Infant Brain Damage

Baby's HeadThe brain is the most important organ in the human body. Electrical impulses from the brain control everything from cognitive thought to muscle movement. However, the brain is also one of the most delicate organs in the body and it is particularly vulnerable during childbirth. Every year hundreds of babies suffer some degree of brain damage as a result of trauma during childbirth. Birth injuries involving brain damage are the most serious and potentially devastating type of birth injuries. This page provides a general summary of the different types and causes of infant brain damage.

Hypoxic-Ischemic Encephalopathy ("HIE")

Hypoxic ischemic encephalopathy ("HIE") (also called perinatal asphyxia) is one of the most severe and dangerous types of birth injury. HIE is an injury to the brain caused by a lack of adequate blood and oxygen. All of the cells in the human body require a constant circulation of oxygen and blood to survive. When the supply of oxygen is interrupted, even for just a short time, cells begin to decay and die. The death of cells due to lack of oxygen is called hypoxia. The brain is particularly vulnerable to hypoxia for 2 simple reasons. First, the brain requires much more oxygen and blood than any other organ in the body. Second, unlike cells in other areas of the body, when brain cells decay and die they can never regenerate. This means damage to the brain caused will be permanent.

Interruption or restriction of blood and oxygen to a baby's brain can be caused by a number of complications during labor and delivery. HIE only occurs in 2.5 out of every 1,000 live births in the U.S., but HIE accounts for 23% of all neonatal deaths worldwide. Between 40-60% of babies affected by HIE will either die or have major mental disabilities. Treatment options for HIE are very limited and mainly focus on the prevention of further damage.

Infant Brain Bleeds: Hemorrhage & Hematoma

Brain bleeds are another category of infant brain injury which occur when the system for circulating blood to the brain is damaged causing bleeding and accumulation of blood in and around the brain. Infant brain bleeds fall into 2 main categories: hemorrhage & hematoma.

Hemorrhage is a medical term generally used to describe internal bleeding -- blood which escapes the circulatory vessels. So infant brain hemorrhage is simply bleeding inside the baby's brain. A hematoma is a collection or pooling of blood outside of the blood vessels. There are several different types of brain hemorrhages hematomas depending on the area in which the bleeding or collection of blood occurs:

Subgaleal Hematoma

A subgaleal hematoma is a pooling of blood which accumulates in the area between the skull and the scalp. Although rare, neonatal subgaleal hematomas can be life-threatening. This type of hematoma results from a rupture of the emissary veins around the skull. The collection of blood in the subgaleal space can trigger hypovolemic shock and permanent damage to the brain. Almost all neonatal subgaleal hematomas are the direct result of external head trauma caused by negligent use of a vacuum extractor or obstetrical forceps during a difficult childbirth.

Cephalohematoma

A cephalohematoma is a small pooling of blood just underneath the skin of the scalp. It may sound similar to subgaleal hematoma but the 2 conditions differ significantly. A cephalohematoma occurs in different area or layer of the head, specifically the periosteum area of the skull. Unlike a subgaleal hematoma, a cephalohematoma cannot spread and therefore does not pose any risk of brain damage.

Periventricular Leukomalacia (PVL)

Periventricular leukomalacia ("PVL") is a specific type of brain injury that occurs in premature infants and frequently causes cerebral palsy and epilepsy. PVL occurs when the "white matter" around the brain ventricles becomes damaged and decays. This decay of the white matter tissue leaves cavities within the brain that fill with fluid. Normally the white matter within the brain facilitates electrical signals and protects brain tissue. The erosion of the white matter resulting from PVL is one of the leading causes of epilepsy; cerebral palsy; and other developmental delays.

A primary cause of periventricular leukomalacia is believed to be reduced oxygen and blood circulation to the developing brain of the fetus during pregnancy. In the early stages of pregnancy, the baby's brain ventricles are especially vulnerable to developmental injury and interruptions. Disruptions of the normal supply of oxygen, blood, and nutrients from mother to baby can easily result in brain injuries. PVL is also known to be caused by infections of the fetal membranes such as chorioamnionitis and other types of maternal infection which disrupt oxygen and blood supply to the baby.

