A diagnosis of Chiari type II malformation can be frightening for parents.
It may come during a pregnancy ultrasound.
It may come shortly after birth.
It may be mentioned alongside words like spina bifida, myelomeningocele, hydrocephalus, shunt, brainstem, or Arnold-Chiari malformation.
For many families, the diagnosis is not just one medical term. It is a whole new world of specialists, imaging, surgeries, feeding questions, breathing concerns, mobility planning, bladder and bowel care, and long-term follow-up.
The first thing to know is this: Chiari type II is different from Chiari type I.
Chiari type I is the most common form overall and is often diagnosed later in childhood or adulthood. Chiari type II is usually present at birth and is closely linked with myelomeningocele, the most serious common form of spina bifida. Mayo Clinic explains that in Chiari type II, more brain tissue extends into the spinal canal than in type I, some areas of the brain are not fully formed, and people with type II almost always have myelomeningocele; many also have hydrocephalus. (Mayo Clinic) This guide explains Chiari type II in clear, parent-friendly language: what it means, how it relates to spina bifida, what symptoms to watch for, how hydrocephalus fits in, what treatment may involve, and what questions to ask your child’s care team.
In This Guide
You will learn:
- What Chiari type II malformation is
- Why it is strongly connected to spina bifida and myelomeningocele
- Why the term “Arnold-Chiari malformation” is often used
- What hydrocephalus means and why shunts may be discussed
- What symptoms parents should watch for in babies and children
- How Chiari type II is diagnosed before or after birth
- What newborn treatment may involve
- What fetal surgery for myelomeningocele can and cannot do
- When Chiari II decompression may be considered
- What long-term care often looks like
- What questions to ask neurosurgery, neurology, urology, rehabilitation, and the spina
bifida clinic
What Is Chiari Type II Malformation?
Chiari type II malformation is a congenital condition in which parts of the cerebellum and brainstem extend downward through the opening at the base of the skull into the upper spinal canal.
That opening is called the foramen magnum. It is the passageway where the brainstem connects to the spinal cord.
In Chiari type II, the anatomy at the back of the brain, brainstem, skull base, and upper spinal canal develops differently before birth. GARD, an NIH rare disease resource, describes Chiari type II as involving both cerebellum and brainstem tissue extending into the foramen magnum, usually along with myelomeningocele. (GARD Information Center) A simple way to explain it is: Chiari type II affects the area where the brain and spine meet, and it is usually part of a larger spina bifida diagnosis.
This is why Chiari type II is usually managed by a pediatric team, often including neurosurgery, neurology, neonatology, urology, orthopedics, rehabilitation, physical therapy, occupational therapy, speech therapy, nutrition, and primary care.
Why Is Chiari Type II Connected to Spina Bifida?
Chiari type II is most often seen in babies with myelomeningocele, a form of spina bifida.
Spina bifida is a neural tube defect, meaning the spine and spinal cord do not form and close completely during early pregnancy. CDC explains that spina bifida can happen anywhere along the spine when the neural tube does not close all the way, which can damage the spinal cord and nerves. (CDC) There are several types of spina bifida, but the type most closely connected to Chiari type II is myelomeningocele. CDC describes myelomeningocele as the most serious type of spina bifida; in this condition, a sac of fluid comes through an opening in the baby’s back, and part of the spinal cord and nerves are in the sac and are damaged. (CDC) Cincinnati Children’s states that Chiari II is typically seen in infants with myelomeningocele and/or hydrocephalus, and that almost all children with myelomeningocele have Chiari II malformation. (Cincinnati Children's Hospital) For parents, the key takeaway is: Chiari type II is usually not an isolated diagnosis. It is usually part of the broader medical picture of open spina bifida, especially myelomeningocele.
Is Chiari Type II the Same as Arnold-Chiari Malformation?
The term Arnold-Chiari malformation is often used for Chiari type II.
Historically, AANS notes that the term “Arnold-Chiari” was later applied to Chiari type II malformation. (AANS) Today, some clinicians and families still use “Arnold-Chiari” to refer to Chiari II, although people sometimes use the term loosely for other Chiari types.
For clarity, parents can ask: “When you say Arnold-Chiari, are you referring specifically to Chiari type II?”
That helps avoid confusion, especially because Chiari type I and Chiari type II are different conditions with different care pathways.
