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Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.

Dementia assessment and reversible contributors

Psychiatry · UK scope · Sources checked 27 Aug 2026 · Clinical review pending

RapidFull
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Acute or rapidly progressive decline is not a routine memory referral

Hours-to-days fluctuation, impaired arousal, focal neurology, seizure, head injury, severe systemic illness, poisoning or loss of basic safety requires an acute delirium or neurological pathway; decline over weeks to a few months may represent rapidly progressive dementia and needs urgent specialist assessment.

Action: Assess ABCDE, glucose, attention, neurological signs and immediate risks; establish the person's baseline and exact time course from collateral information; treat suspected delirium and physiological threats first; and refer urgently to acute medicine, neurology or another relevant service. Do not defer emergency care for cognitive scoring or a routine memory-clinic appointment.

Synopsis

Assess progressive cognitive and functional change respectfully, distinguish dementia from delirium and other contributors, investigate treatable factors without promising reversal, secure specialist subtype diagnosis, and address immediate safety and future planning early.

  • Dementia is acquired cognitive decline severe enough to interfere with everyday independence; it is not an inevitable part of ageing and should not be diagnosed from forgetfulness alone.
  • Take the history from the person and, with consent or another lawful basis, someone who knows them well; ask what changed, when, and how real tasks are affected.
  • Assess memory, language, attention, executive, visuospatial, social and behavioural domains because not every dementia begins with amnesia.
  • Use a validated brief instrument such as 6CIT, Mini-Cog, MIS, TYM or another NICE-listed tool, but do not rule out dementia solely because the result is normal.
  • Investigate delirium, depression, sensory impairment and medicines with anticholinergic burden, alongside physical and metabolic contributors selected through history and examination.
  • Treatable contributors may coexist with neurodegenerative disease; improvement after hearing aids, mood treatment or medicine reduction does not make the original concern imaginary.
  • NICE recommends structural imaging to exclude reversible structural causes and help subtype diagnosis unless dementia is already well established and the subtype is clear.
  • Refer to a specialist dementia diagnostic service after reasonable investigation of reversible contributors when dementia remains suspected.
  • Suspected rapidly progressive dementia belongs in a neurological service with access to cerebrospinal-fluid and other specialist testing, not a standard wait-and-see pathway.
  • Discuss consent for information sharing, driving, work, medication, vulnerability, care coordination and advance planning while the person can express preferences.

    • Key red flags

    A sudden fluctuating change in attention or arousal indicates possible delirium superimposed on cognitive impairment and requires immediate cause-finding and treatment.

    New focal neurological deficit, seizure, severe headache, head injury or abrupt stepwise loss needs urgent stroke, trauma or neurological assessment.

    Progression over weeks or a few months with myoclonus, ataxia, rapidly lost function or unusual neurological signs requires referral to a neurological service able to investigate rapidly progressive dementia.

    Getting lost, unsafe driving, medication errors, scams, fire risk, malnutrition, self-neglect or inability to manage dependants needs a proportionate same-day safety plan.

    Suicidal thinking, severe depression, psychosis, abuse, coercion or financial exploitation must be assessed directly rather than attributed to cognitive impairment.

    A normal brief cognitive score cannot rule out dementia when history shows meaningful progressive decline, high prior ability, language barriers or domain-specific impairment.

    Investigation priorities

    01
    Person and collateral historyFirst step

    Define onset, progression, cognitive domains, daily function, safety, mood, illness, medicines and the person's own goals.

    Management branches

    Acute changeTreat delirium before routine dementia work-up

    Cognition, attention or arousal changes over hours or days or fluctuates from a known baseline.

    1. Assess ABCDE, glucose, neurological signs and immediate safety, obtain collateral timing and use the recommended delirium assessment pathway.
    2. Treat physiological causes and provide supportive delirium care rather than interpreting an acute cognitive score as stable dementia.
    3. After recovery, reassess residual cognition and function and arrange specialist dementia review if progressive pre-illness concern remains.
    Open full textbook →Answer 2 questions
    Sources and review status5 sources · checked 27 Aug 2026 · clinical review pending+
    Sources

    Sources and review status

    National guidance is shown before implementation-dependent detail. Apply principles in context and verify current guidance when a decision affects care. Source check completed 27 Aug 2026; clinical approval remains outstanding.

    • NICE NG97 dementia recommendationsInitial assessment, cognitive tools, reversible contributors, imaging, referral and person-centred post-diagnostic support.
    • NICE CG103 delirium recommendationsAcute recognition, diagnostic assessment and treatment when delirium may explain cognitive change.
    • NHS dementia diagnosis guideCurrent UK patient-facing assessment, memory-service referral and post-diagnostic information.
    • NHS tests for diagnosing dementiaBlood testing, cognitive assessment, imaging purposes and limitations in UK pathways.
    • NICE NG98 hearing-loss recommendationsHearing assessment where dementia or cognitive impairment is suspected or diagnosed.

    Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes

    Authoring stateRapid draftClinical stateAwaiting reviewJurisdictionUnited Kingdom