Cerebral Palsy
Description: Cerebral palsy (CP) sometimes called chronic, nonprogressive neurologic
injury, is a disorder of muscle control or coordination resulting from injury to the brain
during its early (fetal, perinatal, and early childhood) stages of development. There may
be associated problems with intellectual, visual, or other functions.
With cerebral palsy, the problem lies in the brain’s inability to control the
muscles; the muscles themselves and the nerves connecting them to the spinal cord are
perfectly normal. The extent and location of brain injury determine the type and
distribution of the CP.
Spasticity: Stiffness of the muscles (hypertonia) occurs when the brain injury is on the
brain surface (motor cortex) or when it involves those nerves leading from the surface
through the substance of the brain (cortico-spinal, or pyramidal tract) and into spinal
cord. Spasticity is present in about 60 percent of all cases of cerebral palsy.
Dyskinesia: This type, which accounts for roughly 20 percent of all cases of cerebral
palsy, is caused by injury to the basal ganglia area, the brain’s motor switchboard.
Dyskinesia is a term describing the unwanted, involuntary movements of cerebral palsy.
These included slow, writhing movements, particularly of the wrist and fingers
(athetosis), which may be accompanied by more abrupt and jerky movements (choreo-
athetosis). Another form of dyskinesia is comprised of slow, rhythmic movements
involving the trunk or an entire extremity (dystonia). All three forms are more prominent
with voluntary activity or emotional stress. Dyskinesia is sometimes accompanied by
increased muscle tone, or “tension,” which also varies with body position and emotional
state.
Ataxia: Occuring by itself in about 1 percent of all cerebral palsy, ataxia is
characterized by a broad-based, lurching gait with primary balance difficulties. The
injury is in the cerebellum.
Mixed: Approximately 30 percent of individuals with cerebral palsy have a
combination of spasticity and dyskinesia or ataxia, with one type predominating.
With the spastic type of CP, the following terms are used to denote which parts of the
body are affected.
Diplegia – Involvement of the trunk and all four extremities – the legs more so than the
arms.
Hemiplegia – Involvement of one side of the body only.
Paraplegia – Involvement of the legs only.
Quadraplegia – Involvement of both arms, both legs, the head, and the trunk.
There are also cases of monoplegia – involvement of one extremity – and triplegia –
involvement of three extremities; but these are unusual.
Some persons with cerebral palsy have severe disabilities; others have barely detectable
problems with muscle control. There is no universally used, objective method by which
physicians or therapists can adequately categorize patients as having mild, moderate, or
severe degrees of motor dysfunction. Such estimates are usually made subjectively.
CAUSE: Cerebral palsy results from brain injury due to such events as a stroke during
fetal life, lack of oxygen at birth, intracranial hemorrhage, or meningitis during infancy.
In as many as 50 percent of the cases, the specific cause of the injury is not evident.
The type of CP is related to three factors: the causal event, the timing of this event, and
the location of the damage. For example, an intracranial hemorrhage in a susceptible
premature infant may damage the cortico-spinal and associated tracts and result in
spasticity. Or high levels of bilirubin – a product of the breakdown of red blood cells –
may damage the basal ganglia in newborns, resulting in athetosis.
INCIDENCE: The incidence of cerebral palsy varies with different studies. The most
often quoted figure is 1.5 to 2 per thousand live births. The incidence is higher in areas
where there is inadequate prenatal care and accompanying increase in prematurity.
DETECTION: The diagnosis of cerebral palsy is made on the basis of a history of
delayed achievement of motor milestones, observation of abnormal movement, and
abnormal findings in the physical examination (e.g., stiffness, very active knee jerks,
persistent primitive reflexes).
Spasticity or dyskinesia are not always evident during the first few months of life.
However, most cases of cerebral palsy can be detected by twelve months, nearly all by
eighteen months. Some children with abnormalities of posture and movement in the
early months reportedly outgrow them. To do this, except in mild cases, is rare.
Other factors besides insufficient age can make the diagnosis difficult. These include:
Prematurity: An infant born too early or too small must be given extra time to achieve
certain skills. For example, the infant born two months early may be normal but just not
sitting up within the normal range of expected times for full-term infants.
Extremes of normal range: Some babies sit at four months, others not until nine months;
yet both groups may fall within the normal range. Only when the skill is not being
performed after the outer limit of “normal” is reached or when there is a constellation of
abnormal signs can we infer that something is wrong.
Quality of performance: Some infants have the ability to manipulate objects at the
expected age, yet manner in which they do so may indicate an abnormality. That is why
experienced examiners must observe how as well as when infants perform motor
activities. Since the diagnosis of cerebral palsy is based on clinical judgement and not on
blood tests, x-rays, or the like, the observations of skilled examiners are necessary to
make or confirm the diagnosis during infancy.
