Cerebral palsy | |
Cerebral palsy (CP) is an umbrella term encompassing a group of non-progressive, non-contagious conditions that cause physical disability in human development.
Cerebral refers to the cerebrum, which is the affected area of the brain (although the disorder most likely involves connections between the cortex and other parts of the brain such as the cerebellum), and palsy refers to disorder of movement. CP is caused by damage to the motor control centers of the young developing brain and can occur during pregnancy (about 75 percent), during childbirth (about 5 percent) or after birth (about 15 percent) up to about age three.
It is a non-progressive disorder, meaning the brain damage does not worsen, but secondary orthopedic difficulties are common. There is no known cure for CP. Medical intervention is limited to the treatment and prevention of complications arising from CP's effects.
Onset of arthritis and osteoporosis can occur much sooner in adults with cerebral palsy. Further research is needed on adults with CP, as the current literature body is highly focused on the pediatric patient. CP's resultant motor disorder(s) are sometimes, though not always, accompanied by "disturbances of sensation, cognition, communication, perception, and/or behavior, and/or by a seizure disorder".
A 2003 study put the economic cost for CP suffers in the US at $921,000 per case, including lost income. In another study, the incidence in six countries surveyed was 2.12–2.45 per 1000 live births; there has been a slight increase in recent years. Although improvements in neonatal nursing help reduce the number of babies who develop cerebral palsy, they also mean that babies with very low birth weights survive, and these babies are more likely to have cerebral palsy.
Classification
CP is divided into four major classifications to describe the different movement impairments. These classifications reflect the area of brain damaged. The four major classifications are:
- Spastic
- Athetoid/Dyskinetic
- Ataxic
- Mixed
In 30 percent of all cases of CP, the spastic form is found along with one of the other types. There are a number of other, less prevalent types of CP, but these are the most common.
A general classification is as follows:
Spastic
Spastic cerebral palsy is by far the most common type, occurring in 70% to 80% of all cases. People with this type are hypertonic and have a neuromuscular condition stemming from damage to the corticospinal tract or the motor cortex that affects the nervous system's ability to receive gamma amino butyric acid in the area(s) affected by the disability . Spastic CP is further classified by topography dependent on the region of the body affected; these include:
- Spastic hemiplegia (one side being affected). Generally, injury to the left side of the brain will cause a right body deficit, and vice versa. Typically, people that suffer from this type of cerebral palsy are the most ambulatory, although they generally have dynamic equinus on the affected side and are primarily prescribed ankle-foot orthoses to prevent said equinus.
- Spastic diplegia (the lower extremities are affected more than the upper extremities). Most people with disabled diplegia do eventually walk. The gait of a person with Cerebral Palsy diplegia is typically characterised by a crouched gait. Toe walking and flexed knees are common. Hip problems, dislocations, and side effects like strabismus (crossed eyes) are common. Strabismus affects three quarters of people with spastic diplegia. This is due to weakness of the muscles that control eye movement. In addition, these individuals are often nearsighted. In many cases the intelligence of a person with spastic diplegia is unaffected by the condition.
- Spastic quadriplegia (Whole body affected; all four limbs affected equally). Some children with quadriplegia also have hemiparetic tremors; an uncontrollable shaking that affects the limbs on one side of the body and impairs normal movement. A common problem for children with quadriplegia is fluid buildup. Diuretics and steroids are medications administered to decrease any buildup of fluid in the spine that is caused by leakage from dead cells. Hardened feces in a quadriplegia patient are important to monitor because it can cause high blood pressure. Autonomic dysreflexia can be caused by hardened feces, urinary infections, and other problems, resulting in the overreaction of the nervous system and can result in high blood pressure, heart attacks, and strokes. Blockage of tubes inserted into the body to drain or enter fluids also needs to be monitored to prevent autonomic dysreflexia in quadriplegia. The proper functioning of the digestive system needs to be monitored as well.
Occasionally, terms such as monoplegia, paraplegia, triplegia, and pentaplegia may also be used to refer to specific manifestations of the spasticity.
Ataxic
Ataxia (ICD-10 G80.4) type symptoms can be caused by damage to the cerebellum. Forms of ataxia are less common types of Cerebral Palsy, occurring in at most 10% of all cases. Some of these individuals have hypotonia and tremors. Motor skills like 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 of objects.
Athetoid/dyskinetic
Athetoid or dyskinetic is mixed muscle tone—sometimes hypertonia and sometimes hypotonia (Hypotonia will usually occur before 1 year old; the muscle tone will be increased with age and progress to Hypertonia). People with athetoid CP have trouble holding themselves in an upright, steady position for sitting or walking, and often show involuntary motions. For some people with athetoid 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 (such as a toothbrush or pencil). About one quarter of all people with CP have athetoid CP. The damage occurs to the extrapyramidal motor system and/or pyramidal tract and to the basal ganglia. It occurs in 40% of all cases.