Chiari Type I vs Chiari Type II: What Parents Should Know
Parents often search online and find information about Chiari type I, but that information may not apply to a baby with Chiari type II.
| Feature | Chiari Type I | Chiari Type II |
|---|---|---|
| Typical age found | Later childhood, teen years, adulthood, or incidentally | Pregnancy, newborn period, or infancy |
| Main anatomy | Cerebellar tonsils sit low | Cerebellum and brainstem are involved |
| Link to spina bifida | Usually not linked to myelomeningocele | Strongly linked to myelomeningocele |
| Hydrocephalus | Can occur but less central | Common and often central to care |
| Typical care team | Neurology/neurosurgery depending on symptoms | Multidisciplinary pediatric spina bifida team |
| Surgery decision | Often based on symptoms, syrinx, CSF flow, quality of life | Often includes spinal closure, hydrocephalus treatment, and monitoring for brainstem symptoms |
Mayo Clinic notes that in Chiari type II, more tissue goes into the spinal canal compared with type I and many people also have hydrocephalus. (Mayo Clinic) The practical message: Do not assume advice written for adult Chiari type I applies to a newborn or child with Chiari type II.
What Is Myelomeningocele?
Myelomeningocele is the most serious common form of spina bifida.
In myelomeningocele, the spine and spinal canal do not close correctly before birth. The spinal cord and nerves may be exposed or contained in a sac on the baby’s back. Mayo Clinic describes myelomeningocele as a condition in which the backbone and spinal canal do not close correctly before birth. (Mayo Clinic) The effects depend partly on the location and severity of the spinal opening. A higher-level lesion generally has a greater chance of affecting leg movement, sensation, bladder function, bowel function, and orthopedic development. CDC explains that people with spina bifida may get around in different ways, including walking without assistance, using braces, crutches, walkers, or using a wheelchair, and that the location of the spinal defect influences mobility.
(CDC) For parents, this means the diagnosis is not only about the MRI of the brain. It is also about the spinal lesion, nerve function, mobility, bladder and bowel function, skin health, development, and quality of life.
What Is Hydrocephalus, and Why Does It Matter?
Hydrocephalus means there is too much cerebrospinal fluid, or CSF, in and around the brain.
CSF normally cushions the brain and spinal cord. In hydrocephalus, fluid builds up and can enlarge the ventricles, which are fluid spaces inside the brain. CDC explains that many babies born with spina bifida develop hydrocephalus, and that extra fluid can enlarge the ventricles and cause head swelling. Hydrocephalus needs close follow-up and proper treatment to help prevent brain injury. (CDC) In children with myelomeningocele and Chiari type II, hydrocephalus is often one of the most important early neurosurgical issues.
Treatment may involve:
- Careful monitoring of head size and symptoms
- Brain ultrasound, MRI, or CT imaging
- Placement of a ventriculoperitoneal shunt, often called a VP shunt
- In selected centers and cases, consideration of endoscopic third ventriculostomy with
choroid plexus cauterization, often called ETV/CPC The Spina Bifida Association’s neurosurgery guideline notes that neurosurgical care for most infants with myelomeningocele begins with closure of the spinal defect followed by evaluation for hydrocephalus treatment, and that ventricular shunts remain the cornerstone of hydrocephalus treatment in spina bifida while ETV/CPC is an evolving option in selected settings. (Spina Bifida Association)
What Is a Shunt?
A shunt is a small tube system placed by a surgeon to drain extra CSF from the brain to another part of the body, often the abdomen.
CDC describes a shunt as a small hollow tube that drains fluid from the baby’s brain to protect it from excess pressure. CDC also notes that additional surgery may be needed if the shunt becomes clogged or infected, or as the child grows. (CDC) Parents should learn the signs of possible shunt problems because shunts can fail or become infected.
Possible shunt failure symptoms can include:
- Vomiting
- Sleepiness or lethargy
- Irritability
- Headache or neck pain in older children
- Bulging fontanelle in infants
- Rapid head growth
- Downward gaze or “sunsetting” eyes
- Developmental regression
- Worsening balance, movement, or alertness
The Spina Bifida Association recommends teaching families signs of acute shunt failure, including headache, vomiting, lethargy or sleepiness, and chronic shunt failure signs such as accelerated head growth, loss of milestones, or neurological deterioration. (Spina Bifida Association)
What Symptoms Can Chiari Type II Cause?
