Chiari Malformation: Symptoms, Diagnosis, Treatment


A Chiari malformation is a congenital defect, although a few acquired cases have also been found.

When the brain tissue extends into the spinal canal, the condition occurs. It can also be called Arnold Chiari malformation, hindbrain herniation and tonsillar ectopia.

A Chiari malformation affects the area of the back of the head where the brain and spinal cord connect, which is called cerebellum. When part of the skull appears to be smaller or misshapen, it presses on the brain and forces it to face downward.

The cerebellum is located behind the brain stem. Since cerebellum is in charge of controlling the coordination of motion, pressure on it can cause neurological symptoms, such as loss of balance, loss of coordination, vision problems, speech problems and so on.

Chiari malformation is an uncommon disease. Accepting monitoring on a regular basis, taking medications and having surgery can treat the symptoms of Chiari malformation. But some cases may need no treatment as well.

As a rare condition, it is estimated that Chiari malformation happens only to a slightly less than 1 in 1,000. However, a pediatric study in 2016 found that the prevalence of Chiari malformation can be higher to reach 1 in 100 children.

Considering most of these cases have few symptoms, patients with the disease often are detected coincidently when they have imaging tests for other possible reasons. Moreover, girls have a slightly higher chance of getting Chiari malformation than boys.



Chiari malformation is most commonly seen among children. Primary or congenital Chiari malformation often is due to abnormal fetal development, which may be caused by the following reasons:

  • Genetic mutations
  • Lack of proper vitamins and nutrients during pregnancy
  • Infection or a high fever during pregnancy
  • Exposure to hazardous chemicals

Acquired Chiari malformation cases have been also diagnosed. For adults with the condition, it is often associated with an accident or infection when the spinal cord is drained out.



Overall, there are four types of Chiari malformation.

  • Type 1

This is the most common type of Chiari malformation. It has something to do with the lower part of the cerebellum known as tonsils. It often appears to be asymptomatic until teen or adult years.

  • Type 2

This condition involves both the cerebellum and the brain stem. When the backbone and spinal canal don’t close in a normal way at birth, Chiari malformation type 2 happens.

  • Type 3

This type of Chiari malformation is often associated with a condition called hydrocephalus, which refers to fluid accumulation in the brain. In this condition, brain tissues extend into the spinal cord. It is a much rarer type but can also lead to a more serious outcome.

  • Type 4

This type involves the abnormal development of the cerebellum in the back of the head. If the cerebellum failed to develop normally during infancy, it would be fatal.



There are some common symptoms for people with Chiari malformation, but each patient may have different symptoms too.

For infants and children with the condition, they are most likely to experience a headache at the back of the head. Other possible symptoms may include:

  • An enlarged head
  • Dizziness
  • Vomiting
  • Pain in the neck
  • Stiffness in the neck
  • Numbness or tingling in the hands and feet
  • Weakness or loss of pain sensation in the upper body
  • Trouble in gaining weight and swallowing
  • Hearing loss
  • Breathing problem
  • Development delays
  • Seizures



Since the symptoms of Chiari malformation are very similar to other diseases, you’d better go to the doctor and have a detailed diagnosis if your kids have the above-described symptoms.

Usually, the condition is diagnosed with ultrasound devices while the kid is in the womb. Other times, the doctor may base a diagnose on a physical examination and other imaging scans.

In the physical examination, the doctor may ask about family history and check if the kid’s balance, sensation, vision, hearing, memory, and reflexes are okay. After that, the doctor may use a Magnetic Resonance Imaging (MRI) test, X-rays or Computed tomography (CT) scans to help to determine the diagnosis.



Although the researches on Chiari malformation are still ongoing, there are treatment methods available for patients with the condition.

Depending on the type and severity of Chiari malformation, the doctor may take different ways to control the symptoms. When the condition poses no significant influence on the patient’s daily life, the doctor may prescribe some medicines to help to ease the pain. However, if people with the disease have developed neurological symptoms, the doctor may recommend surgery.

The basic surgery is to remove part of bone at the base of the skull so as to relieve the pressure on the spinal area. Under conditions that the kids are with hydrocephalus, the doctor will insert a tube to allow the excess fluid to drain out.

According to previous data, surgical treatment is effective for improving the symptoms for a kid with Chiari malformation.


Keywords: Chiari malformation; Arnold Chiari malformation; hindbrain herniation; tonsillar ectopia.


Related Posts:

What Is Chiari Malformation and What Cause It?

What Are Symptoms and Risk Factors of Chiari Malformation?

How to Diagnose and Treat Chiari Malformation?

What Is Cerebellar Tonsillar Ectopia?

What Are the Basics of Hydrocephalus?

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.