Effects of motor impairment: Children with cerebral palsy, like infants with general
developmental delay, often do not perform expected motor tasks at age-appropriate times.
It is critically important, however, to differentiate between these two groups of children.
The basic indicator is that the generally developmentally delayed child’s abilities are
depressed in all areas, whereas the child with cerebral palsy may be very depressed in
motor activities yet have good socialization and receptive language skills.
The belief that “they will grow out of it”: At times, parents are falsely reassured that,
given time, an infant’s motor delays will resolve on their own. Also, the physician may
be reluctant to make a firm diagnosis of cerebral palsy on the basis of one office visit,
particularly if the child is very young. If there is doubt, the wisest course is to reexamine
the child at frequent intervals or to make a referral to persons highly experienced in
developmental and neurological assessment. The advantages of early treatment if the
child does have cerebral palsy – or the relief and reassurance if the child does not, are
well worth the extra effort.
During infancy, the manifestations of brain injury often change. The initially hypotonic
baby, for example, can later show signs of spasticity. In other cases, athetosis may not be
evident until the child is older. For this reason, diagnosis may not be exact in early
infancy but may be revised as the child’s neuromotor status evolves.
Cerebral palsy is the result of a permanent brain injury and is therefore life-long. While
the brain damage itself is nonprogressive, the resultant muscle control problems are not.
However, their progress can be halted – or at least postponed – with proper therapy,
including frequent elongation of stiff muscles and proper positioning. In some cases,
surgery is necessary to release tight muscles and tendons, particularly of the ankles and
hips. Other orthopedic disorders, such as scoliosis and contractures of the joints, may
become more problematic as the child gets older.
When appropriate therapy is available during the child’s developing years, the parents
can expect to see continued gains in muscle control, strength and awareness of how
certain motor skills are performed. Such gains will result in improved ability to walk,
feed, dress, toilet, or speak. The rate of this improvement, however, is greatly dependent
upon the type of cerebral palsy, the way it is distributed, the degree of muscle
involvement, and the presence of associated problems.
Children with cerebral palsy – provided they have comprehensive evaluation and
treatment – can look forward to an average longevity. All the data supporting a shortened
life span have been faulted by the inclusion of large numbers of individuals who at an
early age were placed in institutions where they received less adequate care.
ACCOMPANYING HEALTH PROBLEMS: Events causing brain injury around the
time of birth are seldom so site-specific that they bring about only one kind of clinical
problem. There are often injuries to different areas of the brain, each of which controls
different functions; therefore, children are usually classified or diagnosed according to
the problem which interferes most with their developmental progress. A child whose
primary difficulty is motor control, but who has problems in other functional areas as
well, is classified as having cerebral palsy with associated problems. These include:
Mental Retardation Around 60 to 70 percent of all children with cerebral palsy are
mentally retarded. This problem is seen less often with spastic diplegia.
Visual impairments Approximately 25 to 45 percent of all children with spastic cerebral
palsy have an eye muscle imbalance problem. Acuity deficits occur with about the same
frequency as in the general population.
Hearing impairment Cerebral palsy, particularly the type associated with brain damage
due to excess bilirubin, may produce, may produce hearing deficits (hearing ability
should therefore be carefully monitored). Also, children with motor problems may spend
a large percentage of their time in a recumbent position, making them more susceptible to
middle ear infections and persistent fluid in the middle ear, which can cause varying
degrees of conductive hearing loss.
Seizures The brain injury which results in cerebral palsy often causes glial scarring on
the cortex, a source of chronic irritation that may precipitate seizure activity in 35 to 45
(some studies report 60 percent) of persons with cerebral palsy. All types of seizures are
reported, grand mal the most frequently.
MEDICAL MANAGEMENT: The interdisciplinary approach. Because the problems
associated with cerebral palsy are numerous and complex, treatment involves the
integrated efforts of specialists from many disciplines. The physical therapist works to
facilitate motor development, to prevent or slow orthopedic problems (such as limited
range of motion or dislocation or joints), and to improve posture and positioning so that
the child may more profitably engage in other types of intervention activities.
The occupational therapist teaches parents to handle the child’s daily living activities –
such as toileting, feeding and dressing. (In many situations, this service is provided by or
shared with the physical therapist). Both the physical and occupational therapists may
help select appropriate equipment, such as special chairs and eating utensils to facilitate
independence and learning.
The speech pathologist monitors the child’s progress in speech and language skills.
While it is unlikely that speech therapy per se will be initiated before age three, this
specialist counsels parents.