What Is Central Pontine Myelinolysis?
Central pontine myelinolysis (CPM) is a neurological disorder
that affects the brain. “Pontine” refers to the stem of the brain, called
the pons. “Myelinolysis” means that the myelin — a covering that
protects the pontine nerve cells — is being destroyed.
CPM usually happens as the result of another illness or medical
condition. The destruction of myelin is generally not spontaneous.
People who have CPM can’t be cured, but their symptoms can be
treated. The nerve damage can become chronic and may lead to permanent
disabilities. Some people will need assistance dressing, feeding themselves,
and accomplishing other routine tasks.
In rare cases, CPM can lead to locked-in syndrome, coma, or even
death. Locked-in syndrome is a condition in which all mobility and muscle
control is lost. People with locked-in syndrome can move only their eyes.
Symptoms of Central Pontine Myelinolysis
Symptoms of CPM involve both movement and cognitive function.
The damage to your myelin sheaths can cause damage to the brainstem nerves.
Nerve damage interferes with the communication between the
nervous system and muscles. As a result, you may suffer from:
- muscle weakness in the face, arms, and legs
- delayed or poor reflexes and responses
- slowed speech and poor enunciation
- swallowing difficulties
- poor balance
CPM can also damage your brain cells. The damage can affect your
mental health as well as your physical health. You may experience mental
confusion or hallucinations, or you may appear to be in a delirious state. Some
people suffer from intellectual impairment as a result of central pontine
Causes of Central Pontine Myelinolysis
The most common cause of CPM is a rapid increase in blood sodium
levels. Sodium is an electrolyte mineral that carries an electrical charge in
your body. Sodium helps regulate your fluid levels, making sure that your cells
are well hydrated. Central pontine myelinolysis can occur when your blood
sodium levels increase sharply and quickly. The reason for this damage is not
entirely clear yet, but it involves the rapid shift of water in the brain
People who are treated for hyponatremia have an
increased risk of developing CPM. Hyponatremia is the state of low blood sodium
levels. Hyponatremia can cause a variety of health conditions. These can
- muscle cramps
Treatment for low sodium levels includes the intravenous
infusion of a sodium solution and can cause the sodium level to rise too
quickly. You are more likely to develop central pontine myelinolysis if you put
off treatment for hyponatremia for two days or more.
Chronic alcoholism, liver disease, and malnutrition increase
your risk of developing CPM. These conditions are likely to cause changes in
your sodium levels.
Diagnosing Central Pontine Myelinolysis
Your doctor will run blood tests to measure your sodium levels
to help diagnose CPM. Magnetic resonance imaging, or MRI, is a test that uses
radio waves to create images of your internal organs. An MRI of your head can
show any damage to your brainstem.
You may also take a brainstem auditory evoked response (BAER)
test. Your doctor will attach electrodes to your head and ears, and then
play a series of clicks and other sounds through headphones. BAER measures your
response time and brain activity when you hear each sound.
Treatment for Central Pontine Myelinolysis
CPM is a serious medical condition and must be treated on an
emergency basis. Get medical care as soon as possible if you experience symptoms
consistent with the condition. Treatment is geared toward managing your
symptoms, and can include:
- fluids and medication to safely regulate your
- dopaminergic medications (such as levodopa) to
increase dopamine and control tremors and difficulties with speech and
swallowing in people who develop Parkinsonian symptoms
- physical therapy to improve balance and retain
range of motion
Outlook for Central Pontine Myelinolysis
People with CPM can improve with appropriate treatment, but may
still have chronic problems with balance, mobility, and response time. CPM was
originally believed to have a mortality rate of 50 percent, but early diagnosis has improved the
outlook. Although some people still die as a result of the damage sustained,
many people with CPM are able to recover. Most people who have recovered from
CPM will still need some ongoing therapy and supportive care to manage the
effects on a long-term basis.
Preventing Central Pontine Myelinolysis
It’s important to manage your blood sodium levels to help
prevent CPM. If you have a condition that puts you at risk for hyponatremia,
make sure you’re aware of the signs of low blood sodium and stay on top of your
It’s important to stay properly hydrated to maintain fluid balance and sodium
levels in your body. Staying hydrated on a daily basis is always recommended.