Sandbox cerebral palsy

Causes

Birth asphyxia is believed to be the principal etiology for cerebral palsy. However, recent studies demonstrated that 70% to 80% of cases of cerebral palsy are due to antenatal factors, while only 10% to 28% of cases are due to birth asphyxia in term and near-term infants. Causes of cerebral palsy are often multifactorial. For example, an intrauterine infection may result in growth restriction, maternal fever, and prematurity, all of which have been associated with cerebral palsy.

Prenatal causes

• Placental insufficiency
• Intrauterine infection
• Chromosomal abnormalities
• Maternal illness
  • Chorioamnionitis
  • Thyroid disease
  • Thrombotic disorders including factor V Leiden mutations
  • TORCH infections (toxoplasmosis, syphilis, rubella, cytomegalovirus, varicella zoster, HIV, herpes viruses)
• Multiple births
• Teratogen exposure
• Metabolic disorders
• Fetal brain malformation

Placental pathology

• Thrombotic lesions
• Placental ischemia has been associated with spastic diplegia
• Chronic villitis
• Pre-eclampsia

Perinatal causes

• Hypoxia-ischemia
• Neonatal encephalopathy
• Periventricular leukomalacia (PVL)
  • PVL increases the risk of cerebral palsy, independent of gestational age.
  • Approximately 75% of infants with cystic PVL develop cerebral palsy.
• Fetal/neonatal stroke
• Hyperbilirubinemia
• Hemolytic disease
• Kernicterus

Postnatal causes

• Stroke
• Trauma
• Infection

Cerebral palsy

Antenatal

Perinatal

Postnatal

Prematurity and low birth weight Intrauterine infections Multiple gestations Pregnancy complications

Birth Asphyxia complicated labour and delivery

Head trauma Meningitis Cardio-pulmonary arrest

In 2004 the International Executive Committee for the Definition of Cerebral Palsy revised the definition of cerebral palsy and described Cerebral palsy (CP) as a group of permanent disorders of the development of movement and posture, causing activity limitation, that are attributed to nonprogressive disturbances that occurred in the developing fetal or infant brain. The motor disorders of cerebral palsy often are accompanied by disturbances of sensation, perception, cognition, communication, and behavior, by epilepsy, and by secondary musculoskeletal problems.

Pathophysiology

Cerebral palsy is a heterogeneous disorder of movement and posture that has a wide variety of presentations, ranging from mild motor disturbance to severe total body involvement. Because of this variability in clinical presentation and the absence of a definitive diagnostic test, defining exactly what cerebral palsy is has been difficult and controversial. It is generally agreed that there are three distinctive features common to all patients with cerebral palsy:

• Some degree of motor impairment, which distinguishes it from other conditions, such as global developmental delay or autism
• An insult to the developing brain, making it different from conditions that affect the mature brain in older children and adults
• A neurologic deficit that is nonprogressive, which distinguishes it from other motor diseases of childhood, such as the muscular dystrophies.

Initial Insult

• The premature neonatal brain is susceptible to two main pathologies intraventricular hemorrhage (IVH) and periventricular leukomalacia (PVL).
• Although both pathologies increase the risk of cerebral palsy, periventricular leukomalacia is more closely related to cerebral palsy and is the leading cause in preterm infants.
• Both IVH and PVL cause cerebral palsy because of the corticospinal tracts, composed of descending motor axons, course through the periventricular region.
• The insult to the brain is believed to occur between the time of conception and age 2 years, at which time a significant amount of motor development has occurred.
• A similar injury to the brain after age 2 years can have a similar effect, however, and often is results in classic picture of cerebral palsy.
• By 8 years of age, most of the development of the immature brain is complete, as is gait development, and an insult to the brain results in a more adult-type clinical picture and outcome.

Disease progression

• Although the neurologic deficit is permanent and nonprogressive, the effect it can have on the patient is dynamic, and the orthopaedic aspects of cerebral palsy can change dramatically with growth and development.
• Growth, along with altered muscle forces across joints, can lead to progressive loss of motion, contracture, and eventually joint subluxation or dislocation, resulting in degeneration that may require orthopaedic intervention.
• Children with cerebral palsy constitute the largest group of pediatric patients with neuromuscular disorders in the United States. The prevalence of cerebral palsy varies around the world according to the amount and quality of prenatal care, the socioeconomic condition of the parents, the environment, and the type of obstetric and pediatric care the mother and child receive. The determination of the true prevalence also is difficult because many children are not diagnosed until age 2 or 3 years; this most often occurs in socioeconomic groups that have decreased access to medical care. In the United States, the occurrence is approximately two per 1000 live births; there are approximately 25,000 new patients with cerebral palsy each year, and approximately 400,000 children with cerebral palsy at any given time. The United States experienced an initial decrease in the number of affected children in the 1950s and 1960s as a result of better understanding and treatment of maternal-fetal Rh incompatibility and improvements in obstetric techniques. More recently, the prevalence of cerebral palsy was thought to be increasing because of the increased survival of premature and low-birth-weight infants; however, two large population-based studies showed that the improved survival of these infants has not contributed to the increase in prevalence of cerebral palsy in the United States. Worldwide, the prevalence ranges from 0.6 to 7.0 cases per 1000 live births. The cost of operative treatment in children with cerebral palsy is substantial. In 1997, there were an estimated 37,000 operative procedures performed, with the most common being gastrostomy tube placements, soft-tissue releases, fundoplications, spinal fusions, and hip osteotomies. These procedures accounted for 50,000 hospital days and $150 million in charges.

