Vascular cognitive impairment

01OverviewDefinition, clinical context and the essential points that orientate the chapter.

Cerebrovascular injury affects cognition through lesion location, cumulative burden and network disconnection. A single thalamic, angular gyrus, caudate or hippocampal infarct can create a disproportionate strategic syndrome. Multiple territorial infarcts produce a patchy profile with focal signs. Long-standing penetrating-artery disease disrupts frontal–subcortical networks, causing slowed thought, poor set shifting, gait dysfunction and emotional lability. Cerebral amyloid angiopathy and previous haemorrhage may contribute both cognitive decline and future bleeding risk.

The diagnosis requires a temporal or pathophysiological link, not merely coexistence of vascular risk and memory symptoms. Reconstruct strokes, transient deficits and the slope of decline; examine gait, reflexes, focal signs and parkinsonism; test executive and processing speed as well as memory. MRI burden and location should fit the phenotype. Marked progressive amnesia or visuospatial disease out of proportion to vascular injury suggests mixed Alzheimer or Lewy body pathology.

Treatment is prevention plus rehabilitation. Vascular risk control reduces future stroke and may protect remaining function, although no intervention guarantees cognitive recovery. Antithrombotic selection depends on non-cardioembolic stroke, atrial fibrillation, haemorrhage history and small-vessel markers, requiring stroke expertise rather than a dementia label. Individual blood-pressure targets and antithrombotic decisions should follow current stroke and local anticoagulation protocols.

Key points

Vascular cognitive impairment spans objective cognitive decline without major dependency through to dementia caused wholly or partly by cerebrovascular disease.
Mechanisms include a strategic infarct, multiple cortical infarcts, subcortical small-vessel disease, cerebral haemorrhage, hypoperfusion and inherited arteriopathy; mixed Alzheimer and vascular pathology is common.
Executive dysfunction, slowed processing, impaired attention, apathy, gait change and urinary symptoms may be more prominent than early storage-memory loss in subcortical disease.
The course can be stepwise after recognised strokes, but small-vessel disease often produces a gradual trajectory; absence of obvious clinical stroke does not exclude vascular contribution.
Imaging abnormalities must be anatomically and quantitatively sufficient to explain the syndrome. A few age-related white-matter hyperintensities do not establish vascular dementia.
Use MRI where possible to characterise infarcts, white-matter disease, lacunes, microbleeds and haemorrhage, while integrating findings with functional and cognitive chronology.
Prevent further stroke through mechanism-specific antithrombotic treatment when indicated, blood-pressure and lipid care, diabetes management, smoking cessation, activity and treatment of atrial fibrillation.
Do not prescribe aspirin or anticoagulation solely to treat cognitive impairment or incidental white-matter change; each requires a recognised vascular indication and bleeding-risk review.
NICE recommends cholinesterase inhibitors or memantine in vascular dementia only when comorbid Alzheimer disease, Parkinson disease dementia or dementia with Lewy bodies is suspected.
Rehabilitation, gait and falls work, mood care, communication support and carer planning address disability even when cognitive drug options are limited.

02AetiologyUnderlying causes, associations and risk factors, with why each one matters.

Strategic infarction

A single thalamic, hippocampal, frontal or other strategically placed infarct can disrupt cognition disproportionate to lesion volume.

Multiple infarcts and small-vessel disease

Accumulated cortical infarcts, lacunes and white-matter injury disconnect distributed networks serving executive function, memory and processing speed.

Haemorrhage and hypoperfusion

Intracerebral bleeding, recurrent hypotension and severe arterial disease can injure cognitive networks through tissue destruction or reduced flow.

Inherited and inflammatory arteriopathy

An unusual age, family history or imaging pattern raises suspicion for genetic, vasculitic and other less common vascular mechanisms.

03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.

1
Focal tissue loss
Infarction or haemorrhage destroys neurons and connections within strategic regions serving memory, language, attention or executive function.
2
Subcortical disconnection
Small-vessel white-matter damage interrupts frontal-subcortical loops, slowing information processing, gait and executive control over everyday tasks.
3
Reduced network reserve
Repeated vascular injury limits network compensation and increases vulnerability to delirium and further small vascular or systemic insults.
4
Mixed neurodegeneration
Alzheimer or Lewy-body pathology commonly coexists and adds progressive memory, perceptual or behavioural dysfunction beyond vascular injury alone.

04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.

Post-stroke cognitive syndrome

Cognitive decline beginning after a clinically recognised stroke and persisting beyond acute delirium supports a vascular relationship, with domain pattern reflecting lesion location.

Subcortical small-vessel pattern

Slowed processing, executive difficulty, apathy, short-stepped gait, falls and urinary urgency with extensive white-matter disease and lacunes suggests subcortical vascular impairment.

