Cause & Timing

Cause & Timing

Of all children with cerebral palsy, 60% are born at term.
MRI of brain showing damage

Cerebral Palsy is the most common motor disability in children caused by abnormal development or damage to the motor area of the brain’s outer layer (called the cerebral cortex), the part of the brain that directs muscle movement. This damage can occur before, during, or shortly after birth.

EXAMPLES OF BRAIN INJURY SEEN IN CP

The brain injury or damage that leads to cerebral palsy can be caused by a number of different events or conditions. Some of these conditions that are associated with an increased risk for cerebral palsy include maternal or infant infection, infant stroke, multiple births, premature birth, genetic abnormalities, and other problems affecting how blood and oxygen move throughout the developing brain.

There is still much to learn about why some babies develop CP and others do not. There are many babies who share similar risk factors but develop very differently. The reasons for this are not yet entirely clear. 

CONGENITAL CP

The majority of children have Congenital Cerebral Palsy (that is, they were born with it), although it may not be detected until months or years later. Possible causes may include genetic abnormalities, congenital brain malformations, maternal infections/fevers, or fetal injury.

ACQUIRED CP

A small number of children have Acquired Cerebral Palsy, which means it begins after birth. Some causes of Acquired Cerebral Palsy include brain damage in the first few months or years of life, brain infections such as bacterial meningitis or viral encephalitis, problems with blood flow to the brain, or head injury from a motor vehicle accident, a fall, or child abuse.

DAMAGE TO THE WHITE MATTER OF THE BRAIN
(periventricular leukomalacia, or PVL)

The white matter of the brain is responsible for transmitting signals inside the brain and to the rest of the body. Damage from PVL looks like tiny holes in the white matter of an infant's brain. These gaps in brain tissue interfere with the normal transmission of signals. Researchers have identified a period of time between 26 and 34 weeks of gestation, in which periventricular white matter is particularly sensitive to injury. 

ABNORMAL DEVELOPMENT OF THE BRAIN
(cerebral dysgenesis)

Mutations in genes, infections, fevers, trauma, and other conditions can interrupt the normal process of brain growth. This can cause brain malformations that interfere with the transmission of brain signals during fetal development.

BLEEDING IN THE BRAIN
(intracranial hemorrhage)

Bleeding inside the brain from blocked or broken blood vessels is commonly caused by fetal stroke. Some babies suffer a stroke while still in the womb because of blood clots in the placenta that block blood flow in the brain. Other types of fetal stroke are caused by malformed or weak blood vessels in the brain or by blood-clotting abnormalities.

SEVERE LACK OF OXYGEN IN THE BRAIN

Asphyxia, a lack of oxygen in the brain caused by an interruption in breathing or poor oxygen supply, is common for a brief period of time in babies due to the stress of labor and delivery. If the supply of oxygen is cut off or reduced for lengthy periods, an infant can develop a type of brain damage called hypoxicischemic encephalopathy, which destroys tissue in the cerebral motor cortex and other areas of the brain.