Chiari malformation is a condition in which the lower part of the brain pushes down into the spinal canal. It is a relatively rare disorder of the brain and spinal canal that can sometimes cause serious complications.
Chiari malformation is a condition in which the lower part of the brain pushes down into the spinal canal. It is a relatively rare disorder of the brain and spinal canal that can sometimes cause serious complications. Having a Chiari malformation may not be life-threatening, but the patient is usually prone to develop life-threatening conditions in the future. The severity of Chiari malformations can vary from person to person, but generally
- Patients experience painful headaches, movement problems and other unpleasant symptoms, but many people will not have any symptoms.
- Surgery can usually stop the symptoms from getting worse and can sometimes improve them, although some problems may remain.
- Most children who undergo surgical treatment experience a reduction in their symptoms. Infants with more severe diseases may have life-threatening complications.
- Without treatment, the disease slowly progresses over years, greatly affecting quality of life. It can even be life-threatening if it involves the mouth and throat.
Chiari malformation can be associated with several serious conditions, including
- Hydrocephalus (excess fluid in the brain)
- Spina bifida (malformation of the spinal cord)
- Syringomyelia (a cavity or cyst called a syrinx in the spinal column)
- Tethered cord syndrome (spinal cord is attached to the spine)
What is Chiari malformation?
Chiari malformation or Arnold-Chiari malformation is usually considered a birth defect. It is a condition where part of the brain called the cerebellum protrudes through an opening in the back of the skull and into the spinal canal. It also can be related to where the bones of the spine don't form properly and membranes protrude out of a child's back. This condition also puts pressure on the nerves and spinal cord and disrupts the flow of cerebrospinal fluid. The disruption of that flow can cause debilitating pain and other severe symptoms. For many, the malformation exists at birth, but it can go years or even decades without presenting any symptoms. Most people are diagnosed with Chiari during childhood, but some will not be diagnosed until they are adults.
Chiari malformation is classified as
Type I
- It is typically discovered during examinations for other conditions in adolescence or early adulthood.
- This condition is characterized as having an undeveloped or improperly formed posterior fossa and upper spinal area.
Type II
- It is the most common.
- In this type, extensions of the rear part of the brain shift down through the bottom of the skull, causing several complications.
- Skull and spine-related birth defects symptoms are associated with type II malformations.
Type III
- It has high death rates.
- Severe neurological defects and life-threatening complications are associated with this condition where portions of the cerebellum and/or brainstem protrude through a deficit in the rear of the head or neck.
Type IV
- The brain fails to develop fully or normally. This is the most severe and rare case.
Symptoms of Chiari malformation
- Vomiting
- Muscle weakness in the head and face
- Difficulty swallowing
- Varying degrees of mental impairment
- Headache
- Neck pain
- Progressive scoliosis (curvature of the spine)
- Difficulty with balance and coordination
- Problems with fine motor skills
- Vision problems, including blurred or double vision and hypersensitivity to bright light
- Tinnitus (buzzing in the ear)
- Hearing loss
- Voice alteration or paralysis
- Frequent gagging and/or choking
- Sleep apnea (briefly ceasing to breathe while sleeping)
- Paralysis or weakness of the arms and legs
- Spasticity (abnormally high muscle tone or tightness)
Causes of Chiari malformation
- The cause of Chiari malformation is unknown.
- Many cases are thought to be the result of part of the skull not being large enough for the brain.
- Type I Chiari malformations can also develop in people with a tethered spinal cord, a build-up of fluid around the brain and some types of brain tumor.
- Chiari malformations can sometimes run in the family. Some children born with it may have inherited a faulty gene that caused problems with their skull development. However, the risk of passing a Chiari malformation to the child is very small.
- Chiari malformations primarily occur because of congenital disorders. However, these malformations may be asymptomatic until triggered by physical trauma, such as an automobile collision. Furthermore, a growing body of evidence suggests that physical trauma can be the sole cause of a type I Chiari malformation.
Treatment of Chiari malformation
- While symptoms can be managed, the main “cure” is brain surgery.
- Painkillers can help relieve headaches and neck pain. If the headaches are severe or the patient has problems caused by pressure on the spinal cord (such as movement difficulties), surgery may be recommended.
- The main procedure for Chiari malformation is called decompression surgery. Under general anesthesia, a cut is made at the back of the head. The surgeon then removes a small piece of bone from the base of the skull. They may also remove a small piece of bone from the top of the spine. This will help reduce the pressure on the brain and allow fluid in and around the brain and spinal cord to flow normally.