Cerebral Palsy

Cerebral Palsy is caused by damage to the motor systems of the brain affecting the child’s ability to perform basic functions such as swallowing and speaking. The word cerebral refers to the brain and palsy refers to a movement disorder. Damage occurs before, during or shortly after birth. When CP occurs before or during birth, it is called congenital. When it occurs after birth it is called acquired. Body movement and muscle coordination is affected. Problems do not occur with the nerves or muscles but occur in the brain’s ability to control movement and posture adequately by sending the wrong messages to the muscles. CP results in poor coordination, poor balance, abnormal movement patterns or a combination of these. It is not a communicable disease, inherited or the primary cause of death. The prevalence of CP is 1.4% to 2.7% of live births.

The cause of congenital Cerebral Palsy, in most cases, is unknown. Some of the factors that may cause its’ development include: infections during pregnancy (rubella, cytomegalovirus, toxoplasmosis), jaundice, severe oxygen shortage in the brain, trauma caused by a difficult birth, Rh factor, bleeding in the brain and low birth weight. Children born with a low birth weight of less than 3 pounds 3 ounces account for at least half of the reported cases of CP. Also, multiple births account for a greater incidence as compared with single births. Other causes include asphyxia during labor and delivery and toxicity.

Several risk factors concerning the mother are identified as being a risk factor for the development of prenatal CP. These factors include: thyroid disorder, previous miscarriage, mental retardation, bleeding in the third trimester, high blood pressure, seizure disorder and alcohol or drug abuse. Other causes include genetic or chromosome abnormalities, exposure to radiation, infections, congenital malformations, and kidney and urinary tract infections in the mother that can lead to brain damage in the fetus.

Perinatal causes include severe brain hemorrhage resulting in neurological damage. Also, insufficient oxygen and blood flow during birth which could be the result of aspirating the first bowel movement during labor and delivery or having the umbilical cord wrapped around the neck. A child who does not cry in the first five minutes of delivery or who has been on a ventilator for over 4 weeks may be at risk.  During delivery of a full term baby, damage to the brain would result in damage to the basal ganglia resulting in uncoordinated and uncontrolled muscle movements. Also, untreated low blood sugar in the newborn can cause brain damage that leads to CP.

A small percentage of babies (10-20% of reported cases) develop CP after birth. Acquired CP can result from brain infections such as meningitis or encephalitis, lack of oxygen to the brain or brain trauma from a car accident, fall, or child abuse.

Cerebral Palsy can be classified in two ways: by site of lesion and by identification of the affected extremities. When classifying by site of lesion, the terms spastic, athetoid, ataxic and mixed are used. When classified by the extremities that are affected, the terms hemiplegia, diplegia, triplegia and quadriplegia are used. From this dual model, the doctor would be able to classify CP based on both the site of lesion and the extremities that are affected. The location and extend of the brain injury would determine the severity from mild to severe.

When classifying Cerebral Palsy by affected extremities, the following terms are used:

Hemiplegia-one arm and one leg on the same side are affected.

Diplegia-both legs are involved. The arms are not affected.

Triplegia-three limbs are affected.

Quadriplegia-both arms and legs are affected.

Classification:

Spastic Cerebral Palsy occurs when there is damage to the pyramidal system of the brain. It is the most common form of CP and represents between 70%-80% of the reported cases. Children with Spastic CP exhibit hypertonic muscle tone which affects control of their voluntary movements since their muscles are rigid and permanently contracted. Attempts to perform a motor activity cause increased tension in the muscles. Breathing is characterized by shallow inspirations and forced expirations. Damage to the cerebral cortex is usually the cause.

The major types of spastic involvement are:

1. Spastic Hemiplegia-involves the arm and leg on one side of the body. Speech is usually OK. The child may have a developmental delay.
2. Spastic Paraplegia-involves the legs only. This is very rare. The child may have problems with breath support.
3. Spastic Quadriplegia-all four limbs are equally affected. The child may have articulation problems and/or dysphonia. Abnormal breathing patterns are caused by weak muscles of the chest wall.
4. Spastic Diplegia-all four limbs are affected. The lower limbs are affected more. The child may experience dysprosody with articulation problems.

