Hydromyelia is a condition that causes headaches, nerve pain and other neurologic symptoms. It happens in children when an abnormal widening in the lower part of their brain causes fluid to pool. Hydromyelia is similar to syringomyelia, but they’re distinct conditions with different causes and treatments.


What is hydromyelia?

Hydromyelia occurs in children when there’s an abnormal widening at the top of their spinal cord’s central canal. This causes a fluid-filled cyst, called a syrinx, to form.


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Where in the brain does hydromyelia occur?

Hydromyelia occurs in the fourth ventricle of your brain. This hollow space is in the lower part of your brain, near your brainstem. It’s filled with cerebrospinal fluid (CSF), which protects your brain from trauma.

The fourth ventricle connects to the central canal. This narrow space runs the length of your spinal cord. The central canal delivers a steady supply of CSF to nourish and protect your spinal cord. It’s lined with a special type of cells (ependymal cells) that are present only in your ventricles and spinal canal.

How does hydromyelia affect a person's well-being?

When fluid builds up, the syrinx expands. This puts pressure on your spinal cord, which can lead to nerve irritation and damage.


Who gets hydromyelia?

Hydromyelia occurs in children with certain brain conditions. These include:

In rare cases, hydromyelia occurs in children with:

How is hydromyelia different from syringomyelia?

Both hydromyelia and syringomyelia cause a cyst-like growth in your brain that affects nerve cells. Hydromyelia and syringomyelia also have similar symptoms. But there are a few differences:


  • Primarily affects infants and children (extremely rare in adults).
  • Cyst forms inside the central canal.
  • Syrinx contains ependymal cells.


  • Primarily affects adults.
  • Cyst occurs next to the central canal.
  • Syrinx doesn’t contain ependymal cells.


Symptoms and Causes

What causes hydromyelia?

Researchers are still working to determine the cause of hydromyelia.

What are hydromyelia symptoms?

Some syrinxes are small and not likely to produce symptoms. Or symptoms may be present but not bothersome.

Children with larger syrinxes may experience nerve (neuropathic) pain, which may cause:

  • Burning sensation.
  • Jolts of shooting or stabbing pain.
  • Numbness.
  • Pins-and-needles or tingling sensation.

Other symptoms include:

  • Headaches.
  • Loss of sensitivity to hot and cold.
  • Muscle stiffness.
  • Scoliosis.
  • Weakness in their arms and legs.

Diagnosis and Tests

How is hydromyelia diagnosed?

Diagnosing hydromyelia may involve one or more evaluations, including:

  • Neurological exam to assess symptom severity. This may include asking about symptoms, observing how your child walks and testing their muscle strength.
  • MRI to detect a syrinx and other spinal cord abnormalities.
  • Electromyography to help rule out syringomyelia.

If imaging reveals a tiny cyst (slit) in the fourth ventricle, is it still hydromyelia?

Your child may still have hydromyelia even if the cyst is tiny. Even a slit can be large enough to cause symptoms. It takes an experienced healthcare provider to detect smaller growths and correctly diagnose them.

Management and Treatment

How is hydromyelia treated?

The most appropriate treatments for your child depend on symptoms and their severity.

  • Mild symptoms or no symptoms might not need treatment.
  • Bothersome symptoms, like muscle stiffness and weakness, may improve with physical therapy.
  • Moderate to severe symptoms often need surgery.

What type of surgery might my child need?

Surgery may be necessary to place a shunt in your child’s brain to support the natural flow of CSF. This device is a small tube that helps their body clear the excess fluid. The procedure involves creating a small passage in the fourth ventricle and inserting a shunt.

Shunting may offer temporary or permanent symptom relief. Some children need more than one shunt procedure.


What can I do to prevent hydromyelia from occurring?

Because scientists don’t yet completely understand what causes hydromyelia, there aren’t any current ways to prevent it.

Outlook / Prognosis

What is the prognosis for children with hydromyelia?

A small number of children’s symptoms stabilize or improve on their own. But this can take years. Children who undergo shunting typically feel better, but symptoms sometimes come back (recurs). Ongoing neurological exams and MRI scans may help healthcare providers detect early signs of recurrence.

Living With

What is daily life with hydromyelia like?

The impact of this condition on daily life depends on symptom severity. Children with mild symptoms might experience only minor disruptions to regular activities and not every day.

Moderate to severe symptoms are more challenging to live with:

  • Pain may come and go without warning.
  • Muscle stiffness or weakness can interfere with your child’s ability to move, play, crawl or walk.
  • Headaches can make your child irritable and uncomfortable.

A note from Cleveland Clinic

Hydromyelia develops when a fluid-filled cyst forms in your brain’s fourth ventricle. Some children experience no symptoms or mild symptoms that don’t need treatment. Moderate to severe symptoms can impact daily life but may improve with a shunt. Some children need more than one shunting procedure.

Medically Reviewed

Last reviewed on 04/07/2022.

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