Type 2 Chiari malformation occurs when both the cerebellum and brainstem descend through the foramen magnum, most often associated with myelomeningocele, a form of spina bifida present at birth. This structural abnormality disrupts cerebrospinal fluid (CSF) flow and can cause neurological, breathing, swallowing, and developmental symptoms in infants and children.
For related neurosurgical conditions, visit our primary hub: Conditions & Treatments.
What Is Type 2 Chiari Malformation?
Type 2 Chiari malformation—also called Arnold-Chiari Type II—is defined by downward displacement of the cerebellum and brainstem into the cervical spinal canal. It is almost always linked to myelomeningocele, where the spinal cord and meninges protrude through an opening in the spine.
Common symptoms include:
- CSF buildup (hydrocephalus)
- Swallowing difficulty
- Breathing abnormalities
- Arm or leg weakness or paralysis
- Scoliosis and spinal deformities
- Feeding problems in infants
- Developmental delays in severe cases
For related cranial and skull-base disorders, see:
What Causes Type 2 Chiari Malformation?
The condition is congenital and forms during fetal development. Myelomeningocele alters normal CSF circulation and pulls the cerebellum and brainstem downward, leading to compression and abnormal pressure patterns in the brain and spine.
Secondary contributors may include spinal tethering, ventriculomegaly, and CSF pressure imbalances.
How Type 2 Chiari Malformation Is Diagnosed
Diagnosis typically occurs shortly after birth or during prenatal imaging. MRI is the gold-standard method for evaluating cerebellar and brainstem displacement, hydrocephalus, and spinal cord abnormalities.
Diagnostic evaluation includes:
- MRI of the brain and cervical spine
- Ultrasound in newborns
- Neurological examination
- Evaluation for breathing, feeding, and swallowing issues
- Spinal imaging to assess myelomeningocele repair needs
Treatment Options for Type 2 Chiari Malformation
Treatment focuses on stabilizing brainstem function, relieving CSF obstruction, and managing myelomeningocele-related complications.
Conservative & Supportive Management
Used when symptoms are mild or stable:
- Monitoring hydrocephalus
- Feeding support
- Respiratory management
- Physical therapy for motor function
Surgical Treatment
Surgery is performed based on symptoms and severity:
- Myelomeningocele repair shortly after birth
- Shunt placement or endoscopic third ventriculostomy (ETV) for hydrocephalus
- Posterior fossa decompression to relieve brainstem compression (selected patients)
- Correction of scoliosis or spinal deformity as the child grows
Surgical goals include protecting neurological function, improving breathing and swallowing, and reducing progressive symptoms.
Outcomes and Long-Term Care
Outcomes depend on brainstem involvement, hydrocephalus control, and timing of myelomeningocele repair. Many children benefit from coordinated neurosurgical, pediatric, and rehabilitation care throughout development.
Expert Neurosurgeons Who Treat Chiari Malformation
Our MN neurosurgery team provides comprehensive infant and pediatric Chiari evaluations:
- Eric S. Nussbaum, MD – Brain & cranial neurosurgery
- Stefano Sinicropi, MD – Complex spine & deformity surgery
- Todd E. Jackman, MD – Spine surgery
- Meysam Kebriaei, MD – Minimally invasive spine procedures
- David Chang, MD – Neurological surgery
FAQs
What is Type 2 Chiari malformation?
It is a congenital condition in which the cerebellum and brainstem descend into the spinal canal, usually with myelomeningocele.
Is Type 2 Chiari malformation more severe than Type 1?
Yes. Type 2 involves both cerebellar and brainstem displacement and is typically diagnosed at birth.
Does Type 2 Chiari malformation cause hydrocephalus?
Yes. Blocked CSF flow commonly leads to hydrocephalus that may require shunt placement or ETV.
How is Type 2 Chiari malformation treated?
Treatment includes myelomeningocele repair, hydrocephalus management, and decompression surgery when needed.
Can children with Type 2 Chiari malformation improve?
With early intervention and coordinated care, many children achieve improved breathing, feeding, and developmental outcomes.
Does Type 2 Chiari malformation always require surgery?
Most children require at least one procedure—typically myelomeningocele repair or hydrocephalus treatment—but each plan is individualized.