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Physical/Occupational Therapy - Common Disorders

  • Cerebral Palsy or CP
  • Myelodysplasia (Spina bifida)
  • Hydrocephalus
  • Muscular Dystrophy

Cerebral Palsy or CP

CP is a neurodevelopmental impairment caused by a nonprogressive defect or lesion in the single or multiple locations in the immature brain. ( Campbell, 1995). This defect can occur in utero or shortly after birth and produces motor and sometimes sensory deficits that are usually evident in early infancy. (Scherzer Tscharnuter, 1990)

CP Classifications

CP has been classified in a number of ways:
A) Classification based on areas of the body showing impairment yields the designation:

    1. monoplegia (one limb)
    2. diplegia (lower limbs)
    3. hemiplegia (upper and lower limbs on one side of the body)
    4. quadriplegia (all limbs)

B) Another classification is based on the most obvious impairment resulting from common brain lesions:

    1. The spastic type where muscles are perceived to be stiff especially during attempted movement results from involvement of the motor cortex or white matter projections to and from the cortical sensorimotor areas of the brain.
    2. Dyskinesia or athetosis is the reflexion of basal ganglia involvement resulting in intermittent muscle tension and involuntary movement patterns.
    3. Ataxia is a function of the lesion in the cerebellum results in general instability.
    4. Hypotonia is not known to be related to a particular lesion and is characterized by diminished resting tension and a decreased ability to generate voluntary movement.

Incidence

The proportions of the various subtypes of CP vary with the reporting source.

Sweden:

hemiplegia accounted for36.4%
diplegia41.4%
quadriplegia7.3%
dyskinesia or athetosis10.0%
ataxia forms5.0%

Statistics from developing countries indicate that up to 63% of the cases in developing countries are preventable and are associated with shortage of care personnel and inadequate financing. CP was a steady-state incidence of about 2.5 per 1000 births until the mid-1950. (Little, 1958) . Followed by a decrease in incidence to about 1.5 per 1000 for about 15 years (1970).

Since then, the incidence has increased to near 1950's levels. The change reflects the changes or increase in the live birth rate of premature infants. Babies weighing less than 1000 grams are 40 times more likely to develop CP. But the reports of long term outcomes of extremely premature infants (born between 24 and 28 weeks) suggest about 75% survival rate with more than 50% of those who survive free of major neuro-developmental impairments. 25% result in major impairments and 11% result in CP.

Causes

CP is a condition with multiple causes leading to damage within the central nervous system. There is a general agreement that the majority of cases of CP:

  1. In full term infants, are due to prenatal (before birth) causes of unknown causes.
  2. Whereas, in the vast majority of preemies, the lesions causing CP develop around the time of birth or perinatal period.

Prematurity, although not thought to be causative, is associated with up to 33% of all cases, including more than 50% of diplegia (Pharaoh et al., 1990)

Prenatal (before birth or during pregnancy) malnutrition, poor maternal prenatal condition and maternal infection are also associated with CP. (Menkes, 1990)

Intercranial hemorrhage, especially among premature infants, is a well established causal factor. Lack of oxygen around the time of birth is a significant event surrounding birth but only a small minority of cases result from such an event.

Treatment Principles

THE GOAL IS TO MAXIMIZE THE CHILD'S POTENTIAL BY ACTIVITIES AND/OR EQUIPMENT THAT DECREASE THE ABNORMAL POSTURES AND MOVEMENTS AND FACILITATE NORMAL POSTURES AND MOVEMENT.

Some postures reduce spasticity or athetosis thereby allowing more normal movement. Do not accept abnormal postures and movement since the constant use of these postures and movement will emphasize and reinforce the problem and lead to deformity. This is especially the case when the child must put forth great effort to do things they are not developmentally ready for. We must proceed very gradually and assist or support the child or change the activity to maximize the use of normal postures/movements.

One of the best ways to facilitate development is to give the movement deprived child CHOICES, so they can communicate what it is they wish to explore, and to RESPECT INITIATION of action so that they are allowed to follow up on what they wish to do without asking for permission.

Myelodysplasia (Spinal, abnormal tissue growth)

Spina bifida represents one of the most exciting and challenging groups with which we can work. Spina bifida is described as "defective development of any part (especially the lower segments) of the spinal cord." (Dorland's Medical Dictionary) .

Classification

  • Aperta (visible or open)
  • Occulta (hidden)

The degree of motor and sensory loss from these lesions may range from no apparent loss to severe impairment. Spina bifida aperta is commonly thought of as myelomeningocele which is an open spinal cord defect that usually protrudes outward. Meningoceles are open spinal cords that are covered by skin and are initially associated with no paralysis.

Etiology (cause)

Spina bifida is often associated with genetic abnormalities. Excess maternal alcohol intake can produce a classic fetal alcohol syndrome with spina bifida. Folic acid deficiency has been identified as a cause of spina bifida in some populations. The decrease in birth incidence is a worldwide trend. Improved medical care has allowed for increased survival and secondarily, an increased prevalence.

Incidence

Incidence at birth has been reported to range from 0.4 to 0.9 per 1000 births, depending on the source. (Shurlteff et al., 1986)

Motor Paralysis

The result of spina bifida is the paraplegia or paralysis of the lower limbs below the level of the lesion. The motor level is defined as the lowest intact functional neuromuscular segment. For example, an L-4 level indicates that the 4th lumbar nerve and the myotome it innervates are functioning, whereas segments below L-4 are not intact.

