Leukoariosis

Related Subjects: |Neurological History taking | Causes of Stroke | Ischaemic Stroke |Hypertension |Small Vessel Disease |CADASIL |CARASIL

Cause is likely lipohyalinosis of small penetrating arteries within the white matter due to chronic hypertension

About

• Subcortical white matter frequent complication of hypertension
• Microvascular disease contributes to the risk of stroke and vascular dementia
• Increased risk of sCH especially with tPA
• Increased risk of basal ganglia and lobar bleeds

Aetiology

• Damage to the cerebral microcirculation
• Leukoaraiosis is a radiological marker for chronic ischaemic damage
• It is associated with greater risk of sICH after tPA?

Risks for small vessel disease

• Hypertension, Diabetes, Coronary artery disease
• Obesity (body mass index 30 or higher)
• Elevated homocysteine, Inactive lifestyle
• Age over 45 in men and over 55 in women

Pathology

• Myelin degeneration, proliferative astrogliosis
• Thickening with hyaline changes, and fibrosis of the wall of small deep vessels
• Coexisting cavitated or non-cavitated small deep infarcts

Clinical

• Stroke - lacunar infarcts and subcortical bleeds
• Vascular dementia - once called Binswanger's disease
• Negative association with AF and carotid disease
• Parkinsonism
• Asymptomatic until late

Other causes of Leukokariosis

• Cerebral amyloid angiopathy (CAA)
• Cerebral autosomal dominant arteriopathy stroke and ischemic leukoencephalopathy (CADASIL).

Investigations

• CT: periventricular hypodensity +/- lacunes
• MRI with high-resolution T2-weighted sequence. Severity can be scored using the FLAIR sequence or high-resolution T2-weighted sequence for deep WM and periventricular WM. Usually seen as bilateral and symmetrical white matter injury surrounding the ventricles and within the corona radiata. Described as caps or rims or halos or subcortical multiple punctuate or patchy, partially confluent or confluent areas. Areas of lacunar infarction are often seen also. Gradient-echo T2-weighted MRI sequences may also find silent cerebral microbleeds

Scoring system based on FLAIR

Deep white matter lesions were scored as follows:
• 0, no lesion
• 1, punctuate foci
• 2, beginning confluent foci
• 3, confluent changes

  Periventricular white matter lesions were scored as follows:

• 0, no changes
• 1, caps or a pencil-thin lining
• 2, smooth halo
• 3, irregular changes extending into deep white matter

Management

• Manage BP, Diabetes and other risk factors. Aim lowest BP tolerated.

References

• Leukoaraiosis, An Independent Risk Factor for Stroke?. Domenico Inzitari. Stroke. 2003;34:2067-2071