Evaluate for alternate/reversible causes of symptoms
Head CT shows cortical atrophy and ventricular enlargement
Associated with elevated CSF protein in 50-70% of cases
AIDS dementia complex
Hypoxic encephalopathy
Anti-NMDA receptor encephalitis
Acute toxic-metabolic encephalopathy 
Prion disease
Hypoglycemia
HIV neurologic complications
Hyperosmolar state 