Strategic infarctRed flag

Abrupt new amnesia, language, executive or behavioural dysfunction after a small thalamic, hippocampal, caudate or dominant angular lesion may produce substantial cognitive disability.

Mixed dementia

Progressive amnestic decline plus substantial infarct or small-vessel burden often represents mixed pathology rather than a forced choice between Alzheimer and vascular disease.

Inherited arteriopathy clue

Migraine with aura, early strokes, psychiatric change and a dominant family history with characteristic anterior temporal or external-capsule MRI lesions can suggest CADASIL and genomic referral.

05InvestigationsWhat to request, why it matters and how to interpret it.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

01
Chronological patient and collateral historyFirst step
Why
Link cognitive change to stroke events, stepwise deterioration or cumulative vascular disease and quantify functional loss.
Interpretation and limitations
A close temporal relationship supports causation, while slow progression does not exclude small-vessel disease. Separate acute post-stroke delirium and depression before assigning persistent impairment.
02
Executive and multi-domain cognitive testing
Why
Capture slowed processing, attention and planning deficits that a memory-heavy screen may miss.
Interpretation and limitations
Timed tasks, verbal fluency and set shifting can expose frontal–subcortical dysfunction. Education, aphasia, motor slowing and visual field loss must be considered when interpreting scores.
03
MRI brain with diffusion, FLAIR and susceptibility sequences
Why
Map recent and old infarcts, white-matter disease, lacunes, microbleeds and previous haemorrhage.
Interpretation and limitations
Judge location and burden against the phenotype. Microbleed distribution may suggest hypertensive arteriopathy or cerebral amyloid angiopathy and informs, but does not alone dictate, antithrombotic decisions.
04
Vascular mechanism assessment
Why
Identify treatable sources of recurrent embolic or small-vessel injury.
Interpretation and limitations
Use blood pressure, ECG and rhythm monitoring, vascular imaging, lipids, glucose or HbA1c, renal function and echocardiography according to the stroke phenotype rather than as a uniform dementia panel.
05
Neurodegenerative assessment or biomarkers
Why
Investigate mixed Alzheimer or Lewy body pathology when the clinical course exceeds vascular explanation.
Interpretation and limitations
Disproportionate episodic-memory storage failure, hallucinations, fluctuation or progressive visuospatial disease may justify memory-service biomarker or functional-imaging assessment.

06Differential diagnosisRealistic alternatives and the features that help distinguish them.

Alzheimer disease

Insidious storage-memory failure with medial temporal atrophy favours Alzheimer disease, although mixed vascular pathology is frequent.

Dementia with Lewy bodies

Visual hallucinations, marked cognitive fluctuation, REM sleep behaviour disorder and spontaneous parkinsonism support dementia with Lewy bodies.

Frontotemporal dementia

Early behavioural, empathy or language change with frontal or anterior temporal atrophy favours a frontotemporal degenerative disorder.

Delirium or depression

Acute fluctuating attention indicates delirium, while prominent low mood and effort-related cognitive performance may reflect depression.

07ManagementImmediate care, first-line treatment, alternatives and escalation.

01New deficitDo not miss acute strokeFirst stepCognition or function changes suddenly, with or without an obvious focal sign.

11. Record last-known-well time, perform ABCDE, check glucose and activate the local stroke pathway for sudden language, neglect, visual, executive or memory change.
22. Obtain urgent brain and vascular imaging and assess reperfusion or haemorrhage management through the stroke team.
33. Treat delirium, seizure, infection and metabolic mimics in parallel, avoiding an assumption that previous dementia explains the event.
44. Defer stable cognitive classification until the acute syndrome and immediate post-stroke delirium have been reassessed.

02AttributeConnect disease burden to cognitionPersistent cognitive decline coexists with known or suspected cerebrovascular disease.

11. Reconstruct the cognitive trajectory, every stroke or transient event, vascular exposures, gait and instrumental functional change with collateral evidence.
22. Test executive speed, attention, memory, language and visuospatial domains and examine focal neurology, gait and parkinsonism.
33. Compare MRI lesion age, location and burden with the syndrome and document whether causation is probable, mixed or uncertain.
44. Refer atypical early-onset or familial small-vessel disease and pursue Alzheimer or Lewy body evaluation when vascular findings are insufficient.

03Prevent and supportProtect remaining brain functionA vascular cognitive formulation has been established.

11. Identify the prior stroke mechanism and prescribe antiplatelet, anticoagulant and lipid treatment only to the evidence-based vascular indication.
22. Agree blood pressure, diabetes, smoking, activity, weight and sleep-apnoea work with tolerability, falls and cerebral perfusion in mind.
33. Provide gait, falls, occupational, speech, mood and cognitive rehabilitation and adapt tasks to executive slowing.
44. Review driving, medication and financial safety, capacity, carer strain and advance planning through coordinated stroke, memory and primary-care services.

