Page 185 - AIDSBK23C

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Pott disease, or tuberculous osteitis, may complicate tuberculosis via hematogenous
dissemination or paraspinal extension in persons with AIDS. Back pain and fever are typical
findings. In comparison with pyogenic abscesses, paraspinal infection with Mycobacterium
tuberculosis is more likely to produce spinal deformity, subligamentous spread and contiguous
multilevel involvement.[790]

SYPHILIS.-- Persons with HIV infection have an increased incidence of neurosyphilis,
reflecting the common risk factor of sexual transmission for both. The disease may be
accelerated when immunosuppression worsens with the appearance of clinical AIDS. The risk
increases when the CD4 lymphocyte count decreases below 350/µL. Persons with a serologic
test for syphilis (RPR) that has a titer higher than 1:128 are at increased risk, compared to
persons with RPR titer no more than 1:32 at the time of diagnosis. Use of antiretroviral therapy
decreases the risk. Males are at greater risk. Clinical presentations include uveitis, altered
cognition, motor weakness, headache, gait abnormality, hearing loss, and Bell's palsy. However,
none of these individual findings is seen in more than a third of cases. Findings on lumbar
puncture with analysis of cerebrospinal fluid include increased leukocytes, increased protein, and
positive VDRL in about three fourths of cases.[791]
Neurosyphilis involvement is usually meningovascular and less commonly encephalitis.
Findings can include acute or chronic meningitis, cranial and peripheral neuropathies, evidence
for dementia, cerebrovascular disease, and myelopathy. Radiologic imaging may reveal
evidence for ischemic infarcts from vascular involvement, primarily in the regions supplied by
middle cerebral artery, or in brainstem or basal ganglia. Syphilitic gummas are uncommon and
may appear as isolated, peripherally located, isodense nodular on unenhanced CT that enhance
intensely with enhanced CT images, while they are isointense on T1 weighted and hyperintense
on T2 weighted MR images.[759] The CSF VDRL may be falsely negative in some cases. High
dose penicillin therapy may therefore be initiated based upon clinical suspicion. However,
serologic or clinical relapse may occur in one sixth of cases, more often in patients with a
positive CSF VDRL or rash of secondary syphilis. Some patients may have repeated relapses.
Relapses can occur over a year following initial therapy.[792,793]

MOVEMENT DISORDERS.-- HIV-associated illnesses can be complicated by
movement disorders. Tremors may be seen with HIV associated dementia (HIVD), with drug
therapies such as trimethoprim-sulfamethoxazole, and rarely with opportunistic infections.
Chorea may occur with lesions involving the subthalamic region, including those caused by HIV
encephalitis, HIVD, PML, and cryptococcosis. Dystonia may occur with toxoplasmosis
involving the basal ganglia, or with HIVD. Myoclonus can occur with HIVD and with
infections, including toxoplasmosis, spinal tuberculosis, herpes zoster radiculitis, and PML.
Parkinsonism, often atypical in presentation, can occur with HIVD as well as infections such as
toxoplasmosis, PML, and tuberculosis.[794]
Opsoclonus–myoclonus syndrome (OMS) has been reported with HIV infection prior to
start of antiretroviral therapy. OMS is characterized by continuous multi-directional chaotic eye
movements and myoclonus. Some patients also exhibit ataxia and there may be an associated
encephalopathy or behavioral disturbance. The etiology is unknown, but infectious, immune, or
paraneoplastic mechanisms have been suggested.[795]
A syndrome resembling amyotrophic lateral sclerosis (ALS) has been described in
patients with HIV infection. These cases occur in younger patients than is typical for classical