White matter is responsible for the delivery of nerve impulses (action potentials) to the grey matter area of the brain. When a person suffers from periventricular leukomalacia, these very basic functions are impaired. Infants diagnosed with cerebral palsy are people most commonly affected by this disorder. This disorder leads to spasticity and intellectual disability. It is also commonly referred to as PVL.
Definition & Facts
Periventricular leukomalacia is a condition where white matter brain tissue near the lateral ventricles (also known as the periventricular region of the brain) goes through necrosis or coagulation. This means death of injured cells causes damage to the brain’s white matter.
- 3 to 4 percent of infants weighing less than 3.3 lbs. have PVL.
- 75 percent of premature infants who die shortly after birth have PVL.
- 4 to 10 percent of those who are born before 33 weeks of gestation but survive three days postpartum have PVL.
- Approximately 60 percent of infants who have PVL are diagnosed with cerebral palsy.
The development of PVL appear to involve two major factors: The decreased oxygen and blood flow to the periventricular region and damage to the glial cells, the cells which support neurons throughout the central nervous system.
Symptoms & Complaints
Intellectual disability, developmental delays, vision loss, hearing loss, and lack of coordination are common among those with periventricular leukomalacia. Patients with this condition may also later develop cerebral palsy or epilepsy later in life.
Infants affected by this disorder generally exhibit motor control problems and stiffness. Spastic diplegia, which involves hyperextension and tightness of muscles and limbs, is the most common type of cerebral palsy caused by PVL.
Some physical symptoms exhibited in PVL are decreased muscle tone in the lower extremities, increased muscle tone in neck extensors, sleep apnea or cessation of breathing during sleep, infant irritability, poor feeding, and in some cases, seizures.
Intrauterine infections, or the presence of bacteria or toxins in the amniotic fluid are the underlying causal factors for PVL, according to experts. The release of toxins in the amniotic fluid affect the sensitive membranes around the fetus. The toxins then injure areas of the developing brain. These toxins can contribute to premature birth.
Other risk factors that may contribute include problems with the placental blood vessels, the gestation of twins, antepartum haemorrhage (vaginal bleeding during pregnancy), inflammation of the umbilical cord tissue (funisitis), fetal illness caused by bacteria in the bloodstream (bacteremia or sepsis), and prenatal cocaine exposure.
Diagnosis & Tests
Diagnosis can be delivered as soon as the infant is born. Initial observations postpartum could be the infant’s extreme stiffness or poor ability to suckle. Cystic periventricular leukomalacia can be diagnosed through the infants’ sonograms during the first day of life in severe cases. Ultrasound imaging may not be sensitive enough to pick up most of white matter damage but will be enough for severe damage to be seen, however.
The most effective way to diagnose PVT is through a magnetic resonance imaging (MRI). MRI or magnetic resonance imaging is able to pick up the lesions and gaps left by pre-natal PVL much better than a sonogram or an ultrasound. An MRI can show the loss or the abnormal density of white matter and ventriculomegaly (the dilation of the lateral ventricles). Infants with known risk factors can be tested approximately 30 days after birth.
Treatment & Therapy
Frequent medical assessments will be necessary to monitor the suspicion of PVL. Once diagnosed, doctors will monitor a premature baby’s heart, lung, intestine and kidney functions in a neonatal intensive care unit (NICU).
After discharge, the infant will still need special care. Usually doctors customize treatment based on the symptoms and associated conditions the infant suffers from as a result of PVL. For infants suffering from cerebral palsy due to PVL, individualized physical therapy and occupational therapy will be necessary to improve the infant’s quality of life.
Researchers are now looking into the possibility of developing treatments to protect the nervous system from damage. Doctors are researching the use of transferrin and insulin growth factors as a form of synthetic neuroprotection to minimize the amount of lesions caused by PVL.
Prevention & Prophylaxis
Early diagnosis is an important component of prevention. Research studies are being conducted on how to develop effective methods to screen and detect possible intrauterine infection. Some tests may be conducted as early as five to seven months of pregnancy. Early detection of infections may enable treatment before infections result in complications and damage to the fetus.