Progression of leukoaraiosis and cognition

Background and Purpose - Leukoaraiosis is used interchangeably with the term white matter lesions on MRI and seen to some degree in more than half of the routine scans in older persons. Clinicians often struggle to explain the implications of these findings to their patients. Recent data on the progression rate of ischemic white matter damage and its cognitive consequences may help in patient counseling and have implications on treatment trials in vascular cognitive impairment. Summary of Review - Leukoaraiosis progresses over time. Its extent at baseline is an important predictor for the subsequent rate of lesion progression. Subjects with punctate abnormalities on MRI have a low tendency for progression, individuals with early confluent and confluent changes tend to progress rapidly. Differences in measurement methods and cohort composition make it difficult to compare progression rates reported by different studies. Nevertheless, in community-dwelling cohorts, white matter lesions volume increased by as much as one quarter per year in subjects with confluent abnormalities at baseline. Progression of leukoaraiosis relates to cognitive decline, but this association is complex and modulated by other morphological factors like brain atrophy. Conclusions - Evidence for rapid progression of widespread leukoaraiosis and the associated cognitive decline in domains particularly affected by cerebral small vessel disease has set the stage for exploratory clinical trials in vascular cognitive impairment using white matter lesions progression as a surrogate marker.