As previously explained, Myelomeningocele’s two most common conditions associated with the brain are Hydrocephalus and Chiari Type II Malformation, also known as Arnold Chiari Malformation (pronounced key – ar- ee). This article will discuss Arnold Chiari Malformation in a person with Spina Bifida.
What is Chiari Malformation?
Chiari malformation is a structural abnormality where brain tissue from the lower back of your skull extends into the spinal canal. This occurs because the skull is smaller than expected, causing the cerebellum to grow downward through the foramen magnum, an opening at the base of the skull. An Austrian pathologist named Professor Chiari discovered it. He graded this malformation into four types in order of severity. Type I is the mildest and the most common, and type III is the most severe. Chiari Malformation Type II usually happens with the most severe form of Spina Bifida called Myelomeningocele. Type IV Chiari Malformation is very rare.
What is Chiari Malformation Type II?
Chiari malformation Type II, also known as Arnold-Chiari malformation, is a congenital malformation of the spine and posterior fossa (the part of the skull at the back of the head containing the cerebellum) commonly seen in children with Myelomeningocele. It involves the cerebellum and brain stem tissue pushing into the foramen magnum. In children with Chiari malformation Type II, the posterior fossa is undersized, causing parts of the cerebellum and brainstem to descend lower than normal. In Chiari malformation Type II, the nerve tissue that connects the two halves of the cerebellum may be missing or only partially formed. Chiari Type II is more severe than Chiari Type I, and this abnormality is responsible for many changes in the brain.
A normal, typical brain looks like the image below. All Illustrations courtesy of Brain and Spine Foundation
Brain with Chiari Malformation Type II looks like the image below.
How common is a Chiari Type II?
It is found in almost all children born with Myelomeningocele.
What are the symptoms of Chiari Malformation Type II?
When brain tissue descends below the fourth cervical vertebra (C4), there is a significant risk of serious symptoms emerging from this abnormality. Minor degrees of brain descent situated above the C3 level are less likely to produce recognizable progressive symptoms. Symptoms of Arnold Chiari malformation at different developmental stages are:
Infancy
- Insufficient breathing
- Stridor (noise on breathing in)
- Weak or absent cry
- Arching of the neck backwards
- Feeding or swallowing difficulties
- Hypersensitivity to objects in their mouth
- Excessive drooling, gagging, or vomiting
Childhood/Young adults
- Muscle weakness or numbness
- Stiff neck or neck pain
- Feeding or swallowing difficulties
- Breathing difficulties
- Hand-eye coordination problems
- Headache, especially after sudden coughing, sneezing, or straining
- Hearing loss and ringing in the ears
- Balance problems
- Curvature of the spine (scoliosis)
- Insomnia (sleep problems)
- Depression
- Inability to gain weight
Please note that symptomatic Chiari malformation Type II’s insufficient breathing to maintain life is currently the leading cause of death in Spina Bifida people, particularly in childhood.
What are the complications of Chiari Malformation Type II?
Chiari malformation can cause severe neurological conditions and developmental delays.
Neurological complications may include:
- Hydrocephalus: Under normal circumstances, the amount of CSF produced is balanced by the amount returned to the bloodstream, keeping the amount of CSF within the ventricles steady. Hydrocephalus occurs when there is an obstruction to the flow of CSF, causing fluid to build up within the brain’s cavities. This fluid build-up can cause pressure on the brain tissues and bones of the skull. The Chiari malformation might also block the flow of cerebrospinal fluid, causing hydrocephalus. Please read our detailed article on Hydrocephalus here.
- Tethered Cord Syndrome: Tethered Cord Syndrome is a neurological disorder resulting from spinal cord malformations. This condition restricts the spinal cord’s movement within the spinal canal, causing it to stretch as the spine grows. Due to the increased length of the spine, this tension, or stretching, of the spinal cord can lead to nerve damage, pain, sensory disturbances, significant muscle weakness, and incontinence, known as Tethered Cord Syndrome (TCS). Please read our detailed article on Tethered Cord Syndrome here.
- Curving of the Spine: Abnormal spine curving can occur in people with Chiari Type II. The spine may curve to the left or right (scoliosis), or it may curve outward (kyphosis). (Refer to image below).
- Syringomyelia: This condition occurs when the flow of cerebrospinal fluid (CSF) is disrupted at the foramen magnum, causing the fluid to accumulate within the spinal cord. This fluid-filled cavity, known as a syrinx, typically forms in the cervical (neck) region but can extend further down the spinal cord. There is not much data on why people with Chiari malformation develop syrinx. (Refer to image below).
The image below shows the curving of the spine
The image below shows syrinx
Development delays may include:
- Cognitive skills: Cognitive skills include thinking, learning and understanding information. A child with a cognitive delay may have trouble following directions or solving a problem.
- Social and emotional skills: These skills include getting along with others, expressing feelings and communicating needs. A child with social or emotional delays may struggle with understanding social cues, having a conversation or dealing with changes to a routine.
- Speech and language skills: Speech and language skills include using and understanding language. A child with speech and language delays may have difficulty speaking words or understanding what others are saying.
