Periventricular Leukomalacia (PVL) and Birth Injury
Periventricular leukomalacia (PVL) is a term that refers to damage of the brain’s white matter, which helps to transmit messages from the brain to the muscles. In cases of PVL, white matter softens and dies around the lateral ventricles, which are located in the top section of the brain.
PVL results from an insufficient level of oxygen (hypoxia) and/or blood flow (ischemia) reaching the periventricular area of the brain. This can occur during pregnancy, the birthing process, or shortly after birth. Like many birth injuries, PVL is more common in premature babies, because they are underdeveloped and more vulnerable to damage. However, PVL also affects full-term infants. Especially when improperly managed, PVL can lead to permanent motor disorders such as cerebral palsy (CP). It may also cause intellectual and disabilities (I/DDs), seizure disorders, vision and hearing deficits, and other complications.
How Do You Pronounce Periventricular Leukomalacia?
Risk Factors for Periventricular Leukomalacia (PVL)
The smaller and more premature a baby is, the more susceptible they are to developing PVL due to decreased oxygen. Infants with the highest risk of developing PVL are those under 32 weeks gestational age. (PVL, however, can occur at any gestational age, including at term.)
Besides prematurity, the following circumstances increase the likelihood that a baby will develop PVL:
- Hypoxic-ischemic events around the time of birth
- Hypocarbia or overventilation (low carbon dioxide in the blood)
- Moderate or severe intraventricular hemorrhage (IVH)
- Respiratory distress
- Lengthy resuscitation following birth
- Apneas and bradycardias
Causes of Periventricular Leukomalacia (PVL)
The main factors involved in the development of PVL are: 1) decreased oxygen/blood flow to the periventricular region, and 2) damage to the glial cells, which comprise most of the white matter and support neurons throughout the nervous system. These issues trigger a sequence of events that lead to the development of PVL.
There are a number of complications that can cause hypoxia/ischemia and resultant PVL. Fetal blood vessels have very thin walls, and the vessels providing nutrients to the periventricular region cannot maintain sufficient blood flow during periods of low oxygen. In addition, low blood pressure (hypotension) can restrict the flow of oxygenated blood to the developing brain. These hypoxic-ischemic events can damage the blood-brain barrier, a network of cells that regulates the flow of nutrients to the brain. A damaged blood-brain barrier can further contribute to greater levels of hypoxia. Injury to the blood-brain barrier also can occur as a result of infections, such as meningitis. Premature infants are especially susceptible to these insults because their cardiovascular and immune systems are not fully developed and they do not have the ability to auto-regulate cerebral blood flow.
Damage to the blood-brain barrier from hypoxic-ischemic injury or infection causes a cascade of inflammatory responses. One of these responses includes the release of molecules called cytokines, which are toxic to the developing brain. Cytokines perpetuate brain injury by damaging nearby areas that were not involved in the initial injury. Further damage is caused by free radicals, which are molecules produced during ischemic episodes. Additionally, when the glial cells become damaged, nearby neurons have little or no support.
Events during or near the time of birth that can lead to the development of PVL include the following:
- Uterine rupture
- Placental problems, such as placental abruption and placenta previa
- Umbilical cord problems, such as a nuchal cord, umbilical cord prolapse, short cord, or cord in a true knot
- Failure to respond to signs of fetal distress
- Delayed emergency C-section
- Oligohydramnios (low amniotic fluid)
- Premature rupture of the membranes (PROM)
- Prolonged and arrested labor
- Intracranial hemorrhages (brain bleeds), which can be caused by a traumatic delivery. Often, intracranial hemorrhages stem from the improper use of forceps and vacuum extractors or labor-induction drugs like Pitocin and Cytotec. Mismanagement of cephalopelvic disproportion (CPD), abnormal fetal presentations, and shoulder dystocia also put a child at risk of having a brain bleed.
- Fetal stroke
- Maternal infections that travel to the baby. These include chorioamnionitis, Group B Strep (GBS), herpes simplex virus (HSV), urinary tract infection (UTI), and bacterial vaginosis.
- Improper management of the baby’s respiratory status after birth. This includes failure to properly manage apnea (periods of breathing cessation) and failure to properly manage a baby on a breathing machine (which can cause overventilation injuries, such as hypocarbia).
Signs and Symptoms of Periventricular Leukomalacia (PVL)
Newborns with PVL do not always manifest obvious signs of this condition. Often, signs and symptoms are not noticeable until the child begins to exhibit developmental delays (motor impairments may be less recognizable in newborns because all newborns are somewhat lacking in coordination). As the child ages, the extent of problems caused by PVL becomes more apparent. However, as an infant, problems sucking or unusual stiffness should cause concern regarding PVL.
Other signs and symptoms of PVL include the following:
- Weakness or altered muscle tone, primarily in the lower extremities
- Vision problems
- Periods of apnea (breathing cessation)
- Low heart rates
Diagnosing Periventricular Leukomalacia (PVL)
PVL typically begins with numerous, small areas of necrosis, followed in more severe cases by cystic formation and more diffuse white matter injury. Prematurity, extreme stiffness, and/or poor ability to suckle should alert the physician that there may be white matter damage. However, newborns may exhibit few or no signs of white matter injury, and PVL can easily be missed if routine screening is not performed.
The preliminary diagnosis of PVL often is made using head-imaging technologies. Soon after an at-risk baby is born, physicians typically order an ultrasound to determine if the baby has white matter damage. However, the low sensitivity of an ultrasound allows for some white matter injury to be missed. Magnetic resonance imaging (MRI) is much better than ultrasound at identifying PVL. MRI can show lesions that are less than 0.5 cm, as well as non-cystic PVL, while an ultrasound typically cannot. An MRI should be performed on infants who had a difficult course of development, especially if there was prematurity, maternal or fetal infection, a known hypoxic-ischemic event during or right after birth, or a traumatic head injury.
