Definition of Cerebral Palsy
Cerebral palsy (CP) is an umbrella term denoting a group of non-progressive, non-contagious motor conditions that cause physical disability in human development, chiefly in the various areas of body movement. Scientific consensus still holds that CP is neither genetic nor a disease, and it is also understood that the vast majority of cases are congenital, coming at or about the time of birth, and/or are diagnosed at a very young age rather than during adolescence or adulthood. It can be defined as a central motor dysfunction affecting muscle tone, posture and movement resulting from a permanent, non-progressive defect or lesion of the immature brain.
Cerebral refers to the cerebrum, which is the affected area of the brain. The disorder may often involve connections between the cortex and other parts of the brain such as the cerebellum. The term palsy in modern parlance refers to disorder of movement, but the word root “palsy” does still technically mean “paralysis” today, even though it is not used as such within the meaning of cerebral palsy.
Cerebral palsy is caused by damage to the motor control centers of the developing brain and can occur during pregnancy, during childbirth, or after birth up to about age three. Resulting limits in movement and posture cause activity limitation and are often accompanied by disturbances of sensation, depth perception, and other sight-based perceptual problems and communication ability; impairments can also be found in cognition, and epilepsy is found in about one-third of cases. CP, no matter what the type, is often accompanied by secondary musculoskeletal problems that arise as a result of the underlying disorder. Cerebral palsy’s nature as a broad category means it is defined mostly via several different subtypes, especially the type featuring spasticity, and also mixtures of those subtypes.
Improvements in the care of newborns has helped reduce the number of babies who develop cerebral palsy and increased the survival those with very low birth weights. There is no known cure, with medical interventions attempting to treat and prevent complications.
Causes of Cerebral Palsy
While in certain cases there is no identifiable cause, typical causes include problems in intrauterine development (e.g. exposure to radiation, infection), asphyxia before birth, hypoxia of the brain, and birth trauma during labour and delivery, and complications in the perinatal period or during childhood. CP is also more common in multiple births.
Between 40% and 50% of all children who develop cerebral palsy were born prematurely. Premature infants are vulnerable, in part because their organs are not fully developed, increasing the risk of hypoxic injury to the brain that may manifest as CP. A problem in interpreting this is the difficulty in differentiating between cerebral palsy caused by damage to the brain that results from inadequate oxygenation and CP that arises from prenatal brain damage that then precipitates premature delivery.
Recent research has demonstrated that intrapartum asphyxia is not the most important cause, probably accounting for no more than 10% of all cases; rather, infections in the mother, even infections that are not easily detected, may triple the risk of the child developing the disorder, mainly as the result of the toxicity to the fetal brain of cytokines that are produced as part of the inflammatory response. Low birthweight is a risk factor for CP – and premature infants usually have low birth weights, less than 2.0 kg, but full-term infants can also have low birth weights. Multiple-birth infants are also more likely than single-birth infants to be born early or with a low birth weight.
After birth, other causes include toxins, severe jaundice, lead poisoning, physical brain injury, shaken baby syndrome, incidents involving hypoxia to the brain (such as near drowning), and encephalitis or meningitis. The three most common causes of asphyxia in the young child are: choking on foreign objects such as toys and pieces of food, poisoning, and near drowning.
Some structural brain anomalies such as lissencephaly may present with the clinical features of CP, although whether that could be considered CP is a matter of opinion (some people say CP must be due to brain damage, whereas people with these anomalies didn’t have a normal brain). Often this goes along with rare chromosome disorders and CP is not genetic or hereditary.
It has been hypothesised that many cases of cerebral palsy are caused by the death in very early pregnancy of an identical twin.
