HIV-associated neurocognitive disorders (HAND)

HIV-associated dementia (HAD)
Occurs in advanced stages of HIV and is characterized by difficulties in attention, memory loss, and apathy. Early signs include jerky eye movements, hyperreflexia, and cerebellar dysfunction.

Diagnosis

• Investigations to rule out alternative conditions
• MRI shows atrophy and diffuse white matter changes
• CSF examination to check non-specific cytochemical abnormalities
• Neuropsychological assessment —to investigate abnormal information processing, psychomotor speed, and recall memory

Vascular myelopathy (VM)
Typically co-occurs with HIV dementia, presenting as spastic paraparesis without a distinct sensory level. Resembles subacute combined degeneration seen in vitamin B12 deficiency.

Diagnosis

• MRI for imaging changes
• Vitamin B12 and homocysteine levels.
• HTLV-1 serology to detect co-infection

Distal sensory peripheral neuropathy (DSPN)
Appears in late-stage AIDS approximately 25% of patients, with paraesthesia, burning pain, and dysesthesia. Weakness is minimal, ankle reflexes are diminished or absent, pain temperature sensations impaired.

Diagnosis

• Assess vitamin B12 and glucose levels
• Nerve conduction studies may indicate an axonal neuropathy.
• Nerve biopsy (rarely needed)

• Mononeuritis multiplex: Associated with HIV vasculitis and CMV.
• Demyelinating polyneuropathy
• Diffuse inflammatory lymphocytosis syndrome (DILS): mimics Sjögren’s syndrome, occurs during immunocompetent stages, and is linked to elevated CD8+ cell counts
• Polyradiculopathy

• Polymyositis: Seen in early HIV stages.
• Zidovudine-Induced Myopathy: Linked to mitochondrial dysfunction.

• Toxoplasmosis: Results in multiple ring-enhancing brain lesions, leading to increased intracranial pressure and headaches.
• Cryptococcal meningitis causes headache, altered mental status, and meningism. MRI reveals meningeal enhancement and hydrocephalous. CSF may reveal pleocytosis.
• Progressive multifocal leukoencephalopathy (PML): caused by JC virus reactivation. Symptoms include headache and focal signs. MRI presents white matter abnormalities, while CSF investigations detect presence of JC virus.
• CMV infection: causes meningoencephalitis, polyradiculopathy. CSF testing confirms presence of CMV virus.