Beyond Achondroplasia

Growing together with Clara

Neurologic signs of cervico-medullary compression

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Lately, I´ve knew about other children with Clara´s age and with achondroplasia that had to undergone emergency cervico-medullary decompression surgery. I know also that some parents observe strange signs in their children without recognizing them to be neurologic alterations. I truly think that many children fortunately have good medical follow-up, others no…, but I believe that is crucial for doctors to inform parents for the alert signs for a possible compression, that can be life treathening.

There is a significant chance to, at some point in the life of a child with achondroplasia, to the spinal cord and brain stem to become compressed. The stunted bone growth at the base of the skull and the spine can cause that.

So, here, at the John Hopkins pediatric neurosurgery page, you can know which physical signs allow an early detection of the neurologic deficits due to compression:

1-Cervico-medullary Myelopathy:

Compression at the foramen magnum – the bony hole at the base of the skull through which the brainstem and spinal cord exit the skull – can cause a child’s brainstem to “kink.” This can cause a child to have:

  • very brisk reflexes
  • numbness
  • weakness
  • difficulty walking
  • loss of bowel and bladder control
  • sleep apnea – periods during sleep when the child stops breathing.


When the narrowing near the base of the spine prevents cerebrospinal fluid (CSF) from flowing freely around the brainstem or in and out of the skull, the CSF collects in ventricles (spaces in the brain). The resulting condition is hydrocephalus. In babies, the most evident symptom of hydrocephalus is a quickly enlarging head circumference. Additional symptoms include:

  • headaches
  • irritability
  • lethargy
  • vomiting

3-Spinal Cord Myelopathy

Sometimes, the vertebrae of achondroplastic children do not grow enough to allow sufficient space for nerves exiting and entering the spinal cord to pass in and out of the bony spinal column. If only a single nerve root is compressed, a child may experience pain, numbness or weakness in a specific arm or leg. They may seem to prefer using one hand over another very early as babies, or complain of pain in their back or affected arm. In more severe cases, the entire spinal cord can be compressed, causing weakness and numbness in the entire body below the spinal cord pinch as well as loss of bowel and bladder control.

Months before Clara had to undergone an emergency cervico-medullary decompression surgery, we asked Clara´s neurosurgeon, Dr. Mário Matos, what were the alarm signs of compression. And he mentioned to us:

– increased tension and bulging fontanelle ( we were constantly checking it)

sudden alteration in her head size (we measure her head regulary and with the same measuring tape)

sudden irritability

– the alteration of the position of her eyes (rolling over)

Even with all our attention and focus on those risks of compression, and specially when Clara started to improve greatly from the sleep apnea at 9 months-old leaving the CPAP and showing none of the neurologic signs mentioned, after a routine MRI, a cervico-medullary compression was observed. Five days later, Clara was on the surgery table for 7 hours for cervico-medullary decompression and bilateral miringotomy. She was 9 months-old.

The neurosurgeon told us it was a matter of days or weeks before Clara started to show neurology deficits signs.

Luckily, Clara hasn´t have any neurologic alteration from the compression once it was resolved on time.

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