Reasoning GP · Algorithm · 1-page summary
Memory deficit in adults
For: adults with a new memory or cognitive concern, raised by them or by family or carers. Not for: children. Acute or fluctuating confusion: delirium first (block 1).
Core rule: the time course decides the route; acute or fluctuating change is delirium until assessed. Treatable causes may coexist with dementia: treat and reassess, but never delay dementia assessment when decline is progressive, or diagnose from a score alone.
0Stop — act now — before the memory work-up
- Sudden new focal neurological signs still present (suspected stroke) → 999. Symptoms resolved (suspected TIA) → TIA service, seen within 24 h (over 1 week ago: within 7 days); no ABCD² to set urgency.
- Danger to self or others → 999 if immediate; otherwise acute mental health (crisis) team Same-day.
- Papilloedema, new seizures, recent head injury or suspected subdural haematoma → Same-day emergency assessment. SDH or NPH on CT → neurosurgery Same-day.
- Suspected autoimmune encephalitis → discuss with neurology Same-day; with seizures, altered consciousness or fever → Same-day emergency assessment.
1Triage by time course — collateral history decides
| Course | Action |
|---|---|
| Hours–days, fluctuating | Delirium until assessed (CG103). Treat the precipitant: infection, hypoxia, dehydration, constipation, retention, pain, medicines, metabolic, withdrawal. Same-day if significantly unwell, unsafe, not assessable in the community or serious precipitant. |
| Weeks–months, rapid | CJD, autoimmune encephalitis → Urgent neurology with CSF access (NG97). |
| Weeks–months, mood-led | Treat depression, then reassess. Do not postpone dementia assessment if progressive. |
| Months–years, insidious | Dementia work-up (block 3) → memory assessment service. |
2Screen — serious and treatable causes
- Progressive focal signs, significant headache, rapid decline → Urgent imaging. Adults with progressive, sub-acute loss of central neurological function → consider direct-access MRI brain within 2 weeks (NG12).
- Young-onset (<65) or atypical → Urgent specialist / neurology referral.
- Contributing: depression, hypothyroidism, low B12/folate, anticholinergics, benzodiazepines, opioids, alcohol, hearing or vision loss. Recovery may be incomplete.
3Assess — once blocks 0–2 are answered
☐ Collateral history from someone who knows them well, including instrumental ADLs ☐ Medicines and anticholinergic burden, alcohol, mood, sleep, hearing, vision ☐ Neurological, cardiovascular and general examination ☐ Validated tool (6CIT, Mini-Cog, 10-CS, MIS, TYM, MoCA), noting education, language, senses ☐ FBC, U&E, calcium, LFTs, TFTs, B12 and folate, HbA1c or glucose
Urine only if urinary symptoms, delirium or infection suspected; HIV and syphilis if risk factors, young-onset or atypical. Imaging by the local route.
4Classify — only if the screen is negative
- Normal ageing — slower recall, better with prompting, not progressive. MCI — objective impairment, function preserved → memory clinic for monitoring.
- Dementia — with functional decline. Alzheimer's: insidious, memory-led. Vascular: stepwise, focal signs. Frontotemporal: behaviour or language first.
- Lewy body — fluctuating cognition, visual hallucinations, parkinsonism, REM sleep behaviour disorder → avoid antipsychotics; record neuroleptic sensitivity prominently.
- Depression — low mood, early waking, anhedonia → treat and reassess; may coexist.
- Uncertain — say so. Treat delirium first; refer suspected dementia rather than wait.
5Treat today — only these
- Review medicines (anticholinergic burden, sedatives, opioids); treat depression, B12/folate and thyroid, then reassess.
- Cholinesterase inhibitors and memantine: start on the advice of a clinician with appropriate expertise. Check pulse; ECG if bradycardia, syncope or conduction disease. Doses: NICE/SPC, BNF, local formulary.
- Distress or agitation: look for pain, delirium, constipation, retention, infection, medicines first. Antipsychotics only if risk of harm or severe distress, with old age psychiatry input; review at least every 6 weeks.
6Refer routinely
- Suspected dementia, after initial assessment → memory assessment service (NG97). Hearing loss → audiology.
- Marked or unexpected decline; new agitation or psychosis → old age psychiatry; carer cannot cope safely → urgent social services and Admiral Nurse: all ≤7 days.
- Carer: register, Carer's Assessment. LPA and advance care planning while capacity remains. Advise the duty to notify DVLA; document it.
7Never reassure by
- A normal cognitive score, or the patient's own account without a collateral history.
- Calling acute confusion "worse dementia" without looking for delirium.
- Treating depression, B12 or thyroid and assuming full reversal.
- Bacteriuria on a urine dip without urinary symptoms as the whole explanation.
- A CT or MRI as proof that it is not Alzheimer's disease.
- Giving an antipsychotic before Lewy body dementia is considered.
8Safety-net — say it to the patient and carer, then document it
999 “Call 999 for sudden weakness, face, speech or vision problems, or if they are an immediate danger to themselves or others.” Same day: “Sudden worsening, confusion that comes and goes, drowsiness, a fever, a fit, or a severe new headache — contact us today.”
Within a week: “A big change in memory or coping, new agitation or hallucinations, or you can no longer cope safely as a carer — book to see us this week.” Reassess cognition after any delirium once it has resolved.
✓Safe to leave primary care only if — all five, documented
No block 0–2 row applies; delirium excluded or treated
Collateral history and function recorded
Bloods, medicines, mood, hearing and vision checked
Memory service referral or review owner and date set
DVLA, carer, capacity and safeguarding addressed; safety-net given
Summary of the full Reasoning GP memory deficit algorithm, which holds the detail, subtypes, prescribing, carer support and evidence. Sources: NICE NG97, CG103, TA217, NG128, NG12 (updated April 2026); DVLA Assessing fitness to drive; GMC confidentiality guidance; Lancet Commission 2024. Clinical reference — follow local memory-service pathways and check doses: NICE/SPC, BNF.