Chiari Malformation – Symptoms and Causes
Overview
Chiari malformation is a neurological condition where brain tissue extends into the spinal canal because of an abnormally small or misshapen skull. This structural problem puts pressure on the brain, forcing it downward.
Improved imaging technology has led to more frequent diagnosis of this condition.
Medical professionals classify Chiari malformation into three types:
| Type | Development | Typical Onset of Symptoms |
|---|---|---|
| Type 1 | Develops as skull and brain grow | Late childhood or adulthood |
| Type 2 | Present at birth (congenital) | Early childhood |
| Type 3 | Present at birth (congenital) | Early childhood |
The classification depends on the specific anatomy of the displaced brain tissue and whether developmental changes exist in the brain or spine. Types 2 and 3 are considered pediatric forms since they are present from birth.
Treatment approaches vary based on the type and severity of symptoms. Options include:
- Regular monitoring
- Medication for symptom management
- Surgical intervention
Some patients may not require any treatment if symptoms are mild or absent. Each case requires individual assessment by healthcare professionals.
Signs and Symptoms
Type 1 Brain Herniation
Type 1 brain herniation usually affects people in their late childhood or adult years. The main symptom is severe headaches that happen after coughing, sneezing, or physical strain.
Other common symptoms include:
- Neck pain
- Balance problems and unsteady walking
- Poor coordination in hands
- Numbness and tingling in hands and feet
- Feeling dizzy
- Swallowing difficulties (sometimes with gagging or choking)
- Changes in speech, like hoarseness
Some people may also experience:
- Ringing or buzzing sounds in the ears
- Muscle weakness
- Slow heartbeat
- Curved spine (scoliosis)
- Breathing problems, including stopping breathing during sleep
Type 2 Brain Herniation
In type 2 brain herniation, more brain tissue extends into the spinal canal compared to type 1.
This condition almost always occurs with a type of spina bifida called myelomeningocele, where the spine and spinal canal don’t properly close before birth.
Common symptoms include:
- Abnormal breathing patterns
- Difficulty swallowing
- Rapid downward eye movements
- Arm weakness
Doctors can often identify this condition during pregnancy with ultrasound or shortly after birth.
Type 3 Brain Herniation
Type 3 brain herniation is the most severe form. Part of the cerebellum (lower back part of the brain) or brainstem pushes through an opening in the skull. This serious condition is diagnosed during pregnancy or at birth.
This type causes significant brain and nervous system problems and has a higher death rate than other types. Immediate medical attention is essential for babies with this condition.
When to Contact a Healthcare Provider
You should see a healthcare provider if you or your child shows any symptoms that might suggest brain herniation. These include:
- Persistent headaches that worsen with coughing or straining
- Balance problems or coordination difficulties
- Numbness or tingling in limbs
- Swallowing problems
- Speech changes
- Breathing irregularities
Remember that many of these symptoms can also be caused by other conditions. A complete medical evaluation is necessary for proper diagnosis. Don’t delay seeking medical help if these symptoms appear, especially if they’re persistent or worsening.
Causes
Chiari malformation type 1 develops when the skull base is abnormally small or misshapen. This structural problem creates pressure on the cerebellum, forcing the lower portion (cerebellar tonsils) to push downward into the spinal canal.
In contrast, Chiari malformation type 2 is almost always found alongside myelomeningocele, a form of spina bifida. This connection points to developmental issues during early formation.
When the cerebellum extends into the spinal canal, it disrupts normal cerebrospinal fluid flow. This disruption can lead to two main problems:
- Fluid buildup in the brain or spinal cord
- Blocked nerve signals between the brain and body
The pressure created when the cerebellum pushes against the spinal cord or lower brainstem is what triggers many symptoms. This mechanical pressure interferes with normal neurological function.
The skull’s shape plays a crucial role in this condition. When the posterior fossa (the skull area that holds the cerebellum) develops too small, it cannot properly contain brain tissue, leading to the downward displacement characteristic of Chiari malformations.
Risk Factors
Some families show patterns of Chiari malformation across generations, suggesting genetic factors may play a role. However, the genetic research in this area remains relatively new and developing.
Complications
Some people with Chiari malformation may never experience symptoms or need treatment. However, others may face serious complications as the condition progresses over time.
Hydrocephalus is a common complication. It causes excess fluid to build up in the brain. This can affect thinking abilities and may require the placement of a shunt.
A shunt is a flexible tube that diverts and drains extra cerebrospinal fluid to another part of the body.
Spina bifida often occurs alongside Chiari malformation, especially type 2. This is a condition where the spinal cord or its protective covering doesn’t fully develop.
In severe cases like myelomeningocele, part of the spinal cord is exposed, which can lead to paralysis.
Syringomyelia affects some Chiari malformation patients. This condition involves the formation of a fluid-filled cavity or cyst (called a syrinx) within the spinal column.
As this syrinx grows larger, it can press against nerves and cause pain, weakness, and muscle stiffness.
Tethered cord syndrome is another possible complication. In this condition, the spinal cord attaches to the spine, causing it to stretch. This can result in serious nerve and muscle damage in the lower body as the person grows.
