Overview
Recognise cognitive and functional impairment caused by cerebrovascular injury, distinguish acute stroke and mixed dementia, use imaging and collateral chronology coherently, and prevent further vascular harm without prescribing dementia drugs outside supported indications.
Reconstruct cognition around vascular events. Ask whether loss followed a stroke, appeared in steps or progressed steadily, and document focal deficits, gait, continence, mood and IADLs. Establish pre-stroke and post-stroke function through collateral. A dramatic ward decline can reflect delirium and deconditioning rather than a new stable dementia stage.
Examine pulse and rhythm, blood pressure including posture when safe, bruits only where clinically relevant, focal neurology, visual fields, speech, gait, parkinsonism and sensation. Cognitive testing should sample executive function and processing speed rather than relying on memory alone. Depression, apathy and aphasia can distort apparent performance.
MRI is preferred when feasible to show cortical and strategic infarcts, lacunes, white-matter hyperintensity, microbleeds and atrophy. CT identifies larger lesions and is often sufficient in acute stroke. Imaging must be proportional to the cognitive phenotype: common incidental small-vessel change does not establish causality.
Aetiology
Large-vessel infarction
Strategic or multiple cortical strokes disrupt memory, language, visuospatial and executive networks according to lesion location.
Cerebral small-vessel disease
Lacunes, white-matter injury and microbleeds damage frontal-subcortical connections, producing slowed processing, executive and gait dysfunction. This increases vulnerability across cognition, function and daily care.
Haemorrhagic and hypoperfusion injury
Intracerebral haemorrhage, cerebral amyloid angiopathy and severe hypoperfusion can leave persistent cognitive impairment. This increases vulnerability across cognition, function and daily care.
Mixed vascular-neurodegenerative disease
Vascular lesions commonly lower the threshold for symptoms from Alzheimer or Lewy-body pathology in later life.
Pathophysiology
- 1Network disconnection
Infarcts and white-matter tract injury disconnect frontal, subcortical and cortical circuits needed for attention, planning and speed.
- 2Cumulative lesion burden
Repeated overt or silent vascular injury reduces reserve, causing stepwise, fluctuating or gradually progressive decline. This influences cognition, mobility and everyday functional reserve.
- 3Strategic-location effect
A small thalamic, hippocampal or angular-gyrus lesion can cause disproportionate cognitive change despite modest total volume.
- 4Endothelial and perfusion dysfunction
Hypertension, diabetes and arteriopathy promote barrier damage, chronic ischaemia and impaired neurovascular coupling. This influences cognition, mobility and everyday functional reserve.
- 5Interaction with neurodegeneration
Vascular injury and amyloid or tau pathology have additive effects, making clean clinical separation difficult. This influences cognition, mobility and everyday functional reserve.
Clinical features and red flags
Slow processing, poor set shifting and reduced initiation dominate over isolated forgetting.
Aphasia, neglect, visuospatial or memory syndrome maps to strategic or cortical vascular injury.
Short-stepped gait, falls, apathy, lability or depression accompanies frontal-subcortical disease.
A dated cognitive and functional decrement follows a cerebrovascular event, with partial plateau or recovery.
Sudden focal or cognitive deficit remains an emergency regardless of established dementia.
Progressive amnesia, hallucinations or parkinsonism exceeds what vascular location and burden explain.
Investigations
- 01
Collateral event-function timelineFirst step - Why
- Connect vascular events to acquired decline.
- Interpretation and limitations
- Map strokes, steps, recovery, IADLs, gait and behaviour and separate acute delirium from stable loss.
- 02
Cognitive and neurological assessment - Why
- Characterise executive and focal deficits.
- Interpretation and limitations
- Use accessible testing plus speech, fields, power, coordination, sensation, gait and parkinsonism examination.
- 03
MRI or CT brain - Why
- Define cerebrovascular burden and alternatives.
- Interpretation and limitations
- Relate infarct location, lacunes, white-matter change, microbleeds and atrophy to phenotype rather than counting lesions.
- 04
Vascular risk assessment - Why
- Find modifiable recurrent-injury drivers. within a safe older-adult assessment.
- Interpretation and limitations
- Assess ECG or rhythm for AF, pressure, lipids, diabetes, smoking, kidney function, weight and sleep-apnoea risk.
- 05
Delirium and contributor work-up - Why
- Explain acute or disproportionate worsening.
