Signs and symptoms
Cerebral palsy is defined as "a group of permanent disorders of the development of movement and posture, causing activity limitation, that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain." While movement problems are the central feature of CP, difficulties with thinking, learning, feeling, communication and behavior often co-occur, with 28% having epilepsy, 58% having difficulties with communication, at least 42% having problems with their vision, and 23–56% having learning disabilities. Muscle contractions in people with cerebral palsy is commonly thought to arise from overactivation.
Cerebral palsy is characterized by abnormal muscle tone, reflexes, or motor development and coordination. The neurological lesion is primary and permanent while orthopedic manifestations are secondary and progressive. In cerebral palsy unequal growth between muscle-tendon unit and bone eventually leads to bone and joint deformities. At first deformities are dynamic. Over time deformities tend to become static and joint contractures develop. Deformities in general and static deformities in specific (
joint contractures) cause increasing gait difficulties in the form of tip-toeing gait due tightness of the tendon Achilles and scissoring gait due to tightness of the hip adductors. These gait patterns are among the most common gait abnormalities in CP children. Yet, orthopaedic manifestations of CP are very diverse. The effects of cerebral palsy fall on a continuum of motor dysfunction, which may range from slight clumsiness at the mild end of the spectrum to impairments so severe that they render coordinated movement virtually impossible at the other end of the spectrum. Although most people with CP have problems with increased muscle tone, some have normal or low muscle tone. High muscle tone can either be due to spasticity or dystonia.
Babies born with severe CP often have an irregular posture; their bodies may be either very floppy or very stiff. Birth defects, such as spinal curvature, a small jawbone, or a small head sometimes occur along with CP. Symptoms may appear or change as a child gets older. Some babies born with CP do not show obvious signs right away. Classically, CP becomes evident when the baby reaches the developmental stage at 6 to 9 months and is starting to mobilise, where preferential use of limbs, asymmetry, or gross motor developmental delay is seen.
Drooling is common among children with cerebral palsy, which can have a variety of impacts including social rejection, impaired speaking, damage to clothing and books, and mouth infections. It can additionally cause choking.
An average of 55.5% of people with cerebral palsy experience lower urinary tract symptoms, more commonly excessive storage issues than voiding issues. Those with voiding issues and pelvic floor overactivity can deteriorate as adults and experience
upper urinary tract dysfunction.
Children with CP may also have sensory processing issues.`
Speech and language disorders are common in people with cerebral palsy. The incidence of dysarthria is estimated to range from 31% to 88%, and around a quarter of people with CP are non-verbal. Speech problems are associated with poor respiratory control, laryngeal and velopharyngeal dysfunction, and oral articulation disorders that are due to restricted movement in the oral-facial muscles. There are three major types of dysarthria in cerebral palsy: spastic, dyskinetic (athetosis), and ataxic.
Early use of augmentative and alternative communication systems may assist the child in developing spoken language skills. Overall language delay is associated with problems of intellectual disability, deafness, and learned helplessness. Children with cerebral palsy are at risk of learned helplessness and becoming passive communicators, initiating little communication. Early intervention with this clientele, and their parents, often targets situations in which children communicate with others so that they learn that they can control people and objects in their environment through this communication, including making choices, decisions, and mistakes.
In order for bones to attain their normal shape and size, they require the stresses from normal musculature. People with cerebral palsy are at risk of low bone mineral density. The shafts of the bones are often thin (gracile), and become thinner during growth. When compared to these thin shafts (diaphyses), the centres (metaphyses) often appear quite enlarged (ballooning). Due to more than normal joint compression caused by muscular imbalances, articular cartilage may atrophy,:46 leading to narrowed joint spaces. Depending on the degree of spasticity, a person with CP may exhibit a variety of angular joint deformities. Because vertebral bodies need vertical gravitational loading forces to develop properly, spasticity and an abnormal gait can hinder proper or full bone and skeletal development. People with CP tend to be shorter in height than the average person because their bones are not allowed to grow to their full potential. Sometimes bones grow to different lengths, so the person may have one leg longer than the other.
