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.

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.

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.

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.

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.

Clinical diagnosis is conducted on individuals with age onset between late teens and late forties who show the initial characteristics for the recessive autosomal cerebellar ataxia.

The following tests are performed:

- MRI brain screening for cerebellum atrophy.

- Molecular genetic testing for SYNE-1 sequence analysis.

- Electrophysiologic studies for polyneurotherapy

- Neurological examination

Prenatal diagnosis and preimplantation genetic diagnosis (PGD) can be performed to identify the mothers carrying the recessive genes for cerebellar ataxia.

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.

Different types of ataxia:

- congenital ataxias (developmental disorders)

- ataxias with metabolic disorders

- ataxias with a DNA repair defect

- degenerative ataxias

- ataxia associated with other features.

A diagnosis of Friedreich's ataxia requires a careful clinical examination, which includes a medical history and a thorough physical exam, in particular looking for balance difficulty, loss of proprioception, absence of reflexes, and signs of neurological problems. Genetic testing now provides a conclusive diagnosis. Other tests that may aid in the diagnosis or management of the disorder include:

- Electromyogram (EMG), which measures the electrical activity of muscle cells,

nerve conduction studies, which measure the speed with which nerves transmit impulses

- Electrocardiogram (ECG), which gives a graphic presentation of the electrical activity or beat pattern of the heart

- Echocardiogram, which records the position and motion of the heart muscle

- Blood tests to check for elevated glucose levels and vitamin E levels

- Magnetic resonance imaging (MRI) or computed tomography (CT) scans, tests which provide brain and spinal cord images that are useful for ruling out other neurological conditions

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).

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.

There is no known cure for cerebral palsy, however there is a large array of treatments proven effective at improving quality of life and relieving some of the symptoms associated with CP, especially SHCP. Some treatments are aimed at improving mobility, strengthening muscle and improving coordination. Although CP is due to permanent damage and is not progressive in nature, without treatment the symptoms can become worse, intensifying in pain and severity, and create complications that were not initially present. Some treatments are preventative measures to help prevent further complications, such as complete paralysis of the arm due to non-use and subsequent worsening hypertonia and joint contracture. Others forms of treatment are corrective in nature. Many treatments target symptoms that are indirectly related to or caused by the SHCP. Many of these treatments are common for other forms of CP as well. Treatment is individualized based on each case and the specific needs of the patient. Treatments are often combined with other forms of treatment and a long term treatment plan is created and continuously evaluated. Treatment can include the following:

- "Physical therapy" – Physical therapy is the most common form of treatment (source needed). It may include sensory stimulation, stretching, strengthening and positioning. Constraint-induced movement therapy is a newer form of physical therapy for SHCP that involves casting or splinting the unaffected arm to promote use of the affected arm (Taub). The theory behind constraint-induced movement therapy is that new neural pathways are created. Alternative forms of physical therapy include yoga and dance. Physical therapy may also include the use of braces while not actively involved with the therapist.

- "Occupational therapy" – Occupational therapy evaluates and treats patients through selected activities in order to enable people to function as effectively and independently as possible in daily life. Occupational therapy is geared toward the individual to achieve optimal results and performance while learning to cope with their disability.

- "Speech therapy" – Due to difficulties in speech, speech therapy is often necessary. Aside from helping with understanding language and increasing communication skills, speech therapists can also assist children that have difficulty eating and drinking.

- "Behavioral therapy" — Psychotherapy and counseling are heavily used in treatment of individuals with SHPD to help them cope emotionally with their needs and frustrations. Counseling through social work can be very beneficial for social issues and adjustments to society. Psychotherapy becomes a more important aspect of therapy when more serious issues such as depression become problematic. Play therapy is a common treatment for all young children with or without disabilities, but can be very useful helping children with SHCP. This therapy again is individualized geared to improve emotional and social development; reduce aggression; improve cooperation with others; assist a child in processing a traumatic event or prepare for an upcoming event such as surgery.