Some children with Chiari type II function well and are monitored closely. Others develop symptoms related to brainstem involvement, hydrocephalus, spinal cord issues, or associated spina bifida complications.
Mayo Clinic lists Chiari type II symptoms that may include changes in breathing, trouble swallowing, downbeat nystagmus, and weakness in the arms. (Mayo Clinic) Newborns and infants may have:
- Noisy breathing
- Stridor, which is a high-pitched breathing sound
- Trouble swallowing
- Gagging, choking, drooling, or vomiting
- Feeding difficulty
- Aspiration, meaning food or liquid enters the airway
- Short pauses in breathing, called apnea
- Weakness in the arms
- Poor control of oral secretions
- Silent or weak cry
- Hydrocephalus symptoms
Nationwide Children’s lists newborn symptoms including noisy breathing, trouble swallowing, aspiration, apnea, and arm weakness, while older babies and children may have worsening hydrocephalus, scoliosis, vision problems, hearing loss, trouble using their hands, or symptoms from a syrinx. (Nationwide Children's Hospital) These symptoms matter because they may signal brainstem dysfunction, shunt problems, hydrocephalus progression, syringomyelia, or tethered cord.
Brainstem Symptoms: Why Breathing and Swallowing Matter
The brainstem helps control essential functions, including breathing, swallowing, airway protection, and communication between the brain and body.
Because Chiari type II involves the brainstem, symptoms like noisy breathing, swallowing difficulty, aspiration, apnea, and poor secretion control deserve prompt attention.
The Spina Bifida Association neurosurgery guideline describes Chiari II as involving abnormality of the brainstem and posterior fossa, with elongation and downward displacement of the medulla and cerebellar vermis into the cervical spinal canal; the guideline notes that associated brainstem dysfunction can vary widely in clinical severity. (Spina Bifida Association) Parents should contact the care team promptly for:
- Noisy breathing or stridor
- Breathing pauses
- Blue spells or color changes
- Choking or coughing with feeds
- Recurrent vomiting with feeding
- Poor weight gain
- Excessive drooling or trouble managing secretions
- Weak or silent cry
- New swallowing difficulty
- New or worsening arm weakness
The Spina Bifida Association specifically identifies brainstem signs such as stridor, silent cry, poor control of oral secretions, and hypopnea or apnea as important signs in infants with myelomeningocele and hydrocephalus management. (Spina Bifida Association)
Sleep and Breathing Problems in Chiari Type II
Sleep-related breathing problems can occur in children with neural tube defects, myelomeningocele, and Chiari malformation.
The Spina Bifida Association’s sleep-related breathing disorder guideline describes several types of breathing disorders in people with neural tube defects, including central apnea, periodic breathing, obstructive apnea, and central hypoventilation. It also notes that infants with myelomeningocele and central respiratory control abnormalities may present with stridor, apnea, and feeding difficulties. (Spina Bifida Association) A sleep study may be discussed if a child has:
- Snoring
- Noisy breathing during sleep
- Pauses in breathing
- Blue spells
- Restless sleep
- Daytime sleepiness
- Morning headaches in older children
- Trouble feeding plus breathing concerns
- Known brainstem symptoms
The Spina Bifida Association recommends screening infants and children with neural tube defects for sleep-related breathing disorder signs and symptoms, and formal sleep evaluation for symptomatic children or those with additional risk factors. (Spina Bifida Association) For parents, the practical takeaway is: Breathing symptoms in Chiari type II should not be dismissed as “just noisy breathing.” They should be discussed with the child’s care team.
Swallowing, Feeding, and Aspiration
Swallowing problems can be one of the most important symptoms in Chiari type II.
A baby or child may have:
- Choking during feeds
- Coughing with liquids
- Gagging
- Vomiting
- Drooling
- Poor weight gain
- Recurrent respiratory infections
- Wet-sounding breathing or voice after feeding
- Aspiration concerns
Cincinnati Children’s notes that Chiari II symptoms can include swallowing problems, slow or noisy breathing, feeding problems, gagging, drooling, and vomiting. (Cincinnati Children's Hospital) Evaluation may include:
- Feeding assessment
- Speech-language pathology evaluation
- Swallow study
- Nutrition support
- ENT evaluation
- Pulmonology or sleep medicine evaluation
- Neurosurgical evaluation if brainstem compression, hydrocephalus, or shunt malfunction
is suspected A swallowing issue does not automatically mean a child needs Chiari decompression, but it does mean the care team should evaluate the cause carefully.