Children with CP are prone to
low trauma fractures, particularly children with higher GMFCS levels who cannot walk. This further impacts on a child's mobility, strength, experience of pain, and can lead to missed schooling or child abuse suspicions. These children generally have fractures in the legs, whereas non-affected children mostly fracture their arms in the context of sporting activities.
Hip dislocation and ankle equinus or planter flexion deformity are the two most common deformities among children with cerebral palsy. Additionally, flexion deformity of the hip and knee can occur. Besides, torsional deformities of long bones such as the femur and tibia are encountered among others.  Children may develop scoliosis before the age of 10 – estimated prevalence of scoliosis in children with CP is between 21% and 64%. Higher levels of impairment on the GMFCS are associated with scoliosis and hip dislocation.  Scoliosis can be corrected with surgery, but CP makes surgical complications more likely, even with improved techniques. Hip migration can be managed by soft tissue procedures such as adductor musculature release. Advanced degrees of hip migration or dislocation can be managed by more extensive procedures such as femoral and pelvic corrective osteotomies. Both soft tissue and bony procedures aim at prevention of hip dislocation in the early phases or aim at hip containment and restoration of anatomy in the late phases of disease.  Equinus deformity is managed by conservative methods especially when dynamic. If fixed/static deformity ensues surgery may become mandatory.
Growth spurts during puberty can make walking more difficult.
Pain and sleep
Pain is common and may result from the inherent deficits associated with the condition, along with the numerous procedures children typically face. When children with cerebral palsy are in pain, they experience worse muscle spasms. Pain is associated with tight or shortened muscles, abnormal posture, stiff joints, unsuitable orthosis, etc. Hip migration or dislocation is a recognizable source of pain in CP children and especially in the adolescent population. Nevertheless, the adequate scoring and scaling of pain in CP children remains challenging. There is also a high likelihood of chronic sleep disorders secondary to both physical and environmental factors. Children with cerebral palsy have significantly higher rates of sleep disturbance than typically developing children. Babies with cerebral palsy who have stiffness issues might cry more and be harder to put to sleep than non-disabled babies, or "floppy" babies might be lethargic. Chronic pain is under-recognized in children with cerebral palsy, even though 3 out of 4 children with cerebral palsy experience pain.
Those with CP may have difficulty preparing food, holding utensils, or chewing and swallowing due to sensory and motor impairments. An infant with CP may not be able to suck, swallow or chew. Gastro-oesophageal reflux is common in children with CP. Children with CP may have too little or too much sensitivity around and in the mouth. Poor balance when sitting, lack of control of the head, mouth and trunk, not being able to bend the hips enough to allow the arms to stretch forward to reach and grasp food or utensils, and lack of hand-eye coordination can make self-feeding difficult. Feeding difficulties are related to higher GMFCS levels. Dental problems can also contribute to difficulties with eating. Pneumonia is also common where eating difficulties exist, caused by undetected aspiration of food or liquids. Fine finger dexterity, like that needed for picking up a utensil, is more frequently impaired than gross manual dexterity, like that needed for spooning food onto a plate. Grip strength impairments are less common.
Children with severe cerebral palsy, particularly with oropharyngeal issues are at risk of undernutrition. Triceps skin fold tests have been found to be a very reliable indicator of malnutrition in children with cerebral palsy.
Associated disorders include "intellectual disabilities, seizures, muscle contractures, abnormal gait, osteoporosis, communication disorders, malnutrition, sleep disorders, and mental health disorders, such as depression and anxiety". In addition to these, "functional gastrointestinal abnormalities contributing to bowel obstruction, vomiting, and constipation" may also arise. Adults with cerebral palsy may suffer from "ischemic heart disease, cerebrovascular disease, cancer, and trauma" more so than a non-affected population. Obesity in people with cerebral palsy or a more severe Gross Motor Function Classification System assessment in particular are considered to be risk factors for multimorbidity. Other medical issues can be mistaken for being symptoms of cerebral palsy, and so may not be treated correctly.
Related conditions can include apraxia, dysarthria or other communication disorders, sensory impairments, urinary incontinence, fecal incontinence, or behavioural disorders.
Seizure management is more difficult in people with CP as seizures often last longer.
The associated disorders that co-occur with cerebral palsy may be more disabling than the motor function problems.