Athetoid Cerebral Palsy is the least common type affecting 5 to 10 percent of reported cases. It occurs from damage to the extrapyramidal system or damage to the basal ganglia and causes mixed muscle tone-hypo or hypertonic which impairs the child’s ability to control involuntary movements and causes slow, writhing movements. This loss of muscle control makes it difficult for the child to walk and grasp objects. The muscles of the face may also be affected causing drooling, grimaces or odd expressions. Abnormal infantile reflexes are common. Speech defects are variable and include different degrees of articulation deficits, phonation and prosody involving stress and rhythm. Breathing patterns may be irregular and uncontrolled patterns with sudden bursts of air during inspiration and expiration.

Ataxic CP affects 5 to 10% of the CP population. The cerebellum is damaged which affects coordination resulting in unsteady, shaky movements or tremors. The hypotonia has a negative impact on the ability to control muscles required to walk, write and dress themselves because of problems with balance, coordination, and depth perception. Damage to the cerebellum causes this type of CP. About half of Ataxic CP children have breathing problems characterized by irregular rate, rhythm and depth of tidal breathing resulting in difficulties with loudness control and the rate of speech. Speech problems are mainly articulation and dysrhythmia.

Mixed CP is a combination of 2 or more of spastic, athetoid and ataxic CP. This classification results in a mixture of hypertonicity and hypotonicity and is seen in approximately 11% of the CP cases.

Using both systems for describing the disease, the doctor is able to classify CP based on the site of the lesion and the affected extremities. CP can affect the child’s motor skills from mild to severe. The location and extent of the brain injury determine the severity of CP. The effects can include extreme weakness, seizures, paralysis, lack of coordination, sensory impairments and reduced control of the arms and legs. It can affect the school age child in class by having trouble writing, drawing and cutting with scissors. The child may have difficulty with receptive and expressive language. Articulation difficulties may result from lack of breath control, movement of the vocal cords, lips, tongue and palate.

Diagnosis:

Diagnosing Cerebral Palsy requires observation over a  period of time. Diagnosis is usually made within the first three years of life and is accomplished by completing tasks for motor skills and reflexes, looking into medical history and performing a variety of formal and informal assessments. Three areas observed are: the acquisition of developmental milestones, muscle tone and muscle function.  Usually parents will begin to notice that their child’s motor skills are different from other children around the 6 month age. Concern of CP continues to grow as the milestones become more evident that they are delayed. Abnormal muscle tone, movements that are not typical for the age of the child and continued infantile reflexes are red flags for the disease. Some of the areas that would signal a diagnosis would be muscle tone that changes from floppy to stiff, one side of the body moves better than the other, poor tongue and lip control, and reflexes like the asymmetric tonic neck reflex that lasts beyond the 6 month stage or the Babinski reflex that lasts longer than a year. Also, early signs of CP include the following:   poor head control after 3 month of age, increased irritability, feeding problems (problems sucking and swallowing), continuous fisting of the hands, scissoring of the legs, pointing of the toes, tremors, seizures,  an exaggerated startle reflex, and a weak or shrill cry. The body can be either very relaxed and floppy or very stiff. When held, babies may arch their backs and extend their arms and legs.

Fine Motor:

Since CP is a motor disorder that affects muscle control and not the direct cause of cognitive, visual, hearing or attention impairments, it is important to understand the effect that CP has on fine motor functions. It’s important to note that involvement varies with each individual as the disease affects each person differently. Motor impairments range from a slight distorted gait to wheelchair bound. The rigidity of the muscles can cause the feet to turn in or the legs to cross while walking. The child may also take large, uncontrolled steps. If needed, the child may be fitted for an AFO brace to stabilize the ankle and calf. CP children often suffer from dislocated hips and tight hamstring calf and ankle muscles. Medical and surgical treatments can help relieve the tight tone. Botox can be used to relax the tight muscles to allow for an increase in motion.  Surgically clipping a muscle can be done to improve mobility. Oftentimes the fine motor skills make it difficult for CP children to dress themselves and feed themselves. Using scissors and writing may be a challenge. It’s common for a CP child’s wrists to be stuck in a downward position. Hand and wrist splints can be used for proper positioning of the fingers and wrist.

