these are usually indistinguishable from similar syndromes caused by other viruses. Arboviral meningitis is characterized by fever, headache, stiff neck, and pleocytosis. Arboviral encephalitis is characterized by fever, headache, and altered mental status ranging from confusion to coma with or without additional signs of brain dysfunction (e.g., paresis or paralysis, cranial nerve palsies, sensory deficits, abnormal reflexes, generalized convulsions, and abnormal movements).
Laboratory criteria for diagnosis
• Fourfold or greater change in virus-specific serum antibody titer, or
• Isolation of virus from or demonstration of specific viral antigen or genomic sequences in tissue, blood, cerebrospinal fluid (CSF), or other body fluid, or
• Virus-specific immunoglobulin (Ig)M antibodies demonstrated in CSF by antibody-capture enzyme immunoassay (EIA), or
• Virus-specific IgM antibodies demonstrated in serum by antibody-capture EIA and confirmed by demonstration of virus-specific serum IgG antibodies in the same or a later specimen by another serological assay (e.g., neutralization or hemagglutination inhibition).
Case classification
Probable: an encephalitis or meningitis case occurring during a period when arboviral transmission is likely, and with the following supportive serology: a single or stable (less than or equal to twofold change) but elevated titer of virus-specific serum antibodies, or serum IgM antibodies detected by antibody-capture EIA but with no available results of a confirmatory test for virus-specific serum IgG antibodies in the same or a later specimen.
Confirmed: an encephalitis or meningitis case that is laboratory confirmed.
Comment: Because closely related arboviruses exhibit serological crossreactivity, positive results of serological tests using antigens from a single arbovirus can be misleading. In some circumstances (e.g., in areas where two or more closely related arboviruses occur, or in imported arboviral disease cases), it may be epidemiologically important to attempt to pinpoint the infecting virus by conducting cross-neutralization tests using an appropriate battery of closely related viruses. This is essential, for example, in determining that
(Continued)
INFECTIVE ENDOCARDITIS
Infective endocarditis has numerous neurological manifestations including stroke, mycotic aneurysms, meningoencephalitis, and septic encephalopathy.
The diagnosis of infective endocarditis has changed since the original van Reyn diagnostic cri- teria were published in 1981. The major clinical criteria are the so-called Duke criteria shown in the Table 6. Modifications to these criteria have been proposed, which include use of molecular markers, positive blood cultures for suspect organisms, and identification of the organism in a metastatic lesion(s).
Table 5 (Continued)
antibodies detected against St. Louis encephalitis virus are not the result of an infection with West Nile (or dengue) virus, or vice versa, in areas where both of these viruses occur.
The seasonality of arboviral transmission is variable and depends on the geographic location of exposure, the specific cycles of viral transmission, and local climatic conditions. Reporting should be etiology- specific (see below; the six encephalitides/meningitides printed in boldface are nationally reportable to CDC):
St. Louis encephalitis/meningitis West Nile encephalitis/meningitis Powassan encephalitis/meningitis Eastern equine encephalitis/meningitis Western equine encephalitis/meningitis
California serogroup viral encephalitis/meningitis (includes infections with the following viruses: La Crosse, Jamestown Canyon, snowshoe hare, trivittatus, Keystone, and California encephalitis viruses).
Other viral CNS infections transmitted by mosquitoes, ticks, or midges (e.g., Venezuelan equine encephalitis/meningitis and Cache Valley encephalitis/meningitis).
Adapted from the website of the Centers for Disease Control. Available at http://www.cdc.gov/epo/dphsi/casedef/
encephalitiscurrent.htm.
Table 6
Duke Criteria for Infective Endocarditis Pathological criteria
Microorganisms demonstrated by culture or histological examination Active endocarditis demonstrated by histological examination Major criteria
Positive blood cultures
• Typical micro-organisms consistent with endocarditis from two separate blood cultures.
• Micro-organisms consistent with endocarditis from persistently positive blood cultures.
Evidence of endocardial involvement
• Echocardiography: oscillating structures, abscess formation, new partial dehiscence of prosthetic valve.
• New valvular regurgitation.
Minor criteria
• Predisposing heart disease.
• Fever higher than 38°C.
• Vascular phenomena.
• Immunological phenomena.
• Microbiological evidence (no major criterion).
• Suspect echocardiography (no major criterion).
Reprinted with permission from Prendergast BD. Diagnostic criteria and problems in infective endocarditis. Heart
2004;90:611–613.
LYME DISEASE (INFECTION BECAUSE OF BORRELIA BURGDORFERI) I
Table 7
Categories of Infective Endocarditis by Duke Criteria Definite: Pathological criteria positive
or two major criteria positive
or one major and two minor criteria positive or five minor criteria positive
Possible: All cases that cannot be classified as definite or rejected Rejected: Alternative diagnosis
Resolution of the infection with antibiotic treatment in less than 4 days No histological evidence
Reprinted with permission from Prendergast BD. Diagnostic criteria and problems in infective endocarditis. Heart 2004;90:611–613, and from BMJ Publishing Group.
Table 8
1996 Case Definition for Lyme Disease From the Centers for Disease Control Clinical description
A systemic, tick-borne disease with protean manifestations, including dermatological, rheumatological, neurological, and cardiac abnormalities. The best clinical marker for the disease is the initial skin lesion (i.e., erythema migrans [EM]) that occurs in 60–80% of patients.
