Chiari malformation

Chiari malformation

Chiari malformation or  Chiari malformation  is an abnormality in the formation of the skull structure that occurs during fetal development. The rare disorder causes part of the brain to enter the spinal cord.

Normally,  the cerebellum  and brainstem lie above the opening that connects the brain to the spinal cord (foramen magnum). In Chiari malformation, part of the cerebellum is pushed past the foramen magnum and down into the spinal cord.

The above conditions occur due to disturbances in the structure of the skull bones. As a result, cerebrospinal function will be disrupted and the flow of cerebrospinal fluid to the brain and spinal cord will be obstructed.

Chiari malformation sometimes causes no symptoms and does not require specific treatment. However, in some cases, Chiari malformation can cause dangerous complications and require treatment.

Chiari malformation type

Based on the severity and the part of the brain that passes through the canal in the spine, Chiari malformation is divided into four types, namely:

Type 1

Type 1 Chiari malformation occurs when the lower part of the cerebellum (cerebellar tonsils) extends past the foramen magnum. Normally, the foramen magnum is only passed by the spinal nerves.

Chiari malformation type 1 is the most common type of Chiari malformation. This type sometimes does not cause symptoms and is usually only detected in adolescents or adults.

Type 2

Type 2 Chiari malformation occurs when the cerebellum and  brainstem  pass through the foramen magnum. In this type, the nerve network that connects the left and right cerebellum is lost or only partially formed. This condition is often accompanied by the appearance of spina bifida type myelomeningocele.

Type 2 Chiari malformation is also called Arnold-Chiari malformation or classic Chiari malformation. The term Chiari malformation itself refers more to this type of Chiari malformation.

Type 3

Type 3 Chiari malformation occurs when part of the cerebellum and brainstem exits the skull through an abnormally formed hole at the back of the skull ( encephalocele ).

Chiari malformation type 3 is the most dangerous type compared to other types.

Type 4

Type 4 Chiari malformation occurs when the cerebellum doesn't develop properly. This type is also known as cerebellar hypoplasia.

Causes of Chiari Malformation

Chiari malformation is caused by disorders of the brain, spinal cord, and skull, which occur during fetal development. This condition occurs due to changes (mutations) in genes, or other conditions that occur in pregnant women.

The following are several conditions in pregnant women that are often associated with the appearance of Chiari malformation in infants and fetuses:

  • Lack of intake of certain nutrients, such  as folic acid
  • Exposure to dangerous chemicals,  drugs , and  alcohol
  • High fever or infection

In some cases, Chiari malformation can occur in adults. This condition can be caused by an injury or infection that causes excessive spinal fluid discharge.

Other diseases associated with Chiari malformation

Patients with Chiari malformation generally suffer from neurological diseases or spinal disorders. Other diseases that often appear when a person has Chiari malformation are:

  • Syringomyelia , namely the appearance of cysts in the spine due to spinal cord disorders
  • Spina bifida type of myelomeningocele, which is the formation of a gap in the spinal column which causes a sac filled with fluid and some spinal nerves to come out
  • Hydrocephalus , which is a buildup of fluid in the brain which at an advanced stage can cause increased pressure on the brain
  • Tethered cord syndrome , which is a condition when the spinal nerves enter the spine causing traction and damage to the nerves of the lower body
  • Spinal curvature abnormalities, including  scoliosis or  kyphosis , which are common in people with syringomelia or those with Chiari malformation type 1

Chiari malformation symptoms

Chiari malformation sometimes does not cause any symptoms, so sufferers only become aware of it when undergoing examinations for other diseases. However, not a few sufferers of Chiari malformation experience symptoms.

Symptoms of Chiari malformation depend on the type the patient is experiencing. Here is the explanation:

Type 1

Symptoms of type 1 Chiari malformation usually appear in early adolescence or adulthood. This condition has typical symptoms in the form of severe headaches that appear when coughing or sneezing. In general, the symptoms of Chiari malformation type 1 include:

  • Dizzy
  • Headache
  • Neck pain
  • Tinnitus
  • Weak
  • Scoliosis
  • Slow heart rhythm
  • Speech disorder
  • Balance disorders
  • Breathing disorders, such as  sleep apnea
  • Poor coordination of hand movements
  • Tingling and numbness in hands and feet
  • Difficulty swallowing, choking or vomiting

Type 2

Symptoms of type 2 Chiari malformation are usually accompanied by myelomeningocele, which is a disorder of spina bifida . Patients with Chiari malformation type 2 can experience symptoms in the form of:

  • Respiratory disorders
  • Arms feel weak
  • Headache
  • Difficult to swallow
  • Difficulty speaking due to disorders of the vocal cords

In infants and children, complaints and symptoms may appear in the form of impaired growth and development, choking, vomiting, and stiffness in the neck.

