White matter hyperintensities

Definition of white matter hyperintensities


White matter describes the deep regions of the brain that contain the axons or "wiring" of the brain, connecting different areas of the brain and allowing for normal cognitive function.

Certain MRI scan sequences can reveal white matter hyperintensities seen as bright signals in otherwise dark brain tissue.  The below images show a range of less severe (left) to severe white matter (right) white matter disease.


White matter hyperintensities, image from Wardlaw et al, 2015, DOI: 10.1161/JAHA.114.001140.

What is the clinical significance of white matter hyperintensities?


Pathology studies have shown abnormalities in blood vessels, white matter tracks, and other tissue within white matter hyperintensities. It is thought that abnormal blood vessel and other cell dysfunction result in white matter hyperintensities.

Causes of white matter hyperintensities

  • Traumatic brain injury

  • Neurodegenerativ

  • Age related changes to blood vessels

  • Hypertension

  • Diabetes

  • Congenital factors

Treatment in patients with white matter hyperintensities

  • Control of hypertension and diabetes

  • Exercise

  • Avoidance of further brain injury