Dementia vs Delirium
How to tell Dementia and Delirium apart when a board question makes them look alike.
Step 2 CK pairs are in open beta while clinical review finishes. Spot an issue? Tell us.
Fluctuating inattention with acute onset identifies delirium.
Side by side
Gradual progressive cognitive decline over months to years with preserved attention early suggests dementia.
Acute fluctuating inattention and altered awareness over hours to days suggests delirium.
Neurodegenerative cortical injury causes chronic decline in memory and executive function.
Acute brain dysfunction from medical insult disrupts attention networks and consciousness regulation.
Dementia workup includes cognitive testing and reversible-cause labs such as TSH and B12, with structural imaging when indicated.
Delirium evaluation focuses on triggers including infection, electrolyte abnormalities, hypoxia, medication effects, and glucose derangements.
The trap
An older patient with known baseline memory loss is assumed to have dementia progression during acute confusion. Missing delirium delays treatment of reversible causes like infection, drug toxicity, or hypoxia.
The repair move
Next best step: treat this as delirium first by identifying and correcting the precipitating medical cause, optimizing oxygenation and hydration, reviewing medications, and using nonpharmacologic reorientation measures. Defer dementia progression labeling until acute delirium resolves.
Try a free question
CoreA 79-year-old man develops sudden confusion and inattention over one day after starting diphenhydramine for insomnia. What is the next best step in management?
Show answer and explanation
Answer: A. Stop offending medication and evaluate for delirium precipitants. Acute fluctuating inattention is delirium until proven otherwise and requires trigger removal and medical evaluation.
Why the other choices are tempting
- B. Wrong. Rapid onset argues against primary dementia progression.
- C. Wrong. Dementia drugs are not immediate treatment for acute delirium.
- D. Wrong. Marked acute inattention is pathologic, not normal aging.
- E. Wrong. Untreated delirium has high morbidity and requires active management.
Flashcards
Tap a card to flip it.
Which cognitive domain change most strongly indicates delirium over dementia?
Acute impaired attention with fluctuating course.
What timeline is most consistent with dementia?
Slow decline over months to years.
Quick answers
What is the fastest way to tell Dementia from Delirium?
Fluctuating inattention with acute onset identifies delirium.
What is the key clue for Dementia?
Gradual progressive cognitive decline over months to years with preserved attention early suggests dementia.
What is the key clue for Delirium?
Acute fluctuating inattention and altered awareness over hours to days suggests delirium.
What is the common trap with Dementia vs Delirium?
An older patient with known baseline memory loss is assumed to have dementia progression during acute confusion. Missing delirium delays treatment of reversible causes like infection, drug toxicity, or hypoxia.