In 30 percent of all cases of CP, the spastic form is found along with one of the other types. There are a number of other, less prevalent types of CP, but these are the most common.
Spastic cerebral palsy is by far the most common type, occurring in 70% to 80% of all cases. People with this type are hypertonic and have a neuromuscular condition stemming from damage to the corticospinal tract, motor cortex, or pyramidal tract that affects the nervous system's ability to receive gamma amino butyric acid in the area(s) affected by the spasticity. Spastic CP is further classified by topography dependent on the region of the body affected; these include:
- spastic hemiplegia (one side being affected). Generally, injury to the left side of the brain will cause a right hemiplegia and injury to the right side a left hemiplegia. Childhood hemiplegia is a relatively common condition, affecting up to one child in 1,000.
- spastic diplegia (whole body affected, but the lower extremities affected more than the upper extremities). Most people with spastic diplegia do eventually walk. The gait of a person with spastic diplegia is typically characterized by a crouched gait. Toe walking and flexed knees are common. Hip problems, dislocations, and side effects like strabismus (crossed eyes) are common. Strabismus affects three quarters of people with spastic diplegia. This is due to weakness of the muscles that control eye movement. In addition, these individuals are often nearsighted. In many cases the IQ of a person with spastic diplegia is normal.
- spastic quadriplegia (Whole body affected; all four limbs affected equally). Some children with quadriplegia also suffer from hemiparetic tremors; an uncontrollable shaking that affects the limbs on one side of the body and impairs normal movement. A common problem with children suffering from quadriplegia is fluid buildup. Diuretics and steroids are medications administered to decrease any buildup of fluid in the spine that is caused by leakage from dead cells. Hardened feces in a quadriplegia patient are important to monitor because it can cause high blood pressure. Autonomic dysreflexia can be caused by hardened feces, urinary infections, and other problems, resulting in the overreaction of the nervous system and can result in high blood pressure, heart attacks, and strokes. Blockage of tubes inserted into the body to drain or enter fluids also needs to be monitored to prevent autonomic dysreflexia in quadriplegia. The proper functioning of the digestive system needs to be monitored as well.
Occasionally, terms such as monoplegia, paraplegia, triplegia, and pentaplegia may also be used to refer to specific manifestations of the spasticity.
This type symptoms can be caused by damage to the cerebellum. Forms of ataxia, such as Bruns' Frontal Ataxia, and Friedreich's Ataxia are less common types of Cerebral Palsy, occurring in at most 10% of all cases. Some of these individuals have hypotonia and tremors. Motor skills like writing, typing, or using scissors might be difficult, as well as problems with balance, especially while walking. It is common for individuals to have difficulty with visual and/or auditory processing of objects.
Athetoid or dyskinetic
Athetoid or dyskinetic is mixed muscle tone - sometimes hypertonia and sometimes hypotonia. People with athetoid CP have trouble holding themselves in an upright, steady position for sitting or walking, and often show involuntary motions. For some people with athetoid CP, it takes a lot of work and concentration to get their hand to a certain spot (like scratching their nose or reaching for a cup). Because of their mixed tone and trouble keeping a position, they may not be able to hold onto objects (such as a toothbrush or pencil). About one-fourth of all people with CP have athetoid CP. The damage occurs to the extrapyramidal motor system and/or pyramidal tract and to the basal ganglia. It occurs in 40% of all cases.