Leukoaraiosis: White Matter Changes – Causes, Imaging & Clinical Significance

Leukoaraiosis (Greek leukos "white" + araios "rarefied") refers to bilateral, symmetric hyperintensities in cerebral white matter on T2/FLAIR MRI, reflecting chronic small-vessel ischemic change (white matter hyperintensities, WMH).

Pathophysiology

• Chronic hypoperfusion → demyelination, axonal loss, gliosis, perivascular space dilation.
• Blood-brain barrier disruption → fluid extravasation.
• Not a disease per se; a radiologic marker of cerebral small vessel disease (cSVD).

Major Risk Factors

• Age – Prevalence >90% by age 80.
• Hypertension – Strongest modifiable risk factor (lipohyalinosis of penetrating arterioles).
• Diabetes mellitus – Microvascular damage.
• Cardiovascular disease – Atrial fibrillation, coronary artery disease, heart failure.
• Smoking, dyslipidemia, obesity, sleep apnea, CKD.
• Genetic: NOTCH3 (CADASIL), COL4A1/A2, HTRA1 (CARASIL).

Grading Scales

• Fazekas Scale (periventricular + deep WMH): 0 (none) → 3 (confluent).
• Scheltens Scale – Regional volumetric scoring.

Clinical Correlates

• Often asymptomatic initially.
• Associated with: gait disturbance, urinary urgency, cognitive decline (processing speed, executive function), depression, stroke recurrence, dementia conversion.
• Not synonymous with lacunar infarcts (though often coexist).

Management

• Aggressive vascular risk factor control (BP <130/80, statin, glycemic control, smoking cessation, exercise).
• Antiplatelet therapy for secondary stroke prevention.
• Monitor cognition/gait; screen for mood disorders.

Leukoaraiosis is a window into brain vascular health—its burden predicts future neurologic decline.