PVL is the type of fetal brain injury that most frequently causes cerebral palsy and related neurologic disorders. PVL CP is a term used to describe cases of cerebral palsy specifically caused by PVL. Even if PVL does not cause cerebral palsy, it can still result in developmental delays and other symptoms.

Hydrocephalus

Hydrocephalus is a very serious type of brain injury which occurs when cerebrospinal fluid (CSF) floods into the ventricle cavities of the brain. Hydrocephalus is commonly seen in newborn infants as a result of external trauma to the head during childbirth. Hydrocephalus can also be caused by chromosomal abnormalities, most notably X-linked hydrocephalus. X-linked hydrocephalus was first described in 1949 and has been the subject of a number of medical journal articles over the last 65 years.

The root word "hydro" means water and "cephalus" refers to the head or brain, so hydrocephalus literally means "water in the brain." Of course, it is not actually "water" that floods the brain, but rather cerebrospinal fluid (CSF). CSF is a fluid that is regularly produced within the brain ventricles. Normally, CSF gets released from the ventricles and circulates to the brain and then the spinal cord before being absorbed into the bloodstream. Hydrocephalus results when the normal outflow of CSF becomes blocked causing a backup of the fluid inside the ventricles. As the CSF continues to build up, it eventually floods back into the ventricle cavities and causes internal pressure.

Hydrocephalus is often caused by external trauma to the baby's skull during childbirth. Excessive pressure or force is often applied to the baby's head during labor and delivery, damaging tissue and rupturing blood vessels within the brain. The excessive blood cells and inflammation that follows can block the circulation of CSF and cause the back-up resulting in hydrocephalus.

Although traumatic hydrocephalus often occurs in a setting of intracranial hemorrhage and is more often a delayed complication, the medical literature clearly reveals cases of traumatic hydrocephalus developing within hours of traumatic brain injury and in the absence of intracranial hemorrhage.

Caput Succedaneum

Caput succedaneum is a medical condition that involves swelling around the head and scalp of a newborn baby. During vaginal childbirth, the head of the baby is often subjected to significant external pressures. This pressure can come from natural compression as the head passes through the birth canal, or from efforts by doctors to assist with delivery. For example, the use of obstetrical forceps or vacuum extractors to maneuver a baby through the birth canal can frequently result in excessive pressure on the head. The excessive external pressure can trigger swelling in the baby's head which is termed caput succedaneum.

Caput succedaneum is not a brain injury or serious medical condition. Mild cases of caput succedaneum are actually quite common and usually resolve on their own without any long term injury or harm to the baby. However, caput succedaneum increases the risks of certain other health conditions such as infant jaundice. Moreover, if the swelling associated with caput succedaneum does not resolve on its own it can potentially lead to more serious conditions that cause brain damage.

Kernicterus

Kernicterus is a very serious type of infant brain damage that can potentially result if infant jaundice is not properly diagnosed and managed after birth. Kernicterus is a very specific type of injury to the brain that is caused by excessive levels of bilirubin. Bilirubin is a substance that naturally occurs in the body when hemoglobin breaks down. When too much bilirubin accumulates in the blood it can become toxic. Jaundice is the health condition caused by excessive bilirubin levels.

When babies are first born, their livers are not fully developed which makes them particularly vulnerable to jaundice. Infant jaundice is very common. Approximately 60-80% of all newborns have some level of jaundice. The most visible symptom of jaundice is a yellowish tint in the white areas of the eyes. In most cases, infant jaundice goes away fairly quickly as the baby's liver begins to catch up. For more serious cases of infant jaundice, phototherapy may be necessary to help stimulate the metabolic processing of bilirubin. For the most extreme cases, other treatments such as blood transfusions may be required.

Proper monitoring and management of infant jaundice are very important. If more serious cases of jaundice are not identified and handled appropriately, the high levels of bilirubin will cause kernicterus. The real danger with infant jaundice is that it is so common that doctors sometimes fail to take it seriously until it is too late. Infant jaundice (even severe cases) can be effectively treated. However, once kernicterus occurs from untreated jaundice the damage to the brain cannot be reversed.