- Fine motor skills: These skills include the ability to coordinate small (fine) muscles. A child with a fine motor delay may have trouble holding an object in their hands or have trouble with colouring and writing.
How is Chiari Malformation II diagnosed?
The following tests can help in diagnosing Chiari Malformation:
MRI (Magnetic Resonance Imaging): The invention of MRI has greatly streamlined the evaluation of structural abnormalities in the cervical spine. An MRI scan can show soft tissues and bones. It helps to see the brain, spinal cord and the flow of cerebrospinal fluid. MRI can show how much the cerebellum extends into your spinal canal. MRI provides high-resolution images with little to no risk to the patient.
CT (Computed Topography): A computed tomography (CT) can also help diagnose Chiari 2 malformation and provide further detail on osseous anatomy. However, the disadvantages of CT include lower resolution, posterior fossa artifact, and ionizing radiation to the child.
Ultrasound: If foetal ventriculomegaly is present, Chiari 2 malformation can be detected with foetal (prenatal) ultrasound in some cases. Foetal ventriculomegaly refers to an abnormal enlargement of the brain’s ventricles, which may indicate a potential issue with the flow of cerebrospinal fluid. Particularly in the later stages of pregnancy, a prenatal ultrasound can detect characteristic signs like the “lemon sign” and “banana sign”, which indicate abnormalities in the foetal skull and cerebellum. A lemon sign is the inward scalloping of the frontal bones of the foetal skull depicting a lemon. A banana sign is an abnormal shape of the cerebellum appearing “banana-like” due to its displacement into the spinal canal.
Physical examinations: To diagnose Chiari Malformation, the doctor will perform a physical exam and check your memory, cognition, balance, touch, reflexes, sensation, and motor skills.
How is Chiari Malformation II treated?
Although it is found in almost all children born with Myelomeningocele, it appears to be asymptomatic in most children. Most children with Chiari malformation Type II have no obvious symptoms and, therefore, need no treatment. However, some children do develop symptoms and should see their doctor promptly. Also, as adolescents and young adults grow, they tend to develop clinical progression.
Treatment depends on your symptoms and their severity. Talk with your doctor about your symptoms and how they affect you, and the doctor will explain the treatments you may need. Chiari malformation Type II that does not show symptoms and does not interfere with daily life may only need regular monitoring by a neurologist and periodic imaging. Your doctor might prescribe pain medications that can ease headaches and pain. Participating in massage therapy or physical therapy might also help. Limiting your physical activity might also help in relieving discomfort.
What is the ‘shunt first’ approach to care for people with Hydrocephalus?
The ‘shunt first’ approach must be given utmost priority. If a child or young adult is symptomatic of Chiari malformation, the first step should be to ensure normal intracranial pressure (ICP) before any consideration of intervention for the Chiari malformation. This means that the patient should have her/his shunt evaluated first. In case of any uncertainty about the shunt function, the system should be examined surgically. Read our detailed article on Hydrocephalus and shunts here.
After confirming that the intracranial pressure (ICP) is normal and the shunt is functioning correctly, the next step is to assess whether the patient’s symptoms are life-threatening or progressively worsening. If there are signs of serious symptoms, surgical intervention should be considered.
What are the surgical options avalaible for Chiari Malformation?
In many cases, surgery is the only treatment available to ease symptoms or stop ongoing damage. Surgery can improve or stabilize symptoms in most people. The purpose of this surgery is to create space and allow or reestablish normal movement of the cerebrospinal fluid (CSF). The most common surgeries are:
Posterior Fossa Decompression: This is the most common procedure to treat a Chiari malformation. In this procedure, your surgeon relieves pressure on your brain, giving it more room, and restores the normal flow of cerebrospinal fluid CSF. In posterior fossa decompression surgery, an incision at the back of the head is made, and a small portion of the bone at the bottom of the skull is removed (a procedure called a craniectomy). In simple words, it relieves pressure (decompression) at the back of the skull (posterior fossa) and allows CSF to flow normally.
Spinal Laminectomy: Depending on how severe the Chiari malformation is, your surgeon may remove a small portion of the bones covering your spinal column (lamina) to restore the flow of CSF and allow more room for your spinal cord.
Electrocautery: To create more room and allow the CSF to drain, your surgeon may apply a small amount of electricity to shrink a small part of your brain called the cerebellar tonsils. These tonsils do not have a recognized function, and they retract without causing any known neurological problems.
Please note that a surgeon proficient in operating on brain malformations should perform these surgeries. Given the intricate nature of these procedures, significant experience is crucial for achieving technical excellence.
According to the National Institute of Health (NIH), in patients requiring Posterior Fossa Decompression, 68% had a complete or near-complete resolution in symptoms, 20% had no improvement, and 12% had mild to moderate residual deficits
What are the surgical complications?
Every surgery comes with possible risks. Surgery around your brain and skull is high risk due to the location of the incision and procedure being near your brain.
According to the National Institute of Health (NIH), in a published series on patients with Chiari 2 malformation who underwent Posterior Fossa Decompression surgery, there was a 37.8% mortality rate in patients who underwent surgery, with follow-up ranging as far out as 6 years. The reasons were as follows:
- Respiratory arrest was the most common cause of mortality in 8 out of 17 patients who died.
