Remember, cerebral palsy is not one specific disorder. Rather, it is an umbrella-like term used to describe a group of disorders that impair movement control, appear in the first few years of a child's life. When health care professionals diagnose a child with cerebral palsy, they rely on a number of diagnostic tests and other evaluations. There is no one definitive diagnostic test for cerebral palsy.
When an infant or toddler is seen with a movement disorder, clinicians start with a complete medical history and physical examination.

Some key factors to consider include:

• Mother's medical history, including diabetes, thyroid disorders, seizure history, or family history of neurological disease (especially hereditary neurodegenerative disease)
• Prenatal history, such as trauma or acute illness, radiation exposure, prenatal care, fetal movements, or prenatal exposure to drugs, toxins, or infections
• Perinatal history, including birth presentation, type of delivery, weight, APGAR score, and complications after birth
• Developmental history, focusing on milestones in gross motor, fine motor, and oral-motor domains
• Infant's medical history, especially seizures, vision or hearing impairments, and mental impairments
• Infant's motor skills, muscle tone, movement patterns, reflexes, and hand preference
  

If the health care provider has reason to suspect that the child may have cerebral palsy or another neurological disorder, he or she may order diagnostic tests to rule out other medical problems that can mimic some of the symptoms associated with cerebral palsy. These include laboratory tests to pinpoint inborn errors of metabolism, thyroid or liver function tests, and chromosomal analyses to rule out various genetic syndromes.

A variety of imaging studies can be performed to take a look at the child's brain. In neonates, a cranial ultrasound may identify structural abnormalities and perhaps signs of hemorrhage or hypoxic-ischemic injury. CT scans of the head are generally used to identify congenital malformations within the brain, as well as intracranial bleeding and periventricular leukomalacia (area of necrosis) in infants. Cranial MRI's are the preferred diagnostic study in older children, because they can define white matter and abnormalities within the brain, and can also measure myelination.

The health care provider may also order an electroencephalogram (EEG) to diagnose seizure disorders, an electromyelogram (EMG) to pinpoint motor neuropathy, and nerve conduction studies (NCS) to identify sensory neuropathy. In older children, intelligence tests may be used to estimate the degree of cognitive impairment.