Aicardi syndrome

BACKGROUND

Aicardi syndrome is a rare genetic condition that affects 300-500 people worldwide, nearly all of them females.

Symptoms of Aicardi syndrome usually first become apparent between three and five months of age. Patients with Aicardi syndrome may exhibit spasms, seizures, mental insufficiency, and/or lesions on the retina.

Many patients with Aicardi syndrome have a partial or complete absence of the corpus callosum, which is a structure in the brain that connects the left half of the brain to the right half.

Aicardi syndrome is typically diagnosed with a clinical examination to check for symptoms. Currently, there is no known way to prevent Aicardi syndrome. Lifespan can vary among patients with Aicardi syndrome, but most patients do not survive past the first or second decade.

Many children with Aicardi syndrome experience lung complications. Patients may have difficulty breathing due to weakened lung muscles; infection of the lungs (such as pneumonia) is a major cause of death. Children with Aicardi syndrome are also more likely to develop tumors, which may cause death in some patients.

CAUSES

A defect in the X chromosome is thought to be involved in the development of Aicardi syndrome. However, the specific gene or genes on the X chromosome that are involved in causing Aicardi syndrome have not yet been identified, so the involvement of the X chromosome has not yet been fully confirmed.

Females have two copies of the X chromosome, while normal males only have one copy of this chromosome. Almost all known cases of Aicardi syndrome are in females. The only known cases of Aicardi syndrome in males have been in abnormal males with two copies of the X chromosome. This suggests that Aicardi syndrome may be a dominant X-linked condition, which means that a mutation on one X chromosome can cause the condition.

Aicardi syndrome is a genetic condition, but it is not thought to be inherited. Rather, Aicardi syndrome is thought to result when a normal gene mutates randomly (during either egg or sperm development or embryonic development) such that it no longer functions properly in the affected child. It is very uncommon for families to have more than one member affected by Aicardi syndrome, which suggests that Aicardi syndrome is not inherited.

SIGNS AND SYMPTOMS

Brain problems: Many patients with Aicardi syndrome have a partial or complete absence of the corpus callosum, which is a structure in the brain that connects the left half of the brain to the right half. Other brain abnormalities may be present in patients with Aicardi syndrome, including cavities, gaps, cysts, or tumors. There may also be unorganized groups of neurons (nerve cells) in the brain. The entire brain may be smaller than normal, or one half of the brain may be significantly smaller than the other half.

Eye problems: Eye problems often affect patients with Aicardi syndrome. Lesions or holes may occur in the retina, which is located in the back of the eye. Holes (called colobomas) may also occur in the iris, which is the colored portion of the eye.

Seizures: Patients with Aicardi syndrome typically experience seizures or spasms, which may be severe.

Lung problems: Many children with Aicardi syndrome experience lung complications. Patients may have difficulty breathing due to weakened lung muscles. Infection of the lungs (such as pneumonia) is a major cause of death.

Porencephalic cysts: Some patients may develop porencephalic cysts, which are fluid-filled gaps or cavities in the brain.

Other symptoms that may occur in patients with Aicardi syndrome include scoliosis (an abnormal curvature of the spine), cleft lip and palate, and gastrointestinal difficulties, such as diarrhea.

DIAGNOSIS

Diagnosis of Aicardi syndrome is usually made during a clinical examination by checking for some of the symptoms, including retinal lesions, seizures, and an absence of the corpus callosum.

Vision exams: Eye exams can be performed to check for eye defects.

Brain imaging: Imaging technologies, such as magnetic resonance imaging (MRI) or a computed tomography (CT) scan, can be used to check for defects in the corpus callosum or for other brain abnormalities. MRI is a noninvasive imaging technique that uses magnetic waves and radio waves to take an image of tissues within the body. A CT scan is a noninvasive imaging technique that uses a series of X-rays to build a picture of the inside of the body.

Brain activity: A procedure called electroencephalography, which measures the electrical activity in the brain, can be used to further check for brain defects in patients. To perform electroencephalography, electrodes are placed on the scalp and used to make recordings of the electrical activity in the brain. Patients with Aicardi syndrome (and patients with other brain disorders) often have abnormal patterns of brain activity.

COMPLICATIONS

Neurological complications: The brain defects in patients with Aicardi syndrome usually result in severe learning disabilities, such as the inability to learn language. Also, developmental delays may be observed in patients with Aicardi syndrome and overall growth may be impaired. Many patients with Aicardi syndrome may have difficulty walking.

Vision problems: Some patients with Aicardi syndrome may become blind or nearly blind, due to the lesions that form on the retina.

Eating problems: Due to brain defects, patients with Aicardi syndrome may have difficulty chewing or swallowing food.

Lifespan can vary among patients with Aicardi syndrome, but typically, many patients do not survive past the first or second decade. Many children with Aicardi syndrome experience lung complications, and infection of the lungs is a major cause of death. Children with Aicardi syndrome are also more likely to develop tumors, and the complications that result may cause death in some patients.

TREATMENT

There is currently no known cure for Aicardi syndrome. Treatment for Aicardi syndrome generally focuses on managing the symptoms and is done on a patient-by-patient basis.

Physical therapy: Physical therapy programs can help patients with managing seizures or accommodating developmental delays.

Seizure medications: Anti-seizure medications are available, which can help reduce the frequency and severity of seizures. Some anti-seizure medications recommended for patients with Aicardi syndrome include Corticotropin (ACTH) and Vigabatrin. Drowsiness, hallucinations, weight gain, or vision loss are side effects of anti-seizure medications.

Back support: For patients that are affected with scoliosis, back braces are available that can help provide additional support and increase comfort.

Feeding tube: Patients who have difficulty eating can benefit from obtaining nutrients through a feeding tube.

Vision assistance: For patients with partial vision loss, eyewear can be used to help improve sight.

INTEGRATIVE THERAPIES

Currently, there is a lack of scientific data on the use of integrative therapies for the treatment or prevention of Aicardi syndrome.

PREVENTION

There are currently no known ways to prevent Aicardi syndrome. However, a number of treatment options exist that allow patients to manage some of the symptoms. Genetic testing is not currently available, because no specific genetic mutation has been implicated in Aicardi syndrome.

AUTHOR INFORMATION

This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

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