- Meningitis or ventriculitis in 6 out of 17 patients who died.
- Aspiration in 2 out of 17 patients who died.
- Biliary atresia in 1 out of 17 patients who died.
What questions should I ask my doctor?
- Do I have a Chiari malformation?
- Is my Chiari malformation symptomatic or asymptomatic?
- What type of treatment do you recommend?
- How often do I need imaging tests to monitor the condition?
- Do you recommend surgery?
- If surgery is needed, what type of surgery will be performed?
- If surgery is needed, what are the complications of the surgery?
- If surgery is needed, are there chances of a repeat surgery?
- If surgery is needed, how long will I take to recover?
- If surgery is needed, what precautions will I have to take?
- Are there long-term side effects of the treatment?
A note from Sasha Foundation
The effects of a Chiari malformation vary from person to person. While some individuals may remain asymptomatic or experience only mild symptoms with minimal impact on their daily lives, others may suffer from severe, debilitating symptoms that require surgical treatment. Affected individuals may have good and bad days, so it is important to listen to your body and be patient with yourself.
While nothing can be done to prevent congenital Chiari malformation Type II, your education on this topic plays a significant role in familiarising yourself with the signs and symptoms of the condition. As explained earlier, Chiari malformation Type II is currently the leading cause of death in Spina Bifida people, so you have to be vigilant, particularly in childhood. Special attention must be given to breathing difficulties, neonatal feeding difficulties and apnea,
According to the National Institute of Health (NIH), the mortality rate is 71% in infants with vocal cord paralysis, arm weakness, or cardiopulmonary arrest within 2 weeks of presentation, in comparison to patients with a more gradual deterioration who had a 23% mortality.
To rule out Chiari malformation, get an MRI done at an early stage of life. It is critical to know all conservative and surgical management strategies for this malformation so you can make an informed call. Talk to others who are observing similar symptoms and learn the actions they are taking.
Visit your doctor promptly if you
- Experience any symptoms of a Chiari malformation or if your symptoms get worse.
- If you have a child with a Chiari malformation and they miss developmental milestones for their age.
- After surgery, if you show signs of an infection like severe pain, swelling or your surgical wound not healing.
Please Note
The information provided on our website is not intended as medical advice for any individual. Since specific cases may differ from the general information presented, SASHA recommends consulting a qualified medical or other professional for personalized advice.
About the Author
Raul/DJ Vivek
Meet Vivek Bharadwaj, a remarkable individual who has defied the odds and soared to new heights despite living with Spina Bifida. As the founder of the Sasha Foundation, Vivek tirelessly advocates for others facing similar challenges. His unwavering commitment to support, awareness, and empowerment had made a lasting impact on the Spina Bifida community.
FAQ
Can a Chiari malformation be prevented?
There’s no known way to prevent a Chiari malformation.
Is Chiari malformation curable?
Although there isn’t a cure for a Chiari malformation, conservative and surgical treatments can help manage your symptoms.
Is a Chiari malformation serious?
A Chiari malformation can be very serious in some cases but not all. In most cases, it doesn’t need any treatment.
What is the life expectancy of someone with a Chiari malformation?
If you don’t have symptoms or you have mild symptoms after a Chiari malformation diagnosis, you’ll likely have a normal life expectancy. Severe symptoms and certain types of Chiari malformation can be fatal.
What’s the outlook for a Chiari malformation?
Your outlook varies depending on the severity and type of Chiari malformation.
When should I see a doctor?
Visit a doctor if you experience symptoms of a Chiari malformation or if your symptoms get worse.
Does Chiari get worse with age?
In some people, they don’t. In others, Chiari malformation can get worse over time and lead to serious complications.
Does Chiari cause cognitive issues?
Yes, in some cases, Chiari can cause cognitive issues.
Does exercise help Chiari malformation?
Yes. The results of this study highlight the significant benefits of cognitive therapeutic exercises in Chiari malformation, with improvements in several key areas, including quality of life, pain management, and ability to perform activities of daily living.
What foods are good for Chiari malformation?
Choose food or drink that is rich in the amino acid tryptophan, such as a milky drink. Avoid stimulants like caffeine and nicotine.
Is Chiari a birth defect?
Yes. A Chiari Type II malformation is a congenital (present at birth) defect and mostly associated with Myelomeningocele.
What are Chiari malformation types III and IV?
Chiari Type III and Type IV are very rare and more serious than types I and II.
What are Chiari malformation types 0 and 0.5?
These forms of Chiari malformation were only defined recently and remain controversial. The terms describe people who experience ‘Chiari-like’ symptoms but whose cerebellum does not extend beyond the base of the skull as far out as is usually necessary to diagnose a Type I Chiari malformation (5mm or more on an MRI scan).
What is Chiari malformation type 1.5?
Some specialists have started to use the term Type 1.5 Chiari malformation to describe people with a form of Chiari malformation, which is more advanced than Type 1 but doesn’t completely fit the criteria for Type II.
Is Chiari malformation curable by Ayurveda?
No.