Causes of Infant Brain Injuries

Brain damage to infants can occur during pregnancy, labor & delivery or shortly after birth. The injury to the brain can be the result of external trauma to the head or interruption of oxygen & blood flow to the baby's brain. Below is an overview of the primary causes of infant brain injuries during pregnancy and childbirth.

Oxygen Deprivation

Deprivation of oxygen to the baby's brain is the leading cause of infant brain injuries during pregnancy or childbirth. The human brain needs a constant supply of oxygen and nutrients in order to survive. This is normally provided by oxygenation blood which is continuously circulated to the brain. When something disrupts the circulation of oxygen and blood to the brain, cells in the brain will begin to decay and die in a very short time. Oxygen deprivation to the brain comes in 2 forms: hypoxia & anoxia. Hypoxia occurs when the amount of oxygen is dangerous decreased, whereas anoxia involves a total lack of oxygen. Hypoxia and anoxia can result from a number of different complications including:

  • Umbilical Cord Problems: if the umbilical cord becomes twisted, compressed or otherwise compromised during delivery it can reduce or even cut off the flow of oxygenated blood to the baby.
  • Placental Abruption: a placental abruption is a prenatal event in which the placenta prematurely detaches from the uterus. When this occurs the oxygen and blood supply to the baby can be severely compromised requiring an emergency c-section.
  • Maternal Health: certain maternal health conditions, such as low blood pressure and serious respiratory disease, can potentially restrict the supply of oxygen from the mother to the baby.
  • Delivery Trauma: a prolonged and difficult passage through the birth canal during vaginal delivery can sometimes cause disruption of the oxygen supply to the baby.
Maternal Infections

Maternal infections are a common complication during pregnancy. If not properly diagnosed and treated, maternal infections can result in damage to the baby's brain. Brain damage from maternal infection typically occurs during labor & delivery or in the late stages of pregnancy. Common types of maternal infection that can potentially lead to infant brain damage include:

  • Chorioamnionitis: Chorioamnionitis (also known as intra-amniotic infection) is a type of bacterial infection that can occur in the amniotic fluid and/or the fetal membranes. Chorioamnionitis often starts with an untreated vaginal infection. The bacteria migrates upward and eventually becomes an intra-amniotic infection. Premature membrane rupture can also lead to Chorioamnionitis.
  • Toxoplasmosis: Toxoplasmosis infections are caused by Toxoplasma gondii - a very common parasite that lives in raw meat and soil. Most people have Toxoplasma gondii in their bodies but their immune system effective blocks it from spreading. However, the immune systems of pregnant women are less effective are blocking this parasite and are therefore more susceptible to a toxoplasmosis infection. A toxoplasmosis infection can be transferred to the baby. Ocular toxoplasmosis can cause injury to the eye that can lead to visual impairment or even blindness. The most common symptoms of ocular toxoplasmosis are floaters and blurred vision.
Additional Resources on Infant Brain Damage
  1. Amaicha Mara Depino, Maternal Infection and the Offspring Brain, J of Neuroscience 26 July 2006, 26 (30).
  2. McLeod R, Boyer K, Karrison T, Kasza K, Swisher C, Roizen N, Jalbrzikowski J, Remington J, Heydemann P, Noble A, Mets M, Holfels E, Withers S, Latkany P, Meier P, for the Toxoplasmosis Study Group. Outcome of Treatment for Congenital Toxoplasmosis, 1981-2004: The National Collaborative Chicago- Based, Congenital Toxoplasmosis Study. Clin Infect Dis 2006;42:1383-95.
  3. Henry, J.D., and Crawford, J.R. (2004). A meta-analytic review of verbal fluency performance in patients with traumatic brain injury. Neuropsychology, 18,4, 629-637.
  4. Russell, E.W. (1995). The accuracy of automated and clinical detection of brain damage and lateralization in neuropsychology. Neuropsychology Review, 5(1), 1-68.
  5. Reitan, R.M., and Wolfson, D. (1988). Traumatic brain injury. Volume I: Pathophysiology and neuropsychological evaluation. Tuscon, AZ: Neuropsychology Press.