Movement and posture limitations are aspects of all CP types and as a result, CP has historically been diagnosed based on parental reporting of developmental motor delays such as failure to sit upright, reach for objects, crawl, stand, or walk at the appropriate age. Diagnosis of ADCP is also based on clinical assessment used in conjunction with milestone reporting. The majority of ADCP assessments now use the Gross Motor Function Classification System (GMFCS) or the International Classification of Functioning, Disability and Health (formerly the International Classification of Impairments Disease, and Handicaps), measures of motor impairment that are effective in assessing severe CP. ADCP is typically characterized by an individual’s inability to control their muscle tone, which is readily assessed via these classification systems.

Magnetic resonance imaging (MRI) is used to detect morphological brain abnormalities associated with ADCP in patients that are either at risk for ADCP or have shown symptoms thereof. The abnormalities chiefly associated with ADCP are lesions that appear in the basal ganglia. The severity of the disease is proportional to the severity and extent of these abnormalities, and is typically greater when additional lesions appear elsewhere in the deep grey matter or white matter. MRI also has the ability to detect brain malformation, periventricular leukomalacia (PVL), and areas affected by hypoxia-ischemia, all of which may play a role in the development of ADCP. The MRI detection rate for ADCP is approximately 54.5%, however this statistic varies depending on the patient’s age and the cause of the disease and has been reported to be significantly higher.

Diagnosis of ataxic cerebral palsy is based on clinical assessment using standardized assessment tools. Diagnosis begins with the observation of slow motor development, abnormal muscle tone, and unusual posture in children that fail to reach developmental milestones. Diagnosis differs in adults and children because a child’s brain is still developing and acquiring new motor, linguistic, adaptive, and social skills. The testing strategy is based on the pattern of development of symptoms, the patient’s family history, and any factors that might influence the diagnosis, such as injury or trauma. Associated disabilities such as those previously described under symptoms associated with ataxic cerebral palsy, i.e., sensory impairment and cognitive dysfunction, are also helpful in diagnosing the disease.

In children, assessment of infantile reflexes is also a diagnostic tool, such as the Moro reflex and the Romberg Test. The Moro reflex is rarely present in infants after 6 months of age and is characterized as a response to a sudden loss of support that causes the infant to feel like it is falling. The infant will respond by abduction and adduction (or spreading and unspreading) of the arms, as well as crying. The Moro reflex is significant in evaluating the integration of the central nervous system and patients with ataxic cerebral palsy will show a persistence and exacerbation of the reflex. In addition, patients with ataxic cerebral palsy will rarely show a positive Romberg test, which indicates that there is localized cerebellar dysfunction.

Physical diagnostic tests, such as cerebral imaging using Computerized Tomography (CT), Magnetic Resonance Imaging (MRI), and ultrasound are also useful, but not preferred to clinical assessments. These neuroimaging techniques can show brain abnormalities that have been found in previous patients with cerebral palsy, i.e., focal infarction and various brain malformations, however in a study of 273 children who were born after 35 weeks of gestation and underwent neuroimaging studies, one-third of the infants showed normal studies. In addition, infants undergo neuroimaging studies once the infant has neurological findings suggestive of cerebral palsy.

For developmental diagnosis in children and infants, there are a number of milestones of motor, linguistic, adaptive, and social behavior, such as.

1. When the child could sit up on their own with or without support

2. Say their first words

3. Feed themselves

4. Play successfully with children of same age

Current forms of prevention are focused during pregnancy, while others are focused immediately after birth. Some methods that have been used include prolonging the pregnancy using interventions such as 17-alpha progesterone, limiting the number of gestations during pregnancy (for pregnancies induced by assistive reproductive technology), antenatal steroid for mothers likely to deliver prematurely, high caffeine for premature births with extremely low birth weights.

Spastic quadriplegia can be diagnosed as early as age one after a noticed delay in development, particularly a delay in rolling, crawling, sitting, or walking. However, depending on the severity, signs may not show up until the age of three. Muscle tone is sometimes used to make the diagnosis for spastic quadriplegia as affected children often appear to be either too stiff or too floppy.