Computed tomography, or CT scanning, is less useful for the diagnosis of PVL in very preterm infants because it detects fewer lesions than does MRI or ultrasound. In term infants, however, CT can identify the loss of periventricular white matter, as well as ventricular enlargement. Even with the best head imaging, however, some white matter damage will be missed and films will be read as normal.
Modes and timing of diagnostic techniques include the following:
- Although PVL cannot typically be seen on an initial ultrasound scan in the first 24 hours after brain insult, the scan will usually show some periventricular damage. If there are cystic changes, they will usually be seen after approximately 1 – 3 weeks. This emphasizes the importance of serial scans.
- Routine ultrasound screening should be performed on all infants with a gestational age less than 33 weeks, or with birth weight less than 1500 grams, to identify abnormalities in the brain. Screening should also be performed in all births where birth trauma is suspected.
- Screening should be performed to detect IVH (brain bleeds), with an initial scan being performed on extremely low birth weight infants at risk for abnormalities.
- When abnormalities are detected, more frequent examinations are performed to assess the progression of PVL.
- MRI should be used for better assessment of the extent of white matter damage. An MRI has better sensitivity and specificity than ultrasound, and CT scans and can show injury at one day of age.
Prevention and Treatment of Periventricular Leukomalacia (PVL)
Delaying or preventing decreased oxygenations during premature birth is considered one of the most important steps in decreasing the risk of PVL. Additionally, strategies that emphasize the maintenance of adequate blood supply and flow in the brain should be utilized to help prevent PVL. Low blood pressure, constricted blood vessels in the brain, and conditions that impair normal functioning of the blood vessels should be avoided. It is essential to prevent hypocarbia, hypoxemia, and abnormal blood pressure.
While no specific cure exists for PVL, therapeutic hypothermia (brain/body cooling) has proven very effective in treating infants with hypoxic-ischemic encephalopathy at or near term. Hypothermia treatment works by cooling the brain and decreasing the amount of cellular death. When administered within six hours of life, the treatment can prevent or reduce the severity of neurological injury associated with HIE, such as PVL.
Another neuroprotective agent shows promise. Some research has found that when a mother is given the steroid betamethasone during pregnancy, it can reduce the risk of PVL in the baby. Further research is needed in this area. Magnesium sulfate can also confer neuroprotective effects on babies likely to be born prematurely and may prevent PVL.
In general, therapy for PVL focuses on teaching caregivers to handle, feed, dress, and toilet their children. Babies with PVL should be monitored for the development of disorders such as cerebral palsy, intellectual impairment, visual problems, and epilepsy.
Short-Term and Long-Term Outlooks for Babies with Periventricular Leukomalacia (PVL)
Babies with PVL in the NICU may have apnea, difficulty feeding, an inability to control facial movements, decreased tone (limpness) in their lower extremities, neck stiffness, and seizures. Newborns with PVL are also usually irritable. Once children with PVL are older, they are likely to miss certain developmental milestones due to motor problems and intellectual disabilities. Visual-motor dysfunction is common and many children with PVL are diagnosed with spastic cerebral palsy.
Periventricular Leukomalacia (PVL) and Medical Malpractice
Areas of negligence may include the following:
- Failure to properly monitor the baby and recognize fetal distress
- Failure to diagnose and treat disorders that can lead to premature birth
- Failure to prevent issues that can cause hypoxic-ischemic injury
- Improper use of forceps or vacuum extractors
- Failure to obtain adequate informed consent, which includes advising the mother of the risks and alternatives of delivery methods, medication usage, etc.
- Failure to properly deliver the baby and follow standards of care when performing a C-section or vaginal delivery
- Over-ventilation of the newborn, causing hypocarbia
- Failure to timely and appropriately resuscitate.
When underlying conditions are not properly diagnosed and treated, it is negligence. When conditions like hypoxic-ischemic encephalopathy and PVL result from this negligence, it constitutes medical malpractice.
Birth Injury Attorneys Helping Children with Periventricular Leukomalacia (PVL)
At Reiter & Walsh, P.C., our award-winning lawyers represent victims of birth injury every day. We are dedicated to helping clients obtain compensation for medical expenses and care to secure the future of their children. If your loved one was diagnosed with periventricular leukomalacia (PVL), we encourage you to reach out today for a free legal consultation.
Free Case Review | Available 24/7 | No Fee Until We Win
Phone (toll-free): 888-419-2229
Press the Live Chat button on your browser
Complete Our Online Contact Form
Video: Our Periventricular Leukomalacia (PVL) Discuss HIE and Birth Injury
- Volpe, JJ. Neurology of the Newborn, 4th ed, WB Saunders, Philadelphia 2001.
- Kinney HC. “The near-term (late preterm) human brain and risk for periventricular leukomalacia: a review.” Semin Perinatol 2006; 30:81.
- Woodward LJ, Anderson PJ, Austin NC, et al.” Neonatal MRI to predict neurodevelopmental outcomes in preterm infants.” N Engl J Med 2006; 355:685.
- Khwaja O, Volpe JJ.” Pathogenesis of cerebral white matter injury of prematurity.” Arch Dis Child Fetal Neonatal Ed 2008; 93:F153.
- Volpe JJ. “Encephalopathy of prematurity includes neuronal abnormalities”. Pediatrics 2005; 116:221.