What is Lissencephaly?
Lissencephaly is a genetic disorder of the brain in which the brain does not develop the folds and grooves that is needed for normal functioning of the brain. Lissencephaly is an extremely rare condition and affects the mental development of the child to a significant degree.
Lissencephaly has been classified into three types which are type I, II, and III of which type I is the most severe and type III is the mildest form of Lissencephaly.
Anatomically speaking, the brain has a number of folds and grooves which are required to accommodate the numerous amounts of brain tissues in a closed space. In cases of Lissencephaly, these grooves and folds are missing and the brain is completely smooth resulting in inappropriate functioning of the brain causing neural and developmental defects in a child.
This grooving and folding of the brain start during fetal development. Abnormal genes are thought to be the main cause of Lissencephaly, although certain viral infections during pregnancy and poor blood blow to the fetus may also cause this condition. The treatment for Lissencephaly is mainly supportive and there is no clear cut cure for this condition.
What are the Causes of Lissencephaly?
As stated, Lissencephaly is a genetic condition and studies have identified several gene malformations that may contribute to development of Lissencephaly. Additionally, certain viral infections and poor blood flow to the fetus is also one of the causes for Lissencephaly.
Lissencephaly develops when the fetus is about 14 weeks old. It is in this phase of fetal development that the nerve cells begin to move to other areas of the brain as they develop but in cases of Lissencephaly these nerve cells do not move resulting in the brain abnormality. Certain genetic medical conditions like Walker-Warburg syndrome have also been associated with Lissencephaly.
What are the Symptoms of Lissencephaly?
A child born with Lissencephaly may have an extremely small head but this is not so in all the cases of Lissencephaly. Some of the other symptoms of Lissencephaly are:
- Problems with feeding
- Failure to thrive
- Not reaching developmental milestones on time
- Intellectual disability
- Deformed fingers or hands
- Persistent muscle spasms
- Psychomotor retardation
- Frequent bouts of seizures
How is Lissencephaly Diagnosed?
In case if there is a family history of Lissencephaly in any of the parents then they can go for an ultrasound examination at about 20 weeks of pregnancy to check whether the fetus has Lissencephaly or not. Apart from this, for confirmatively diagnosing Lissencephaly, the treating physician after observing the symptoms may recommend advanced imaging of the brain in the form of CT or MRI scans to look for areas where folding has not taken place of the brain and confirm the diagnosis and degree of severity of Lissencephaly. Majority of children suffer from grade III which is the mild form of Lissencephaly.
How is Lissencephaly Treated?
There is no cure for Lissencephaly and the treatment aims at providing support and comfort to the child. Children who have problems with feeding and have difficulty swallowing food may need an NG tube placed for nutritional purposes.
In cases where a child has hydrocephalus due to Lissencephaly then surgery may be required to drain the excess fluid accumulated in the brain. Medications will be required to control seizures as a result of Lissencephaly.
What is the Prognosis of Lissencephaly?
The overall prognosis of Lissencephaly depends on the severity of the condition. A child suffering from grade I Lissencephaly which is the most severe form will have an extremely poor prognosis for functioning normally and may not develop beyond a three month level in terms of function. Children with mild forms of Lissencephaly tend to more or less lead a normal lifestyle with very little if any brain abnormalities due to Lissencephaly.