Cerebral palsy (CP) primarily affects movement and muscle tone, but symptoms vary widely from one person to another. Some children show subtle signs like a slight limp, while others have significant difficulty with movement, speech, and daily tasks. Symptoms typically become noticeable during the first or second year of life, though milder cases may not be confirmed until a child is a few years older.
Early Signs in Infants
The earliest clues usually involve missed or delayed motor milestones: rolling over, sitting up, crawling, and walking. A baby who feels unusually floppy when picked up, or whose limbs seem stiff and resistant to movement, may be showing early signs. In many infants who go on to receive a CP diagnosis, a distinct pattern emerges: low muscle tone in the neck and trunk combined with stiffness in the arms and legs. This mix, where the body feels “floppy” in the center but tight in the limbs, is the most common early tone pattern, seen in roughly 28% of high-risk infants studied.
Another early indicator is asymmetry. If a baby consistently favors one hand before age one, or if muscle tone in one arm feels noticeably different from the other, that can point toward unilateral CP, which affects one side of the body. Stiffness in the arms that appears from around seven months of age has been linked to a CP diagnosis by 21 months.
Babies with CP also tend to hold onto newborn reflexes longer than expected. Reflexes like the startle reflex, the grasp reflex, and the reflex that causes a baby to turn its head when its cheek is stroked normally fade during the first six months as voluntary movement takes over. When these reflexes persist well beyond that window, it can signal that the brain’s motor control pathways aren’t developing typically.
Muscle Tone and Movement Problems
The hallmark of CP is altered muscle tone, and it shows up in different ways depending on the type.
Spastic CP is the most common form. Muscles are persistently stiff, and reflexes are exaggerated. You might notice a child walking on their toes, crouching while walking, or crossing their knees in a scissor-like pattern. The stiffness can affect one side of the body, both legs, or all four limbs.
Dyskinetic CP involves involuntary movements that the person can’t control. These take several forms: slow, writhing motions (athetosis), sudden irregular jerky movements (chorea), or twisting, repetitive postures that can be painful (dystonia). These movements often worsen with stress or effort and may lessen during sleep.
Ataxic CP affects balance and coordination. Walking may appear unsteady, and tasks requiring precision, like reaching for a toy or buttoning a shirt, can be shaky and difficult.
Many people have a mix of these types. The severity also ranges enormously. At the mild end, a child walks independently but may struggle with advanced skills like running or jumping. At the severe end, independent movement is extremely limited even with assistive devices like wheelchairs.
Speech and Communication Difficulties
About 90% of people with CP experience some degree of dysarthria, a condition where the muscles used for speaking don’t work smoothly. This doesn’t reflect intelligence. It reflects the same type of motor control problem that affects the limbs, but applied to the tongue, lips, jaw, and vocal cords.
The most prominent speech features include a strained or strangled voice quality, imprecise pronunciation, a slow rate of speech, monotone delivery, and frequent pauses to breathe. In adults with CP, speech intelligibility averages around 59%, meaning listeners understand roughly six out of every ten words. For people with severe dysarthria, the number drops much lower, sometimes making verbal communication impractical without assistive technology.
Children who are nonverbal or minimally verbal can often communicate effectively through eye-gaze devices, picture boards, or speech-generating apps. The communication challenge is a motor problem, not necessarily a language or thinking problem.
Feeding and Swallowing Issues
The same muscle control difficulties that affect speech also affect eating and drinking. Children with CP often have trouble coordinating the complex sequence of chewing, moving food to the back of the mouth, and swallowing safely. Specific signs include chewing with the mouth open due to poor jaw control, difficulty keeping food or liquid from spilling out of the mouth, and unintentional drooling caused by weak lip closure rather than excess saliva production.
A more serious concern is aspiration, where food or liquid enters the airway and reaches the lungs instead of the stomach. This can trigger recurrent chest infections or pneumonia. Some children cough when food goes down the wrong way, which is a protective reflex. Others experience “silent aspiration,” where food enters the airway without triggering a cough at all. A wet, gurgly quality to a child’s voice or cry after eating can be a sign that food is sitting near the vocal cords.
Oral primitive reflexes that should disappear in infancy, like a tongue-thrust reflex that pushes food out of the mouth or a tonic bite reflex that clamps the jaw shut, sometimes persist in children with CP and make feeding considerably harder.
Seizures and Epilepsy
Epilepsy is one of the most common conditions that occurs alongside CP. CDC data from a multi-site tracking network found that about 42% of children identified with CP also had epilepsy. Seizures can look different depending on the child: some involve full-body convulsions, while others cause brief staring spells or subtle jerking in one limb. Epilepsy in CP is caused by the same underlying brain differences that affect movement.
Cognitive and Learning Differences
CP is not an intellectual disability, though the two can overlap. Many people with CP have typical or above-average intelligence. When cognitive differences do occur, they range from mild learning difficulties to more significant intellectual disability, depending on which areas of the brain were affected. It’s common for people to underestimate the cognitive abilities of someone with CP because speech or motor difficulties can mask what the person understands and knows.
Children with CP may also experience visual processing problems, not necessarily with the eyes themselves but with how the brain interprets what the eyes see. This can affect reading, navigating spaces, and recognizing objects. Hearing loss occurs in some cases as well, though it’s less common than visual difficulties.
How Symptoms Change Over Time
CP itself is not progressive, meaning the underlying brain difference doesn’t get worse. But symptoms can shift as a child grows. A toddler with mild stiffness may develop more noticeable gait problems as their body gets bigger and heavier. Muscle tightness can gradually pull joints out of alignment, leading to pain and reduced range of motion in the hips, spine, or ankles. Adults with CP frequently report increased fatigue and joint pain compared to their younger years, partly because their bodies have been compensating for movement differences over decades.
Early intervention with physical therapy, occupational therapy, and speech therapy can meaningfully improve a child’s functional abilities. The brain is most adaptable in the first few years of life, so therapies started early tend to have the greatest impact on how a child learns to move, communicate, and manage daily tasks.