*Note: I am not a doctor and any questions regarding these or any other tests should be directed to your doctor!!*

Being a new mom of a child with dwarfism, in particular, a child with Achondroplasia. One of the questions that gets quickly asked is “What tests should we have done?”

Right from the start, these are common, known recommendations, along with the reasons why. Most of these can be found in Health Supervision for Children With Achondroplasia. Which is also found on the sidebar.

Right after receiving the diagnoses of Achondroplasia, several tests should be preformed as a matter to safe guard your child’s health and well-being. Achondroplasia is not just a visual impairment (one you can see) but it is a physical impairment. A child with Achondroplasia is structurally different than an average height child. Common placement of bones are located and grow differently than in a person who is average height.

In no particular order:

1. An MRI of the head, neck and spine.
- The reason for this is to check the Foreman Magnum (FM). The FM or Cervico-medullary Myelopathy is located at the base of the head and neck. In an average height person, the FM is usually perfectly round. The spinal cord runs through the FM and connects to the brain. For an average height person, the FM doesn’t draw concerns from the doctor’s unless there is an abnormality, as in Achondroplasia. People with Achondroplasia have a smaller than normal FM. Instead of opening being round, a person with Achon has a FM that is shaped more like an old-fashioned key hole. It is wider at one end than the other. If the spinal cord gets trapped in the smaller end of the FM, death can occur due to the brain failing to get the signal to continue breathing. The spinal cord basically gets pinched.

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.
Brainstem compression can ultimately lead to death if it is left untreated, so parents and physicians of achondroplastic children should watch for the symptoms outlined above.

- John Hopkins

The MRI of the spine to to check for Spinal Stenosis. Stenosis is common in people with Achondroplasia. If it is going to present a problem, it will occur later in life.

Spinal stenosis can cause a wide variety of symptoms throughout the body. The most common symptoms are:

pain,
numbness,
tingling, and
weakness

2. CT of the Brain.
- All individuals with Achondroplasia have “Hydrocephalus”. I quote this because it is not the typical Hydrocephalus that we think of. People with Achondroplasia have extra ventricle fluid within their brains. On appearance this is the cause for the larger head. On a CT, the extra fluid can be seen, but it doesn’t mean there is a problem. This is Cerebrospinal fluid (CSF) that bathes the brain daily. In a majority of cases, this is typical. People with Achondroplasia have what is called Extra-Axiel Fluid. Which means as quickly as their body makes the fluid, they can absorb it. The fluid is free flowing and is not blocked. When the CFS becomes block or is Non-Communicating the child has to be seen by a Neurosurgeon to evaluate the need for a shunt.

A shunt is a flexible but sturdy silastic tube. A shunt system consists of the shunt, a catheter, and a valve. One end of the catheter is placed in the CNS – most usually within a ventricle inside the brain, but also potentially within a cyst or in a site close to the spinal cord. The other end of the catheter is commonly placed within the peritoneal (abdominal) cavity, but may also be placed at other sites within the body such as a chamber of the heart or a cavity in the lung where the CSF can drain and be absorbed. A valve located along the catheter maintains one-way flow and regulates the rate of CSF flow.

3. A Sleep Study or Polysomnogram
- Is a multi-channel study of the child’s breathing during sleep. This study records episodes of Apnea (cessation of breathing). There are two types of Apnea, Obstructive and Central.
Obstructive Apnea (OA) is most common in children with Achondroplasia. This refers to the abnormally small airway within the nasal cavity and throat area. OA is usually cause because the Tonsils and Adenoids are blocking a part of the airway. A surgery called a T&A can be preformed to remove the obstruction to improve breathing. Gastro-oesophageal reflux has also been known to cause OA. Having a Pulmonologist, Gastroenterologists and ENT review these results will hopefully eliminate the problem.

Central Apnea (CA) can be caused because of the FM cord compression. CA occurs when the brain does not receive the signal to keep breathing. The brain forgets to breath and the end result can be death. Pharmaceutical Caffeine can be used in treatment for controlling apnea, however, there has been a coralation between apnea and seizures in children with Achondroplasia and Caffeine therapy should not be used until an EEG has be preformed.

4. An X-ray of the Spine.
- Because all children with Achondroplasia develop Kyphosis or curvature of the lower spine. This needs to be monitored. Simple activites such as avoiding unsupported sitting, keeping the child on the floor or on their back will help reduce and eliminate the risk of progressive Kyphosis. In some children, around 10% will continue to develop a moderate to marked kyphosis, regardless of parental deterents…(Knoah). The child should be followed by an Orthopedic Surgeon who has experience dealing with dwarfism and Achondroplasia. I cannot stress this enough. It is not “okay” to have any Ortho follow your child. They must either HAVE experience dealing with dwarfism or is willing to contact someone who is!

From birth, you should have the child followed by a dwarfism specialist. This may be a Genetist or major Skeletal Dysplasia Center. Your child will Thank You for being informed!

So, there you have it. These tests, should be preformed early in the child’s life to establish a baseline record of all vital markers. That way if a problem is found later on, your doctor’s have a record of how and why it has changed. If you have any questions about any of these tests or the possible outcomes, please consult you physican.