How Is Chiari Type II Diagnosed?
Chiari type II is often diagnosed before birth or shortly after birth because it is usually associated with myelomeningocele.
During pregnancy Spina bifida can often be seen on prenatal ultrasound. CDC notes that during pregnancy, screening tests such as alpha-fetoprotein testing and ultrasound may help detect spina bifida.
(CDC) When myelomeningocele is found, the care team may also evaluate:
- The spinal lesion level
- Ventricular size
- Hindbrain herniation
- Foot or leg positioning
- Fetal movement
- Other congenital findings
- Whether the family may be eligible for fetal surgery evaluation
After birth After birth, diagnosis and follow-up may involve:
- Physical exam
- Head circumference measurements
- Spinal lesion evaluation
- Cranial ultrasound in newborns
- MRI of the brain and spine
- CT scan in selected cases
- Swallow study
- Sleep study
- Urodynamic testing for bladder function
- Orthopedic and rehabilitation evaluation
Nationwide Children’s notes that diagnosis may occur at birth or during pregnancy with fetal ultrasound, and that MRI is the best test for diagnosing Chiari malformations when imaging is needed. (Nationwide Children's Hospital)
What Happens After a Prenatal Diagnosis?
A prenatal diagnosis of myelomeningocele and Chiari type II can feel overwhelming. Parents may be asked to make decisions quickly while also processing fear, grief, uncertainty, and hope.
A good care plan usually includes counseling from a multidisciplinary team.
The Spina Bifida Association recommends that families consult with a multidisciplinary team before birth to establish a joint delivery plan and plan of care. It also recommends meeting with parents soon after fetal spina bifida diagnosis to discuss the expected impact on the child and family, prenatal closure options, newborn care, long-term multidisciplinary care, and prognosis for neurologic capabilities and limitations. (Spina Bifida Association) Parents may meet with:
- Maternal-fetal medicine
- Pediatric neurosurgery
- Neonatology
- Fetal surgery specialists
- Pediatric urology
- Orthopedics
- Rehabilitation medicine
- Genetics or genetic counseling
- Social work
- Nursing care coordinators
- Spina bifida clinic staff
The goal is not only to explain the diagnosis. It is to help parents understand the plan before delivery, immediately after birth, and long term.
Fetal Surgery for Myelomeningocele: What Parents Should Know
Some babies with myelomeningocele may be evaluated for prenatal repair, also called fetal surgery. This is surgery performed before birth to close the spinal opening.
Fetal surgery is not appropriate for every pregnancy, and it is not available everywhere. It requires careful evaluation at a specialized center.
The landmark Management of Myelomeningocele Study, or MOMS trial, compared prenatal repair with postnatal repair. CHOP summarizes that the MOMS trial directly compared open prenatal surgery versus postnatal repair in 183 patients and found that fetal surgery reduced the need to divert fluid from the brain, improved mobility, increased the chance of independent walking, and reduced or reversed hindbrain herniation findings related to Chiari II. (Children's Hospital of Philadelphia) CDC also states that the MOMS trial found that closing spina bifida during pregnancy can decrease the risk of death in infancy from spina bifida, decrease the need for shunting by the end of the first year of life, and improve motor function in childhood. CDC also emphasizes that the procedure has risks, including placental problems and infection. (CDC) The Spina Bifida Association neurosurgery guideline notes that MOMS showed improved fetal and infant outcomes, including reduced need for ventricular shunts, reduced radiographic indicators of Chiari II, and improved lower-extremity motor function, but that these benefits were offset by higher maternal morbidity, higher incidence of premature delivery, and obstetric risks in later pregnancies. (Spina Bifida Association) The parent-friendly takeaway: Fetal surgery may improve some outcomes for selected babies, but it is major surgery for both mother and baby. It requires individualized counseling about benefits, risks, eligibility, location, delivery planning, and long-term follow-up.
