White matter damage (WMD) is damage to the so-called white matter of the brain. White matter are the fibrous tracts of the brain that make up a large part of the whole brain. Periventricular leukomalacia (PVL), which is addressed in this section of this site, is a form of WMD adjacent to the ventricles of the brain, often due to fluctuations in blood pressure or inflammation associated with prematurity. WMD can occur in other areas of the brain for other reasons.
The range of severity and possible subsequent long-term outcomes from WMD is wide. In many cases, the area of damage may have a larger impact than the extent of damage; the various functions of the brain are often controlled by very specific and well defined areas. For this reason, a limited amount of damage in the wrong place can mean lasting and possibly severe effects. Conversely, some babies can recover from extensive damage provided no vital areas are affected. Brain function, especially in babies, is flexible in that, depending on circumstance, it has an ability to recover if a certain neural pathway is damaged. Sometimes the brain can find a new route to send information and commands from one part of the brain to another to get around the problem.