Another important diagnostic factor is the persistence of primitive reflexes past the age at which they should have disappeared (6–12 months of age). These reflexes include the rooting reflex, the sucking reflex, and the Moro reflex, among others.

Magnetic resonance imaging (MRI) or a computed tomography scan (CT scan) may be used to locate the cause of the symptoms. Ultrasound may be used for the same function in premature babies.

Because cerebral palsy refers to a group of disorders, it is important to have a clear and systematic naming system. These disorders must be non-progressive, non-transient, and not due to injury to the spinal cord. Disorders within the group are classified based on two characteristics- the main physiological symptom, and the limbs that are affected. For a disorder to be diagnosed as spastic quadriplegia, an individual must show spastic symptoms (as opposed to athetotic, hypertonic, ataxic, or atonic symptoms) and it must be present in all four limbs (as opposed to hemiplegic, diplegic, or triplegic cases).

While a diagnosis may be able to be made shortly after birth based on family history and observation of the infant, it is often postponed until after the child is between 18–24 months old in order to monitor the possible regression or progression of symptoms.

Doublecortin positive cells, similar to stem cells, are extremely adaptable and, when extracted from a brain, cultured and then re-injected in a lesioned area of the same brain, they can help repair and rebuild it. The treatment using them would take some time to be available for general public use, as it has to clear regulations and trials.

The muscle spasticity can cause gait patterns to be awkward and jerky. The constant spastic state of the muscle can lead to bone and tendon deformation, further complicating the patient's mobility. Many patients with spastic hemiplegia are subjected to canes, walkers and even wheelchairs. Due to the decrease in weight bearing, patients are at a higher risk of developing osteoporosis. An unhealthy weight can further complicate mobility. Patients with spastic hemiplegia are a high risk for experiencing seizures. Oromotor dysfunction puts patients at risk for aspiration pneumonia. Visual field deficits can cause impaired two-point discrimination. Many patients experience the loss of sensation in the arms and legs on the affected side of the body. Nutrition is essential for the proper growth and development for a child with spastic hemiplegia.

Diagnosis of pseudobulbar palsy is based on observation of the symptoms of the condition. Tests examining jaw jerk and gag reflex can also be performed. It has been suggested that the majority of patients with pathological laughter and crying have pseudobulbar palsy due to bilateral corticobulbar lesions and often a bipyrimidal involvement of arms and legs. To further confirm the condition, MRI can be performed to define the areas of brain abnormality.

In any manifestation of spastic CP, clonus of the affected limb(s) may intermittently result, as well as muscle spasms, each of which results from the pain and/or stress of the tightness experienced, indicating especially hard-working and/or exhausted musculature. The spasticity itself can and usually does also lead to very early onset of muscle-stress symptoms like arthritis and tendinitis, especially in ambulatory individuals in their mid-20s and early-30s. As compared to other types of CP, however, and especially as compared to hypotonic CP or more general paralytic mobility disabilities, spastic CP is typically more easily manageable by the person affected, and medical treatment can be pursued on a multitude of orthopaedic and neurological fronts throughout life.

Physical therapy and occupational therapy regimens of assisted stretching, strengthening, functional tasks, and/or targeted physical activity and exercise are usually the chief ways to keep spastic CP well-managed, although if the spasticity is too much for the person to handle, other remedies may be considered, such as various antispasmodic medications, botox, baclofen, or even a neurosurgery known as a selective dorsal rhizotomy (which eliminates the spasticity by eliminating the nerves causing it).

MRI is often done to diagnose PSP. MRI may show atrophy in the midbrain with preservation of the pons giving a "hummingbird" sign appearance.

The prognosis for those with spastic muscles depends on multiple factors, including the severity of the spasticity and the associated movement disorder, access to specialised and intensive management, and ability of the affected individual to maintain the management plan (particularly an exercise program). Most people with a significant UMN lesion will have ongoing impairment, but most of these will be able to make progress. The most important factor to indicate ability to progress is seeing improvement, but improvement in many spastic movement disorders may not be seen until the affected individual receives help from a specialised team or health professional.