What Happens After Birth?
Newborn care depends on whether the spinal defect was repaired before birth or needs closure after birth.
For babies born with open myelomeningocele, early care may include:
- Protecting the spinal lesion
- Preventing infection
- Positioning to avoid pressure on the lesion
- Neurosurgical evaluation
- Closure of the spinal defect
- Monitoring for hydrocephalus
- Brain imaging
- Assessment of leg movement and sensation
- Bladder and kidney evaluation
- Feeding and breathing evaluation
- Family education
The Spina Bifida Association recommends protecting the newborn myelomeningocele placode with clean, moist dressings and closing new myelomeningocele within 48 hours of birth in viable newborns. (Spina Bifida Association) If hydrocephalus is present or progresses, the team may discuss shunt placement or another CSF diversion procedure. If brainstem symptoms are severe, the team may evaluate whether hydrocephalus treatment is functioning and whether posterior fossa decompression is needed.
The Spina Bifida Association recommends considering Chiari II decompression for neonates in a brainstem crisis only after confirming that the shunt or other CSF diversion is functioning adequately. (Spina Bifida Association)
Does Every Child With Chiari Type II Need Chiari Decompression Surgery?
No.
Many children with Chiari type II are monitored and do not undergo decompression surgery unless the malformation is causing significant symptoms.
Cincinnati Children’s states that children with Chiari II typically do not undergo surgery unless the malformation is causing breathing and swallowing difficulties, in which case decompression surgery may be recommended. (Cincinnati Children's Hospital) When decompression is considered, it is often because of serious brainstem-related symptoms such as:
- Stridor
- Apnea
- Respiratory distress
- Severe swallowing dysfunction
- Aspiration
- Poor secretion control
- Vocal cord problems
- Progressive neurological decline
- Brainstem crisis
Importantly, symptoms that look like Chiari II worsening can sometimes be triggered by hydrocephalus or shunt malfunction. The Spina Bifida Association notes that symptomatic Chiari II may be precipitated by hydrocephalus or shunt failure, which is why CSF diversion must be assessed carefully. (Spina Bifida Association) The practical message: Before assuming Chiari decompression is needed, the team often checks whether hydrocephalus is controlled and whether any shunt or CSF diversion system is working properly.
Long-Term Care: Chiari II Is Part of Lifelong Spina Bifida Care
Chiari type II is usually managed within the broader lifelong care of spina bifida.
CDC emphasizes that health issues in spina bifida vary by person and change with age, and that people with spina bifida may need doctors who focus on different parts of the body, including orthopedics, urology, and neurosurgery. (CDC) Long-term care may include:
- Neurosurgery follow-up for Chiari II, hydrocephalus, shunts, tethered cord, and syrinx
- Urology follow-up for bladder function, kidney protection, catheterization plans, and
infection prevention
- Bowel management planning
- Orthopedic care for hips, feet, scoliosis, and mobility
- Physical therapy and occupational therapy
- Speech and feeding therapy when needed
- Rehabilitation medicine
- Skin checks and pressure injury prevention
- Developmental and school support
- Neuropsychology or learning support
- Sleep medicine if breathing concerns exist
- Transition planning into adolescent and adult care
CDC notes that bladder problems in spina bifida can increase the risk of UTIs and kidney damage, and that bathroom plans can support health and independence. CDC also highlights the importance of skin checks because children and adults with spina bifida may have limited feeling and may not notice injuries. (CDC) This is why a multidisciplinary spina bifida clinic can be so valuable. The Spina Bifida Association recommends encouraging families to develop a relationship with a multidisciplinary spina bifida clinic. (Spina Bifida Association)
Tethered Cord, Syrinx, and Other Related Concerns
Children with spina bifida and Chiari type II may also be monitored for other neurological issues.
Tethered cord A tethered cord means the spinal cord is attached in a way that can cause stretching as the child grows. CDC explains that many people with open spina bifida have tethered spinal cords, which can cause back pain, scoliosis, leg and foot weakness, changes in bladder or bowel control, and other problems. (CDC)
- Syrinx
- A syrinx is a fluid-filled cavity in the spinal cord. Nationwide Children’s notes that children with Chiari II may have extra fluid in the brainstem or spinal cord, called a syrinx, which may cause arm or leg pain or walking difficulty. (Nationwide Children's Hospital)
- Scoliosis and orthopedic changes
- Scoliosis, foot deformities, hip issues, and mobility changes may occur depending on the spinal lesion and neurological function.