Incidence and prevalence
In the industrialised world, the incidence of cerebral palsy is about 2 per 1000 live births. The incidence is higher in males than in females; the Surveillance of Cerebral Palsy in Europe (SCPE) reports a M:F ratio of 1.33:1. Variances in reported rates of incidence across different geographical areas in industrialised 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 (for example, the extent to which children with mild cerebral palsy are included), the incidence rates converge toward the average rate of 2:1000.
In the United States, approximately 10,000 infants and babies are diagnosed with CP each year, and 1200-1500 are diagnosed at preschool age.
Overall, advances in care of pregnant mothers and their babies has not resulted in a noticeable decrease in CP. This is generally attributed to medical advances in areas related to the care of premature babies (which results in a greater survival rate). Only the introduction of quality medical care to locations with less-than-adequate medical care has shown any decreases. The incidence of CP increases with premature or very low-weight babies regardless of the quality of care.
Prevalence of cerebral palsy is best calculated around the school entry age of about six years, the prevalence in the U.S. is estimated to be 2.4 out of 1000 children
The SCPE reported the following incidence of comorbidities in children with CP (the data are from 1980-1990 and included over 4,500 children over age 4 whose CP was acquired during the prenatal or neonatal period):
- Mental retardation (IQ <>
- Active seizures: 21%
- Mental retardation (IQ <>
- Blindness: 11%
The SCPE noted that the incidence of comorbidities is difficult to measure accurately, particularly across centers. For example, the actual rate of mental retardation may be difficult to determine, as the physical and communicational limitations of people with CP would likely lower their scores on an IQ test if they were not given a correctly modified version.
Apgar scores have sometimes been used as one factor to predict whether or not an individual will develop CP.
Symptoms
All types of CP are characterized by abnormal muscle tone(i.e. 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 spasticity, 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 virtually unnoticeable to "clumsy" and awkward movements on one end of the spectrum to such severe impairments that coordinated movements are almost impossible on 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, change, or become more severe as a child gets older. Some babies born with CP do not show obvious signs right away.
Secondary conditions can include seizures, epilepsy, speech or communication disorders, eating problems, sensory impairments, mental retardation, learning disabilities, and/or behavioral disorders.
History
CP, then known as "Cerebral Paralysis", was first identified by English surgeon William Little in 1860. Little raised the possibility of asphyxia during birth as a chief cause of the disorder. It was not until 1897 that Sigmund Freud, then a neurologist, suggested that a difficult birth was not the cause but rather only a symptom of other effects on fetal development. Research conducted during the 1980s by the National Institute of Neurological Disorders and Stroke (NINDS) suggested that only a small number of cases of CP are caused by lack of oxygen during birth.
Causes
Despite years of debate, the cause of the majority of cases of CP is uncertain.
Some contributing causes of CP are asphyxia, hypoxia of the brain, birth trauma, premature birth, central nervous system infections and certain infections in the mother during and before birth. CP is also more common in multiple birth.
Studies at the University of Liverpool have led to the hypothesis that many cases of cerebral palsy, and other conditions that an infant has at birth, are caused by the death in very early pregnancy of an identical twin. This may occur when twins have a joint circulation through sharing the same placenta. Not all identical twins share the same blood supply (monochorionic twins), but if they do, the suggestion is that perturbations in blood flow between them can cause the death of one and damage to the development of the surviving fetus. It is common knowledge amongst obstetricians and midwives that a small dead fetus (fetus papyraceus) may sometimes be found attached to a placenta following birth. In the past, this has not been considered important and knowledge of the so called ‘vanishing twin’ has been suppressed to avoid triggering feelings of loss, grief, or guilt in mothers. The pathological consequences depend on the severity and the stage of development of the fetus when the imbalances in blood flow between the fetuses occur. It has been proposed that such pathology could account, not just for cerebral palsy, but for developmental abnormalities of the eye, heart, and gut, and other specific brain abnormalities such as neuronal migration disorders e.g. lissencephaly and holoprosencephaly, which occur during very early fetal development.
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 CP 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 percent 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 these people never had a normal brain). Often this goes along with rare chromosome disorders and CP is not genetic or hereditary.
Diagnosis
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. The American Academy of Neurology published an article in 2004 reviewing the literature and evidence available on CT and MRI imaging. They suggested that 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 tumor (which a few studies suggest are present 5 to 22%). Furthermore, an abnormal neuroimaging study indicates a high likelihood of associated conditions, such as epilepsy and mental retardation.
