The rise of AIDS in the 1980s and 1990s has led to
an increase in the number of diagnosed cases of neurosyphilis.
Late syphilis consists of ongoing inflammatory
disease most likely in the aorta or nervous system (neurosyphilis), the latter
occurring in about 10% of patients. The neurosyphilis of the late stage can
consist of 1) asymptomatic neurosyphilis, 2) meningovascular syphilis, and 3)
parenchymal neurosyphilis which has two forms. One form of parenchymal
neurosyphilis consists of general paresis, which occurs about 20 years after
infection and includes cognitive impairment, myoclonus, dys-arthria,
personality changes, irritability, psychosis, grandiosity and mania. Untreated
general paresis leaves the patient a helpless invalid. The second form of
parenchymal neurosyphilis is tabes dorsalis with onset 25 to 30 years
after initial infection. Tabes features
loss of position and vibratory sense, areflexia in lower extremities, chronic
pain, ataxia and incontinence.
The original screening test for syphilis is the
venereal dis-ease research laboratory (VDRL) test. This test has a significant
false-positive rate, especially in the elderly and in patients with addictions
and autoimmune disorders (Kaufman, 1990b). The VDRL test may revert to negative
after a number of years, and 20 to 30% of patients in the stage of late
syphilis have a negative (nonreactive) VDRL result. A more specific test is the
fluores-cent treponemal antibody screen, which is positive 95% of the time in
neurosyphilis. The false-positive rate for the fluorescent treponemal antibody
screen is extremely low, and reversion to a nonreactive state is unlikely. In
addition to a positive VDRL result, the CSF in patients with neurosyphilis
generally shows pleocytosis.
Dementia secondary to neurosyphilis produces
various physical findings in advanced cases. These may include dysar-thria,
Babinskiâ€™s reflex, tremor, Argyll Robertson pupils, myelitis and optic atrophy.
Although notorious, delusions of grandeur in neurosyphilis are rare. A reactive
CSF VDRL result or a positive serum fluorescent treponemal antibody result in a
patient with neurological symptoms who cannot document treatment should be treated
with appropriate therapy. Penicillin often improves cognitive deficits and
corrects CSF abnormalities, but complete recovery is rare.