Feeding Issues:

Difficulties with jaw control and mobility with tongue, lips and cheeks can complicate feeding for the CP child due to high or low muscle tone. Forward thrusting of the tongue due to decreased tongue strength pushes the food forward and limits the laterization of the bolus to the teeth. Because of this, a sucking pattern is developed where the tongue mashes the bolus against the hard palate and the food is swallowed without being chewed.  Also, an open mouth position is common in CP children resulting in bolus leakage and drooling. If the muscles of the larynx and epiglottis are weak, there is not sufficient protection of the airway during swallowing. But, if there is high muscle tone, the pharynx is constricted and swallowing is difficult. Sometimes these swallowing issues make if necessary to pursue alternate feeding methods such as the use of the nasogastric tube or the gastorstomy tube so proper nourishment can be achieved.

In addition to swallowing problems, high muscle tone and extra movements cause the CP child to burn a large amount of calories and develop low weight. If the child displays sensory defensiveness, the child may not take nourishment by mouth which could lead to weight loss.

Condition:                                    
Abnormal neurological control

 

Complications:

• Lack selective control of muscle activity and anticipatory regulation
• Dysphagia
• Cough and airway clearance difficulties
• Respiratory muscle weakness   

Sucking and swallowing problems in the first 12 months of life are common and a high percentage require nonoral feedings on at least one occasion.  Swallowing is a complex process that involves the sequence of intricate timed maneuvers by a large number of muscles.  Muscle weakness creates a disturbance in the coordination of this sequence and often leads to swallowing difficulties.  Individuals with spastic quadriplegic cerebral palsy are most likely to be affected; however, dysphagia may be present in any of the cerebral palsy types.

Both the oral and pharyngeal phases of swallowing may be affected.  In the oral phase, the failure of proper bolus formation may impede swallowing.  In the pharyngeal phase, esophageal peristalsis, glottic closure and the coordination of swallowing and breathing may lead to aspiration of solids and liquids during feeding.  There may also be aspiration of secretions into the airway due to inadequate protective reflexes.  Coughing is also a complex action which requires the strong contraction of the abdominal and intercostal muscles, and precise coordination of these muscles in conjunction with the glottic muscles.  In addition, individuals with cerebral palsy appear to have a diminished sensitivity to cough.  It has been speculated that this may occur due to the result of desensitization of airway irritant receptors from chronic aspiration.  In addition, individuals with cerebral palsy often lead sedentary lifestyles.  Exercise is known to produce deep breathing which aids in the clearance of secretions and opens up underventilated lung regions.  Lack of exercise makes those with cerebral palsy prone to infection and hypoxemia. (Solomon, 1998)

Visual-Motor:

About 40% of people with CP have visual impairment as well. The causes would relate to prematurity and a lack of oxygen to the brain which results in damage to the retina, optic nerve or occipital lobe. These impairments affect motor function and perceptual skills. If their balance is altered, this could cause delays in achieving motor milestones such as crawling and walking. Children with hemiplegia commonly have a loss of vision in a section of their visual field which affects depth perception. Cortical blindness is caused by damage to the brain that prohibits the conversion of visual stimuli into a visual image. The eye and optic nerve are functioning properly, but they are not receiving the visual messages from the brain. Optic atrophy is damage to the optic nerve that prohibits the brain from receiving visual stimuli and transferring it into a visual image.

Hearing:

Approximately 15% of children with CP have a hearing impairment caused by bleeding in the brain or a lack of oxygen to the brain. The severity ranges from slight to profound and can have a negative effect of the child’s speech and language acquisition. It can also have an effect on their auditory processing skills such as short term memory, sequencing and organizing skills.

Sensory:

Children with CP often have sensory problems which affect their proprioception causing them to lean to one side when sitting or not be aware of their postures. Also, they may be tactile defensive with new textures resulting in the child to become overloaded easily when introduced to textures, sounds and other external stimuli.

