Leukoaraiosis, also referred as ischemic demyelination or age-related white matter disease, is a radiological term given to diffuse white matter rarefaction. It consists of bilateral patchy or diffuse white matter changes often observed on imaging studies 6-7.
It is commonly observed with elderly people, and it is a finding related to vascular dementia.
Pathogenesis and, especially, its clinical significance, are still incompletely understood 3,5.
It appears to be a multifactorial process that can result from arteriosclerotic changes in the vulnerable deep penetrating vessels supplying the deep white matter and periventricular regions that lack collateral supply. Hence, it is associated with diabetes and hypertension; chronic hypertensive encephalopathy is considered the most common cause of leukoaraiosis.
Lacunar infarcts in the basal ganglia occur due to the same reason.
Histology from these lesions show atrophy of axons and decreased myelin.
On both CT and MRI, leukoaraiosis is characterised by bilateral patchy or confluent white matter changes. A scale has been proposed by Fazekas to quantify the degree of white matter changes.
On CT, white matter changes appear has non-enhancing hypodensities.
- hypointense or isointense, less conspicuous than on T2/FLAIR
T1 C+ (Gd)
History and etymology
The term comes from the Greek (leuko = white and araios = rarefaction) and was first proposed by Vladimir Hachinski, a Ukrainian-born Canadian neurologist 6.
The differential diagnosis is wide and includes multiple diseases involving the white matter, including:
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