Chiari malformation

Overview

Chiari malformation is a medical condition characterized by the displacement of brain tissue into the spinal canal. It occurs when a portion of the skull, either abnormally shaped or smaller in size, exerts pressure on the brain, causing it to be pushed downward into the spinal canal.

While Chiari malformation is considered rare, the frequency of diagnoses has increased due to the utilization of advanced imaging tests. Medical professionals classify Chiari malformations into three categories based on the anatomy of the displaced brain tissue and the presence of developmental abnormalities in the brain or spine.

Chiari malformation type 1 typically manifests during the developmental stages of the skull and brain. However, its signs and symptoms may not become apparent until late childhood or adulthood. On the other hand, Chiari malformation types 2 and 3 are congenital conditions present from birth and primarily affect pediatric patients.

The form, degree, and accompanying symptoms of a Chiari malformation all affect how it is treated. Treatment options include routine observation, prescription drugs, and surgery. Sometimes no medical intervention is required.

Symptoms

Many individuals with Chiari malformation may remain asymptomatic and may not require any treatment. Often, the condition is incidentally discovered during diagnostic tests conducted for unrelated health concerns. However, the type and severity of Chiari malformation can give rise to a range of issues and symptoms in affected individuals.

These are the more prevalent kinds of Chiari malformations:

• Type 1
• Type 2

The signs and symptoms of these types can nevertheless be life-changing even if they are less severe than the pediatric variant, type 3, which is more uncommon.

Chiari malformation type 1

Signs and symptoms of Chiari malformation type 1 commonly manifest during late childhood or early adulthood. Headaches are the most prevalent and severe symptom associated with this condition. These headaches often occur following sudden exertion, such as straining, coughing, or sneezing. In addition to headaches, individuals with Chiari malformation type 1 may experience:

• Dizziness
• Pain in the neck
• Balance issues (unsteady gait)
• Weak fine motor skills such as poor hand coordination
• Hands and feet that are numb and tingly
• Issues with speech, such as hoarseness
• Swallowing issues that are occasionally followed by gagging, choking, and vomiting

Less frequently, those who have a Chiari malformation could encounter:

• Back curvature (scoliosis) brought on by damage to the spinal cord
• Issues with breathing, such as central sleep apnea, in which a person stops breathing while they are sleeping.
• Tinnitus, which causes a ringing or buzzing in the ears.
• Weakness
• Slow heart rate

Chiari malformation type 2

Compared to Chiari malformation type 1, more tissue penetrates the spinal canal in Chiari malformation type 2.

The signs and symptoms can include those connected to myelomeningocele, a kind of spina bifida that almost invariably occurs alongside Chiari malformation type 2. The spinal canal and backbone fail to correctly close before delivery in myelomeningocele.

Some warning signs and symptoms include:

• Rapid downward eye motions
• Arm weakness
• Changes in respiratory patterns
• Issues with swallowing, such as gagging

A type 2 Chiari malformation is typically detectable through ultrasound during pregnancy. It is one of the potential findings during prenatal screening. Alternatively, a diagnosis of type 2 Chiari malformation can also be made shortly after birth or during early infancy.

Chiari malformation type 3

In Chiari malformation type 3, which is the most severe form of the condition, either the brainstem or a portion of the cerebellum (located at the lower back of the brain) protrudes through a skull defect at the back. This particular type of Chiari malformation is typically identified either at birth or through prenatal ultrasound examination.

The death rate for this kind of Chiari malformation is higher, and it may also result in neurological issues.

Consult your doctor for an evaluation if you or your kid exhibits any of the signs and symptoms that could point to a Chiari malformation.

A thorough medical evaluation is crucial because many symptoms of Chiari malformation can potentially be linked to other illnesses.

Causes

In Chiari malformation type 1, the skull section housing a part of the brain (cerebellum) is either too small or deformed, resulting in pressure and crowding on the brain. In this condition, the lowest section of the cerebellum, known as the tonsils, is displaced and extends into the upper spinal canal.

A kind of spina bifida called myelomeningocele is almost often linked to Chiari malformation type 2 cases.

When the cerebellum is forced into the upper spinal canal in Chiari malformation, it can impede the normal flow of cerebrospinal fluid, which serves as a protective cushion for the brain and spinal cord. This obstruction in cerebrospinal fluid circulation can lead to the accumulation of fluid in the brain or spinal cord, as well as disruptions in the transmission of signals from the brain to the rest of the body.

Additionally, the pressure exerted by the displaced cerebellum on the spinal cord or lower brainstem can result in neurological signs and symptoms. These symptoms can arise due to the compression and interference with the normal functioning of these vital neurological structures.

Risk factors

There is proof that some families are predisposed to the Chiari malformation. The investigation into a potential genetic component, though, is still in its early stages.