User:Sophiemaijoor/sandbox

Types
People with hydranencephaly are born with this defect, but most of the time, the symptoms appear in a later stadium. After birth, the usual characteristics of newborns appears. They can swallow, cry, sleep and their head is in proportion to their body. However, after a few weeks, the infants start to become irritable and develop an increased muscle tone. After a few months, the brain start to fill with cerebrospinal fluid (hydrocephalus). This has several consequences. Infants start to development problems with seeing, hearing, growing and learning. The missing parts of the brain and the amount of cerebrospinal fluid can also lead to seizures, spasm, problems with regulating their body temperature, and breathing and digestion problems. Besides problems in the brain, hydranencephaly can also be seen on the outside of the body. Hydrocephalus leads to more cerebrospinal fluid in the brain what need space. This leads to an enlarged head.

The cause of hydranencephaly is not clear. Hydranencephaly is a result of an injury of the nervous system or an abnormal development of the nervous system. The neural tube closes in the 6th week of the pregnancy, so hydranencephaly develops during these weeks of the pregnancy. The cause of these injuries/development is not clear. Their are a couple of theories about the causes.


 * blockage in the carotid artery: some researchers think that a blockage of the carotid artery leads to the under-/no development of the brain. The carotid artery is the most important blood supplier of the brains. With a blockage, the brain barely receive blood. Blood is necessary for development and keeping in tact of the brains.
 * inherited condition.
 * infections: during the pregnancy, a woman can develop an infection in the uterus what can lead to problems with the neural tube.
 * environmental toxins: during the pregnancy, a woman can be exposed to environmental toxins what can have effect on the health of the infant.