Vascular Dementia

1. Definition

Vascular dementia (VaD) is a cognitive decline due to cerebrovascular disease, resulting from ischemic or hemorrhagic brain injury affecting cognition.

  • 2nd most common dementia after Alzheimer’s disease
  • Often mixed pathology (VaD + Alzheimer’s)

2. Epidemiology 

  • Accounts for 15–20% of dementias
  • ↑ incidence with:
    • Age
    • Vascular risk factors
  • More common in men
  • Strong association with:
    • Hypertension
    • Diabetes
    • Stroke history

3. Pathophysiology

A. Mechanisms

  1. Large vessel disease
    • Multi-infarct dementia
  1. Small vessel disease (most common)
    • Lacunar infarcts
    • White matter ischemia
  1. Strategic infarcts
    • Thalamus, hippocampus, angular gyrus
  1. Hypoperfusion states
    • Cardiac failure, hypotension

B. Subtypes 

1. Multi-infarct dementia

  • Stepwise decline
  • Cortical deficits

2. Subcortical ischemic vascular dementia (SIVD)

  • Includes Binswanger disease
  • White matter changes
  • Executive dysfunction

3. Strategic infarct dementia

  • Single infarct → disproportionate deficit

4. Mixed dementia

  • VaD + Alzheimer’s (very common)

4. Risk Factors 

Modifiable

  • Hypertension (MOST IMPORTANT)
  • Diabetes mellitus
  • Dyslipidemia
  • Smoking
  • Atrial fibrillation

Non-modifiable

  • Age
  • Male sex
  • Prior stroke

5. Clinical Features

A. Cognitive Profile

  • Executive dysfunction (earliest & prominent)
  • ↓ attention
  • ↓ processing speed
  • Memory less affected early (vs Alzheimer’s)

B. Pattern of Decline

  • Stepwise deterioration (classic)
  • Fluctuating course
  • Periods of stability

C. Focal Neurological Signs 

  • Hemiparesis
  • Hyperreflexia
  • Babinski sign
  • Gait disturbance

D. Other Features

  • Pseudobulbar palsy
  • Emotional lability
  • Early urinary incontinence
  • Depression common

6. Comparison with Alzheimer’s 

Feature

Vascular Dementia

Alzheimer’s

Onset

Sudden/stepwise

Insidious

Progression

Fluctuating

Gradual

Memory

Mild early

Severe early

Executive function

Early affected

Late

Neuro deficits

Present

Absent early

Imaging

Infarcts, WM changes

Cortical atrophy

 

7. Diagnosis

A. Diagnostic Criteria

  • Cognitive impairment affecting ≥1 domain
  • Evidence of cerebrovascular disease
  • Temporal relationship (stroke → decline)

 

B. DSM-5 Terminology

  • “Major neurocognitive disorder due to vascular disease”

C. Investigations

1. MRI Brain (BEST TEST)

  • White matter hyperintensities
  • Lacunes
  • Cortical infarcts

2. CT Brain

  • Infarcts
  • Leukoaraiosis

3. Blood tests (to exclude reversible causes)

  • B12
  • TSH
  • Glucose
  • Lipids

8. Diagnostic Criteria Systems 

NINDS-AIREN Criteria

Requires:

  1. Dementia
  2. Cerebrovascular disease
  3. Relationship between the two

 

9. Management 

A. Core Principle

 PREVENT FURTHER VASCULAR EVENTS

 

B. Risk Factor Control 

  • BP control (target individualized)
  • Glycemic control
  • Lipid lowering (statins)
  • Smoking cessation

C. Antiplatelet Therapy

  • Aspirin / Clopidogrel
  • Indicated if ischemic stroke/TIA history

D. Anticoagulation

  • If atrial fibrillation → DOAC/warfarin

E. Cognitive Enhancers

  • Limited benefit but may be used:
    • Donepezil
    • Rivastigmine(especially in mixed dementia)

F. Non-Pharmacological

  • Cognitive rehabilitation
  • Physiotherapy
  • Fall prevention

10. Prognosis

  • Worse than Alzheimer’s in some cases
  • Stepwise decline
  • High mortality (due to vascular events)

11. Important Differentials

  • Alzheimer’s disease
  • Lewy body dementia
  • Frontotemporal dementia
  • Normal pressure hydrocephalus

12. Advanced Concepts 

A. Binswanger Disease

  • Subcortical VaD
  • Extensive white matter ischemia
  • Gait + executive dysfunction

B. CADASIL 

  • Genetic small vessel disease
  • Migraine + strokes + dementia
  • NOTCH3 mutation