Periventricular Leukomalacia

Periventricular leukomalacia (PVL) is a type of brain injury most common in very premature babies.

• PVL is injury to the white matter around the fluid-filled ventricles of the brain. White matter transmits information between nerve cells, the spinal cord, and from one part of brain to the other
• PVL is common in very premature, low birthweight babies. It is the second most common complication involving the central nervous system in premature infants.
• PVL can cause damage to the nerve pathways that control motor movements, resulting in muscles that are tight, spastic, or resistant to movement, in addition to being weak.
• Babies with PVL have a higher risk of cerebral palsy and may have learning difficulties and other developmental problems.
• There is no treatment for PVL. The prognosis varies depending on the severity of the damage to the brain.

Every child with PVL is unique and will have his or her own set of symptoms, which often become apparent over time as the child develops, rather than all at once.

The most common symptoms of PVL are:

• Trouble with vision and with eye movements
• Trouble with movement, and tight muscles
• Developmental delay that is increasingly apparent over time

Although the exact cause of PVL is not known, the condition is thought to be caused when the areas of the brain around the ventricles (the fluid-filled spaces of the brain) don’t get enough blood. This area of the brain is very prone to injury, especially in premature babies whose brain tissue is fragile. The more premature a baby is, the higher the risk for PVL.

Other factors that may be associated with PVL include:

• Bleeding inside the brain (intraventricular hemorrhage)
• Premature rupture of membranes (amniotic sac)
• Infection inside the uterus

Newborns may not show symptoms of PVL in the first few days of life. However, since premature infants have an increased risk of developing the condition, doctors may perform the following diagnostic tests:

• Cranial ultrasound: a painless test that uses sound waves to view the baby's brain through the soft spot on top of the head (fontanel)
• Magnetic resonance imaging (MRI): this imaging procedure uses a magnetic field and radio to produce a detailed picture of the brain without exposing the infant to X-rays. PVL is a term that describes the way the affected infant’s brain looks on an MRI.

Clinicians in the Fetal-Neonatal Neurology Program at Boston Children's Hospital provide comprehensive early and accurate diagnosis of periventricular leukomalacia and other brain injuries acquired by newborns and young infants. Because newborns' brains are in a crucial window of rapid development, we identify problems as early as possible and act quickly to prevent as much damage as possible.

Although there is no treatment for PVL, we may recommend other types of care for your child, such as:

• Physical therapy
• Occupational therapy
• Speech-language therapy
• Vision therapy

Most of these therapies are provided through early intervention programs in your community. Here at Boston Children's, we work to connect families to early intervention and support them in other ways such as transitioning to another program in our hospital that specializes in caring for older children.

The long-term outlook for babies with PVL depends upon the severity of the initial brain damage. The types of symptoms vary widely and can range from a child who has minimal problems to a child who has severe delays and problems with movement.

Clinicians in our Fetal-Neonatal Neurology Program provide early and accurate diagnosis of PVL and other brain injuries acquired by newborns and young infants. We follow newborns who’ve been seen in the Neonatal Intensive Care Unit (NICU) at Boston Children’s as well as other hospitals. After your baby has been discharged from the NICU, we continue to monitor his neurological progress to provide treatments that will help his long-term development.

Boston Children’s neurologist Joseph Volpe, MD, has made his life’s work the study of PVL, which is responsible for many cognitive, behavioral and motor disabilities in children born prematurely. Volpe’s work has helped doctors understand which infants are at risk for this sort of brain injury and how it could be prevented or treated. Volpe is considered by many to have founded the field of neonatal neurology. His textbook, Neurology of the Newborn, is a standard in the field.

Children who develop PVL often have problems with their vision that is related to the brain injury instead of a problem with the eyes. This “cerebral visual impairment” can be difficult to diagnose and treat. It is important to identify this problem because these types of visual impairments can affect a child’s ability to learn in school. Janet Soul, MDCM, is conducting a research study of cerebral visual impairment in children who were born prematurely.

If you want to look for other clinical trials going on throughout Boston Children’s, search here.

Periventricular leukomalacia: Reviewed by Benjamin C. Warf, MD; © Boston Children’s Hospital; posted in 2012