Learning points today:
1. In patients with HIV and CD4 count <400, the most common CNS lesions are due to toxoplasmosis and primary CNS lymphoma.
2. In diagnosing toxoplasmosis in HIV patients with CNS lesions, toxo immunoglobulin levels are helpful in deciding whether or not to empirically treat. Many cases of toxo in HIV are due to reactivation of toxoplasmosis. Here is a nice chart from the CDC that describes how to interpret the IgM and IgG levels.
3. In developing countries, make sure to consider TB and neurocysticercosis for patients with HIV (CD4<200) and CNS lesion(s).