As previously noted, there are often few signs of white matter injury in newborns. Occasionally, physicians can make the initial observations of extreme stiffness or poor ability to suckle. The preliminary diagnosis of PVL is often made using imaging technologies. In most hospitals, premature infants are examined with ultrasound soon after birth to check for brain damage. Severe white matter injury can be seen with a head ultrasound; however, the low sensitivity of this technology allows for some white matter damage to be missed. Magnetic resonance imaging (MRI) is much more effective at identifying PVL, but it is unusual for preterm infants to receive an MRI unless they have had a particularly difficult course of development (including repeated or severe infection, or known hypoxic events during or immediately after birth). No agencies or regulatory bodies have established protocols or guidelines for screening of at-risk populations, so each hospital or doctor generally makes decisions regarding which patients should be screened with a more sensitive MRI instead of the basic head ultrasound.

PVL is overdiagnosed by neuroimaging studies and the other white matter lesions of the brain are underestimated. It is important to differentiate PVL from the following major white matter lesions in the cerebral hemispheres: edematous hemorrhagic leukoencephalopathy (OGL), telentsefalny gliosis (TG), diffuse leukomalacia (DFL), subcortical leukomalacia (SL), periventricular hemorrhagic infarction (PHI), intracerebral hemorrhage ( ICH), multicystic encephalomalacia (ME), subendymal pseudocyst. Diffuse white matter lesions of the cerebral hemispheres of the brain, accompanied by softening and spreading to the central and subcortical areas are more likely DFL, PHI and ME.

PBP is aggressive and relentless, and there were no treatments for the disease as of 2005. However, early detection of PBP is the optimal scenario in which doctors can map out a plan for management of the disease. This typically involves symptomatic treatments that are frequently used in many lower motor disorders.

Hereditary spastic paraplegias can be classified based on the symptoms; mode of inheritance; the patient’s age at onset; the affected genes; and biochemical pathways involved.

The incidence of cerebral palsy has increased in the past 40 years. It has been estimated that in the United States cerebral palsy occurs in 4 out every 1000 births. Of these births about 20–30% of them have spastic hemiplegia. Spasticity overall, is the more common type of cerebral palsy, whereas as non-spastic cerebral palsy is less common. Studies show that spastic type cerebral palsy is on the rise, and the occurrence of diplegia type is decreasing. The prevalence of cerebral palsy is higher in areas of low socioeconomic status. This could potentially be because cerebral palsy incidence increases as birth weight decreases.

Doublecortin positive cells, Similar to stem cells, are extremely adaptable and, when extracted from a brain, cultured and then re-injected in a lesioned area of the same brain, they can help repair and rebuild it. The treatment using them would take some time to be available for general public use, as it has to clear regulations and trials.

Because the causes of CP are varied, a broad range of preventative interventions have been investigated.

Electronic fetal monitoring has not helped to prevent CP, and in 2014 the American College of Obstetricians and Gynecologists, the Royal Australian and New Zealand College of Obstetricians and Gynaecologists, and the Society of Obstetricians and Gynaecologists of Canada have acknowledged that there are no long-term benefits of electronic fetal monitoring. Prior to this, electronic fetal monitoring was widely used to prop up obstetric litigation.

In those at risk of an early delivery, magnesium sulphate appears to decrease the risk of cerebral palsy. It is unclear if it helps those who are born at term. In those at high risk of preterm labor a review found that moderate to severe CP was reduced by the administration of magnesium sulphate, and that adverse effects on the babies from the magnesium sulphate were not significant. Mothers who received magnesium sulphate could experience side effects such as respiratory depression and nausea. Caffeine is used to treat apnea of prematurity and reduces the risk of cerebral palsy in premature babies, but there are also concerns of long term negative effects. A moderate level of evidence has been shown for giving women antibiotics during preterm labour when their waters had not broken was associated with an increased risk of cerebral palsy in the child. Additionally, allowing a preterm birth to proceed rather than trying to delay the birth also had a moderate level of evidence for increased risk of cerebral palsy in the child.

Cooling high-risk full-term babies shortly after birth may reduce disability, but this may only be useful for some forms of the brain damage that causes CP.

In the industrialized world, the incidence of overall cerebral palsy, which includes but is not limited to spastic diplegia, is about 2 per 1000 live births. Thus far, there is no known study recording the incidence of CP in the overall nonindustrialized world. Therefore, it is safe to assume that not all spastic CP individuals are known to science and medicine, especially in areas of the world where healthcare systems are less advanced. Many such individuals may simply live out their lives in their local communities without any medical or orthopedic oversight at all, or with extremely minimal such treatment, so that they are never able to be incorporated into any empirical data that orthopedic surgeons or neurosurgeons might seek to collect. It is shocking to note that—as with people with physical disability overall—some may even find themselves in situations of institutionalization, and thus barely see the outside world at all.

From what "is" known, the incidence of spastic diplegia is higher in males than in females; the Surveillance of Cerebral Palsy in Europe (SCPE), for example, reports a M:F ratio of 1.33:1. Variances in reported rates of incidence across different geographical areas in industrialized countries are thought to be caused primarily by discrepancies in the criteria used for inclusion and exclusion.

When such discrepancies are taken into account in comparing two or more registers of patients with cerebral palsy and also the extent to which children with mild cerebral palsy are included, the incidence rates still converge toward the average rate of 2:1000.

In the United States, approximately 10,000 infants and babies are born with CP each year, and 1200–1500 are diagnosed at preschool age when symptoms become more obvious. It is interesting to note that those with extremely mild spastic CP may not even be aware of their condition until much later in life: Internet chat forums have recorded men and women as old as 30 who were diagnosed only recently with their spastic CP.

Overall, advances in care of pregnant mothers and their babies has not resulted in a noticeable decrease in CP; in fact, because medical advances in areas related to the care of premature babies has resulted in a greater survival rate in recent years, it is actually "more" likely for infants with cerebral palsy to be born into the world now than it would have been in the past. Only the introduction of quality medical care to locations with less-than-adequate medical care has shown any decreases in the incidences of CP; the rest either have shown no change or have actually shown an increase. The incidence of CP increases with premature or very low-weight babies regardless of the quality of care.

Preventing or delaying premature birth is considered the most important step in decreasing the risk of PVL. Common methods for preventing a premature birth include self-care techniques (dietary and lifestyle decisions), bed rest, and prescribed anti-contraction medications. Avoiding premature birth allows the fetus to develop further, strengthening the systems affected during the development of PVL.

An emphasis on prenatal health and regular medical examinations of the mother can also notably decrease the risk of PVL. Prompt diagnosis and treatment of maternal infection during gestation reduces the likelihood of large inflammatory responses. Additionally, treatment of infection with steroids (especially in the 24–34 weeks of gestation) have been indicated in decreasing the risk of PVL.

It has also been suggested that avoiding maternal cocaine usage and any maternal-fetal blood flow alterations can decrease the risk of PVL. Episodes of hypotension or decreased blood flow to the infant can cause white matter damage.

As age increases, spasticity makes for more noticeable effects in bones and joints and muscle function. This is often mistakenly said to mean that "spasticity increases as people with spastic CP age", which is a misrepresentation of the knock-on effects of spasticity with age. The clinical reality is that spasticity intensities remain constant but an increasing age in to middle-adulthood and the early elder years self-evidently changes the body structure, body response times and body adaptiveness capabilities markedly, leading to very different interplays between the body's spasticity and the body itself as the body 'degrades' across the twilight years.

That being said, cerebral palsy, including spastic cerebral palsy, is notable for a glaring overall research deficiency—the fact that it is one of the very few "major" groups of conditions on the planet in human beings for which medical science has not yet (as of 2011) collected wide-ranging empirical data on the development and experiences of young adults, the middle aged and older adults. An especially puzzling aspect of this lies in the fact that cerebral palsy as defined by modern science was first "discovered" and specifically addressed well over 100 years ago and that it would therefore be reasonable to expect by now that at least some empirical data on the adult populations with these conditions would have long since been collected, especially over the second half of the 20th century when existing treatment technologies rapidly improved and new ones came into being. The vast majority of empirical data on the various forms of cerebral palsy is concerned near-exclusively with children (birth to about 10 years of age) and sometimes pre-teens and early teens (11–13). Some doctors attempt to provide their own personal justifications for keeping their CP specialities purely paediatric, but there is no objectively apparent set of reasons backed by any scientific consensus as to why medical science has made a point of researching adult cases of multiple sclerosis, muscular dystrophy and the various forms of cancer in young and older adults, but has failed to do so with CP.