Presentation: bones
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). When compared to these thin shafts (diaphyses) the 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 at different lengths, so the person may have one leg longer than the other.
Prognosis
CP is not a progressive disorder (meaning the actual brain damage does not worsen), but the symptoms can become worse over time due to 'subdual damage.' A person with the disorder may improve somewhat during childhood if he or she receives extensive care from specialists, but once bones and musculature become more established, orthopedic surgery may be required for fundamental improvement. People who have CP tend to develop arthritis at a younger age than normal because of the pressure placed on joints by excessively toned and stiff muscles.
The full intellectual potential of a child born with CP will often not be known until the child starts school. People with CP are more likely to have some type of learning disability, but this is not related to a person's intellect or IQ level. Intellectual level among people with CP varies from genius to mentally retarded, as it does in the general population, and experts have stated that it is important to not underestimate CP sufferer's capabilities and to give them every opportunity to learn.
The ability to live independently with CP also varies widely depending on the severity of the disability. Some individuals with CP will require personal assistant services for all activities of daily living. Others can live semi-independently, needing support only for certain activities. Still others can live in complete independence. The need for personal assistance often changes with increasing age and associated functional decline. However, in most cases persons with CP can expect to have a normal life expectancy; survival has been shown to be associated with the ability to ambulate, roll, and self-feed. As the condition does not directly affect reproductive function, some persons with CP have children and parent successfully.
According to OMIM, only 2% of cases of CP are inherited (with glutamate decarboxylase-1 as one known enzyme involved.) There is no evidence of an increased chance of a person with CP having a child with CP.
Treatment
There is no cure for CP, but various forms of therapy can help a person with the disorder 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; drugs to control seizures, alleviate pain, or relax muscle spasms (e.g. benzodiazepienes, 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 synthesizers. For instance, the use of a standing frame can help reduce spasticity and improve range of motion for people with CP who use wheelchairs. Nevertheless, 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.
Early Nutritional Support In one cohort study of 490 premature infants discharged from the NICU, the rate of growth during hospital stay was related to neurological function at 18 and 22 months of age. The study found a signficant decrease in the incidence of cerebral palsy in the group of premature infants with the highest growth velocity. This study suggests that adequate nutrition and growth play a protective role in the development of cerebral palsy.
Physical therapy (PT) 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 life-long physical therapy 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.
Orthotic devices such as ankle-foot orthoses (AFOs) are often prescribed to minimise gait irregularities. AFOs have been found to improve several measures of ambulation, including reducing energy expenditure and increasing speed and stride length.
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.
Advanced Biomechanical Rehabilitation (ABR) ABR is a unique biomechanically based rehabilitation approach for children and young adults with brain injury that brings predictable recovery of musculoskeletal structure and motor functions. ABR improves musculoskeletal structure so significantly that normal motor functions recover spontaneously, making special training and management for "motor disabled" unnecessary.
Hyperbaric oxygen therapy Recent studies have demonstrated a dramatic improvement in CP symptomology when hyperbaric oxygen therapy is used as a treatment. In 1989, researchers in Brazil reported an alleviation in symptomology and other characteristics in a study involving 218 cerebral palsy patients. Significant enhancements were documented showing improved vision, hearing and speech as well as a reduction of spasticity by 50%, which occurred in 94% of study patients. Since the publication of the São Paulo review, other studies on the efficacy of hyperbaric oxygenation have been published though the number of subjects have remained low. An editorial published by the Undersea and Hyperbaric Medical Society in 2007 reviewed all publications to date and called for further research that will include "basic science research to determine a reasonable mechanism of action" for hyperbaric oxygenation as well as "clinical studies of the highest possible methodological rigor".
Nutritional counseling may help when dietary needs are not met because of problems with eating certain foods.
Both massage therapy and hatha yoga are designed to help relax tense muscles, strengthen muscles, and keep joints flexible. Hatha yoga breathing exercises are sometimes used to try to prevent lung infections. More research is needed to determine the health benefits of these therapies for people with CP.
Surgery for people with CP 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.
- 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 aleiviating the continuous muscle flexation. Baclofen in an of itself is a muscle relaxer and is often given PO 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.
- Botulinum Toxin A (Botox) injections into muscles that are either spastic or have contractures, the aim being to relieve the disability and pain produced by the inappropriately contracting muscle.
Another way is that a new study has found that cooling the bodies and blood of high-risk full-term babies shortly after birth may significantly reduce disability or death.
