Educational draft · awaiting clinical reviewThe full textbook explains uncertainty but does not replace live national or local guidance, specialist advice, or current prescribing information.
Dementia assessment and reversible contributors
Psychiatry · UK scope · Sources checked 27 Aug 2026 · Clinical review pending
!
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.
Overview
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.
Start with change from the person's own lifelong and recent baseline. Ask about learning new information, repeating questions, word finding, planning, judgement, navigation, recognising objects, social behaviour and personality. Then connect symptoms to function: managing medicines and money, cooking, shopping, transport, technology, work, caring, washing and dressing. Education, occupation, language, culture, sensory impairment and learning disability affect test performance, so a population score must not substitute for an individual trajectory.
Speak to the person directly and preserve privacy and autonomy. With permission, obtain examples and dates from someone who knows them well; if sharing is restricted, clinicians can still receive relevant collateral without disclosing confidential information. Establish whether family interpretation is supportive, conflicted or potentially coercive. A structured informant measure such as IQCODE or the Functional Activities Questionnaire can supplement, not replace, a detailed account. Ask the person's priorities and what they think explains the change.
Practice
Two practice questions
Your practice draft is saved in this browser.
Question 1 of 2
0 correct
PsychiatryOriginal SBA
Normal cognitive-screen result
A retired multilingual professor has eighteen months of progressive navigation and financial-management difficulty, corroborated by a partner, but scores within the normal range on a brief cognitive instrument. What is the best next step?
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.
Time course directs urgency. Delirium changes attention and arousal over hours or days and fluctuates, whereas common neurodegenerative dementias progress over months or years. Depression may reduce concentration, effort, sleep and confidence, but severe mood symptoms and dementia can coexist. Weeks-to-months progression, myoclonus, ataxia, seizures or rapidly accumulating neurological signs demands urgent neurological review for inflammatory, infectious, toxic, metabolic, neoplastic and prion causes. Treat delirium first when it cannot be separated confidently from dementia.
Perform physical, neurological and mental-state examinations. Check vision, hearing, gait, parkinsonism, focal signs, nutrition, alcohol use, sleep and cardiovascular risk. Review prescribed, over-the-counter and non-prescribed medicines, focusing on anticholinergic burden, sedatives, opioids and drugs that accumulate with organ impairment. Do not withdraw essential treatment abruptly; agree a staged medication plan and monitor both cognition and the condition for which the medicine was prescribed.
NICE calls for appropriate blood and urine tests rather than one universal panel. Local pathways commonly use blood count, renal and electrolyte, liver, thyroid, calcium, glucose or HbA1c, B12 and folate according to context, with infection, HIV, syphilis, sleep, autoimmune or toxicology testing only when clinical features justify it. A urine culture is not a general dementia test. Correct deficiency, endocrine disturbance, dehydration, infection or organ failure, while recognising that treatment may improve function without excluding concurrent dementia.
Use a validated brief cognitive instrument adapted to communication and sensory needs. Record which tool, language, aids and conditions were used and examine domain pattern rather than only the total. Anxiety, fatigue, pain and low literacy can lower a score; high prior ability or focal language, executive or visuospatial decline can leave a total apparently normal. NICE specifically says not to rule out dementia from a normal score. Formal neuropsychology is useful when impairment, cause or subtype remains unclear.
Specialist dementia services integrate clinical criteria, neurological examination, cognitive profile and imaging. NICE advises structural imaging to rule out reversible structural causes and assist subtype diagnosis unless the dementia and subtype are already clear. CT may identify large stroke, tumour, subdural collection or hydrocephalus; MRI better characterises vascular and regional patterns. Neither a normal scan nor isolated atrophy establishes or excludes dementia. Further biomarker or functional imaging is used only when subtype uncertainty would change management.
The phrase reversible causes needs care. Delirium, depression, hearing loss, sleep disorder, medicines, endocrine disturbance and deficiency are important because treating them can improve cognition and wellbeing. Some leave residual deficits, some recur, and many coexist with brain disease. Avoid promising that a blood test will make symptoms disappear or using a contributor to close the diagnostic pathway. Reassess cognition and function after treatment at a clinically meaningful interval and refer if concern remains.
Diagnosis includes consequences and support. Assess home safety, driving, medication administration, finances, cooking, falls, nutrition, firearms or other hazards, work and dependent-care responsibilities without assuming incapacity. Capacity is decision-specific. Provide a named care coordinator, accessible information, and discussion of subtype, prognosis uncertainty, advance care planning, lasting powers or national equivalents, and research opportunities. Tell the person about relevant driving notification requirements and insurer obligations for their jurisdiction.
