HIV-associated dementia

Abstract

The World Health Organization estimates that worldwide there are 40.3 million people infected with HIV (www.who.int/hiv/epi-update2005_en.pdf). Of these, only 2 million live in developed countries and have access to the cocktail of antiretroviral drugs referred to as highly active antiretroviral therapy (HAART). HIV-associated dementia (HAD) along with its less severe forms of minor and asymptomatic neurocognitive impairment is a major complication of HIV disease. Its occurrence in the developing world is the subject of an interesting article by Wong et al.1 in this issue of Neurology . HAD is primarily a feature of advanced HIV disease. HAART has reduced its incidence in half; it now affects approximately 10% of patients with advanced disease. Paradoxically, in developed countries, the prevalence of HAD has increased as an unintended consequence of the very positive effects of HAART on the lifespan of HIV-infected individuals.2 That HAD even occurs in the era of HAART may be due to late commencement or to interruption of HAART or because of insufficient penetration of some HAART regimens through the blood–brain barrier3,4 or other yet-to-be-defined reasons.5 Late or intermittent use of HAART in turn is related to the lack of recognition of cognitive impairment as well as to patient/physician concerns over the potential for HAART toxicity. The recent …