Signs and Symptoms of Cerebral Palsy
All types of cerebral palsy are characterized by abnormal muscle tone (e.g., slouching over while sitting), reflexes, or motor development and coordination. There can be joint and bone deformities and contractures (permanently fixed, tight muscles and joints). The classical symptoms are spasticities, spasms, other involuntary movements (e.g., facial gestures), unsteady gait, problems with balance, and/or soft tissue findings consisting largely of decreased muscle mass. Scissor walking (where the knees come in and cross) and toe walking (which can contribute to a gait reminiscent of a marionette) are common among people with CP who are able to walk, but taken on the whole, CP symptomatology is very diverse. The effects of cerebral palsy fall on a continuum of motor dysfunction, which may range from slight clumsiness at the mild end of the spectrum to impairments so severe that they render coordinated movement virtually impossible at the other end of the spectrum.
Babies born with severe CP often have an irregular posture; their bodies may be either very floppy or very stiff. Birth defects, such as spinal curvature, a small jawbone, or a small head sometimes occur along with CP. Symptoms may appear or change as a child gets older. Some babies born with CP do not show obvious signs right away. Classically, CP becomes evident when the baby reaches the developmental stage at 61⁄2 to 9 months and is starting to mobilise, where preferential use of limbs, asymmetry, or gross motor developmental delay is seen.
Secondary conditions can include seizures, epilepsy, apraxia, dysarthria or other communication disorders, eating problems, sensory impairments, intellectual disability, learning disabilities, urinary incontinence, fecal incontinence, and/or behavioural disorders.
Speech and language disorders are common in people with cerebral palsy. The incidence of dysarthria is estimated to range from 31% to 88%. Speech problems are associated with poor respiratory control, laryngeal and velopharyngeal dysfunction, and oral articulation disorders that are due to restricted movement in the oral-facial muscles. There are three major types of dysarthria in cerebral palsy: spastic, dyskinetic (athetosis), and ataxic.
Speech impairments in spastic dysarthria involve four major abnormalities of voluntary movement: spasticity, weakness, limited range of motion, and slowness of movement. Speech mechanism impairment in athetosis involves a disorder in the regulation of breathing patterns, laryngeal dysfunction (monopitch, low, weak, and breathy voice quality). It is also associated with articulatory dysfunction (large range of jaw movements), inappropriate positioning of the tongue, and instability of velar elevation. Athetoid dysarthria is caused by disruption of the internal sensorimotor feedback system for appropriate motor commands, which leads to the generation of faulty movements that are perceived by others as involuntary. Ataxic dysarthria is uncommon in cerebral palsy. The speech characteristics are imprecise consonants, irregular articulatory breakdown, distorted vowels, excess and equal stress, prolonged phonemes, slow rate, monopitch, monoloudness, and harsh voice. Overall language delay is associated with problems of intellectual disability, hearing impairment, and learned helplessness. Children with cerebral palsy are at risk of learned helplessness and becoming passive communicators, initiating little communication. Early intervention with this clientele, and their parents, often targets situations in which children communicate with others so that they learn that they can control people and objects in their environment through this communication, including making choices, decisions, and mistakes.
In order for bones to attain their normal shape and size, they require the stresses from normal musculature. Osseous findings will therefore mirror the specific muscular deficits in a given person with CP. The shafts of the bones are often thin (gracile) and become thinner during growth. When compared to these thin shafts (diaphyses), the centres (metaphyses) often appear quite enlarged (ballooning). With lack of use, articular cartilage may atrophy, leading to narrowed joint spaces. Depending on the degree of spasticity, a person with CP may exhibit a variety of angular joint deformities. Because vertebral bodies need vertical gravitational loading forces to develop properly, spasticity and an abnormal gait can hinder proper and/or full bone and skeletal development. People with CP tend to be shorter in height than the average person because their bones are not allowed to grow to their full potential. Sometimes bones grow to different lengths, so the person may have one leg longer than the other.
Pain and sleep disorders
Pain is common and may result from the inherent deficits associated with the condition, along with the numerous procedures children typically face. Pain is associated with tight and/or shortened muscles, abnormal posture, stiff joints, unsuitable orthosis, etc. There is also a high likelihood of chronic sleep disorders secondary to both physical and environmental factors.
Risk Factors for Cerebral Palsy
During pregnancy, cytokines cause inflammation, which can lead to brain damage in the baby. Fever in the mother during pregnancy or delivery also can cause this problem. Viral infections such as chickenpox, rubella (german measles), and cytomegalovirus (CMV), and bacterial infections such as infections of the placenta or fetal membranes, or maternal pelvic infections increase the risk of Cerebral Palsy.