Diagnostic disclosure should be paced and person-centred. Ask how much the person wants to know, who should attend and what terminology they prefer. Explain what evidence supports the conclusion, what remains uncertain, which contributors are being treated and what follow-up will occur. Avoid language suggesting an empty life or inevitable immediate dependence. A diagnosis can enable treatment, practical adjustments and planning, but continued review is needed when course, function or neurological features diverge from expectation.
Key points
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.
Aetiology
01
Neurodegenerative disease
Progressive neuronal and network injury from Alzheimer's, Lewy-body, frontotemporal and related diseases produces domain-specific cognitive and functional decline.
02
Vascular brain injury
Large or small vessel disease, strategic infarction and haemorrhage can impair executive, motor and cognitive function alone or alongside degeneration.
03
Treatable contributors
Delirium, depression, medicine burden, sensory loss, sleep disorder, deficiency and systemic illness can cause or amplify cognitive impairment.
04
Mixed causation
Older adults commonly have interacting neurodegenerative, vascular, medical and psychosocial factors rather than one pathologically pure explanation.
Pathophysiology
1
Network reserve loss
Progressive synaptic and neuronal damage reduces the brain's ability to sustain memory, language, attention and executive processing under ordinary demand.
2
Domain-specific circuit injury
The location and sequence of network involvement determine whether episodic memory, visuospatial ability, behaviour, language or executive control changes first.
3
Vascular disconnection
Infarction and small-vessel damage interrupt cortical-subcortical pathways, often slowing processing and impairing planning, gait and emotional regulation.
4
Systemic cognitive load
Pain, inflammation, metabolic imbalance, sensory deprivation and sedating medicines expose limited reserve and may create disproportionate functional decline.
Clinical features and red flags
Progressive cognitive syndrome
Memory, language, executive, visuospatial or social-cognitive change advances over months or years rather than representing one isolated lapse.
Functional interference
New difficulty with complex or basic daily activities marks dementia-level impact when not better explained by physical or environmental barriers.
Delirium pattern
Abrupt fluctuating attention and arousal signals acute brain dysfunction that may occur with or without pre-existing dementia.
Depressive cognitive symptoms
Low mood, anhedonia, sleep change, guilt, reduced effort and subjective failure may impair cognition but can coexist with neurodegeneration.
Medicine or sensory contributor
Anticholinergic or sedative exposure, poor hearing and impaired vision can worsen testing, communication and everyday cognitive performance.
Rapid neurological syndrome
Weeks-to-months decline with seizures, movement disorder, ataxia or focal signs requires expedited neurological investigation for uncommon treatable causes.
Red flags requiring action
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.
Investigations
01Person and collateral historyFirst step
Why
Define onset, progression, cognitive domains, daily function, safety, mood, illness, medicines and the person's own goals.
Interpretation and limitations
Concrete longitudinal examples carry more weight than age stereotypes; collateral difference prompts exploration of context, privacy and reliability.
02Validated brief cognitive instrument
Why
Sample cognition systematically using a NICE-listed tool adapted for language, education, vision and hearing.
Interpretation and limitations
A normal score cannot exclude dementia, and a low score cannot identify cause without clinical and functional evidence.
03Physical, neurological and mental-state examination
Acute or focal findings change urgency; absent signs do not negate a well-supported progressive functional history.
04Targeted blood, urine and medicine review
Why
Detect metabolic, endocrine, nutritional, infectious, organ and medication contributors selected for the clinical context.
Interpretation and limitations
Treat abnormalities and reassess, but avoid assuming an incidental result fully explains persistent progressive impairment.
Differential diagnosis
01
Delirium
Acute fluctuating attention and arousal indicates medical brain dysfunction that needs immediate cause treatment and may coexist with dementia.
02
Depression
Mood, sleep, motivation and concentration changes can resemble dementia, but both syndromes may be present and deserve active treatment.
03
Medication or substance effect
Anticholinergics, sedatives, opioids, alcohol and drug accumulation may impair cognition, gait and alertness in a dose- and vulnerability-dependent way.
04
Sensory or communication barrier
Hearing, vision, language, literacy and aphasia can depress test performance and simulate disengagement unless assessment is adapted.
05
Functional cognitive disorder
Internally inconsistent cognitive difficulty may reflect altered attention and belief rather than neurodegeneration, but requires positive specialist formulation rather than dismissal.
Management
01Acute changeTreat delirium before routine dementia work-upFirst stepCognition, attention or arousal changes over hours or days or fluctuates from a known baseline.+
1Assess ABCDE, glucose, neurological signs and immediate safety, obtain collateral timing and use the recommended delirium assessment pathway.
