How does a doctor diagnose cerebral palsy?
Early signs of cerebral palsy may be present from birth. Most children with cerebral palsy are diagnosed during the first 2 years of life. But if a child’s symptoms are mild, it can be difficult for a doctor to make a reliable diagnosis before the age of 4 or 5.
Nevertheless, if a doctor suspects cerebral palsy, he or she will most likely schedule an appointment to observe the child and talk to the parents about their child’s physical and behavioral development.
Collaborative evaluation of child
Doctors diagnose cerebral palsy by evaluating a child’s motor skills and taking a careful and thorough look at their medical history. In addition to checking for the most characteristic symptoms — slow development, abnormal muscle tone, and unusual posture — a doctor also has to rule out other disorders that could cause similar symptoms. Most important, a doctor has to determine that the child’s condition is not getting worse.
Distinguishing CP from other conditions
Although symptoms may change over time, cerebral palsy by definition is not progressive. If a child is continuously losing motor skills, the problem more likely begins elsewhere – such as a genetic or muscle disease, metabolism disorder, or tumors in the nervous system. A comprehensive medical history, special diagnostic tests, and, in some cases, repeated check-ups can help confirm that other disorders are not at fault.
Additional tests are often used to rule out other movement disorders that could cause the same symptoms as cerebral palsy. Neuroimaging techniques that allow doctors to look into the brain (such as an MRI scan) can detect abnormalities that indicate a potentially treatable movement disorder. If it is cerebral palsy, an MRI scan can also show a doctor the location and type of brain damage.
Neuroimaging methods include:
- Cranial ultrasound. This test is used for high-risk premature infants because it is the least intrusive of the imaging techniques, although it is not as successful as the two methods described below at capturing subtle changes in white matter – the type of brain tissue that is damaged in cerebral palsy.
- Computed tomography (CT) scan. This technique creates images that show the structure of the brain and the areas of damage.
- Magnetic resonance imaging (MRI) scan. This test uses a computer, a magnetic field, and radio waves to create an anatomical picture of the brain’s tissues and structures. Doctors prefer MRI imaging because it offers finer levels of detail.
On rare occasions, metabolic disorders can masquerade as cerebral palsy and some children will require additional tests to rule them out. Most of the childhood metabolic disorders have characteristic brain abnormalities or malformations that will show up in an MRI.
Other types of disorders can also be mistaken for cerebral palsy. For example, coagulation disorders (which prevent blood from clotting) can cause prenatal or perinatal strokes that damage the brain and cause symptoms characteristic of cerebral palsy. Because stroke is so often the cause of hemiplegic cerebral palsy, a doctor may find it necessary to perform diagnostic testing on children with this kind of cerebral palsy to rule out the presence of a coagulation disorder. If left undiagnosed, coagulation disorders can cause additional strokes and more extensive brain damage.
Identifying, treating and moving on with life
To confirm a diagnosis of cerebral palsy, a doctor may refer a child to additional doctors with specialized knowledge and training, such as a child neurologist, developmental pediatrician, ophthalmologist (eye doctor), or otologist (ear doctor). Additional observations help a doctor make a more accurate diagnosis and begin to develop a specific plan for treatment.