Cord Blood Therapy: There are no published randomized controlled trials or meta-analysis of this treatment modality in cerebral palsy. In March 2008 a boy that was diagnosed with cerebral palsy appeared on the Today Show with his family. The parents noted that he could not walk on his own and appeared to be "swallowing his tongue" at times. He was eventually diagnosed with cerebral palsy and could only walk with the aid of a walker for a short time. Earlier this year he participated in a clinical trial involving his own cord blood that his parents had saved when he was born. Within 5 days after the procedure he was walking on his own and talking, something his mother said he was not capable of on his own and it was doubtful he would ever be able to do on his own. The doctors also told his parents that if his rate of progress continues uninterrupted until he is 7 he will be pronounced cured. The parents message to the audience was "Bank your babies cord blood or donate it if you do not want to keep it. But you never know when you may need it."
Conductive education (CE) was developed in Hungary from 1945 based on the work of András Pető. It 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 an alternative therapy in which people with CP learn how to control their affected muscles. Some people learn ways to reduce muscle tension with this technique. Biofeedback does not help everyone with CP.
Neuro - cognitive therapy. A new approach to treating cerebral palsy from [Snowdrop]. It is based upon two proven principles. (1). Neural Plasticity. The brain is capable of altering its own structure and functioning to meet the demands of any particular environment. Consequently if the child is provided with an appropriate neurological environment, he will have the best chance of making progress. (2)Learning can lead development. As early as the early 1900s, this was being proven by a psychologist named Lev Vygotsky. He proposed that children's learning is a social activity, which is achieved by interaction with more skilled members of society. There are many studies, which provide evidence for this claim. there are however, as yet no controlled studies on neuro - cognitive therapy.
Patterning is a controversial form of alternative therapy for people with CP. The method is promoted by The Institutes for the Achievement of Human Potential (IAHP), a Philadelphia nonprofit, but has been criticized by the American Academy of Pediatrics. The IAHP's methods have been endorsed by Linus Pauling, as well as some parents of children treated with their methods.
Cultural aspects
Use of terms when referring to people with CP
Many people would rather be referred to as a person with a disability instead of handicapped. "Cerebral Palsy: A Guide for Care" at the University of Delaware offers the following guidelines:
Impairment is the correct term to use to define a deviation from normal, such as not being able to make a muscle move or not being able to control an unwanted movement. Disability is the term used to define a restriction in the ability to perform a normal activity of daily living which someone of the same age is able to perform. For example, a three year old child who is not able to walk has a disability because normal three year old can walk independently. Handicap is the term used to describe a child or adult who, because of the disability, is unable to achieve the normal role in society commensurate with his age and socio-cultural milieu. As an example, a sixteen-year- old who is unable to prepare his own meal or care for his own toileting or hygiene needs is handicapped. On the other hand, a sixteen-year- old who can walk only with the assistance of crutches but who attends a regular school and is fully independent in activities of daily living is disabled but not handicapped. All disabled people are impaired, and all handicapped people are disabled, but a person can be impaired and not necessarily be disabled, and a person can be disabled without being handicapped.
The term "spastic" describes the attribute of spasticity in types of spastic CP. In 1952 a UK charity called The Spastics Society was formed. The term "spastics" was used by the charity as a term for people with CP. The word "spaz" has since been used extensively as a general insult to disabled people, which some see as extremely offensive. It is also frequently used to insult able-bodied people when they seem overly anxious or unskilled in sports. The charity changed its name to Scope in 1994. In the United States the word spaz has the same usage as an insult, but is not generally associated with CP.
Misconceptions
A common misconception about those born with Cerebral Palsy is that they are less intelligent than those born without it. Cerebral Palsy is defined as damage to the part of the brain that controls movement; areas of the brain that define a person's intelligence are not affected by CP.
Spastic Cerebral Palsy, the most common form of CP, causes the muscles to be tense, rigid and movements are slow and difficult. This can be misinterpreted as cognitive delay due to difficulty of communication. Individuals with cerebral palsy can have learning difficulties, but sometimes it is the sheer magnitude of problems caused by the underlying brain injury that prevents the individual from expressing what cognitive abilities they do possess.
Public perception
Those with CP are sometimes stigmatized and shunned. This has lessened since the 1950s thanks to public education and to United Cerebral Palsy in the U.S. and similar organizations in other countries. Prior to that time the great majority were often sent to asylums or confined to attics. They were perceived to be the products of incest and partial smothering.
Thomas Galton believed that there was a correlation between physical disability and aptitude, and this attitude remained prevalent as concerned CP until the 1970s.
Only individuals with brain damage in the hippocampus or the frontal cerebral cortex develop mental retardation. While learning difficulties and CP may be associated, it is common for individuals with CP to lead normal lives.
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