2Treat physiological causes and provide supportive delirium care rather than interpreting an acute cognitive score as stable dementia.
3After recovery, reassess residual cognition and function and arrange specialist dementia review if progressive pre-illness concern remains.
02Progressive concernInvestigate contributors and referMonths-to-years cognitive change is affecting function and no immediate medical emergency dominates.+
1Take person and collateral histories, examine, use an adapted validated brief cognitive tool, review medicines and complete appropriate blood and urine tests.
Complications
01
Loss of everyday safety
Navigation, medication, cooking, driving and financial errors can cause injury, exploitation and crisis before basic self-care is affected.
02
Delirium vulnerability
Reduced cognitive reserve greatly increases delirium risk during infection, surgery, hospital transfer, pain and medicine change.
03
Mood and suicide risk
Fear, depression, grief, psychosis and awareness of decline may cause severe distress and require direct suicide assessment.
04
Carer and relationship strain
Uncertainty, role change, communication difficulty and round-the-clock supervision can harm both the person and those supporting them.
05
Premature loss of autonomy
Global incapacity assumptions, over-disclosure and risk-averse restriction can remove lawful choice before decision-making ability is actually lost.
Monitoring and follow-up
Review cognition together with real-world function, mood, sleep, sensory ability, medicines and physical health rather than repeating one total score alone.
Reassess after treating delirium, depression, deficiency, endocrine disease, sensory loss or medication burden to identify residual progressive change.
Track driving, medication management, nutrition, cooking, falls, wandering, scams, work and dependent-care risk with proportionate support.
Ask at each review what information may be shared, who the person wants involved and whether communication or advocacy needs changed.
Escalate acceleration, seizures, myoclonus, focal signs, gait change, new incontinence or systemic illness rather than attributing all decline to dementia.
Ensure the named coordinator, care plan, advance-planning documents and emergency contacts transfer across primary, hospital and social-care settings.
Special situations
Function defines clinical weight
A cognitive symptom becomes more concerning when it newly disrupts medicines, money, navigation, communication, work or personal care.
Normal scores can mislead
High premorbid ability and focal executive, language or visuospatial syndromes may escape a short memory-heavy screening instrument.
Treatable is not exclusive
Depression, hearing loss and anticholinergic medicines can worsen cognition while an underlying neurodegenerative process remains present.
Imaging answers selected questions
Structural scans assist cause and subtype but neither isolated atrophy nor a normal result independently determines the diagnosis.
Assessment is also intervention
Accessible explanation, safety adaptation and advance planning can improve autonomy even before every subtype uncertainty is resolved.
Common pitfalls
01
Attributing cognitive concern to normal ageing without a domain, timeline and functional assessment.
02
Diagnosing dementia during an unresolved delirium or using an acute hospital cognitive score as the person's stable baseline.
03
Ruling out dementia because one brief instrument is normal or diagnosing it because a score is low.
04
Ordering a fixed laboratory panel without history and examination, then treating an incidental result as the complete explanation.
05
Stopping important anticholinergic or sedating medicines abruptly without considering indication, withdrawal and a monitored alternative.
06
Interpreting CT or MRI as a standalone diagnostic or exclusion test for Alzheimer's disease.
07
Assuming dementia means global incapacity, excluding the person from discussion or sharing unrestricted information with relatives.
08
Sending weeks-to-months rapid neurological decline through a routine memory-clinic pathway.
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.
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.
05Structural brain imaging
Why
Exclude important structural causes and assist specialist subtype formulation when dementia is not already well established and clear.
Interpretation and limitations
Imaging supports clinical diagnosis; normal CT or MRI does not rule out Alzheimer's disease or another dementia.
06Specialist neuropsychology or biomarkers
Why
Clarify whether impairment exists, its profile or subtype when uncertainty remains and the result would change management.
Interpretation and limitations
Select testing rather than using every biomarker; age and comorbidity affect specificity and results require specialist integration.
2
Treat identified depression, sensory, medication, metabolic and other contributors and document response without closing the pathway prematurely.
3Refer to a specialist dementia diagnostic service when dementia remains suspected and arrange structural imaging through the appropriate local pathway.
03After diagnosisTurn explanation into support and planningSpecialist assessment establishes dementia or a high-confidence cognitive diagnosis requiring continuing care.+
1Explain subtype, uncertainty and expected changes in accessible language and agree consent-based information sharing and a named coordinator.
2Address driving, work, medication, nutrition, falls, finance, vulnerability, carer needs and practical occupational strategies without assuming incapacity.
3Offer early and recurring opportunities for advance planning, legal advice, research, treatment and review of emerging physical, cognitive and support needs.