Illnesses in a newborn baby such as bacterial meningitis, viral encephalitis, and severe or untreated jaundice increase the risk of Cerebral Palsy.
Premature birth, low birth weight, breech, multiple babies increase the risk, also.
Diagnosis of Cerebral Palsy
The diagnosis of cerebral palsy has historically rested on the patient’s history and physical examination. Once diagnosed with cerebral palsy, further diagnostic tests are optional. Neuroimaging with CT or MRI is warranted when the etiology of a patient’s cerebral palsy has not been established – an MRI is preferred over CT due to diagnostic yield and safety. When abnormal, the neuroimaging study can suggest the timing of the initial damage. The CT or MRI is also capable of revealing treatable conditions, such as hydrocephalus, porencephaly, arteriovenous malformation, subdural hematomas and hygromas, and a vermian tumour (which a few studies suggest are present 5–22% of the time).
Furthermore, an abnormal neuroimaging study indicates a high likelihood of associated conditions, such as epilepsy and intellectual disability.
The diagnosis of cerebral palsy can sometimes be made shortly after birth, but is often postponed until the child is 18–24 months of age, in order to evaluate the functional status and the progression or regression of the symptoms.
Cerebral palsy (CP) is divided into four major classifications to describe different movement impairments. These classifications also reflect the areas of the brain that are damaged. The four major classifications are: spastic, ataxic, athetoid/dyskinetic and mixed.
Spastic cerebral palsy, or cerebral palsy where spasticity (muscle tightness) is the exclusive or almost-exclusive impairment present, is by far the most common type of overall cerebral palsy, occurring in upwards of 70% of all cases. People with this type of CP are hypertonic and have what is essentially a neuromuscular mobility impairment (rather than hypotonia or paralysis) stemming from an upper motor neuron lesion in the brain as well as the corticospinal tract or the motor cortex. This damage impairs the ability of some nerve receptors in the spine to properly receive gamma-Aminobutyric acid, leading to hypertonia in the muscles signaled by those damaged nerves.
As compared to other types of CP, and especially as compared to hypotonic or paralytic mobility disabilities, spastic CP is typically more easily manageable by the person affected, and medical treatment can be pursued on a multitude of orthopedic and neurological fronts throughout life. In any form of spastic CP, clonus of the affected limb(s) may sometimes result, as well as muscle spasms resulting from the pain and/or stress of the tightness experienced. The spasticity 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. Occupational therapy and physical 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).
Ataxia-type symptoms can be caused by damage to the cerebellum. Ataxia is a less common type of cerebral palsy, occurring between 5% and 10% of all cases. Some of these individuals have hypotonia and tremors. Motor skills such as writing, typing, or using scissors might be affected, as well as balance, especially while walking. It is common for individuals to have difficulty with visual and/or auditory processing. They usually have an awkward gait and as well with some dysarthria.
Athetoid cerebral palsy or dyskinetic cerebral palsy is mixed muscle tone – both hypertonia and hypotonia mixed with involuntary motions. People with dyskinetic CP have trouble holding themselves in an upright, steady position for sitting or walking, and often show involuntary motions. For some people with dyskinetic CP, it takes a lot of work and concentration to get their hand to a certain spot (like scratching their nose or reaching for a cup). Because of their mixed tone and trouble keeping a position, they may not be able to hold onto objects, especially small ones requiring fine motor control (such as a toothbrush or pencil). About 10% of individuals with CP are classified as dyskinetic CP but some have mixed forms with spasticity and dyskinesia. The damage occurs to the extrapyramidal motor system and/or pyramidal tract and to the basal ganglia. In newborn infants, high bilirubin levels in the blood, if left untreated, can lead to brain damage in the basal ganglia (kernicterus), which can lead to dyskinetic cerebral palsy.
