HIV-Associated Neurocognitive Disorders: An Evolving Landscape

For decades, neurological complications have been recognized as a significant aspect of HIV infection. Even as our understanding of these complications has evolved alongside the epidemic and advancements in treatment, they remain a concern, particularly as people living with HIV (PLWH) age. Historically focused on AIDS dementia complex, current research highlights a broader spectrum of neurocognitive impairments, even in the era of effective antiretroviral therapy (ART).

From AIDS Dementia Complex to HAND

In the late 1990s, cognitive and motor impairments stemming from opportunistic infections were often categorized as AIDS dementia complex (ADC), also known as HIV-associated dementia (HAD) or HIV/AIDS encephalopathy [1]. ADC typically occurred when the CD4+ cell count fell below 200 cells/microliter and could be an early sign of AIDS [4]. Symptoms included declines in thinking, memory, reasoning, judgment, concentration and problem-solving, alongside changes in personality, speech, and motor skills [3].

Today, the focus has shifted towards HIV-associated neurocognitive disorder (HAND). While definitions have evolved, HAND encompasses a range of cognitive, motor, and behavioral impairments. Some researchers initially noted features resembling parkinsonism within HAND, though current definitions prioritize cognitive symptoms [2].

The Impact of Antiretroviral Therapy

The advent of highly active antiretroviral therapy (HAART), now commonly referred to as ART, has dramatically altered the landscape of HIV-related neurological complications. ART effectively controls HIV infection and protects many PLWH from developing ADC [3]. ART can not only prevent or delay the onset of ADC but also improve mental function in individuals already experiencing cognitive decline [4].

Yet, despite the success of ART, HIV-associated neurocognitive disorder remains prevalent [2]. This suggests that even with viral suppression, neurological complications can persist, highlighting the need for ongoing research and monitoring.

Current Research and Future Directions

Modern research is increasingly focused on the evolving array of neurological complications that emerge as PLWH age. This includes investigating the long-term effects of HIV on brain health and identifying strategies to mitigate neurocognitive decline. Researchers are exploring how HIV may affect the brain through various mechanisms, including direct damage to nerve cells, inflammation, and generalized inflammation that can contribute to memory issues and other age-related conditions [3].

Key Takeaways

• AIDS dementia complex (ADC) was a common neurological complication of advanced HIV infection before the widespread employ of ART.
• ART has significantly reduced the incidence of ADC and can improve cognitive function in those already affected.
• HIV-associated neurocognitive disorder (HAND) remains prevalent despite ART, indicating a need for continued research.
• Neurological complications in PLWH are evolving, particularly with increasing age.