Injury to the developing brain can occur at any time from gestation to early childhood and typically is categorized as prenatal, perinatal, or postnatal. Contrary to popular belief, fewer than 10% of injuries that result in cerebral palsy occur during the birth process, with most occurring in the prenatal period. A wide variety of risk factors for cerebral palsy have been identified in the prenatal period, including risk factors inherent to the fetus (most commonly genetic disorders), factors inherent to the mother (seizure disorders, mental retardation, and previous pregnancy loss), and factors inherent to the pregnancy itself (Rh incompatibility, polyhydramnios, placental rupture, and drug or alcohol exposure). External factors, such as TORCH syndrome (toxoplasmosis, other agents, rubella, cytomegalovirus, herpes simplex), also can lead to cerebral palsy in the prenatal period. Occurrences in the absence of any known risk factors may be caused by some yet unknown factor during this critical time in brain development. Several more recent studies have suggested a possible role of chorioamnionitis as one of these factors.

Cerebral palsy in the perinatal period, from birth until a few days after birth, typically is associated with asphyxia or trauma that occurs during labor. Oxytocin augmentation, umbilical cord prolapse, and breech presentation all have been associated with an increased occurrence of cerebral palsy. Only 10% of cases of cerebral palsy occur during this time period, and most patients with cerebral palsy have no history of asphyxia. Although cerebral palsy is often associated with low Apgar scores during this period, many neonates have low scores because of other conditions, such as genetic disorders, that are completely unrelated to asphyxia. Low-birth-weight infants (<1500 g) are at dramatically increased risk of cerebral palsy, with an incidence of 60 per 1000 births compared with two per 1000 births in infants of normal weight. This increased incidence is believed to be caused by the fragility of the periventricular blood vessels, which are highly susceptible to physiologic fluctuations during pregnancy ( Fig. 33-1 ). These fluctuations, which include hypoxic episodes, placental pathology, maternal diabetes, and infection, can injure these vessels and lead to subsequent intraventricular hemorrhages. These injuries are graded on a scale from I to IV ( Table 33-1 ), with an increased incidence of neurologic consequences such as hydrocephalus and cerebral palsy in grade III (bleeding into ventricles with dilation) and grade IV (bleeding into brain substance). In addition, the periventricular area, which is important for motor control, is especially susceptible from the 26th to the 32nd week of pregnancy. If this area is injured, diplegia usually results. Often, a synergistic combination of events leads to brain injury and the subsequent development of cerebral palsy. Pregnancies involving multiple births also are at increased risk for cerebral palsy, primarily because of their association with premature delivery.

Classification

The Manual Ability Classification System (MACS) describes how children with cerebral palsy (CP) use their hands to handle objects in daily activities. MACS describes five levels. The levels are based on the children’s self-initiated ability to handle objects and their need for assistance or adaptation to perform manual activities in everyday life.

Does the child handle most kind of daily activities independently ( during play and leisure, eating and dressing)

Yes

No

Does the child handle even more difficult tasks with fair speed and accuracy and does not need alternative ways to perform

Does the child perform number of mannual tasks which commonly need to prepared or adapted and help is needed occasionally

Yes

No

Yes

No

Level 1 Handles objects easily and successfully

Level 2 Handles most objects with reduced quality and speed of acheivement

Level 3 Handles objects with difficulty but needs preparation

Can the child perform easy activites with frequent support

Yes

No

Level 4 Handles easy activites with limitations and support

Level 5 Cannot handle daily activites has severely limited abilities to perform even simple actions

Prognosis

• Prognosis for motor functions in patients with cerebral palsy depends on the type and severity of motor impairment.
• Individuals with cerebral palsy on average have a life expectancy that is 44% of normal.
• Mortality risk increases with increasing number of impairments.
• The strongest predictors of early mortality are immobility and impaired feeding ability.