NEUROLOGICAL DISORDERS DUE TO HIV
Figure 11.3 HIV encephalopathy (T2-weighted axial MRI) in young patient (20s). Bilateral hyperintensity involving the cerebral white matter in association with volume loss denoted by prominence of the cerebral sulci.
• Signs of a spastic paraparesis without a sensory level • Resembles subacute combined degeneration due to vitamin B12 deficiency • MRI usually normal • Check B12 level and, if low normal, methylmalonic acid levels. If low, treat with B12 as monthly intramuscular injection • Consider checking indicated HTLV-1 serology as co-infection may occur
Peripheral nerve syndromes Distal sensory peripheral neuropathy (DSPN) • Twenty-five percent of AIDS patients • Occurs late in AIDS • Symptoms of paresthesias, burning pain, dysesthesias • Signs: little or no weakness, reduced or absent ankle reflexes. Impaired sensation to pain and temperature (mainly a small-fiber neuropathy) • Neuropathy due to antiretroviral drugs (e.g., ddC, ddI, d4T) is very similar. • Other drugs that may also cause neuropathy include isoniazid, vincristine, thalidomide, and metronidazole.
303