Key medicines and prescribing safety3 treatments · regimens, roles and cautions

Reduces recurrent atherothrombotic stroke risk when previous non-cardioembolic infarction provides an indication, thereby limiting additional vascular brain injury.

Clopidogrel after non-cardioembolic ischaemic stroke

A common long-term secondary-prevention regimen is 75 mg orally once daily after the acute antiplatelet phase, selected according to current stroke guidance and individual tolerance.

It does not treat cognition directly and should not be started for white-matter change alone. Review bleeding, interactions, adherence and whether atrial fibrillation instead requires anticoagulation.

Lowers recurrent ischaemic vascular risk in people with a qualifying stroke or atherosclerotic indication.

High-intensity statin after ischaemic stroke

Current secondary-prevention pathways commonly use atorvastatin 80 mg once daily unless interactions, adverse-effect risk or another clinical factor justifies a lower intensity.

Check liver profile and interaction history and assess muscle symptoms. Statins are not prescribed specifically to slow Alzheimer disease or incidental cognitive impairment, and haemorrhage context may need specialist review.

Prevents unsupported cognitive prescribing while encouraging accurate recognition of mixed pathology where symptomatic treatment may be reasonable.

No routine cholinesterase inhibitor for pure vascular dementia

Do not initiate donepezil, rivastigmine, galantamine or memantine for vascular dementia unless suspected comorbid Alzheimer disease, Parkinson disease dementia or Lewy body dementia creates a NICE indication.

Do not equate lack of a cognitive drug with lack of treatment. Vascular prevention, rehabilitation, mood care, environmental adaptation and carer support remain active interventions.

08ComplicationsImportant consequences, why they occur and why they matter clinically.

Recurrent stroke and stepwise decline

An untreated vascular mechanism can cause further infarction or haemorrhage with abrupt additional cognitive and physical disability.

Gait, falls and urinary dysfunction

Subcortical disease disrupts motor and bladder networks, causing imbalance, falls, fractures, urgency and progressive loss of independence.

Executive and safeguarding harm

Impaired planning and judgement compromise safe management of medicines, finances, cooking and driving, increasing vulnerability to exploitation.

Mood and carer burden

Apathy, depression, emotional lability and physical disability reduce participation and increase sustained family and professional support needs.

09Monitoring and follow-upTreatment response, safety checks and longer-term review.

Track recurrent stroke or TIA symptoms, blood pressure, lipids, diabetes, rhythm and adherence at intervals matched to the vascular mechanism and medicines.
Review executive function, gait, falls, continence, mood and instrumental activities rather than focusing only on delayed recall.
Monitor bleeding, anaemia, renal function and interactions for antithrombotic treatment, revisiting risk after falls, haemorrhage or new microbleed information.
Repeat cognitive and functional assessment after rehabilitation and vascular events, separating residual deficit from delirium and depression.
Reassess the subtype if decline becomes steadily amnestic, hallucinations or fluctuation emerge, or imaging burden no longer explains clinical progression.

10Special situationsVariants, exceptions and circumstances that change the usual approach.

Small infarct, large effect

A lesion in a strategic thalamic, hippocampal, caudate or dominant parietal node can disrupt a whole cognitive network despite modest infarct volume.

Stepwise is not mandatory

Cumulative small-vessel injury often causes gradual slowing and gait change, so a smooth trajectory does not exclude a vascular contribution.

Imaging needs proportionality

White-matter hyperintensities are common with age; the burden, location and associated lacunes or microbleeds must plausibly account for the syndrome.

Mixed pathology is ordinary

Alzheimer and vascular injury frequently coexist, and acknowledging both can better explain phenotype and open appropriate prevention and cognitive treatment pathways.

Prevention remains worthwhile

Established cognitive impairment does not remove the benefit of preventing another stroke, provided targets and medicines are balanced against frailty and bleeding.

11Common pitfallsFrequent interpretation and management errors.

01
Diagnosing vascular dementia from hypertension plus mild white-matter change ignores whether the brain injury is sufficient to explain functional decline.
02
Withholding acute stroke assessment because the patient already has dementia can miss reperfusion treatment and preventable disability.
03
Starting aspirin for cognitive impairment without prior vascular indication creates bleeding risk without established cognitive benefit.
04
Using a memory-heavy screen alone under-detects processing-speed and executive deficits typical of subcortical small-vessel disease.
05
Rejecting mixed pathology can lead to missed Alzheimer treatment or inadequate vascular secondary prevention.