Cerebral Palsy Classifications

Spastic CP is the most common type of CP. People with spastic CP have increased muscle tone. Spasticity is a category of movement disorders where the brain’s inability to control or fine tune muscle activation result in stiffness of an arm, hand or leg. Spastic CP is described by what parts of the body are affected:

• Spastic hemiplegia/hemiparesis typically affects the arm and hand on one side of the body, but it can also include the leg.
• Spastic diplegia/diparesis involves muscle stiffness that is predominantly in the legs and less severely affects the arms and face.
• Spastic quadriplegia/quadriparesis is the most severe form of cerebral palsy. It is caused by widespread damage to the brain or significant brain malformations.

(See examples further below on the page.)

What is Diplegia?

Diplegia is a term used when cerebral palsy compromises the movement control of the lower limbs (legs) more significantly than those of the upper limbs. ("di" means two)

What is Quadriplegia?

Quadriplegia is a term used when all four limbs, both arms and both legs have impaired control. ("quad" means four)

What is Hemiplegia?

Hemiplegia is a term used when one side including upper and lower limbs (arm and leg) is severely impaired (usually the upper limb more so than the lower limb).

Dyskinetic cerebral palsy (also includes athetoid, choreoathetoid, and dystonia) is a category of movement disorders represented by abnormal uncontrolled jerky movements that occur when an area of the brain called basal ganglia is damaged. Patients with dystonia are unable to “fine-tune voluntary movements,” like shaking hands with a friend. (See examples further below on the page.)

Ataxia cerebral palsy affects balance and depth perception. Individuals with ataxic CP may be unsteady when they walk and may have a difficult time controlling their hands or arms.

Mixed types of CP refer to symptoms that do not correspond to any single type of CP, but are a mix of types. The most common type of mixed cerebral palsy is spastic-dyskinetic CP.

In a patient with spasticity, the examiner attempts to quickly bend or flex the patient’s knee. When doing so the examiner can feel (and at times see) what is commonly referred to as “catch.” In other words, the examiner is initially able to start bending the knee, but the movement is suddenly curtailed. In other words, the movement is stopped or prevented for a short period then the muscle “let go” and the bending or movement continues as the examiner to pushes. The quicker and stronger the examiner tries to bend the knee the more intense is the “catch.” The muscle lying in front of our thighs is called quadriceps and it must stretch to allow the knees to bend. In this example, as soon as the knee is pushed into bending the quadriceps spasticity blocks the movement.

Spasticity is found in multiple muscles in patients with cerebral palsy. Therefore proper and fine-tuned movements of the limbs or any part of the body are compromised and often limited. Anytime a muscle is stretched the reflex is triggered and this stops or interrupts the movement momentarily or throughout the range of motion.

A child with spasticity trying to walk, while the foot is on the ground (in every step) the calf muscles are stretched primarily as the leg bone rolls forward over the foot. As soon as this rolling mechanism starts, the stretch reflex in the calves is triggered and makes the movement stop. Sometimes the spasticity is so significant that the muscle is never stretched, it becomes short and the result is the patient, usually young children walking on their toes. This is called equinus deformity.

Today, we know that, of the three muscles that constitutes the so-called calf muscles on each leg, only two, are spastic in many patients (they are called medial and lateral gastrocnemius). The third muscle, which is called soleus, is often not so compromised by spasticity.

It is believed that, muscles grow due to the bones’ growth. Muscles themselves are being activated, shortening, and stretching all day long. Just think of a child: they never stop—they are constantly running, jumping, falling. A muscle that is constantly “under the influence of spasticity” rarely has a chance to stretch fully during such activities. Bone growth can be affected by cerebral palsy, but the muscles tend “fall further behind.” This situation leads to what is commonly known as muscle shortening or later, muscle contracture. The joints that are controlled by those muscles become less mobile.

The strong two muscles that help us bend our hips are called ileo-psoas. The same way as with the calf muscles, psoas is often spastic in cerebral palsy. When psoas spasticity is severe, this muscle may shorten. In this situation the hip cannot stretch or extend all the way. This is called hip flexion deformity. The hip or hips are always bent a bit when the person tries to stand or walk, or even when they are lying down.