HIV-associated neurocognitive disorder

Background

• Previously called AIDS dementia complex

Epidemiology

• Severe HAND less common following ART
• First factors include lack of viral suppression, low nadir CD4 count, and increasing age
• Other risk factors include hypertension, dyslipidemia, diabetes, and coinfections such as hepatitis C

Clinical Manifestations

• Spectrum that includes asymptomatic neurocongitive impairment (impairment only noted on formal tests), mild neurocognitive disorder (affects functioning), and HIV-associated dementia (inability to perform ADLs)
• Not necessarily progressive
• Wide range of symptoms, including inattention, poor concentration, irritability, apathy, mood changes, motor dysfunction
• Head imaging often shows global atrophy

Differential Diagnosis

• CNS viral escape, with CSF HIV viral load compared to simultaneous plasma viral load
• Primary CNS lymphoma
• Progressive multifocal leukoencephalopathy caused by JC virus
• Cryptococcus
• Toxoplasma
• Obstructive sleep apnea
• Low vitamin B12
• Thyroid disease
• Syphilis
• Other causes of cognitive impairment unrelated to HIV, including subclinical depression, drug use, educational deprivation, socioeconomic status, and Alzheimer dementia

Diagnostic Criteria

• Uses the Frascati criteria 2007
• Based on formal assessment of at least five neurocognitive domains, including attention-information processing, language, abstraction-executive, complex perceptual motor skills, memory including learning and recall, simple motor skills or sensory perceptual skills
• Exclusion of other causes

	Neurocognitive Status	Functional Status
Asymptomatic neurocognitive impairment	1 SD below mean in 2 cognitive domains	no impairment in activities of daily living
Mild neurocognitive disorder		impairment in activities of daily living
HIV-associated dementia	2 SD below mean in 2 cognitive domains	marked impairment in activities of daily living