- Interpretation and limitations
- Use 4AT, medicine review, mood, hearing, vision and targeted medical tests whenever trajectory changes.
Differential diagnosis
Alzheimer disease
Prominent progressive episodic-memory encoding with medial temporal atrophy suggests Alzheimer dominance, though mixed disease is frequent.
Lewy-body dementia
Visual hallucinations, REM-sleep behaviour, parkinsonism and marked cognitive fluctuation point beyond ordinary vascular variability. Distinguish it through chronology, examination and targeted testing.
Delirium and depression
Acute inattention or mood-related slowing can mimic deterioration and require parallel assessment and treatment. Distinguish it through chronology, examination and targeted testing.
Normal-pressure hydrocephalus
Gait-predominant decline, urinary symptoms and ventriculomegaly may justify specialist CSF-dynamics assessment. Distinguish it through chronology, examination and targeted testing.
Medication and systemic disease
Sedatives, anticholinergics, hypotension, hypoglycaemia and organ failure can worsen executive performance and falls. Distinguish it through chronology, examination and targeted testing.
Management
01Diagnostic sequenceLink phenotype, function and vascular injuryFirst stepPersistent cognitive decline occurs with stroke or vascular disease.+
- 1Exclude acute stroke and delirium and obtain a dated collateral cognitive and functional trajectory.
- 2Complete executive, focal, mood and gait assessment with MRI or CT and vascular risk evaluation.
- 3Diagnose vascular or mixed dementia only when lesion burden and location plausibly fit the impairment.
02First-line preventionPrevent another vascular injury safelyFirst lineA cerebrovascular mechanism and modifiable risks are present.+
- 1Determine cardioembolic, non-cardioembolic, haemorrhagic or primary-prevention context before prescribing antithrombotic therapy.
- 2Individualise pressure, lipid, diabetes, smoking, exercise and nutrition measures against posture, bleeding and treatment burden.
Complications
Recurrent stroke and disability
Further infarction or haemorrhage adds focal impairment, dysphagia, dependency and mortality. Anticipatory multidisciplinary prevention and review are therefore important.
Gait disorder and falls
Frontal-subcortical injury, weakness and impaired judgement combine with vascular medicines and postural hypotension. Anticipatory multidisciplinary prevention and review are therefore important.
Emotional and behavioural change
Apathy, depression, lability, disinhibition and slowed initiation affect rehabilitation and relationships. Anticipatory multidisciplinary prevention and review are therefore important.
Swallowing and continence difficulty
Stroke burden and executive impairment increase aspiration, malnutrition, urgency and care needs. Anticipatory multidisciplinary prevention and review are therefore important.
Polypharmacy and treatment harm
Aggressive pressure or glucose control, bleeding and interactions can undermine cognition, mobility and quality of life.
Monitoring and follow-up
- Review new focal or fluctuating change urgently rather than waiting for routine dementia follow-up.
- Track blood pressure including posture, AF treatment, lipids, diabetes, renal function, bleeding and medicine adherence.
- Follow gait, falls, swallowing, mood, IADLs and carer workload alongside cognition.
- Reassess mixed pathology if amnesia, hallucinations, fluctuation or parkinsonism becomes prominent.
- Align stroke, memory and primary-care plans so antithrombotic and monitoring ownership is explicit.
Special situations
Stepwise is not mandatory
Small-vessel cognitive impairment can progress gradually without clinically recognisable strokes.
Location can outweigh volume
A strategic small infarct may be more cognitively important than extensive silent white-matter change.
Aspirin is not a dementia drug
Antithrombotic treatment requires its own vascular indication and benefit-harm assessment.
Mixed pathology is frequent
Alzheimer and vascular changes often contribute together rather than competing for a single label.
Apathy is not laziness
Frontal-subcortical injury impairs initiation and needs cueing and rehabilitation strategies.
Prevention cannot reverse infarction
The aim is avoiding further injury while adapting to established loss.
Common pitfalls
- 01
Calling incidental white-matter change the sole cause of cognitive symptoms.
- 02
Missing acute stroke because vascular dementia is already documented.
- 03
Giving antiplatelet treatment solely for a dementia label without a vascular indication.
- 04
Using donepezil routinely for pure vascular dementia contrary to NICE subtype guidance.
- 05
Pursuing aggressive pressure or glucose targets despite falls, posture symptoms or hypoglycaemia.
- 06
Neglecting depression, gait and carer support while focusing on brain imaging.