How is Cerebral Palsy Diagnosed?

Parents are often the first to notice that their infant is not developing normally. Infants with cerebral palsy are often slow to roll over, sit, crawl, or walk. When an infant develops more slowly than usual it is called developmental delay.

Some of the skills that infants should have include:

  • Holding own head up when lying flat in a bed at 3 months
  • Holding a sitting position without help and rolling over by 6 months
  • Walking by 15 months
  • Speaking several words by 18 months old and 2 word phrases by 2 years of age 

It is important for parents to alert their clinician if their child is not meeting these milestones and the clinician should initiate an evaluation to determine why the child’s development is slow.

Doctors diagnose cerebral palsy by obtaining a complete medical history, reviewing the child’s development and examining the child, paying special attention to the child’s movements. In addition to checking for the most common symptoms – such as slow development, abnormal muscle tone and unusual posture – a doctor also has to make sure the child doesn’t have something else that could cause similar symptoms.

Some children have hypotonia (low muscle tone), which means that their muscles are too relaxed. In this case, the baby may seem floppy. Other children have hypertonia (high muscle tone) which makes their muscles seem stiff. Sometimes a child can have hypotonia at birth that changes to hypertonia over the first few years of life. Children with CP may also have unusual posture or favor one side of their body.

What is most important to the doctor is making sure that the child’s condition is not getting worse. Although cerebral palsy symptoms may change over time, children with cerebral palsy do not usually lose function. That means, if a child does seem to be losing motor skills, the problem is probably not cerebral palsy. It is more likely a genetic condition, muscle disease, a metabolism disorder or tumor in the nervous system. A complete medical history, special medical tests, and, in some cases, repeated check-ups can help confirm whether or not the child has cerebral palsy.

Once the diagnosis of cerebral palsy has been made based on medical history and physical examination, your doctor may order tests to try to figure out the cause of the cerebral palsy.

Some other tests a doctor might order include:

  • Cranial ultrasound. This test is used for high-risk premature infants because it is the least intrusive of the imaging techniques. However, it is not as effective as the two methods described below at seeing small changes in “white matter” – which is the type of brain tissue that is affected in cerebral palsy.
  • Computed tomography (CT) scan. This technique creates images that show brain injury and major brain malformations. It is quicker to do so a baby may not need to be sedated but it is not as good a picture of the brain structure as an MRI scan. There are occasional reasons a CT scan might be preferred over an MRI scan including a strong suspicion of certain viral infections during gestation, when a baby is too high risk to be sedated for a MRI scan or when an image is needed in an emergency such as during an acute trauma event or suspected child abuse.
  • Magnetic resonance imaging (MRI) scans.  This test uses a computer, a magnetic field, and radio waves to create a picture of the brain’s tissues and structures. Doctors prefer MRI imaging because it offers better detail and does not involve radiation. Most infants and young children will need to be sedated since getting a good image requires the child to lie absolutely still during the scan.

What can CP be Confused with Clinically

Metabolic Disorders

On rare occasions, metabolic disorders can be mistaken as cerebral palsy and some children will require additional tests to rule them out. 

Specialized Knowledge and Training

To confirm a diagnosis of cerebral palsy, a doctor may send a child to other doctors who have specialized knowledge and training or to specialty clinics where these doctors work with a team of health professionals who specialize in working with children with cerebral palsy and other developmental delays. These clinicians might be child neurologists, developmental pediatricians, genetic specialists, ophthalmologists (eye doctors), audiologists (hearing specialists) and physiatrists (rehabilitation specialists). Over time, other specialists like orthopedists (specialists in bone surgery, optimizing walking patterns and insuring optimal skeletal alignment) and therapists such as physical and occupational therapists and speech and language pathologists will be important members of the child’s treatment team. 

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American Academy for Cerebral Palsy and Developmental Medicine