Softening or destruction of the white matter of the brain. Brain tissue that surrounds fluid-filled parts of the brain (ventricles) is destroyed. It tends to occur mainly in premature or newborn babies who have been deprived of oxygen or have poor blood flow to parts of the brain. Intrauterine infections and premature membrane rupture tend to predispose infants to this condition. This type of brain destruction can cause cerebral palsy. Severity of symptoms varies according to the degree of injury to the brain.
- Enlarged brain ventricle
- Neurological problems
- Developmental problems
- Asymptomatic during newborn period
- Mental retardation
Preventing or delaying premature birth is considered the most important step in decreasing the risk of PVL. Common methods for preventing a premature birth include self-care techniques (dietary and lifestyle decisions), bed rest, and prescribed anti-contraction medications. Avoiding premature birth allows the fetus to develop further, strengthening the systems affected during the development of PVL. An emphasis on prenatal health and regular medical examinations of the mother can also notably decrease the risk of PVL. Prompt diagnosis and treatment of maternal infection during gestation reduces the likelihood of large inflammatory responses. Additionally, treatment of infection with steroids (especially in the 24-31 weeks of gestation) have been indicated in decreasing the risk of PVL. It has also been suggested that avoiding maternal cocaine usage and any maternal-fetal blood flow alterations can decrease the risk of PVL. Episodes of hypotension or decreased blood flow to the infant can cause white matter damage.
As previously noted, there are often few signs of white matter injury in newborns. Occasionally, physicians can make the initial observations of extreme stiffness or poor ability to suckle. The preliminary diagnosis of PVL is often made using imaging technologies. In most hospital, premature infants are examined with ultrasound soon after birth to check for brain damage. Severe white matter injury can be seen with a head ultrasound; however, the low sensitivity of this technology allows for some white matter damage to be missed. Magnetic resonance imaging (MRI) is much more effective at identifying PVL, but it is unusual for preterm infants to receive an MRI unless they have had a particularly difficult course of development (including repeated or severe infection, or known hypoxic events during or immediately after birth). No agencies or regulatory bodies have established protocols or guidelines for screening of at-risk populations, so each hospital or doctor generally makes decisions regarding which patients should be screened with a more sensitive MRI instead of the basic head ultrasound.
The prognosis of patients with PVL is dependent on the severity and extent of white matter damage. Some children exhibit relatively minor deficits, while others have significant deficits and disabilities.
Current Treatments Currently, there are no treatments prescribed for PVL. All treatments administered are in response to secondary pathologies that develop as a consequence of the PVL. Because white matter injury in the periventricular region can result in a variety of deficits, neurologists must closely monitor infants diagnosed with PVL in order to determine the severity and extent of their conditions. Patients are typically treated with an individualized treatment. It is crucial for doctors to observe and maintain organ function: visceral organ failure can potentially occur in untreated patients. Additionally, motor deficits and increased muscle tone are often treated with individualized physical therapy treatments. Treatment Challenges The fetal and neonatal brain is a rapidly changing, developing structure. Because neural structures are still developing and connections are still being formed at birth, many medications that are successful for treatment and protection in the adult central nervous system (CNS) are ineffective in infants. Moreover, some adult treatments have actually been shown to be toxic to developing brains. Future Treatments Although no treatments have been approved for use in human PVL patients, a significant amount of research is occurring in developing treatments for protection of the nervous system. Researchers have begun to examine the potential of synthetic neuroprotection to minimize the amount of lesioning in patients exposed to ischemic conditions.