What is Vascular Brain Disorder (VBD)?

Vascular Brain Disorder (VBD): Definition and Clinical Implications

Vascular Brain Disorder (VBD) refers to a spectrum of cognitive deficits attributed to or accelerated by cerebrovascular injury, encompassing conditions from mild cognitive impairment to dementia caused by vascular pathology in the brain. 1

Definition and Terminology

VBD is more commonly referred to in current medical literature as Vascular Cognitive Impairment (VCI), which serves as an umbrella term for cognitive disorders associated with cerebrovascular disease. This terminology includes:

• Vascular Cognitive Impairment (VCI) - the broad spectrum of cognitive changes due to vascular pathology
• Vascular Dementia (VaD) - more severe form with functional impairment
• Vascular Mild Cognitive Impairment (vMCI) - milder form without significant functional impairment
• Cerebral Small Vessel Disease (CSVD) - a key pathological component of VCI 1, 2

Pathophysiology

VBD/VCI results from various cerebrovascular pathologies:

• Macrovascular disease:

  • Large vessel strokes (macroangiopathy, arteriosclerosis)
  • Cortical or subcortical infarcts

• Microvascular disease:

  • Small vessel disease (microangiopathy, arteriolosclerosis)
  • White matter lesions (leukoaraiosis)
  • Lacunar infarcts
  • Microhemorrhages
  • Enlarged perivascular spaces 1, 2

• Endothelial dysfunction:

  • Blood-brain barrier failure
  • Fibroid necrosis
  • Microaneurysm formation 2

Clinical Presentation

The pattern of cognitive deficits in VBD may include impairments in:

• Attention
• Learning and memory
• Language
• Perception
• Processing speed
• Executive functions (social cognition, problem-solving, decision-making)
• Focal stroke syndromes (aphasia, spatial neglect) 1

Diagnostic Framework

Diagnosis of VBD/VCI requires three main components:

1. Cognitive assessment: Validated cognitive screens and assessments to identify cognitive deficits
2. Neuroimaging: To identify cerebrovascular pathology
3. Functional assessment: To determine impact on daily activities 1

Neuroimaging Findings

• MRI (preferred modality):

  • White matter hyperintensities on T2-weighted images
  • Lacunar infarcts (small subcortical infarcts <1cm)
  • Microbleeds
  • Enlarged perivascular spaces 1, 2

• CT Head:

  • Can detect infarctions, white matter changes, and brain atrophy
  • Less sensitive than MRI for detecting small vessel disease 1

Relationship to Other Conditions

VBD/VCI frequently coexists with other neurodegenerative processes:

• Mixed pathology with Alzheimer's disease is common
• Can occur in association with other vascular conditions:
  • Heart failure
  • Hypertension
  • Atrial fibrillation
  • Diabetes
  • Renal failure 1, 3

Clinical Significance

VBD/VCI is associated with significant impacts on morbidity, mortality, and quality of life:

• Second most common form of dementia after Alzheimer's disease 3
• Occurs in approximately 30% of individuals after a first stroke 1
• Risk increases with age, stroke severity, and stroke recurrence
• Can occur without overt stroke symptoms due to covert cerebrovascular disease 1

Management Implications

Early identification of VBD/VCI is crucial as progression may be slowed through:

• Aggressive treatment of vascular risk factors
• Blood pressure management
• Treatment of diabetes, hyperlipidemia, and obesity
• Smoking cessation 2, 4

Neuropathological Assessment

In post-mortem examination, VBD is characterized by:

• Cerebrovascular disease including infarcts and hemorrhages
• Vascular abnormalities (atherosclerosis, arteriolosclerosis)
• Multiple subcortical ischemic lesions in basal ganglia and deep white matter 1, 5

VBD represents a significant clinical entity with substantial impact on cognitive function and quality of life, requiring prompt identification and management of vascular risk factors to potentially slow disease progression.