Chiari Malformation Type I in Children
Chiari malformation (CM) is a problem with how the brain sits in the skull. The brain
normally sits fully inside the skull. With a Chiari malformation, the lower part of
brain (cerebellum) dips down through a normal opening (foramen magnum) at the bottom
the skull. In some cases, more brain tissue also dips down through this opening. This
puts pressure on parts of the brain and spinal cord, and can cause mild to severe
symptoms. These can include head or neck pain and trouble with balance or movement.
most cases, the problem is present at birth (congenital).
There are 4 types of Chiari malformations:
Type I (CM-I). This is the most common type. Part of the cerebellum dips down through the bottom
of the skull. This type is most often congenital (also called primary CM), but is
often not found until a child is a teen or young adult. In rare cases, this type may
also develop later in life. This is known as acquired or secondary CM. It occurs from
a loss of spinal fluid. This can happen because of an injury, contact with harmful
substances, or an infection.
II (CM-II or Arnold-Chiari malformation).
Part of the cerebellum and the
brain stem dip down through the bottom of the skull. This is most often seen in
babies born with spinal myelomeningoceles or spina bifida. A myelomeningocele is
when a part of the spinal cord and backbone (spine) develop outside the body. A
common problem with Type II CM is too much fluid on the brain (hydrocephalus). The
extra fluid causes the pressure in the brain to increase and the skull bones to
expand beyond normal size.
This type is the most severe. The cerebellum, brain stem, and
possibly other parts of the brain dip down through the bottom of the skull. In rare
cases, the brain and brain covering may poke out through the back of the head or
neck. A baby with Type III CM may not live long. Children who do will have severe
nervous system problems, such as thinking problems, seizures, and muscle
Type IV. This is a very rare condition where the brain doesn't develop fully.
Most babies with this type don't survive.
Health experts don't know the exact cause of a congenital Chiari malformation type
problem during fetal growth may cause the defect. It may be caused by contact with
harmful substances during pregnancy. Or it may be linked with genetic problems that
acquired Chiari malformation type I happens to a person after birth. It is caused
extra leaking of spinal fluid from the lower back (lumbar) or chest (thoracic) areas
the spine. This can happen because of an injury, contact with harmful substances,
Your child may not have any symptoms. Or symptoms may develop slowly over time. Most
children don't have symptoms until they are teens or young adults.
The most common symptoms are headaches or pain in the back of the head or neck. The
headaches and pain are made worse by coughing, laughing, or sneezing.
child may also have other symptoms of a Chiari malformation type I. These include:
- Hoarseness or trouble speaking
- Trouble swallowing
- Rapid, back and forth eye movements (nystagmus)
- Periods of not breathing during sleep (sleep apnea)
- Weakness or abnormal movements
- Trouble with balance
- Abnormal reflexes
- Abnormal shape of the spine (scoliosis)
Your child may also have a pocket of fluid in the spinal cord or brain stem. This
is called a syrinx. A syrinx can cause trouble walking or pain in the arms or legs.
child with no symptoms, the problem may be found when imaging tests are done for other
reasons. For a child with symptoms, the healthcare provider will ask about your child's
health history and give your child a physical exam. They may refer your child to a
Imaging tests are done to discover a Chiari malformation type I. Your child may have
one or more of these tests:
MRI. This test uses large magnets and a computer to make detailed pictures of the inside
of the body. In some cases, a special dye is injected into a vein for the test. This
dye helps show organs more clearly.
CT scan. This test uses a series of X-rays and a computer to create detailed pictures of the
inside of the body. A CT scan is more detailed than a regular X-ray.
Your child may be treated by neurologists and neurosurgeons. These are experts in
brain and spinal cord problems. Treatment will depend on your child’s symptoms, age,
and general health. It will also depend on how severe the condition is.
With no symptoms. Your child’s health may be watched closely. This may include frequent physical exams
and MRI tests. Your child’s healthcare provider may advise surgery to prevent problems.
Your child's healthcare provider may prescribe medicines to reduce
pain. Or they may advise decompression surgery. This is done to relieve pressure on
the brain, or to restore the flow of spinal fluid.
With few or
no symptoms, but a syrinx.
Your child's healthcare provider may suggest
keeping a close watch on the problem with a special type of MRI called cine phase
contrast. This helps look for blocked spinal fluid flow. Your child may need surgery,
based on the MRI results or if symptoms get worse.
of sleep apnea.
Your child may need a sleep study. In this test, your child
will be watched during sleep to look for problems. A sleep study can also help the
healthcare provider decide on additional treatment.
possible that your child may not have any symptoms in the future. But some children
develop complications. These include:
- Long-term pain
- Development of syrinx
- Permanent damage to muscles or nerves
Carefully watching for changes in your child’s health can help prevent complications.
This helps to make sure that treatment is done early.
is hard for healthcare providers to predict how a Chiari malformation type I will
a child’s long-term health. Your child may not have any changes caused by the defect.
they may have nervous system problems that get worse. Your child’s health will be
closely watched. This will include frequent physical exams and imaging tests, such
MRI. There is ongoing research as how to best manage Chiari malformations.
When to Call a Healthcare Provider
your child's healthcare provider if you notice any changes in your child. Be sure
call if you notice problems with:
- Walking or moving
- With a
Chiari malformation, the lower part of the brain dips down through a normal opening
at the bottom of the skull. In some cases, more brain tissue also dips down through
this opening. In most cases, the problem is present at birth (congenital).
- The most
common symptoms are headaches or pain in the back of the head or neck. The headaches
and pain are made worse by coughing, laughing, or sneezing.
- Treatments include careful watching, surgery, and frequent exams and tests.
- Carefully watching for changes in your child’s health can help prevent
complications. This helps to make sure that treatment is done early.
Tips to help you get the most from a visit to your child’s healthcare provider:
- Know the reason for the visit and what you want to happen.
- Before your visit, write down questions you want answered.
- At the visit, write down the name of a new diagnosis, and any new medicines, treatments,
or tests. Also write down any new instructions your provider gives you for your child.
- Know why a new medicine or treatment is prescribed and how it will help your child.
Also know what the side effects are.
- Ask if your child’s condition can be treated in other ways.
- Know why a test or procedure is recommended and what the results could mean.
- Know what to expect if your child does not take the medicine or have the test or procedure.
- If your child has a follow-up appointment, write down the date, time, and purpose
for that visit.
how you can contact your child’s healthcare provider after office hours, on weekends,
and on holidays. This is important if your child becomes ill and you have questions
or need advice.