Cognition:

Due to brain damage, some form of mental retardation is found in approximately two thirds of people with CP. This can range from mild to severe. Since physical impairments make it difficult to assess the person with CP, the scores obtained from formal measures may not be an accurate picture of the person. Since CP is a motor disorder, many of the children who suffer from CP are impaired only by their motor impairment and are able to succeed in the cognitive demands of their daily life.

Growth:

Delayed growth can be caused by swallowing difficulties. Since it takes a long time for someone with CP to finish a meal, little food has been actually ingested. Also, poor lip closure and tongue thrust also contribute to loss of food making it difficult for the child to receive enough calories to grow normally. Also, muscles that are hypertonic or hypotonic can affect the growth of a child with CP.

Speech:

Speech characteristics vary from child to child and can range from severely impaired to no impairment at all. Speech dysfunctions include respiratory, phonatory, articulatory, prosodic and velopharyngeal inadequacies.  Articulation errors may be present due to hypotonicity or hypertonicity of the speech muscles. The motor speech disorders, if any, would be dysarthria and/or apraxia. Respiration is often compromised by immature lungs which may cause asthma, aspiration pneumonia, sleep apnea and chronic obstructive pulmonary disease. The lungs may be healthy but the use of them may be compromised due to muscle control and/or weakness. Voice may be breathy or weak and the child may speak with low volume and monotone. Children with spastic diplegia and spastic quadriplegics are more likely to have speech disorders than are hemiplegics or paraplegics. Motor difficulties result in dysarthria. CP children initiate speech using higher lung volumes and use more air during speech due to reduced vital capacities and difficulty with neuromuscular control. (Solomon, 1998)

Evaluation:

A team approach is recommended for the evaluation of a child suspected of having CP. Some of the professionals involved in the assessment would include an orthopedist, developmental pediatrician, physical and occupational therapist, speech-language pathologist, social worker, psychologist, social worker and a special educator. The family is most important in the child’s management of intervention strategies because it is the family who will follow through on the therapy recommendations offered by the specialists involved.

Speech Evaluation:

The speech and language assessment will include formal testing and informal testing. The formal testing will give a standardized score in the areas of receptive/expressive language, articulation, vocabulary, pragmatics, oral motor skills, auditory comprehension and memory skills. Areas tested will be determined by the age and abilities of the child. For those children who suffer from impulsivity, attention difficulties, behavior issues, cognitive impairment or physical limitations may require special modifications such as an AAC device, word processor, quiet room, smaller sessions, repetition of directions, redirection to task, enlarged pictures and use of eye gaze. Untimed testing may be required for children with physical limitations or problems with processing. Test results will help with strengths and weaknesses and formulation of goals but they may not be a true picture of what the child can do in the classroom. Informal testing needs to be performed to gain a truer picture of the child in the classroom setting of environmental setting.

Informal testing includes interviews and observations. The interviews provide an insight in to the child’s functioning in their natural environment that formal testing can’t identify. A parent interview is essential as well as a teacher interview. The teacher can give helpful information for providing modifications required for the child as well as the child’s strengths and weaknesses. Behavioral observations by the SLP will give valuable information about how well the child communicates and understands and the degree of cueing and compensation required to function in their environment. It is recommended that several observations be made on different days to give a more balanced picture of the child’s functioning.

Speech Therapy:

Speech disorders may include developmental articulation errors and motor speech disorders (dysarthria and apraxia). Traditional articulation therapy can be used for articulation errors. If motor skills are compromised, oral motor exercises would benefit to increase awareness of the tongue and articulators and increase strength. Children with CP often demonstrate deficits in vocabulary skills

If swallowing or feeding issues are suspected, a swallow study should be preformed. The SLP should coordinate intervention techniques and strategies with the physician and caregivers if a swallowing problem is present.

Careful observation of the patient should be done to assess the respiratory mechanism and respiratory support. A determination should be made about the respiratory pattern used: clavicular, thoracic or diaphragmatic-abdominal breathing. To measure maximum phonation time, the patient should be able to produce an adequate amount of air and be able to sustain phonation long enough to communicate effectively. By measuring the maximum phonation time, respiratory and glottal closure can be assessed. Elementary children should be able to sustain vowels for approximately 10 seconds. Reduced vital capacities result in inadequate support for phonation and articulation. Breathing may be rapid and/or irregular with lack of thoracic movement. (Solomon, 1998)

In making a voice evaluation, it’s important to remember that laryngeal dysfunction is responsible for harsh voices, short phrasing and prosodic abnormalities. General hypotonicity results in strained vocal quality, hard glottal onset and reduced intensity.

