Adverse Events Associated with Childhood Vaccines Evidence Bearing on Causality (1994) / Chapter Skim
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3 Neurologic Disorders
3 Neurologic Disorders
Pages 34-58
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From page 34... ...
and is characterized by the rapid onset of flaccid motor weakness with depression of tendon reflexes and inflammatory demyelination of peripheral nerves. Both of these demyelinating complications were noted after the introduction of rabies vaccines grown in animal brain or spinal cord.
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In drawing analogies to human diseases, it should be noted that different inbred strains of animals show different susceptibilities, and although myelin basic protein is similar between species, the encephalitogenic region of myelin basic protein differs between different species (Martin et al., 19921. In Latin America, a rabies vaccine was prepared in unmyelinated neonatal mouse brains to avoid the use of central nervous system myelin.
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From page 36... ...
However, recent imaging studies with enhanced magnetic resonance imagers have defined a characteristic pattern of multiple enhancing white matter lesions in patients with ADEM, and in the future, magnetic resonance imaging findings may give better data on nonfatal, nonbiopsied cases of suspected postimmunization ADEM. Multiple Sclerosis The establishment of a relation between acute central and peripheral nervous system demyelinating disease and infections and vaccines has opened the question of a possible relation to chronic demyelinating disease, specifically, multiple sclerosis.
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From page 37... ...
Optic neuritis represents a lesion in the optic nerve behind the orbit but anterior to the optic chiasm. This cranial nerve is an extension of the central nervous system, and so when there is demyelinating disease, it represents central demyelination, not peripheral nerve demyelination.
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From page 38... ...
-positive individuals, spinal fluid cell counts may be as high as 100 to 200/mm3. The characteristic electrodiagnostic features are those of demyelination with variable degrees of admixed, presumably secondary, axonal degeneration.
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From page 39... ...
These criteria continue to be in general use and are reproduced in the box entitled Definition of Guillain-Barre Syndrome and Criteria for Diagnosis; recently proposed electrodiagnostic criteria are given in the box entitled Proposed Electrodiagnostic Criteria for Demyelination of Peripheral Nerve (Asbury and Cornblath, 19901. The features required for diagnosis include progressive motor weakness and areflexia.
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Features Strongly Supportive of the Diagnosis A Clinical features (ranked in order of importance)
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B Cerebrospinal fluid (CSF)
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From page 42... ...
In the swine flu incident of 1976-1977 (Langmuir et al., 1984;
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From page 43... ...
, the risk of developing GBS in the 6 weeks following vaccination was some six- to eightfold greater than that for those who were not vaccinated, even though the overall incidence was only about 1 per 100,000 vaccinees. What it was about the swine flu vaccine that led to GBS on rare occasions has never been discovered; nevertheless, the capacity of that particular vaccine to trigger excess cases of GBS is thoroughly documented.
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From page 44... ...
A small proportion, perhaps 15 percent, of Semple vaccinees who develop a neuroparalytic adverse event have characteristic GBS. Of interest, these patients develop high levels of antibody to myelin basic protein, a central myelin constituent in serum and cerebrospinal fluid (Hemachudha et al., 1987a, 19881.
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From page 45... ...
Pathology and Pathogenesis A characteristic pathologic feature of GBS is the presence of mononuclear cell infiltrates in peripheral nerves and roots in both a diffuse and a perivenular distribution (Arnason and Soliven, 1992; Asbury et al., 19691. Lesions are patchy and variable, and some patients may show almost no cellular inflammation (Honavar et al., 19911.
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From page 46... ...
Numerous anti-nerve antibodies that bind to various protein, glycoprotein, and glycolipid moieties have been described in patients with GBS, but none occur in more than a fraction of cases. Whereas the P2 myelin protein, which is specific for peripheral nerve, and selected peptide fragments of it are capable of inducing experimental allergic neuritis under appropriate conditions, the P2 myelin protein does not appear to play a role in GBS.
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From page 47... ...
This issue was also considered above in the section Antecedent Events. The data from the Monitoring System for Adverse Events Following Immunization show fewer cases of GBS per year, but such an analysis does not allow for the systematic underreporting that probably occurred.
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From page 48... ...
In general, when pleocytosis in cerebrospinal fluid is present, the term encephalitis is used, implying an inflammatory response within the brain. The term Encephalopathy is used when an illness clinically appears like an encephalitis but no inflammatory response is evident (Cherry et al., 19881.
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From page 49... ...
The Vaccine Injury Table defines the vaccines and adverse events that are covered under the National Vaccine Injury Compensation Program. Health care providers must report the occurrence of an adverse event listed in the table if it falls within the specified latencies from vaccination.
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Individuals who return to a normal necrologic state after the acute encephalopathy shall not be presumed to have suffered residual necrologic damage from the vaccine; any subsequent chronic encephalopathy shall not be presumed to be a sequela of the acute encephalopathy. Children with evidence of a chronic encephalopathy secondary to genetic, prenatal, or perinatal factors shall not be considered to have a condition set forth in the Vaccine Injury Table.
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From page 51... ...
The diagnosis is suggested by the clinical presentation and is strengthened by the detection of high titers of serum antibodies against measles virus and the presence of oligoclonal measles virus antibodies in the cerebrospinal fluid. The ultimate confirmation is based on the classical appearance of Cowdry type A inclusion bodies as well as the detection of measles antigen in the brain tissue obtained by biopsy or at autopsy.
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From page 52... ...
Measles virus was finally cultured from a patient's brain tissue by cocultivation of the brain cells with indicator cells (Horta-Barbosa et al., 1969; Payne et al., 1969) and by a deliberate fusion with indicator cells (Barbanti-Brodano et al., 19701.
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From page 53... ...
The earliest manifestations of infantile spasms are subtle and are easily missed, making it difficult to identify the precise age at onset. Recently, the National Vaccine Injury Compensation Program proposed clarification of its definition of residual seizure disorder as a seizure occurring within 72 hours of vaccination followed by two or more afebrile seizures over the next 12 months, with the seizures separated by at least 24 hours (U.S.
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From page 54... ...
. Brachial Neuritis Brachial neuritis, also known as brachial plexus neuropathy or, in the United Kingdom, as neuralgic amyotrophy, has been linked to vaccination or administration of antiserum since brachial neuritis was first described a half century ago.
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From page 55... ...
Baublis JV, Payne RE. Measles antigen and syncytium formation in brain cell cultures from subacute sclerosing panencephalitis (SSPE)
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Held JR, Adaros HL. Neurological disease in man following administration of suckling mouse brain antirabies vaccine.
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Epidemiologic studies of measles, measles vaccine, and subacute sclerosing panencephalitis. Pediatrics 1977;59:505-512.
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From page 58... ...
U.S. Public Health Service, National Vaccine Injury Compensation Program; Revision of the Vaccine Injury Table; Proposed Rule.
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