Laboratory criteria for diagnosis
• Isolation of Borrelia burgdorferi from a clinical specimen, or
• Demonstration of diagnostic immunoglobulin M or immunoglobulin G antibodies to B. burgdorferi in serum or cerebrospinal fluid (CSF). A two-test approach using a sensitive enzyme immunoassay or immunofluorescence antibody followed by Western blot is recommended.
Case classification
Confirmed: a case with EM or a case with at least one late manifestation (as defined below) that is laboratory- confirmed.
Comment: This surveillance case definition was developed for national reporting of Lyme disease; it is not intended to be used in clinical diagnosis.
Definition of terms used in the clinical description and case definition:
• EM. For purposes of surveillance, EM is defined as a skin lesion that typically begins as a red macule or papule and expands over a period of days to weeks to form a large round lesion, often with partial central clearing. A single primary lesion must reach greater than or equal to 5 cm in size.
Secondary lesions also may occur. Annular erythematous lesions occurring within several hours of a tick bite represent hypersensitivity reactions and do not qualify as EM. For most patients, the expanding EM lesion is accompanied by other acute symptoms, particularly fatigue, fever, headache, mildly stiff neck, arthralgia, or myalgia. These symptoms are typically intermittent. The diagnosis of EM must be made by a physician. Laboratory confirmation is recommended for persons with no known exposure.
• Late manifestations. Late manifestations include any of the following when an alternate explanation is not found:
1. Musculoskeletal system. Recurrent, brief attacks (weeks or months) of objective joint swelling in one or a few joints, sometimes followed by chronic arthritis in one or a few joints. Manifestations not considered as criteria for diagnosis include chronic progressive arthritis not preceded by brief attacks and chronic symmetric polyarthritis. Additionally, arthralgia, myalgia, or fibromyalgia syndromes alone are not criteria for musculoskeletal involvement.
2. Nervous system. Any of the following, alone or in combination: lymphocytic meningitis; cranial neuritis, particularly facial palsy (may be bilateral); radiculoneuropathy; or, rarely,
encephalomyelitis. Encephalomyelitis must be confirmed by demonstration of antibody production against B. burgdorferi in the CSF, evidenced by a higher titer of antibody in CSF than in serum.
Headache, fatigue, paresthesia, and mildly stiff neck alone are not criteria for neurological
involvement.
Table 8 (Continued)
3. Cardiovascular system. Acute onset of high-grade (second- or third-degree) atrioventricular conduction defects that resolve in days to weeks and are sometimes associated with myocarditis.
Palpitations, bradycardia, bundle branch block, or myocarditis alone are not criteria for cardiovascular involvement.
• Exposure. Exposure is defined as having been (less than or equal to 30 days before onset of EM) in wooded, brushy, or grassy areas (i.e., potential tick habitats) in a county in which Lyme disease is endemic.
A history of tick bite is not required.
• Disease endemic to county. A county in which Lyme disease is endemic is one in which at least two confirmed cases have been previously acquired or in which established populations of a known tick vector are infected with B. burgdorferi.
Adapted from the website of the Centers for Disease Control. Available at http://www.cdc.gov/epo/dphsi/print/
lyme_disease_current.htm.
Table 9
Diagnostic Criteria for Neurocysticercosis
Categories of criteria Criteria
Absolute 1. Histological demonstration of the parasite from biopsy of a brain or spinal cord lesion.
2. Cystic lesions showing the scolex on CT or MRI.
3. Direct visualization of subretinal parasites by funduscopic examination.
Major 1. Lesions highly suggestive of neurocysticercosis on neuroimaging studies.
a2. Positive serum EITB
bfor the detection of anticysticercal antibodies.
3. Resolution of intracranial cystic lesions after therapy with albendazole or praziquantel.
4. Spontaneous resolution of small single enhancing lesions.
cMinor 1. Lesions compatible with neurocysticercosis on neuroimaging studies.
d2. Clinical manifestations suggestive of neurocysticercosis.
e3. Positive CSF ELISA for detection of anticysticercal antibodies or cysticercal antigens.
4. Cysticercosis outside the CNS.
fEpidemiologic 1. Evidence of a household contact with Taenia solium infection.
2. Individuals coming from or living in an area where cysticercosis is endemic.
3. History of frequent travel to disease endemic areas.
a
CT or MRI showing cystic lesions without scolex, enhancing lesions, or typical parenchymal brain calcifications.
b
EITB assay using purified extracts of Taenia solium antigens, as developed by the Centers for Disease Control and Prevention (Atlanta, GA).
c
Solitary ring-enhancing lesions measuring less than 20 mm in diameter in patients presenting with seizures, a nor- mal neurological examination, and no evidence of an active systemic disease.
d
CT or MRI showing hydrocephalus or abnormal enhancement of the leptomeninges, and myelograms showing mul- tiple filling defects in the column of contrast medium.
e
Seizures, focal neurological signs, intracranial hypertension, and dementia.
f
Histologically confirmed subcutaneous or muscular cysticercosis, plain X-ray films showing “cigar-shaped” soft-tissue
ff