Articulation deficiencies affect production of fricatives, affricatives, laborious and slow rate of speech. Muscle weakness, instability and problems finding target points of articulation contribute to articulation errors and abnormal prosody. Abnormal jaw movements during speaking and tongue movements are restricted also.

Velopharyngeal inadequacy results in hypernasality. The child should be encouraged to speak with a greater degree of oral opening and to use a more posterior placement of the tongue, if able. If hypernasality persists as the child matures, other treatment options can be explored, such as a palatal lift.

Phonological difficulties include voicing difficulties, consonant cluster reduction, final consonant deletion, vowelization of /l/ and /r/.

The first step in therapy would be to satisfy the pre-speech requisites such as head control, coordination of respiration, coordination of breathing and phonation and posture control. After these objectives have been met, vocal play and babbling practice would start for the very young. For the older child, work on coordinating respiration, phonation, resonation and articulation. When the child is able to inhibit abnormal reflexes and perform movements for speech, artic training can begin. Traditional articulation therapy would consist of increasing speed, range and accuracy of the tongue, lips and jaw. Begin with oral exercises, then placement exercises. Select target phonemes according to stimulability of sounds and the developmental stage of the child. Choose stimulable, visible and developmentally appropriate sounds first.

Treat:

• Consonants produced correctly in prevocalic position first.
• Distortions before substitutions.
• Motor involved misarticulations should be delayed.
  Use auditory/visual stimulation.
• Work on voice/voiceless contrasts. Children with CP substitute voiced for voiceless consonants.
• Strengthen inspiration and expiration muscles for breath control.
• Practice diaphragmatic breathing, blowing, and abdominal strengthening by use of sit-ups for muscle weakness.
• For spasticity, combine strengthening with relaxation, muscle lengthening and facilitation of normal movement patterns.
• Some CP children will not have normal artic. Work on compensations.
• Practice phonating while performing laryngeal adduction exercises such as bearing down, squeezing palms together, pulling up on the chair with hands.
  

If verbal communication can’t be achieved due to physical handicaps, an AAC device may be introduced. Cognitive abilities will need to be considered and motor abilities need to be taken in to consideration. Proper symbols must be found for the AAC device according to the child’s cognitive ability, visual acuity and environment.

The SLP works to improve the child’s vocabulary skills by providing a variety of experiences through the use of thematic units, reading books and hands-on experiences. Oftentimes, the child has limited experiences due to their physical limitations and lack of social interaction. When poor vocabulary skills are due to neurological deficits instead of lack of experience, the SLP must provide the child with compensatory strategies. The SLP works with the child’s teacher and family to ensure that the child progresses and generalizes strategies to the classroom and home environment. (Solomon, 1998)

Poor oral motor skills have a negative impact on the child/s ability to speak, eat and manage drooling. An individualized treatment plan should be established by the SLP consisting of an oral motor stimulation program involving deep pressure and stroking of the lips, tongue, cheeks and gums. The deep pressure helps to improve muscle tone and the stroking provides sensory input and helps to alleviate oral defensiveness. The SLP works in partnership with the occupational therapist to develop a feeding program for the child. Pureed foods may be recommended or adaptive feeding equipment, such as a special spoon or bowl, may be introduced to assist the child in feeding himself or herself.

Since the effects of CP vary from one child to another, careful and thorough assessment should be performed and an intervention program should be developed based on the specific strength and needs of the child. Since cerebral palsy can have a severe effect on the child’s communication skills, impact can be realized in the child’s socialization, academics and vocation goals. It is important to begin assessment as early as possible to prepare the child for the future. A multidisciplinary team including the parents is most effective for meeting the child’s needs. Consultation among the professionals is essential to ensure the best treatment possible. Due to the continued development of devices and medical knowledge and multiple impairments that can co-occur with the disease, assessment and intervention must be an on-going process.