- "Surgery" – Although surgery may become necessary in some cases, physical therapy and the consistent use of braces can help mitigate the need for surgery. Surgical procedures are painful with long and difficult recoveries and do not cure the condition. Most common, is surgery that effectively lengthens the muscle. This type of surgery is usually performed on the legs, but can be performed on the arms as well. Surgeries also may be necessary to realign joints. Other, less popular surgical techniques try to reduce spasticity by severing selected overactive nerves that control muscles. This procedure, known as selective dorsal root rhizotomy, is still somewhat controversial, and is generally used only on the lower extremities of severe cases. Other experimental surgical techniques are also being investigated. The benefits of surgery can also be negated or reversed if the patient does not participate in physical therapy and braces (or casts) are not worn regularly.

- "Medicinal" – Medication targeting symptoms associated with spasticity is also a relatively new treatment that is utilized, but is still in the early stages of development. Drugs such as baclofen, benzodiazepines (e.g., diazepam), tizanidin, and sometimes dantrolene have shown promise in the effort to diminish spasticity. Botulinum toxin ("Botox") type A may reduce spasticity a few months at a time and has frequently been considered a beneficial treatment for children with SHCP and other forms of CP. Botox has been shown to be especially beneficial to reducing spasticity in the gastrocnemius (calf) muscle. This therapy can improve range of motion, reduce deformity, improve response to occupational and physical therapy, and delay the need for surgery. Botox injections have also shown advantages for upper extremities. There is still some doubt for the effectiveness, and some side effects to the relaxed muscles have been a loss of strength for patients with some muscle control. Casting, in conjunction with Botox injections may be an additional option for better results. Research is constantly investing in new improvements and more experimental therapy and treatment.

Treatment depends on diagnosing the specific pathology causing this symptom. Should it be caused by use of stimulants or other substances, then it may involve removing these drugs from use.

Recovery of hyperreflexia can occur between several hours to several months after a spinal cord injury; however, the phase of recovery is likely to occur in stages rather than on a continuum. The late stage can be defined as between two weeks and several months. Individuals with a severe spinal cord injury (SCI) mainly present with a later stage of recovery because during the early stages they present with spinal shock. Reflex and motor recovery can sometimes return simultaneously.

As a matter of everyday maintenance, muscle stretching, range of motion exercises, yoga, contact improvisation, modern dance, resistance training, and other physical activity regimens are often utilized by those with spastic CP to help prevent contractures and reduce the severity of symptoms.

Major clinical treatments for spastic diplegia are:

- Baclofen (and its derivatives), a gamma amino butyric acid (GABA) substitute in oral (pill-based) or intrathecal form. Baclofen is essentially chemically identical to the GABA that the damaged, over-firing nerves cannot absorb, except that it has an extra chemical 'marker' on it that makes the damaged nerves 'think' it is a different compound, and thus those nerves will absorb it. Baclofen is noted for being the sole medication available for GABA-deficiency-based spasticity which acts on the actual cause of the spasticity rather than simply reducing symptomatology as muscle relaxants and painkillers do. The intrathecal solution is a liquid injected into the spinal fluid for trial, and if successful in reducing spasticity, thereafter administered via an intrathecal pump, which has variously been proven potentially very dangerous on one or another level with long-term use (see article), including sudden and potentially lethal baclofen overdose, whereas the oral route, which comes in 10- or 20-milligram tablets and the dosage of which can be gently titrated either upward or downward, as well as safely ceased entirely, has not.

- Antispasmodic muscle relaxant chemicals such as tizanidine and botulinum toxin (Botox), injected directly into the spastic muscles; Botox wears off every three months.

- Phenol and similar chemical 'nerve deadeners', injected selectively into the over-firing nerves in the legs on the muscle end to reduce spasticity in their corresponding muscles by preventing the spasticity signals from reaching the legs; Phenol wears off every six months.

- Orthopedic surgery to release the spastic muscles from their hypertonic state, a usually temporary result because the spasticity source is the nerves, not the muscles; spasticity can fully reassert itself as little as one year post-surgery.

- Selective dorsal rhizotomy, a neurosurgery directly targeting and eliminating ("cutting" or "lesioning") the over-firing nerve rootlets and leaving the properly firing ones intact, thereby permanently eliminating the spasticity but compelling the person to spend months re-strengthening muscles that will have been severely weakened by the loss of the spasticity, due to the fact of those muscles not really having had actual strength to begin with.