The involvement of individuals may present in one of 3 ways:

  1. complete cord transections or paralysis;
  2. incomplete lesions have mixed presentation of spasticity and voluntary control;
  3. skip lesions, where function has been observed below the level of the lesion. It is important to note the musclus that are working or to note the presence of spasticity or reflexes to determine if a "skip" lesion exists.

Hydrocephalus

Hydrocephalus is excessive accumulation of cerebrospinal fluid in the ventricles of the brain. Approximately 25% or more of these children with spina bifida are born with hydrocephalus. In addition, 60% develop it after surgical closure of their back lesion. (Reigel 1993)

Arnold Chiari Type II

Cerebellar hypoplasia with downward displacement of the hindbrain through the foramen magnum is usually associated with hydrocephalus.

Shunting

80 to 90% of the children with hydrocephalus will require a shunt from the lateral ventricles to the peritoneal space where the fluid is reabsorbed.

Repeated or prolonged shunt malfunction and infections lead to additional functional and cognitive decline. Shunt dysfunction is often gradual with subtle symptoms. Aides and teachers should be familiar with these symptoms to facilitate early detection and appropriate referral.

Early Warning Signs and Symptoms of Shunt Dysfunction

  • Changes in speech
  • Projectile vomiting
  • Fever and malaise
  • Recurring headache
  • Decreased activity level
  • Decreased school performance
  • Onset of or increase deviation of the eye which the child cannot overcome (strabismus)
  • Changes in appetite and weight
  • Incontinence begins or worsens
  • Onset or worsening of curvature of the spine (scoliosis)
  • Personality change (irritability)
  • Decreased or static grip strength
  • Difficult to arouse in the morning
  • Decreased visuomotor coordination
  • Decreased visual acuity
  • Decreased visuoperceptual coordination
  • Onset or increased frequency of seizures

Kilburn and Associates (1985) have suggested that static or declining grip strength may be an early indicator of shunt malfunction or Arnold Chiari Malfunction. Upper extremity weakness regardless of lesion level is often a sign of progressive loss of function. The emergence of spasticity where none was detected previously or an increase in spasticity or abnormal reflexes is presumed to be related to an underlying progressive loss of function requiring urgent attention until proven otherwise.

In addition to progressive spasticity, decline in motor or sensation or pain or a change in bladder or bowel function must be closely monitored. Spinal cord tethering at the site of initial spinal defect repair is a relatively common cause of loss of function.

Muscular Dystrophy

Muscular Dystrophy (M.D.) is a progressive diffuse weakness of all muscle groups characterized by a degeneration of muscle cells that are replaced by fat and fibrous tissue. There are several types of muscular dystrophy; the most common form is Duchenne Muscular Dystrophy. This is an inherited sex-linked disorder which affects males generally and has an incidence of about .02 per 1000 individuals. There are other less common types of Muscular Dystrophy which can affect females.

Parents are usually unaware of any difficulty until after the child starts walking. At this point the child's walk resembles that of a duck and he has difficulty climbing steps or getting up from a lying down position. Over time, ranging from months to years, the child becomes weaker and less mobile, eventually ending up in a wheelchair. Children with muscular dystrophy tend to lose function of proximal; muscles (e.g., shoulder) over distal muscles (e.g., hand). Besides causing weakness in the voluntary muscles, this disease also damages the involuntary muscles of the heart and diaphragm. Because of this, seldom to children with muscular dystrophy live beyond adolescence.

Classroom Issues Regarding Muscular Dystrophy

For most children with this condition the following issues will need to be addressed in the school setting:

  1. Proper positioning is important to prevent deformities and maximize function in all activities.
  2. The classroom staff may need to assist in maintaining range of motion through daily exercises; as the disease progresses deformities can occur rapidly.
  3. Feeding may need to be addressed with more intensity as the disorder progresses; adaptive feeding devices may be needed.
  4. Speech musculature has a tendency to deteriorate which may necessitate an augmentative or alternative system for communication.
  5. Special equipment may be needed to increase independence in performing fine motor and self help skills.
  6. Children with muscular dystrophy tend to tire easily.

Traumatic Brain Injuries

Open and penetrating head injuries will not be considered here.
Brain injury resulting from a closed head injury may be related to primary and secondary mechanical factors.

  1. Primary injuries are related to the forces that occur at the time of the initial impact.
  2. Secondary injury results from the forces that occur in relation to the impact, forces which account for a significant amount of the overall damage. i.e., one of the most frequent causes of secondary injury is cerebral edema (swelling of the brain) which left unchecked can lead to increased pressure in the brain leading to:
    • brain herniation
    • brain stem death, and
    • irreversible coma (Pang 1985)

Medical Intervention

Medical intervention for children with traumatic train injury may include:

  1. Surgery
  2. Drugs to decrease pressure
  3. Mechanical ventilation (hyperventilation) or assisted ventilation at a greater rate than usual to temporarily reduce pressure between the skull and the brain.

Rehabilitation

As medical technology improves survival rates we can expect to be increasingly involved with the rehabilitation of children with traumatic brain injury. Interventions to maintain or improve joint flexibility or prevent deformity include:

  1. Stretching
  2. Strengthening
  3. Positioning to prevent soft tissue contractures or deformity or to decrease the influence of abnormal postures.
  4. Positioning may be used to increase the tolerance to gravity to allow the circulation to adapt vertical body alignment.
  5. Balance and coordination exercises address problems of postural control.
  6. Transfer training to increase mobility.