Type 3

Symptoms of type 3 Chiari malformation are present from birth. Some of the symptoms can be the same as Chiari type 2 malformation which is accompanied by disorders of the nervous system, such as nystagmus , seizures, deafness , and impaired physical and mental development. Type 3 is the most severe type of Chiari malformation.

In addition to the above symptoms, type 3 Chiari malformation is often accompanied by hydrocephalus, which is a buildup of fluid in the cavities of the brain which causes the size of the head to increase.

When to see a doctor

Check with  your doctor  if you or your child has symptoms of Chiari malformation or other conditions associated with Chiari malformation.

If you have been diagnosed with Chiari malformation, take control according to the examination schedule given by the doctor. This is so that the development of your condition is always monitored.

Diagnosis of Chiari malformation

The doctor will ask about the patient's symptoms and medical history, followed by a physical examination, especially  examination of nerve function . After that, the doctor will carry out supporting examinations to confirm the diagnosis, such as:

  • Computerized tomography (CT scan), to detect brain damage, bone and blood vessel abnormalities, brain tumors, or other conditions that may be associated with Chiari malformation
  • Magnetic resonance imaging (MRI), to see abnormalities in the patient's brain structure, as well as to monitor the severity and progress of the patient's condition when diagnosed with Chiari malformation
  • X-rays , to see abnormalities in the skull and spine that may be associated with Chiari malformation

Chiari malformation treatment

Treatment of Chiari malformation depends on the symptoms and severity. For patients who are asymptomatic (asymptomatic), treatment is usually not necessary. However, the doctor will monitor the patient's progress by conducting periodic MRI examinations.

In patients who experience mild symptoms, the doctor will provide treatment according to the symptoms that appear. For example, if the patient has a headache or neck pain, the doctor will prescribe pain relievers.

If the patient's symptoms are severe, the doctor will perform surgery to reduce pressure on the brain and spine, and improve the flow of cerebrospinal fluid. The method of operation performed includes:

  • Posterior fossa decompression , to reduce pressure on the brain
  • Electrocautery , to shrink the lower part of the cerebellum
  • Third ventriculostomy , to improve cerebrospinal fluid flow
  • Spinal laminectomy , to relieve pressure on the spinal cord and spinal nerve roots

Please note, surgery can relieve symptoms, but cannot repair nerve damage that has occurred due to Chiari malformation. Even so, patients with nerve damage can undergo medical rehabilitation or physiotherapy after surgery.

The healing process after surgery usually lasts around 4–6 weeks. Doctors will advise Chiari malformation patients not to do strenuous physical activity and lift weights for up to 2-3 weeks after surgery.

After surgery, patients must also carry out routine controls to the doctor so that complications can be prevented and the progress of their condition can be monitored. Especially for patients who also suffer from myelomeningocele or hydrocephalus , doctors will provide further treatment to treat these two conditions.

Complications of Chiari malformation

Chiari malformation can cause damage to the cerebellum and spinal cord. This condition is also often associated with hydrocephalus, syringomylia , spina bifida  tethered cord syndrome , and spinal disorders, such as scoliosis or kyphosis.

Some of the complications that can arise from Chiari malformation surgery are cerebrospinal fluid discharge, infection of the lining of the brain ( meningitis ), impaired function of the brain and nervous system, respiratory arrest, injury to blood vessels (arteries) in the spine, or brain bleeding.

Chiari malformation prevention

There are several efforts that can be made by pregnant women so that Chiari malformation does not occur during fetal development, including:

  • Adequate nutrition needed by mother and fetus during pregnancy
  • Increase folic acid intake, for example from vegetables and fruit
  • Take folic acid, iron and calcium supplements according to the doctor's advice
  • Avoid exposure to hazardous substances, including alcohol and drugs
  • Undergo routine pregnancy control to the doctor
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