The parent-friendly takeaway: New weakness, worsening walking, new pain, increasing scoliosis, hand changes, or bladder/bowel changes should be reported to the care team. These symptoms may relate to shunt problems, tethered cord, syrinx, orthopedic changes, or other issues.
Red Flags: When Parents Should Call the Care Team Promptly
Contact your child’s healthcare team promptly or seek urgent care if your child has:
- Trouble breathing
- Noisy breathing, stridor, or blue spells
- Pauses in breathing
- Trouble swallowing
- Choking, aspiration, or feeding difficulty
- Poor control of oral secretions
- Weak or silent cry
- Repeated vomiting
- New or worsening sleepiness
- Severe headache or neck pain in an older child
- Bulging fontanelle or rapidly increasing head size in an infant
- Downward gaze or new eye movement changes
- New arm weakness or hand clumsiness
- New or worsening leg weakness
- Loss of developmental milestones
- New walking difficulty
- New bladder or bowel changes
- Fever, redness, drainage, or swelling near a surgical site
- Signs of shunt malfunction or infection
Nationwide Children’s advises parents to contact the child’s doctor right away for changes involving breathing, swallowing, feeding, speaking, walking, or moving, and to call if the child has severe headache or neck pain. (Nationwide Children's Hospital)
What Parents Can Track at Home
Parents do not need to become doctors. But tracking patterns can help the medical team.
Consider keeping notes on:
- Feeding changes
- Choking, gagging, coughing, or vomiting
- Breathing changes
- Sleep symptoms
- Head size concerns in infants
- Alertness and irritability
- Arm and hand use
- Leg movement
- Mobility milestones
- Skin redness or pressure spots
- Bladder or bowel changes
- UTIs or fevers
- Shunt-related symptoms
- Developmental milestones
- School or learning changes in older children
Bring this information to appointments. It can help the team decide whether symptoms are stable, improving, or worsening.
Questions to Ask After a Chiari Type II Diagnosis
A parent-facing blog should end with practical questions families can bring to appointments.
Questions about the diagnosis
- Does my child have Chiari type II, Arnold-Chiari malformation, or another Chiari type?
- Is my child’s Chiari type II associated with myelomeningocele?
- What level is the spinal lesion?
- Is hydrocephalus present?
- Is there a syrinx?
- Is there any brainstem compression or brainstem dysfunction?
- Are there swallowing or breathing concerns?
- What imaging has been done, and what imaging will be repeated?
Questions during pregnancy
- Should we be referred to a fetal surgery center for evaluation?
- Is prenatal repair an option in this pregnancy?
- What are the benefits and risks of fetal surgery in our case?
- What are the benefits and risks of postnatal repair?
- Where should delivery happen?
- Will neonatal neurosurgery be available at delivery?
- What should we expect in the first 24–48 hours after birth?
- What specialists should we meet before delivery?
Questions after birth
- When will the spinal lesion be closed?
- How will the team monitor hydrocephalus?
- Does my baby need a shunt or ETV/CPC?
- What signs of shunt failure should we watch for?
- Are breathing or swallowing studies needed?
- Does my baby need feeding support?
- Will my baby need NICU care?
- What therapies should start early?
Questions about long-term care
- Should our child be followed in a multidisciplinary spina bifida clinic?
- How often should neurosurgery follow-up happen?
- What signs of tethered cord should we watch for?
- What signs of syrinx should we watch for?
- What bladder and bowel plan is recommended?
- What mobility support may be needed?
- What skin checks should we do at home?
- Should we avoid latex exposure?
- What developmental or school supports may be needed later?
- How do we plan transition to adult care as our child gets older?
How to Explain Chiari Type II to Family Members
Here is a simple explanation parents can use: “Chiari type II is a condition usually seen in babies with myelomeningocele, the more serious form of spina bifida. It means parts of the lower brain and brainstem are positioned lower than expected near the opening where the skull meets the spine. It can affect spinal fluid flow and may be associated with hydrocephalus. Our child’s doctors are watching for breathing, swallowing, feeding, hydrocephalus, shunt issues, movement, bladder and bowel function, and development.”
