Types of cerebral palsy
Although there are many different ways of describing or categorizing the way cerebral palsy affects an individual (this will be discussed more in the next section), people often divide it into the following four subtypes:
Spastic cerebral palsy
Spastic cerebral palsy is by far the most common type of cerebral palsy, comprising roughly 80% of all cases. Children with spastic cerebral palsy have lesions in the upper motor neurons of the central nervous system. This damage leads to hypertonia (extreme muscle tension) in the muscles that receive signals from damaged portions of the brain. Hypertonia can cause involuntary muscle contractions, spasms, and secondary pain and/or stress. Additional side effects of spastic cerebral palsy include joint deformities, scoliosis, hip dislocation and more.
Ataxic cerebral palsy
Ataxic cerebral palsy is the least common type, occurring in roughly 5-10% of all CP cases. It is caused by damage to the cerebellum and affects controlled movements and fine motor skills. This includes balance and coordination (particularly while walking) and precise movements such as writing. In young children, hypotonia is a common manifestation of ataxic CP. Unlike the rare form of degenerative neurological disease ataxia, ataxic cerebral palsy is a non-progressive condition. It is common for children with ataxic cerebral palsy to have difficulty with visual processing (depth perception and eye movement control) and/or speech.
Athetoid/dyskinetic cerebral palsy
Athetoid/dyskinetic cerebral palsy (ADCP) occurs in roughly 0.27 per 1,000 live births and comprises 15-20% of CP cases. This subtype is the result of damage to the basal ganglia, the part of the brain responsible for regulating voluntary movements. In many cases, ADCP is caused by hypoxic-ischemic encephalopathy/HIE (brain damage due to a lack of oxygenated blood) or kernicterus (brain damage due to severe or improperly-managed jaundice).
ADCP causes a combination of hypertonia, hypotonia, and involuntary motions. Children with ADCP may have trouble sitting upright, walking, grasping objects, performing fine motor tasks, sucking, swallowing, and talking. ADCP is further characterized into three subgroups based on the nature of the movements:
Mixed cerebral palsy
Mixed cerebral palsy involves a combination of symptoms that don’t all fit within a single subtype of CP. For example, a child may have both hypertonia and hypotonia. In other words, some of their muscles are too tight, while others are too loose.
Signs and symptoms of cerebral palsy
Although “signs” and “symptoms” are often used as interchangeable terms, they have their own specific definitions:
Because cerebral palsy affects different people in different ways, there is no one sign or symptom used individually to diagnose it. Most people with cerebral palsy are diagnosed as infants or toddlers, but others do not show clear signs or express symptoms until they are a bit older and developmental delays (missed milestones) become more obvious. Click here to learn more about early signs of cerebral palsy.
Neonatal predictors of cerebral palsy
Other common signs of cerebral palsy
Birth injuries and other causes of cerebral palsy
The following are some examples of birth injuries and other environmental factors that can cause or increase the risk of cerebral palsy:
Conditions associated with cerebral palsy
No two cases of cerebral palsy are identical. Depending on the location and severity of the initial brain injury, the conditions and side effects associated with cerebral palsy will vary. Factors such as treatment, therapy, environment and age also affect a person’s functional potential. However, common conditions associated with CP – aside from mobility impairments – include the following. Please note that incidence estimates have been rounded to the nearest five and that some come from studies with small sample sizes:
Diagnosing Cerebral Palsy
The diagnosis of cerebral palsy is typically based on a physical examination and the child’s medical history. Neuroimaging with CT or MRI is warranted when the cause of a child’s cerebral palsy has not been established. These tests can also help to determine the timing of the initial damage and the likelihood of associated conditions such as epilepsy and developmental disabilities.
Some people with cerebral palsy are diagnosed in early infancy, and most receive their diagnosis by age two. However, cerebral palsy may go undetected until children miss major developmental milestones; sometimes, a diagnosis is not made until age four or five. Because clinical signs of cerebral palsy evolve as the nervous system matures, the diagnostic process usually involves multiple trips to the child’s primary physician, as well as several other specialists.
Furthermore, the time at which a cerebral palsy diagnosis is made often depends on the type of cerebral palsy the child has. For instance:
Preventing Cerebral Palsy
As an added bonus, we have made a list just for you, to further help reduce pain during pregnancy: