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.

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.

Once the diagnosis of polymicrogyria has been established in an individual, the following approach can be used for discussion of prognosis:

A pregnancy history should be sought, with particular regard to infections, trauma, multiple gestations, and other documented problems. Screening for the common congenital infections associated with polymicrogyria with standard TORCH testing may be appropriate. Other specific tests targeting individual neurometabolic disorders can be obtained if clinically suggested.

The following may help in determining a genetic etiology:

Family history

It is important to ask for the presence of neurologic problems in family members, including seizures, cognitive delay, motor impairment, pseudobulbar signs, and focal weakness because many affected family members, particularly those who are older, may not have had MRI performed, even if these problems came to medical attention. In addition, although most individuals with polymicrogyria do present with neurologic difficulties in infancy, childhood, or adulthood, those with mild forms may have no obvious deficit or only minor manifestations, such as a simple lisp or isolated learning disability. Therefore, if a familial polymicrogyria syndrome is suspected, it may be reasonable to perform MRI on relatives who are asymptomatic or have what appear to be minor findings. The presence of consanguinity in a child's parents may suggest an autosomal recessive familial polymicrogyria syndrome.

Physical examination

A general physical examination of the proband may identify associated craniofacial, musculoskeletal, or visceral malformations that could indicate a particular syndrome. Neurologic examination should assess cognitive and mental abilities, cranial nerve function, motor function, deep tendon reflexes, sensory function, coordination, and gait (if appropriate).

Genetic testing

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.

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.

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

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.

Parents of a proband

- The parents of an affected individual are obligate heterozygotes and therefore carry one mutant allele.

- Heterozygotes (carriers) are asymptomatic.

Sibs of a proband

- At conception, each sibling of an affected individual has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier.

- Once an at-risk sibling is known to be unaffected, the risk of his/her being a carrier is 2/3.

- Heterozygotes (carriers) are asymptomatic.

Offspring of a proband

- Offspring of a proband are obligate heterozygotes and will therefore carry one mutant allele.

- In populations with a high rate of consanguinity, the offspring of a person with GPR56-related BFPP and a reproductive partner who is a carrier of GPR56-related BFPP have a 50% chance of inheriting two GPR56 disease-causing alleles and having BFPP and a 50% chance of being carriers.

Other family members of a proband.

- Each sibling of the proband's parents is at a 50% risk of being a carrier

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.

Among the methods of diagnosing tropical spastic paraparesis are MRI (magnetic resonance imaging) and lumbar puncture (which may show lymphocytosis).

Pathologically, PMG is defined as “an abnormally thick cortex formed by the piling upon each other of many small gyri with a fused surface.” To view these microscopic characteristics, magnetic resonance imaging (MRI) is used. First physicians must distinguish between polymicrogyria and pachygyria. Pachygria leads to the development of broad and flat regions in the cortical area, whereas the effect of PMG is the formation of multiple small gyri. Underneath a computerized tomography (CT scan) scan, these both appear similar in that the cerebral cortex appears thickened. However, MRI with a T1 weighted inversion recovery will illustrate the gray-white junction that is characterized by patients with PMG. An MRI is also usually preferred over the CT scan because it has sub-millimeter resolution. The resolution displays the multiple folds within the cortical area, which is continuous with the neuropathology of an infected patient.

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.

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.

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.

Progressive Bulbar Palsy is slow in onset, with symptoms starting in most patients around 50–70 years of age. PBP has a life expectancy typically between 6 months and 3 years from onset of first symptoms. It is subtype of the Motor Neurone Diseases (MND) accounting for around 1 in 4 cases. Amyotrophic lateral sclerosis (ALS) is another sub-type. Pure PBP without any EMG or clinical evidence of abnormalities in the legs or arms is possible, albeit extremely rare. Moreover, about twenty-five percent of patients with PBP eventually develop the widespread symptoms common to ALS.

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 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.

Delayed diagnosis of cervical spine injury has grave consequences for the victim. About one in 20 cervical fractures are missed and about two-thirds of these patients have further spinal-cord damage as a result. About 30% of cases of delayed diagnosis of cervical spine injury develop permanent neurological deficits. In high-level cervical injuries, total paralysis from the neck can result. High-level tetraplegics (C4 and higher) will likely need constant care and assistance in activities of daily living, such as getting dressed, eating and bowel and bladder care. Low-level tetraplegics (C5 to C7) can often live independently.

Even with "complete" injuries, in some rare cases, through intensive rehabilitation, slight movement can be regained through "rewiring" neural connections, as in the case of the late actor Christopher Reeve.

In the case of cerebral palsy, which is caused by damage to the motor cortex either before, during (10%), or after birth, some people with tetraplegia are gradually able to learn to stand or walk through physical therapy.

Quadriplegics can improve muscle strength by performing resistance training at least three times per week. Combining resistance training with proper nutrition intake can greatly reduce co-morbidities such as obesity and type 2 diabetes.

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).

The prognosis for Tropical spastic paraparesis indicates some improvement in a percentage of cases due to immunosuppressive treatment. A higher percentage will eventually lose the ability to walk within a ten-year interval.

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.

Incomplete spinal cord injuries result in varied post injury presentations. There are three main syndromes described, depending on the exact site and extent of the lesion.

1. The central cord syndrome: most of the cord lesion is in the gray matter of the spinal cord, sometimes the lesion continues in the white matter.

2. The Brown–Séquard syndrome: hemi section of the spinal cord.

3. The anterior cord syndrome: a lesion of the anterior horns and the anterolateral tracts, with a possible division of the anterior spinal artery.

For most patients with ASIA A (complete) tetraplegia, ASIA B (incomplete) tetraplegia and ASIA C (incomplete) tetraplegia, the International Classification level of the patient can be established without great difficulty. The surgical procedures according to the International Classification level can be performed. In contrast, for patients with ASIA D (incomplete) tetraplegia it is difficult to assign an International Classification other than International Classification level X (others). Therefore, it is more difficult to decide which surgical procedures should be performed. A far more personalized approach is needed for these patients. Decisions must be based more on experience than on texts or journals.

The results of tendon transfers for patients with complete injuries are predictable. On the other hand, it is well known that muscles lacking normal excitation perform unreliably after surgical tendon transfers. Despite the unpredictable aspect in incomplete lesions tendon transfers may be useful. The surgeon should be confident that the muscle to be transferred has enough power and is under good voluntary control. Pre-operative assessment is more difficult to assess in incomplete lesions.

Patients with an incomplete lesion also often need therapy or surgery before the procedure to restore function to correct the consequences of the injury. These consequences are hypertonicity/spasticity, contractures, painful hyperesthesias and paralyzed proximal upper limb muscles with distal muscle sparing. Spasticity is a frequent consequence of incomplete injuries. Spasticity often decreases function, but sometimes a patient can control the spasticity in a way that it is useful to their function. The location and the effect of the spasticity should be analyzed carefully before treatment is planned. An injection of Botulinum toxin (Botox) into spastic muscles is a treatment to reduce spasticity. This can be used to prevent muscle shorting and early contractures.

Over the last ten years an increase in traumatic incomplete lesions is seen, due to the better protection in traffic.

Gross examination exposes a pattern of many small gyri clumped together, which causes an irregularity in the brain surface. The cerebral cortex, which in normal patients is six cell layers thick, is also thinned. As mentioned prior, the MRI of an infected patient shows what appears to be a thickening of the cerebral cortex because of the tiny folds that aggregate causing a more dense appearance. However gross analysis shows an infected patient can have as few as one to all six of these layers missing.

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.