Patients are randomized to receive antiretroviral therapy alone (AZT plus ddI or ddC), antiretroviral therapy plus intravenous Ara-C, or antiretroviral therapy plus intrathecal Ara-C. All patients receive 24 weeks of antiretroviral therapy. Beginning at week 2, patients on the intravenous Ara-C arm receive daily infusions of Ara-C over 5 days, with cycles repeating every 21 days. Patients on the intrathecal Ara-C arm receive single administrations of Ara-C at weeks 2, 3, 4, 5, 6, 8, 10, 12, 16, 20, and 24. A brain biopsy confirmation or in situ hybridization will be required within 7 days after study entry. Patients are followed every 4 weeks.