Spastic cerebral palsy (aka bilateral spasticity) is a type of CP where spasticity (aka muscle tightness) is either the dominant or exclusive impairment present.

• Hypertonic, i.e. present with very stiff and tight muscle groups, far greater than typical humans

• Neuromuscular mobility impairment, rather than hypotonia or paralysis, which stems from an UMN lesion in the brain. The corticospinal tract or the motor cortex may be secondarily affected
• Spastic muscles are continuously contracting, and there is apparent weakness of their antagonists, causing abnormal positions of the joints on which they act. Abnormal postures are usually associated with the antigravity muscles, which are extensors in the leg and the flexors in the arm
• Deformities of joints develop, which may become fixed contractures with time
• Changes in spasticity and postures may occur with excitement, fear or anxiety, and pain which increase muscle tension
• The UMN lesion in the brain impairs the ability of some nerve receptors in the spine, to properly receive GABA. That leads to hypertonia in the muscles signalled by those damaged nerves. The limbs and body areas in which hypertonia manifests can be any or even all of them, depending which specific nerve roupings within the spine are rendered unable to receive GABA. Thus, spastic CP is often designated by body topography
• Although it has its origins in brain injury, it is a collection of orthopedic and neuromuscular issues, because of how it manifests Sx over the course of the person's lifespan. It is thus not the same as brain damage
• If combined with verbal speech challenges and strabismus, it may APPEAR to have cognitive problems, but this is false since intelligence is not affected by spasticity itself

• Spastic hemiplegia, where 1 side is affected. Generally, injury to muscle nerves controlled by the brain's L side will cause a R body deficit, and vice versa. Patients that have spastic hemiplegia are the most ambulatory of all, although they generally have dynamic equinus (limping instability) on the affected side, and are primarily prescribed ankle-foot ortheses to prevent the equinus
• Spastic monoplegia, where 1 single limb is affected
• Spastic diplegia, is where the lower extremities are affected, with little to no upper body spasticity. It is the most common of the spastic forms (75%). Most patients are fully ambulatory, but are tight and have a scissors gait. There is flexed knees and hips to varying degrees, and moderate to severe adduction, stemming from tight adductor muscles and comparatively weak abductor muscles
• Spastic triplegia, where 3 limbs are affected
• Spastic quadriplegia, where all 4 limbs are more or less equally affected. These patients 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 may salso have hemiparetic tremors, an uncontrollable shaking that afects the limbs on 1 side of the body, and impairs normal movement

• By far the most common type of overall CP, occurring in 75% of all cases