[Age-related white matter lesions (leukoaraiosis): an update].

Leukoaraiosis (age-related white matter hyperintensities) is the most frequently seen lesion on brain magnetic resonance (MR) images. This lesion is a subject of much current interest, because a number of multicenter studies have revealed that it is associated with various disturbances and poor prognoses. Leukoaraiosis corresponds to various pathologies, including demyelination, apoptosis, edema, dilated perivascular spaces, axonal damage, gliosis, and infarcts. Also noted in leukoaraiosis are changes in small vessels, such as fibrohyalinosis and venous collagenosis. The main cause of leukoaraiosis is thought to be chronic ischemia; other causes include edema and breakdown of the blood-brain barrier. Major risk factors for leukoaraiosis are age and hypertension. Disturbances that are related to leukoaraiosis include stroke, dementia, cognitive impairment, gait disturbance, fall, and depression. Leukoaraiosis is also a risk factor for death. Technologies, such as automatic volumetry, tissue segmentation, diffusion tensor imaging, magnetization tensor imaging, diffusion kurtosis imaging, and ultra-high field MR imaging may provide further insights into leukoaraiosis.