Background:  HAART has altered the natural history of pediatric HIV/AIDS, dramatically reducing mortality and the incidence of progressive encephalopathy. However, a significant minority of HIV-infected children still exhibits evidence of central nervous system (CNS) disease. The aim of this study is to determine the prevalence and evolution of CNS disease over time in HIV-infected children in the HAART era.

Methods:  This retrospective longitudinal study examined changes in the CNS and medical status of all active pediatric HIV patients in our clinic enrolled on treatment protocols. We compared the CNS disease classification, cognitive test scores, computed tomography brain scan abnormality ratings, and virologic and immunologic data from the most recent evaluation in which an IQ test was administered to an evaluation approximately 2 years prior. Each patient’s CNS status was classified according to specific criteria as either encephalopathic, CNS compromised, or not compromised based on data from cognitive testing, neuroimaging, and neurologic exams. Repeated measures ANOVA was used to examine change over time from the earlier (#1) to the most recent (#2) evaluation.

Results:  Of 79 patients, 66 (mean age 16 years, range 8.7 to 25), 86% with vertically acquired HIV infection, had an evaluation approximately 2 years prior (mean time between evaluations 2.2 years). Of the 66, 23 (35%) were classified as having CNS disease (17% encephalopathy, 18% CNS compromise). None of the 66 patients had a change in their CNS classification from evaluation 1 to 2. In addition, there was no significant change over time in the mean full scale IQ (95.9 to 95.6), verbal IQ (93.5 to 93.1), or performance IQ (99.3 to 99.1) of the total sample. Analysis of individual scores revealed a significant change in only 2 children in full scale IQ, 1 child in verbal IQ, and 6 children in performance IQ. Mean computed tomography brain scan abnormality ratings also were stable over time. No significant change was found between the 2 time points in mean log₁₀ plasma HIV RNA (3.1 to 2.9), absolute CD4 count (652 to 618), or CD4 percentage (28.2 to 28.0).

Conclusions:  Despite treatment with HAART, a substantial number of children and adolescents with HIV infection exhibit evidence of CNS disease. Over a 2-year period in the HAART era, this CNS disease appears relatively stable. New strategies need to be developed to prevent or reverse this major complication of pediatric HIV infection.