HIV NCD is a chronic, typically gradual cognitive decline directly attributable to HIV infection's effects on the central nervous system; Delirium is an acute disturbance in attention and awareness developing over a short period, with a tendency to fluctuate, and is common in individuals with HIV infection due to opportunistic infections or medication effects.
HIV NCD develops gradually over the course of HIV disease; Delirium develops acutely, over hours to days, often in the context of an acute medical complication (opportunistic infection, medication toxicity) superimposed on a person's baseline.
HIV NCD is a persistent, chronic condition; Delirium is, by definition, expected to resolve once its underlying acute cause is treated, though it can occur superimposed on an existing HIV NCD.
HIV NCD's cognitive profile often includes psychomotor slowing and executive dysfunction; Delirium's hallmark is a fluctuating disturbance in attention and awareness, often with additional acute features like disorganized thinking or perceptual disturbances.
Both impair functioning, but delirium poses acute safety and medical urgency that chronic HIV NCD alone does not.
A chronic, stable cognitive decline without acute fluctuation in attention/awareness points away from delirium; an acute change from a person's cognitive baseline, especially with a fluctuating course, should prompt urgent delirium workup even in someone with known HIV NCD.
The key differential question is timeline and fluctuation: an acute, fluctuating change from baseline points to delirium (which requires urgent medical evaluation), while a gradual, chronic, stable decline points to HIV NCD itself.
In an individual with HIV infection and any baseline cognitive impairment, an acute superimposed delirium can be mistaken for simple progression of HIV NCD, delaying identification and treatment of a reversible acute cause.
A person with HIV infection and a 2-year history of gradually worsening slowed thinking, stable day to day, fits HIV NCD; the same person developing sudden confusion and inattention over 24 hours, worse at night, should be urgently evaluated for delirium.
| Feature | Neurocognitive Disorder Due to HIV Infection | Delirium |
|---|---|---|
| Onset | HIV NCD: gradual, over months to years | Delirium: acute, over hours to days |
| Course | Relatively stable, chronic | Fluctuating |
| Urgency | Chronic management | Requires urgent medical evaluation for a reversible cause |
A neurocognitive disorder attributable to documented HIV infection, with cognitive decline not better explained by non-HIV conditions, including HIV-associated opportunistic infections or malignancies affecting the central nervous system.
An acute, fluctuating disturbance in attention and awareness, developing over a short period, with an additional cognitive disturbance, that is a direct physiological consequence of an underlying medical condition, substance, or other cause.