What Is It?
Cortical dysplasia is a malformation of the cortex of the brain which can lead to pediatric epilepsy conditions. It is considered congenital, meaning that it is present at birth, occurring during development of the embryo and fetus.
Normally, the brain cells, the neurons, are born during development in the innermost part of the brain, near the ventricles, the fluid-filled spaces within the brain. As they develop, they travel outwards to populate the outermost grey matter of the brain, the cerebral cortex. The normal cortex has a very specific and complex architecture with 6 primary layers of neurons. In some children this process of development does not occur properly in some parts of the brain. As a result the cortex in that area develops abnormally, often without the normal layers, architecture and connections that are required for the normal functioning of the brain.
This abnormal development is termed cortical dysplasia. It can occur in small, discrete parts of the cortex or can involve large areas of the brain. For example, cortical dysplasia involving an entire cerebral hemisphere is termed hemimegancephly.
While it can occur sporadically without any obvious cause, in some disorders it may be a part of a larger genetic abnormality of the child. An example of this are the tubers of Tuberous Sclerosis which resemble other forms of cortical dysplasia in many ways.
What Types of Symptoms Are Typical?
The most typical presenting symptom of these malformations is pediatric epilepsy, recurrent seizures in an infant or young child. The specific types of seizures and the neurological development of the child varies depending on many factors and the extent of involvement of the cortex. It is rare for seizures due to this disorder to present first in later childhood or adulthood.
How Is The Diagnosis Typically Made?
After presenting with seizures, a child will often undergo a thorough work-up which includes a neurological examination, imaging studies, such as a CT scan
or MRI scan
, and an electroencephalogram.
Cortical dysplasia can be subtle on MRI and practically invisible on CT. Other imaging studies such as PET scanning sometimes helps to find the abnormal location in the brain.
Electroencephalograms are performed by placing electrodes on the scalp and recording the electrical activity of the brain. Sometimes this can help localize where the seizures are coming from. If not, occasionally more invasive monitoring studies are performed to confirm the location of seizure origin.
What Are Some Common Treatments?
The treatment of epilepsy is complex and varies considerable from patient to patient. In general, treatment begins with anti-epileptic medications to help control the seizures. In some patients, this works well and is all that is needed.
In those patients who fail multiple medications or who have a very severe malformation, surgical treatment may be necessary. Generally, surgery is only performed if the neurologists and neurosurgeons can convince themselves that the seizures are in fact coming from one cortical dysplasia location. In such a case, some patients will be offered surgical treatment which involves identifying the malformation in the operating room and removing that part of abnormal brain. Success rates of these procedures vary considerably depending on the specific disease, the localization of seizures and many other factors.
As with all diseases of the nervous system, each patient is different. Epilepsy is a particularly complex example. Therefore, treatment suggestions and decisions should be made with the patient's own treating physician or physician team.
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This site is not intended to offer medical advice. Every patient is different, and only your personal physician can help to counsel you about what is best for your situation. What we offer is general reference information about various disorders and treatments for your education.