What is the Difference Between Chiari 1 and 2

The key difference between Chiari 1 and 2 is that Chiari 1 is a type of Chiari malformation in which a small amount of brain tissue extends into the spinal canal, while Chiari 2 is a type of Chiari malformation in which a greater amount of brain tissue extends into the spinal canal.

Chiari malformation is a medical condition where brain tissue extends into the spinal canal. It occurs when a part of the skull is misshaped or smaller than its typical size. This presses on the brain and forces it downward. There are three types of Chiari malformation. Chiari 1 develops in late childhood or adulthood, while Chiari 2 and 3 are present at birth (congenital).

CONTENTS

1. Overview and Key Difference
2. What is Chiari 1 
3. What is Chiari 2
4. Similarities – Chiari 1 and 2
5. Chiari 1 vs 2 in Tabular Form
6. Summary – Chiari 1 vs 2

What is Chiari 1?

Chiari 1 is a type of Chiari malformation that develops in late childhood or adulthood. In this type, a small amount of brain tissue is extended into the spinal canal. Chiari 1 is the most common type of Chiari malformation. Symptoms generally occur after a sudden coughing, sneezing, or straining. They include severe headache, neck pain, unsteady gait, numbness and tingling in hands and feet, poor hand coordination, dizziness, difficulty swallowing, speech problems (hoarseness), ringing or buzzing in the ears, weakness, slow heart rhythm, curvature of the spine, and breathing problems such as sleep apnea.

There are different causes for this condition, including contact with harmful substances during pregnancy, linkages with genetic problems that run in the family, or excess leaking of spinal fluid from the lower back or chest areas of the spine. Chiari 1 can be diagnosed through physical examinations, MRI, and CT-scan. Furthermore, the treatment options for Chiari malformation type 1 include painkillers, decompression surgery, and other procedures such as endoscopic third ventriculostomy, ventriculoperitoneal shunting, untethering, and spinal fixation.

What is Chiari 2?

Chiari 2 is a type of Chiari malformation in which a greater amount of brain tissue extends into the spinal canal when compared to Chiari malformation type 1. Chiari 2, as well as Chiari 3, develop at birth (congenital). The signs and symptoms of Chiari 2 can be related to a form of spina bifida called myelomeningocele. In this condition, the backbone and the spinal canal do not close properly before birth. The signs and symptoms include changes in the breathing pattern, noisy breathing, apnea, swallowing problems such as gagging, aspiration, quick downward eye movements, weakness in the arms, hydrocephalus that keeps worsening over time, abnormal shape of the spine, eyesight problems, hearing loss, and trouble using hands to pick up and use small objects.

Chiari malformation type 2 is usually diagnosed with ultrasound during pregnancy and MRI and CT scan during early infancy. Chiari malformation type 2 treatment options are surgery to ease pressure in the brain and let spinal fluid flow, closing myelomeningocele, putting a shunt in the spinal cord to drain fluid from a syrinx, treatment for bowel and bladder problems, special feedings, and breathing supports.

What are the Similarities Between Chiari 1 and 2?

• Chiari 1 and 2 are two types of Chiari malformation.
• In both types, the cerebellum (a brain tissue) at the back of the skull protrudes through a normal opening in the skull and joins the spinal canal.
• Both were discovered by Arnold–Chiari.
• They may have a genetic influence.
• Both types may have similar symptoms, such as breathing problems and difficulty swallowing.
• They can be diagnosed through imaging tests.
• They can be treated through decompression surgery.

What is the Difference Between Chiari 1 and 2?

Chiari 1 is a type of Chiari malformation in which a small amount of brain tissue extends into the spinal canal, while Chiari 2 is a type of Chiari malformation in which a greater amount of brain tissue extends into the spinal canal. Thus, this is the key difference between Chiari 1 and 2. Furthermore, Chiari 1 usually develops in late childhood or adulthood, while Chiari 2 usually develops at birth.

The below infographic presents the differences between Chiari 1 and 2 in tabular form for side by side comparison.

Summary – Chiari 1 vs 2

A Chiari malformation is a medical condition where brain tissue (cerebellum) extends into the spinal canal. Chiari 1 and 2 are two types of Chiari malformation. In Chiari 1, a small amount of brain tissue extends into the spinal canal, while in Chiari 2, a greater amount of brain tissue extends into the spinal canal. So, this is the key difference between Chiari 1 and 2.

Reference:

1. “Chiari Malformation Type I.” Johns Hopkins Medicine, 28 Oct. 2021.
2. “Chiari Malformation Type II.” Golisano Children’s Hospital – University of Rochester Medical Center.

Image Courtesy:

1. “Chiari-1-Malformation 13W – MR T2 sagittal – 001a” By Hellerhoff – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Chiari2”  By see above – Rekate HL. The definition and classification of hydrocephalus: a personal recommendation to stimulate debate. Cerebrospinal Fluid Res. 5, 2. 2008. doi:10.1186/1743-8454-5-2. PMID 18211712. (CC BY 2.0) via Commons Wikimedia