Mixed cerebral palsy is symptoms of athetoid, ataxic and spastic CP appearing simultaneously, each to varying degrees, and both with and without certain symptoms of each. Mixed CP is the most difficult to treat as it is extremely heterogeneous and sometimes unpredictable in its symptoms and development over the lifespan.
Prevention from Cerebral Palsy
There is no way to prevent CP related to genetics. However, there are some steps people can take to reduce the risk of the developmet problems of babies including CP before and during pregnancy, as well as after birth.
- Get vaccinated for diseases such as rubella may prevent an infection that could cause fetal brain damage before pragnancy and control your health conditions.
- During pregnancy, avoid any infection that might harm your developing baby by controling your health
- A flu shot protect you against serious illness from the flu.
- Talk to your doctor if there is a difference in the blood type or Rh incompatibility between you and your baby.
- See your doctor regularly to prevent premature birth, low birth weight.
- After pregnancy, protect your baby from injuries and get it vaccinated to protect from infections.
Treatment of Cerebral Palsy
Treatment for cerebral palsy is a lifelong multi-dimensional process focused on the maintenance of associated conditions. In order to be diagnosed with cerebral palsy the damage that occurred to the brain must be non-progressive and not disease-like in nature. The manifestation of that damage will change as the brain and body develop, but the actual damage to the brain will not increase. Treatment in the life of cerebral palsy is the constant focus on preventing the damage in the brain from prohibiting healthy development on all levels. The brain, up to about the age of 8, is not concrete in its development. It has the ability to reorganise and reroute many signal paths that may have been affected by the initial trauma; the earlier it has help in doing this the more successful it will be.
Various forms of therapy are available to people living with cerebral palsy as well as caregivers and parents caring for someone with this disability. They can all be useful at all stages of this disability and are vital in a person with cerebral palsy’s ability to function and live more effectively. In general, the earlier treatment begins the better chance children have of overcoming developmental disabilities or learning new ways to accomplish the tasks that challenge them. The earliest proven intervention occurs during the infant’s recovery in the neonatal intensive care unit (NICU). Treatment may include one or more of the following: physical therapy; occupational therapy; speech therapy; water therapy; drugs to control seizures, alleviate pain, or relax muscle spasms (e.g. benzodiazepines, baclofen and intrathecal phenol/baclofen); hyperbaric oxygen; the use of Botox to relax contracting muscles; surgery to correct anatomical abnormalities or release tight muscles; braces and other orthotic devices; rolling walkers; and communication aids such as computers with attached voice synthesisers. For instance, the use of a standing frame can help reduce spasticity and improve range of motion for people with CP who use wheelchairs.
However, there is only some benefit from therapy. Treatment is usually symptomatic and focuses on helping the person to develop as many motor skills as possible or to learn how to compensate for the lack of them. Non-speaking people with CP are often successful availing themselves of augmentative and alternative communication systems such as Blissymbols. Constraint-induced movement therapy (CIMT) has shown promising evidence in helping individuals with neurological disorders that have lost most of the use of an extremity. Research has proven the positive benefits of CIMT for people who have had a stroke and traumatic brain injury. However, later studies have addressed the application of CIMT for children with CP challenged with hemiparesis, that show a significant benefit in constraint-induced movement therapy for children with cerebral palsy who are challenged with hemiparesis.
Physiotherapy programs are designed to encourage the patient to build a strength base for improved gait and volitional movement, together with stretching programs to limit contractures. Many experts believe that lifelong physiotherapy is crucial to maintain muscle tone, bone structure, and prevent dislocation of the joints.
Occupational therapy helps adults and children maximise their function, adapt to their limitations and live as independently as possible.
Speech therapy helps control the muscles of the mouth and jaw, and helps improve communication. Just as CP can affect the way a person moves their arms and legs, it can also affect the way they move their mouth, face and head. This can make it hard for the person to breathe; talk clearly; and bite, chew and swallow food. Speech therapy often starts before a child begins school and continues throughout the school years.
