Armstrong – Table of Contents

note since it could lead to confusion with tetanus. Varying degrees of limb paralysis was
noted occasionally in some cases. The eye muscles were usually not involved. The
Babinski (up-going great toe sign) was usually positive indicating brain or spinal cord
involvement (upper motor nerve cell involvement). The cerebrospinal fluid usually
showed little or no change to chemical, microscopic or bacteriological studies, The
cerebrospinal fluid pressure might be slightly increased, and cell counts, predominantly
lymphocytes (white blood cells), as high as 200-300 per cubic millimeter had been
observed. Armstrong stated that these clinical features were non-specific and could occur
with many acute inflammatory and viral infections of the central nervous system. Death,
which might follow in 30 to 40 percent of the cases, usually occurred from the third to the
tenth day following onset of symptoms. Recovery, when it took place, was usually rapid
and complete; however, some intellectual impairment and localized limb weakness might
occur as residual manifestations in some cases.
Microscopic examination of the central nervous system in fatal cases disclosed
areas of loss of myelin (a fatty substance in the brain and within the sheath of nerve
fibers) around blood vessels (perivascular demyelinization) and inflammatory cellular
infiltration scattered throughout the white matter of the brain, usually including the spinal
cord as well. Armstrong described these findings as non-specific, similar to and
indistinguishable from the lesions encountered in the encephalitis that occurred after
smallpox, measles, chickenpox and mumps.
Armstrong described no distinguishing or predictive epidemiological features or
factors predisposing to this complication after vaccination. Some cases tended to occur in
rural or urban clusters, among some families, at various ages from several months to 22