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 and occupational 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. Prognosis 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. Minor tissue damage Minor white matter damage usually is exhibited through slight developmental delays and deficits in posture, vision systems, and motor skills. Many patients exhibit spastic diplegia, a condition characterized by increased muscle tone and spasticity in the lower body. The gait of PVL patients with spastic diplegia exhibits an unusual pattern of flexing during walking. Progression Those patients with severe white matter injury typically exhibit more extensive signs of brain damage. Infants with severe PVL suffer from extremely high levels of muscle tone and frequent seizures. Children and adults may be quadriplegic, exhibiting a loss of function or paralysis of all four limbs. Cerebral palsy Many infants with PVL eventually develop cerebral palsy. The percentage of individuals with PVL who develop cerebral palsy is generally reported with significant variability from study to study, with estimates ranging from 20% to more than 60%. One of the reasons for this discrepancy is the large variability in severity of cerebral palsy. This