Conductive education (CE) is a unified system of rehabilitation for people with neurological disorders including cerebral palsy, Parkinson’s disease and multiple sclerosis, amongst other conditions. It is theorised to improve mobility, self-esteem, stamina and independence as well as daily living skills and social skills. The conductor is the professional who delivers CE in partnership with parents and children. Skills learned during CE should be applied to everyday life and can help to develop age-appropriate cognitive, social and emotional skills. It is available at specialised centres.
Biofeedback is a therapy in which people learn how to control their affected muscles. Biofeedback therapy has been found to significantly improve gait in children with cerebral palsy.
Patterning is a controversial form of alternative therapy for people with CP. The IAHP’s methods have been endorsed by Linus Pauling, as well as some parents of children treated with their methods.
Massage therapy is designed to help relax tense muscles, strengthen muscles, and keep joints flexible. More research is needed to determine the health benefits of these therapies for people with CP.
Occupational therapy (OT) enables individuals with CP to participate in activities of daily living that are meaningful to them. A family-centred philosophy is used with children who have CP. Occupational therapists work closely with families in order to address their concerns and priorities for their child. Occupational therapists may address issues relating to sensory, cognitive, or motor impairments resulting from CP that affect the child’s participation in self-care, productivity, or leisure. Parent counselling is also an important aspect of occupational therapy treatment with regard to optimising the parent’s skills in caring for and playing with their child to support improvement of their child’s abilities to do things. The occupational therapist typically assesses the child to identify abilities and difficulties, and environmental conditions, such as physical and cultural influences, that affect participation in daily activities. Occupational therapists may also recommend changes to the play space, changes to the structure of the room or building, and seating and positioning techniques to allow the child to play and learn effectively.
Botulinum toxin injections are given into muscles that are spastic or sometimes dystonic, the aim being to reduce the muscle hypertonus that can be painful. A reduction in muscle tone can also facilitate bracing and the use of orthotics. Most often lower extremity muscles are injected. Botulinum toxin is focal treatment, meaning that a limited number of muscles can be injected at the same time. The effect of the toxin is reversible and a reinjection is needed every 4–6 months.
Surgery usually involves one or a combination of:
Loosening tight muscles and releasing fixed joints, most often performed on the hips, knees, hamstrings, and ankles. In rare cases, this surgery may be used for people with stiffness of their elbows, wrists, hands, and fingers. Selective Percutaneous Myofascial Lengthening (SPML) is one example.
The insertion of a baclofen pump usually during the stages while a patient is a young adult. This is usually placed in the left abdomen. It is a pump that is connected to the spinal cord, whereby it sends bits of Baclofen alleviating the continuous muscle flexion. Baclofen is a muscle relaxant and is often given by mouth to patients to help counter the effects of spasticity.
Straightening abnormal twists of the leg bones, i.e. femur (termed femoral anteversion or antetorsion) and tibia (tibial torsion). This is a secondary complication caused by the spastic muscles generating abnormal forces on the bones, and often results in intoeing (pigeon-toed gait). The surgery is called derotation osteotomy, in which the bone is broken (cut) and then set in the correct alignment.
Cutting nerves on the limbs most affected by movements and spasms. This procedure, called a rhizotomy (“rhizo” meaning root and “tomy” meaning “a cutting of” from the Greek suffix tomia), reduces spasms and allows more flexibility and control of the affected limbs and joints.
Orthotic devices such as ankle-foot orthoses (AFOs) are often prescribed to achieve the following objectives: correct and/or prevent deformity, provide a base of support, facilitate training in skills, and improve the efficiency of gait.
The available evidence suggests that orthoses can have positive effects on all temporal and spatial parameters of gait, i.e. velocity, cadence, step length, stride length, single and double support. AFOs have also been found to reduce energy expenditure.
Cooling high-risk full-term babies shortly after birth may reduce disability.
Hyperbaric oxygen therapy (HBOT), in which pressurised oxygen is inhaled inside a hyperbaric chamber, has been studied under the theory that improving oxygen availability to damaged brain cells can reactivate some of them to function normally. However, HBOT results in no significant difference from that of pressurised room air, and some children undergoing HBOT may experience adverse events such as seizures and the need for ear pressure equalisation tubes.