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Delirium and dementia
Delirium is an acute, fluctuating disturbance of attention and consciousness with a physical cause that must be found and treated; dementia is a gradual, persistent decline in cognition with attention preserved early on — and a patient with dementia is at high risk of delirium.
Why it matters in the exam
Exam questions present an older inpatient who has suddenly become confused, sleeps by day and is agitated at night, and ask for the diagnosis and the next step. The key is acute onset, fluctuation and impaired attention (the CAM tool). Quiet (hypoactive) delirium is common and missed. Treatment is to find and treat the cause — infection, drugs (mainly anticholinergics, benzodiazepines and opioids), metabolic disturbances, urinary retention, constipation, pain and withdrawal — and to use non-drug measures. A low-dose antipsychotic is reserved for agitation that endangers the patient or others, and benzodiazepines only for alcohol or benzodiazepine withdrawal.
In dementia questions ask about the work-up for reversible causes (B12, TSH, blood count, electrolytes, calcium, kidney and liver tests, brain imaging) and about telling the types apart: Alzheimer — memory first, gradual progression; vascular — stepwise decline with vascular risk factors; Lewy body — visual hallucinations, fluctuation, parkinsonism and severe sensitivity to antipsychotics; frontotemporal — personality and behaviour change at a younger age; normal-pressure hydrocephalus — unsteady gait, urinary incontinence and confusion. Cholinesterase inhibitors (donepezil and others) for mild to moderate dementia, memantine for moderate to severe. Depression in an older person can mimic dementia and is worth checking.
Key points
- Delirium: acute, fluctuating, impaired attention, a physical cause.
- Dementia: gradual, attention preserved early; exclude reversible causes.
- Delirium treatment: the cause and non-drug measures; antipsychotic only for dangerous agitation.
- Lewy: visual hallucinations, fluctuation, parkinsonism, antipsychotic sensitivity.
- Cholinesterase inhibitors for mild to moderate; memantine for moderate to severe.
Summary table
| Feature | Delirium | Dementia | Exam notes |
|---|---|---|---|
| Onset | Acute, hours to days | Gradual, months to years | Sudden onset points to delirium |
| Course | Fluctuating, worse at night | Progressive and relatively stable through the day | Lewy body dementia fluctuates too |
| Attention and consciousness | Impaired attention, altered consciousness | Attention preserved early | CAM: acute onset and fluctuation, inattention, plus one of disorganised thinking or altered consciousness |
| Cause | Physical: infection, drugs, metabolic, urinary retention, withdrawal | Degenerative or vascular; exclude reversible causes | B12, TSH, calcium, imaging |
| Treatment | Treat the cause, orientation, glasses and hearing aids, sleep, avoid restraints | Cholinesterase inhibitors, memantine, support | Antipsychotic only for dangerous agitation; not in Lewy body |
| Types of dementia | — | Alzheimer, vascular, Lewy body, frontotemporal, normal-pressure hydrocephalus | Lewy: visual hallucinations and antipsychotic sensitivity |
Free exam questions
איזו מבין התרופות הבאות פחות :מתאימה לטיפול בדליריום (the question as examined, in Hebrew)
- א. Olanzapine
- ב. Ziprasidone
- ג. Quetiapine
- ד. Risperidone
מחקר השווה בין 8,276 חולי סוכרת עם דמנציה לעומת 8,276 חולי סוכרת ללא דמנציה התואמים להם מבחינת גיל ומין. במחקר זה נבדקו התרופות אותן נטלו המטופלים לסוכרת, ונבדק הקשר בין נטילת תרופות שונות לסוכרת לבין התפתחות דמנציה. מהו המדד המתאים לתיאור גודל האפקט בסוג המחקר המתואר? (the question as examined, in Hebrew)
- א. Odds Ratio
- ב. Relative Risk
- ג. Confidence interval
- ד. Kaplan-Meier analysis
מחלת אלצהיימר היא .הסיבה השכיחה ביותר לדמנציה במבוגרים מהי הסיבה השנייה בשכיחותה? (the question as examined, in Hebrew)
- א. תרופות
- ב. המטומה סבדוראלית
- ג. אוטמים מוחיים מרובים
- ד. הידרוצפלוס
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Sources
- NICE guideline CG103, 2010, updated 2023 — Delirium: prevention, diagnosis and management in hospital and long-term care
- NICE guideline NG97, 2018 — Dementia: assessment, management and support
- American Geriatrics Society Beers Criteria, 2023 — Potentially inappropriate medication use in older adults
- Kaplan and Sadock's Synopsis of Psychiatry, 12th edition (2021) — Neurocognitive Disorders
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.