delirium vs. dementia

Last reviewed 08/2023

  • mode of onset: acute or subacute (Del); chronic or subacute (Dem)

  • poor attention: characteristic (Del); late event (Dem)

  • conscious level: often affected - may be wild fluctuations (Del); normal (Dem)

  • hallucinations and misinterpretations: common (Del); late events (Dem)

  • fear, agitation and aggression: common (Del); not common in the early stages (Dem)

  • totally disorganised thought with palpably unreal ideas: common - often flight of ideas (Del); late feature - usually poverty of thought (Dem)

  • motor signs: postural tremor, myoclonus, asterixis (Del); none, or late feature (Dem)

  • speech: slurred (Del); normal (Dem)

  • dysphasia: none (Del); often present (Dem)

  • dysgraphia: often prominent (Del); if present, in keeping with degree of dementia (Dem)

  • short and long term memomy: poor (Del); often normal until late (Dem)

Key: Del = delirium; Dem = dementia