Although HSP is a progressive condition, the prognosis for individuals with HSP varies greatly. It primarily affects the legs although there can be some upperbody involvement in some individuals. Some cases are seriously disabling while others are less disabling and are compatible with a productive and full life. The majority of individuals with HSP have a normal life expectancy.

Since pseudobulbar palsy is a syndrome associated with other diseases, treating the underlying disease may eventually reduce the symptoms of pseudobulbar palsy.

Possible pharmacological interventions for pseudobulbar affect include the tricyclic antidepressants, serotonin reuptake inhibitors, and a novel approach utilizing dextromethorphan and quinidine sulfate. Nuedexta is an FDA approved medication for pseudobulbar affect. Dextromethorphan, an N-methyl-D-aspartate receptor antagonist, inhibits glutamatergic transmission in the regions of the brainstem and cerebellum, which are hypothesized to be involved in pseudobulbar symptoms, and acts as a sigma ligand, binding to the sigma-1 receptors that mediate the emotional motor expression.

PSP is frequently misdiagnosed as Parkinson's disease because of the slowed movements and gait difficulty, or as Alzheimer's disease because of the behavioral changes. It is one of a number of diseases collectively referred to as Parkinson plus syndromes. A poor response to levodopa along with symmetrical onset can help differentiate this disease from PD. Also, patients with the Richardson variant tend to have an upright or arched-back posture as opposed to the stooped-forward posture of other Parkinsonian disorders, although PSP-Parkinsonism (see below) may show the stooped posture. Early falls are characteristic, especially with Richardson-syndrome.

As athetosis is relatively difficult to treat, efforts are being made to help those with the condition live and perform tasks more effectively and more efficiently. One such example of work that has been recently undertaken is a project to help those affected with athetosis to use a computer with more ease. Software for the control of the computer uses joysticks that perform linear filtering to aid in control.

An additional possible treatment option for those afflicted with the symptom is neurostimulation. Studies have begun, and in cerebral palsy patients affected with dystonia-choreoathetosis, it has been demonstrated that neurostimulation has been an effective treatment in lessening symptoms in patients. There has not been a tremendous amount of experimentation, though, in this as a possible treatment option.

There are several different treatment approaches to dealing with athetosis. The most common methods are the use of drugs, surgical intervention, and retraining movements of the afflicted person. It is suggested that training a person to relearn movements can be helpful in select situations. Though, generally, this type of treatment will not work, in certain cases it can be found to be very helpful in treating the symptom of athetosis.

Drugs can also be used in the treatment of athetosis, however their collective effectiveness is not very convincing. There is not a single drug that is a standard among treatment. Many different medicines can be used, including:

- Artane

- Cogentin

- Curare, though not practical due to respiratory paralysis

- Tetrabenazine

- Haloperidol

- Thiopropazate

- Diazepam

Most instances of drug use where the symptoms seem to be lessened tend to be in more mild cases of athetosis.

Treatment by surgical intervention can obviously have the most immediate impact, again however, it is not a cure-all. In patients that have cerebral palsy as the cause of their athetosis, it has been demonstrated that a subthalamotomy tends to help relieve the extent of athetosis in approximately half of patients. Additionally, late 19th and early 20th century surgical accounts state that athetosis can be relieved by the removal of a part of the cerebral motor cortex or by cutting a part of the posterior spinal roots. Patients who undergo surgical treatment to relieve the athetosis often see significant improvement in the control of their limbs and digits. While surgery is often very beneficial in the short term and can produce near immediate results, in the long term it has been seen that its effects are not incredibly long lasting.