Do all children with HPE have movement problems
From Holoprosencephaly
Do all children with HPE have muscle and movement problems?
The vast majority of kids that I've seen with holoprosencephaly of any form have some movement problems. What you have to remember is they're born with normal limbs and muscles. It's the nervous system and the control of muscles that is abnormal. That can be varied. But there is almost always some impairment of movement.
We classify movement problems into different types. You can classify them based on muscle tone:
Hypotonia: low tone. Hypertonia: high tone.
Some kids have low tone completely, so we consider them hypotonic. Some have low tone in the trunk and neck, which is called axial or trunkal hypotonia, but their limbs are hypertonic. Often times the legs are more spastic, which is one type of hypertonia.
Spasticity is an increase in muscle tone dependent on the speed of movement. The faster I move the limb, the higher the resistance against it. If I move the limb slowly, there's very little resistance, but if I move it fast, there’s a lot of resistance.
Spasticity we think of as primarily due to an abnormal motor cortex, which has direct connections to the muscles to produce voluntary movement.
Another type of movement disorder is called dystonia.
Dystonia is not velocity dependent. Sometimes you can work the muscle tone out. For example, the faster you work the limb the more you may get it to loosen up.
With dystonia, the tone can vary so that there are different levels of resistance based on the time of day. It’s possible that when the child is sleeping the abnormal tone may go away so the child feels limper. Spasticity doesn't vary much throughout the day. Dystonia is responsive to how tired the child is, if he is agitated or crying, the limbs may be rigid, but if the child is happy, the limbs may be more relaxed. Dystonia gets worse as you try and move, as it interferes with voluntary movement. Things like pain and agitation make dystonia worse. The main distinguishing feature of dystonia is fluctuating stiffness.
Dystonia is due to problems in the basal ganglia, which are the deep structures in the brain that don't directly control movement but modify movement.
How are Dystonia, Spasticity and Hypotonia treated?
Medications
Spasticity- There are various medications that work for it. The two main ones are Diazepam (valium) and Baclofen.
Click here to learn more about medications that treat spasticity
Hypotonia- There is no medication for hypotonia.
Dystonia- Typically we use Artane and Sinemet.
Our anecdotal experience at the Carter Centers has led us to use artane, as it seems to do a better job treating dystonia.
Artane can sometimes decrease rigidity and dystonia. Some patients have shown improved oromotor and upper extremity function with use of Artane. Artane doesn't cause dramatic changes, but you see more initiation of movement, especially of the arms, as well as more fluid movements of the arms, better ability to do what they want to do, better control of voluntary movements, and reduction in overall tone of the body. Click here to read more about Artane and the potential side effects
Dystonia has more potential to improve function with medication. With spasticity, medication improves comfort, but not function. It also makes it easier to diaper and brace them.
Other treatments
Bracing and physical therapy can help by strengthening the muscles and avoiding contractures. Contractures occur when you get reduced range of motion, so physical therapy prevents contractures.
Physical therapy is important for treating hypotonia, spasticity and dystonia. It’s important to stretch and do range of motion exercises on a daily basis to prevent loss of range of motion. Range of motion exercises doesn't improve function but it maintains range.
There are some alternative treatments available. Acupuncture is the one that has been studied most extensively in the West. It can help to reduce pain and muscle tone and to increase comfort. It is possible that there are other alternative treatments that can reduce muscle tone.
Click here to learn more about neuromuscular problems and treatment options
