What Is Cortical Dysplasia?

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Before children are born, developing neurons (aka brain cells) organize into layers to form the cerebral cortex, the outermost part of the brain.

But in some children, the brain cells fail to organize in the way they're genetically supposed to. When this occurs, the cerebral cortex does not form properly. This condition is known as cortical dysplasia and is associated with seizures, epilepsy, and developmental delays.

Because the neurons failed to migrate into their proper formation, brain connectivity is altered in specific circuits of the brain which leads to impaired functioning. Instead, brain signals sent through neurons send incorrect signals.

Occasionally, larger than normal neurons will develop in certain areas of the brain which affects the development of cortical synaptic connectivity.

Cortical dysplasia belongs to a larger family of disorders known as malformations of cortical development. It is a spectrum of derangement in the development of the cortex that causes epilepsy in children.

This article explores the causes, diagnosis, the types of cortical dysplasia, and details treatment options.

Focal Cortical Dysplasia

The most common type of cortical dysplasia seen in children is focal cortical dysplasia (FCD). It is a term used to describe developmental malformations of neurons limited to the focal zones in any lobe of the cerebral cortex.

Focal cortical dysplasia is the most common cause of intractable epilepsy and seizures in children and a frequent cause of seizures in adults.

Intractable epilepsy describes seizures that cannot be controlled by medication. Approximately 1 in 3 people with epilepsy experience intractable seizures.

Epilepsy associated with FCD is difficult to treat in both children and adults and is the number one reason children undergo surgery for epilepsy.

Types of Focal Cortical Dysplasia

Focal cortical dysplasia has cycled through several classifications based on the complex abnormalities associated with the condition.

The term was first used to describe specific malformations of the brain in 1971. These malformations comprised enlarged and irregular brain cells and enlarged balloon cells in some.

Currently, there are three main types of FCD, based on the appearance of biological tissues:

  • FCD Type I: The brain cells have an abnormal organization in the cortex. It often involves the temporal lobe of the brain. Type I is difficult to detect in a brain scan. It is often seen in adults and detected when patients start having seizures. 
  • FCD Type II: This is a more severe form of cortical dysplasia where the brain cells look abnormal in addition to the abnormal arrangement of the cells. This type is more common in children and involves both the temporal and frontal lobes of the brain. It is usually seen on magnetic resonance imaging (MRI).
  • FCD Type III: Besides the abnormalities found in type I and type II, there is also damage to other parts of the brain associated with tumors, stroke, or traumatic brain damage acquired early in life.

Cortical Dysplasia Symptoms

The most common symptom of cortical dysplasia is seizures.

A seizure, also known as fits, is a sudden uncontrolled electrical surge in the brain that can cause a range of symptoms depending on which parts of the brain are involved. Seizures can cause changes in behavior, movement, feelings, and levels of consciousness.  

If two or more seizures occur at least 24 hours apart and the cause of it cannot be identified, then it is considered to be epilepsy.

Seizures can start at any age. About two-thirds of children with focal cortical dysplasia develop seizures by five years of age and most patients have seizures by age 16.

Other symptoms that show up for cortical dysplasia are those related to the area of the brain that is affected. These symptoms can include development and language delays, visual concerns and weakness, and cognitive impairment, particularly when seizures start at an early age.

Causes

Cortical dysplasia can sometimes occur because of genetics or a brain injury, but in most cases, the abnormal development of the brain before a child is born causes cortical dysplasia.

Diagnosis

Your doctor makes a diagnosis of epilepsy based on your child’s health, past medical history, and your family’s history. They will also perform a detailed physical examination and try to learn as much as they can from you about your child's seizures. They might also perform blood tests.

If the doctor suspects cortical dysplasia, further tests will be prescribed. These include electroencephalogram (EEG), magnetic resonance imaging (MRI), and a tissue sample.

If the MRI is normal, your doctor will prescribe other imaging tests such as the positron emission tomography (PET) scan, SISCOM, or magnetoencephalography (MEG), to determine the location of the brain where the seizures arise.

Focal cortical dysplasia is rarely visible on a CT scan and sometimes remains undetectable on an MRI too. In other cases, the affected area shown in an MRI scan can, in reality, be larger than what is revealed by the MRI. This can affect the outcomes of surgery.

For that reason, doctors use other powerful imaging tests such as the combination of high-resolution MRI and the FDG-PET test to identify cortical dysplasia.

Cortical Dysplasia Treatment

The primary focus of the treatment for cortical dysplasia is controlling seizures.

Medication

Your doctor will generally prescribe antiepileptic drugs (AEDs). AEDs are considered the first line of treatment to help control seizures caused by cortical dysplasia.

If medication cannot control seizures after a trial of two or more antiepileptic drugs, then surgery may be necessary.

Seizures are difficult to control with medication in focal cortical dysplasia and many people have drug-resistant seizures. Only about 1 in 5 people with FCD achieve good seizure control with medication alone.

Surgery

Surgery for cortical dysplasia can include removing a section of the brain responsible for the seizures or the implantation of a small device to regulate electronic brain activity and reduce the incidence of seizures.

Other Treatment Options

Your doctor may also prescribe a ketogenic diet, which may help reduce seizures. Other non-surgical options include diet therapies like a modified Atkins diet and a low glycemic index diet.

Coping

Both the treatment and the disorder itself impact patients with cortical dysplasia. Treatments can cause dizziness, fatigue, poor coordination and balance among other side effects.

Medication for seizures can also cause bone density loss, alter mood, and affect thinking and other organs of the body.

Surgery too carries a risk of infection, seizures, and decreased motor control. 

But without any treatment, seizures can worsen and reduce the quality of life. It can also lead to other medical problems.

Coping with epilepsy can be distressing and isolating for your child. The stress of living with a chronic condition can also cause depression. Support groups and counseling can be helpful in coping and managing epilepsy.

The key to managing seizures is to be healthy, and that means developing healthy habits including good sleep routines, diet and exercise, and looking after the emotional health of your child.

It is also vital to pay attention to triggers that cause seizures and follow the treatment plan prescribed by your doctor.

When to Call Your Doctor

Call your doctor immediately if:

  • Medications have side effects.
  • Seizures continue or get worse.
  • For any questions or concerns.

A Word From Verywell

Witnessing your child experience seizures can be extremely distressing and worrying for you, but your doctor will guide you through the coping and treatment process.

Medication and lifelong therapies can help minimize the side effects of cortical dysplasia and help your child. While many things will be a challenge, over time you and your child will learn to cope with the help of your support network.

Also, don’t hesitate to talk to a mental health professional if you or your child feel overwhelmed and need emotional support.

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7 Sources
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