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Alzheimer disease
Alzheimer disease is the most common cause of dementia: a gradual decline that usually begins with short-term memory (hippocampal involvement) and spreads to language, visuospatial function and executive function; symptomatic treatment is cholinesterase inhibitors and memantine, and anti-amyloid antibodies suit only early disease with proven amyloid.
Why it matters in the exam
The exam asks about the typical clinical picture (forgetting recent events, repeating questions, relative preservation of old memories and social behaviour early on), the work-up to exclude reversible causes (B12, TSH, blood count, electrolytes, calcium, glucose and brain imaging), and treatment: donepezil, rivastigmine or galantamine at every stage, and memantine in the moderate-to-severe stage.
Newer points that are asked: the 2024 biological definition is based on biomarkers (amyloid PET, cerebrospinal fluid, plasma p-tau217); lecanemab and donanemab modestly slow decline in patients with mild impairment and proven amyloid, and require MRI monitoring because of ARIA (brain oedema or haemorrhage), whose risk is higher in APOE ε4 homozygotes. The Lancet Commission lists modifiable risk factors — 12 in 2020 (about 40% of cases) and 14 in 2024 (about 45%), including hearing loss, hypertension, diabetes, smoking, inactivity, social isolation and high LDL.
Another recurring topic is safety and support: driving, managing money, wandering, medications and weapons at home, and support for the main caregiver, who is at risk of burnout and depression. Advance planning — an enduring power of attorney and advance directives — is also done early, while the patient still has capacity.
Key points
- The most common cause of dementia; recent memory is affected first.
- Work-up: B12, TSH, basic blood tests and brain imaging.
- Cholinesterase inhibitors at all stages; memantine in the moderate-to-severe stage.
- Anti-amyloid antibodies — only in mild impairment with proven amyloid; MRI monitoring for ARIA.
- Lancet: 14 modifiable risk factors (2024), about 45% of cases.
Summary table
| Issue | Key point | Exam point |
|---|---|---|
| Picture | Recent memory affected first, then language, spatial and executive function | Social behaviour relatively preserved early |
| Work-up | B12, TSH, blood count, electrolytes, calcium, glucose, liver and kidney tests, CT or MRI | Exclude reversible causes and depression |
| Imaging and biomarkers | Medial temporal lobe atrophy; amyloid PET, CSF, p-tau217 | Biomarkers — mainly before anti-amyloid treatment |
| Cholinesterase inhibitors | Donepezil 5 mg → 10 mg, rivastigmine, galantamine | Bradycardia, syncope, nausea, weight loss |
| Memantine | NMDA receptor antagonist, moderate-to-severe stage | Can be combined with a cholinesterase inhibitor |
| Anti-amyloid antibodies | Lecanemab, donanemab — mild impairment with proven amyloid | MRI monitoring; ARIA; caution with anticoagulants |
In the full version for subscribers
- A simple algorithm
- Memory aid
- Exam traps
- 5 review cards
- Enough for IMLE
The full version is open to subscribers of: Geriatrics, Medical licensing exam (IMLE), Internal medicine, Family medicine, Neurology, Psychiatry.
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Sources
- Alzheimer's Association Workgroup — Revised criteria for diagnosis and staging of Alzheimer's disease, 2024 — Core biomarkers and clinical staging
- Dementia prevention, intervention, and care — Lancet Commission, 2020 and 2024 updates — Modifiable risk factors
- Appropriate use recommendations for lecanemab and donanemab, 2023–2024 — Eligibility, MRI monitoring and ARIA
- Hazzard's Geriatric Medicine and Gerontology, 8th edition (2022) — Alzheimer disease and other dementias
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.