Cerebral palsy (CP) is divided into four major classifications to describe different movement impairments. These classifications also reflect the areas of the brain that are damaged. The four major classifications are:

Mild Cases of Cerebral Palsy:

Spastic cerebral palsy is by far the most common type of overall cerebral palsy, occurring in 70% to 80% of all cases. Moreover, spastic CP accompanies any of the other types of CP in 30% of all cases.

People with this type of CP are hypertonic and have what is essentially a neuromuscular mobility impairment (rather than hypotonia or paralysis stemming from an upper motor neuron lesion in the brain as well as the corticospinal tract or the motor cortex, this damage impairs the ability of some nerve receptors in the spine to properly receive gamma amino butyric acid, leading to hypertonia in the muscles signaled by those damaged nerves.

As compared to other types of CP, and especially as compared to hypotonic or paralytic mobility disabilities, spastic CP is typically more easily manageable by the person affected, and medical treatment can be pursued on a multitude of orthopedic and neurological fronts throughout life. Spastic CP is classified by topography dependent on the region of the body affected; these include:

Spastic hemiplegia is one side being affected. Generally, injury to muscle-nerves controlled by the brain's left side will cause a right body deficit, and vice versa. Typically, people that have spastic hemiplegia are the most ambulatory of all the forms, although they generally have dynamic equinus on the affected side and are primarily prescribed ankle-foot orthoses to prevent said equinus.[11]

Spastic diplegia is the lower extremities affected, with little to no upper-body spasticity. The most common form of the spastic forms, most people with spastic diplegia are fully ambulatory, but are "tight" and have a scissors gait. Flexed knees and hips to varying degrees, and moderate to severe adduction (stemming from tight adductor muscles and comparatively weak abductor muscles), are present. Gait analysis is often done in early life on a semi-regular basis, and assistive devices are often provided like walkers, crutches or canes; any ankle-foot orthotics provided usually go on both legs rather than just one. In addition, these individuals are often nearsighted. The intelligence of a person with spastic diplegia is unaffected by the condition. Over time, the effects of the spasticity sometimes produce hip problems and dislocations (see the main article and spasticity for more on spasticity effects). In three-quarters of spastic diplegics, also strabismus (crossed eyes) can be present as well.

• Spastic monoplegia is one single limb being affected.
• Spastic triplegia is three limbs being affected.
• Spastic quadriplegia is all four limbs more or less equally affected. People with spastic quadriplegia are the least likely to be able to walk, or if they can, to desire to walk, because their muscles are too tight and it is too much of an effort to do so. Some children with spastic quadriplegia also have hemiparetic tremors, an uncontrollable shaking that affects the limbs on one side of the body and impairs normal movement.

In any form of spastic CP, clonus of the affected limb(s) may sometimes result, as well as muscle spasms resulting from the pain and/or stress of the tightness experienced. The spasticity can and usually does also lead to very early onset of muscle-stress symptoms like arthritis and tendinitis, especially in ambulatory individuals in their mid-20s and early-30s. Physical therapy and also athletic training regimens of assisted stretching, strengthening, and targeted physical activity and exercise are usually the chief ways to keep spastic CP well-managed, although if the spasticity is too much for the person to handle, other remedies may be considered, such as various antispasmodic medications, botox, baclofen, or even a neurosurgery known as a selective dorsal rhizotomy (which eliminates the spasticity by eliminating the nerves causing it).

Ataxia type symptoms can be caused by damage to the cerebellum. The forms of 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 such as writing, typing, or using scissors might be affected, as well as balance, especially while walking. It is common for individuals to have difficulty with visual and/or auditory processing.

Athetoid or dyskinetic cerebral palsy is mixed muscle tone — 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 quarter 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 10% to 20% of all cases.[12] In newborn infants, high bilirubin levels in the blood, if left untreated, can lead to brain damage in certain areas (kernicterus). This may also lead to athetoid cerebral palsy.

Athetoid cerebral palsy:

Hypotonia is the opposite of hypertonia; people with hypotonic CP have musculature that is limp, and can move only a little or not at all. Although physical therapy is usually attempted to strengthen the muscles (in a similar way to how PT is used to stretch and loosen the tight muscles of hypertonic individuals), it is not always fundamentally effective.