This explanation helps family members understand that Chiari type II is not just a single MRI finding. It is part of a larger care picture.
Key Takeaways
Chiari type II is a congenital malformation involving the lower brain, brainstem, skull base, and upper spinal canal.
It is usually associated with myelomeningocele, the most serious common form of spina bifida. It is also commonly associated with hydrocephalus, which may require close monitoring, shunt placement, or another CSF diversion procedure.
The most important symptoms for parents to recognize include:
- Breathing changes
- Noisy breathing or stridor
- Apnea or blue spells
- Swallowing problems
- Feeding difficulty
- Poor control of secretions
- Vomiting
- Arm weakness
- Signs of shunt malfunction
- New neurological changes
Not every child with Chiari type II needs Chiari decompression surgery. Many are monitored, and treatment often focuses first on spinal closure, hydrocephalus management, feeding and breathing evaluation, and long-term spina bifida care.
The most important point is this: Chiari type II care is not one decision. It is a coordinated, lifelong care plan.
With the right medical team, careful monitoring, family education, and early intervention, many children with spina bifida and Chiari type II can receive care that supports function, safety, development, and quality of life.
Frequently Asked Questions About Chiari Type II and Spina Bifida
What is Chiari type II malformation?
Chiari type II malformation is a congenital condition in which parts of the cerebellum and brainstem extend downward through the opening at the base of the skull into the upper spinal canal. It is usually associated with myelomeningocele, a form of spina bifida. (GARD Information Center)
Is Chiari type II the same as Arnold-Chiari malformation?
The term “Arnold-Chiari malformation” has historically been used for Chiari type II. AANS notes that “Arnold-Chiari” was later applied to Chiari type II malformation. (AANS)
Is Chiari type II always linked to spina bifida?
Chiari type II is very strongly linked to myelomeningocele, the most serious common form of spina bifida. Mayo Clinic states that people with type II almost always have myelomeningocele.
(Mayo Clinic)
What is myelomeningocele?
Myelomeningocele is a severe form of spina bifida in which a sac of fluid comes through an opening in the baby’s back, and part of the spinal cord and nerves are in the sac. CDC describes it as the most serious type of spina bifida and notes that it can cause moderate to severe disabilities. (CDC)
What symptoms can Chiari type II cause in babies?
Symptoms may include noisy breathing, trouble swallowing, aspiration, pauses in breathing, arm weakness, feeding problems, gagging, drooling, vomiting, and hydrocephalus-related symptoms. Nationwide Children’s lists these symptoms in newborns and children with Chiari II.
(Nationwide Children's Hospital)
Does every baby with Chiari type II need a shunt?
Not every baby necessarily needs a shunt, but hydrocephalus is common in babies with spina bifida and Chiari type II. CDC explains that hydrocephalus needs close follow-up and may be treated with a shunt to drain extra fluid from the brain. (CDC)
What are signs of shunt failure?
Signs can include vomiting, headache, sleepiness, irritability, accelerated head growth, loss of developmental milestones, neurological deterioration, or changes in alertness. The Spina Bifida Association recommends teaching families signs of acute and chronic shunt failure. (Spina Bifida Association)
Does Chiari type II always need decompression surgery?
No. Many children with Chiari II do not undergo decompression unless the malformation is causing significant breathing or swallowing problems. Cincinnati Children’s states that children with Chiari II typically do not undergo surgery unless breathing and swallowing difficulties occur.
(Cincinnati Children's Hospital)
Can fetal surgery help Chiari type II?
Fetal surgery for myelomeningocele may reduce the need for shunting, improve mobility outcomes, and improve or reverse hindbrain herniation findings in selected pregnancies, but it also carries maternal and fetal risks. CHOP and CDC summarize these findings from the MOMS trial. (Children's Hospital of Philadelphia)
What specialists should care for a child with Chiari type II and spina bifida?
Care often involves pediatric neurosurgery, neurology, urology, orthopedics, rehabilitation medicine, physical therapy, occupational therapy, speech therapy, nutrition, sleep medicine, pulmonology, developmental specialists, social work, and primary care. CDC notes that people with spina bifida often need doctors who focus on different parts of the body, including orthopedics, urology, and neurosurgery. (CDC)