Recent research indicates that the biomolecule taurine may be effective for hypertonia, perhaps through its benzodiazepine-like modulation of the inhibitory neurotransmitter GABA or the neuromuscular effects of increasing intracellular calcium levels.

Baclofen, diazepam and dantrolene remain the three most commonly used pharmacologic agents in the treatment of spastic hypertonia. Baclofen is generally the drug of choice for spinal cord types of spasticity, while sodium dantrolene is the only agent which acts directly on muscle tissue. Tizanidine is also available. Phenytoin with chlorpromazine may be potentially useful if sedation does not limit their use. Ketazolam, not yet available in the United States, may be a significant addition to the pharmacologic armamentarium. Intrathecal administration of antispastic medications allows for high concentrations of drug near the site of action, which limits side effects.

In some cases, spastic cerebral palsy is caused by genetic factors.

The genetic factors for spastic cerebral palsy include:

Although it has its origins in a brain injury, spastic CP can largely be thought of as a collection of orthopaedic and neuromuscular issues because of how it manifests symptomatically over the course of the person's lifespan. It is therefore not the same as "brain damage" and it need not be thought of as such. Spastic quadriplegia in particular, especially if it is combined with verbal speech challenges and strabismus, may be misinterpreted by the general population as alluding to cognitive dimensions to the disability atop the physical ones, but this is false; the intelligence of a person with any type of spastic CP is unaffected by the condition "of the spasticity itself".

In spastic cerebral palsy in children with low birth weights, 25% of children had hemiplegia, 37.5% had quadriplegia, and 37.5% had diplegia.

There are two types of normal pressure hydrocephalus: idiopathic and secondary. The secondary type of NPH can be due to a subarachnoid hemorrhage, head trauma, tumor, infection in the central nervous system, or a complication of cranial surgery.

Diagnosis consists of a variety of tests, including but not limited to:

- Measurement of orthostatic blood pressure

- Coordination

- rapid, alternating movements

- stroking of heel from along the opposite shin from knee to ankle

- finger-to-nose testing.

- Primary sensory modalities are examined with the following methods, searching for focal sensory loss, graded distal sensory loss, or levels of decreased sensation, hyperesthesia or dysesthesia.

- light touch

- pin-prick

- temperature

- position

- vibration

- Focused gait examination, which examines stationary position and walking abnormalities. Walking generally exposes any faults within the complex neurological communication between systems as weight is shifted from one foot to the other.

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

Diagnosis of NPH is usually first led by brain imaging, either CT or MRI, to rule out any mass lesions in the brain. This is then followed by lumbar puncture and evaluation of clinical response to removal of CSF. This can be followed by continuous external lumbar CSF drainage during 3 or 4 days.

- CT scan may show enlarged ventricles without convolutional atrophy.

- MRI may show some degree of transependymal migration of CSF surrounding the ventricles on T2/FLAIR sequence. Imaging however cannot differentiate between pathologies with similar clinical picture like Alzheimer's dementia, vascular dementia or Parkinson's disease.

- Following imaging, lumbar puncture is usually the first step in diagnosis and the CSF opening pressure is measured carefully. In most cases, CSF pressure is usually above 155 mmHO. Clinical improvement after removal of CSF (30 mL or more) has a high predictive value for subsequent success with shunting. This is called the "lumbar tap test" or Miller Fisher test. On the contrary, a "negative" test has a very low predictive accuracy, as many patients may improve after a shunt in spite of lack of improvement after CSF removal.

- Infusion test is a test that may have higher sensitivity and specificity than a lumbar puncture, but is not performed in most centers. The outflow conductance (Cout) of the cerebrospinal fluid (CSF) system is a parameter considered by some centers to be predictive in selection for hydrocephalus surgery. Cout can be determined through an infusion test. This is not a test that is normally performed prior to shunting, but may become more accepted.

- In some centers, External lumbar drainage has been shown to have the highest sensitivity and specificity with regards to predicting a successful outcome following surgery.