Types of Cerebral Palsy
Children with CP have damage to the area of their brain that controls muscle tone. Depending on where their brain injury is, and how big it is, their muscle tone may be too tight, too loose, or a combination of too tight and loose. Muscle tone is what lets us keep our bodies in a certain position, like sitting with our heads up to look at the teacher in class. Changes in muscle tone let us move.
Bend your arm to move your hand up to touch your nose. To do that, you must shorten, or increase the tone in the muscle in the front of the upper part of your arm (biceps muscle) while you lengthen, or decrease the tone in the back of the upper part of your arm (triceps muscle). To move your arm smoothly without jerks and without hitting yourself in the nose, the tone in muscles used to make that movement must change in a way that is just right—an even change to tighten one while loosening the other. Children with CP are not able to change their muscle tone in a smooth and even way, so their movements may be jerky or wobbly.
Spastic Cerebral Palsy
If muscle tone is too high or too tight, the term spastic is used to describe the type of cerebral palsy. Children with spastic CP have stiff and jerky movements because their muscles are too tight. They often have a hard time moving from one position to another or letting go of something in their hand. This is the most common type of CP. About half of all people with CP have spastic CP.
Ataxic Cerebral Palsy
Low muscle tone and poor coordination of movements is described as ataxic (a-tax-ick) CP. Kids with ataxic CP look very unsteady and shaky. They have a lot of shakiness, like a tremor you might have seen in a very old person, especially when they are trying to do something like write or turn a page or cut with scissors. They also often have very poor balance and may be very unsteady when they walk. Because of the shaky movements and problems coordinating their muscles, kids with ataxic CP may take longer to finish writing or art projects.
Athetoid Cerebral Palsy
The term athetoid is used to describe the type of cerebral palsy when muscle tone is mixed – sometimes too high and sometimes too low. Children with athetoid CP have trouble holding themselves in an upright, steady position for sitting or walking, and often show lots of movements of their face, arms and upper body that they don’t mean to make (random, involuntary movements). These movements are usually big. For some kids with athetoid CP, it takes a lot of work and concentration to get their hand to a certain spot (like to scratch their nose or reach for a cup). Because of their mixed tone and trouble keeping a position, they may not be able to hold onto things (like a toothbrush or fork or pencil). About one-fourth of all people with CP have athetoid CP.
Mixed Cerebral Palsy
When muscle tone is too low in some muscles and too high in other muscles, the type of cerebral palsy is called mixed. About one-fourth of all people with CP have mixed CP.