Understanding Cerebral Palsy

Cerebral Palsy

• Cerebral palsy (CP) is a neurodevelopmental condition affecting movement and posture, beginning in early childhood and lasting throughout life.
• CP was originally reported by Little in 1861, initially called "cerebral paresis".
• According to the American Academy for cerebral palsy and developmental medicine (1977), CP refers to a non-progressive central nervous system (CNS) deficit.
• Lesions in the brain, either single or multiple, lead to motor and sometimes sensory abnormalities.
• CP can be caused by factors present during pregnancy (in-utero), labor and delivery (congenital), or various factors during early development (acquired).
• CP involves a group of permanent disorders that occur in early development.
• CP is attributed to non-progressive disturbances in the developing fetal or infant brain, limiting activity.

Definition of CP

• Bax (1964) defined CP as a movement and posture disorder stemming from a defect or lesion in the immature brain.
• Mutch and colleagues (1992) redefined CP as an umbrella term for non-progressive (but often changing) motor impairment syndromes stemming from brain lesions/anomalies in the early stages of development.

Incidence and Prevalence

• Approximately 550,000-764,000 Americans have a CP diagnosis.
• Approximately 9,750 new cases occur annually.
• The incidence of CP in developed countries is estimated at 2-2.5 per 1,000 live births.
• Spastic diplegia has increased in prevalence among CP cases.
• Incidence is generally slightly higher in premature neonates, largely due to anoxia).
• CP is somewhat more prevalent in males

Risk Factors

• 70-80% of CP cases are attributed to antenatal risk factors (prematurity, low birth weight, intrauterine infections, multiple gestation, pregnancy complications)
• 10% of CP cases are attributed to perinatal risk factors (birth asphyxia, complicated labor and delivery)
• Postnatal risk factors include non-accidental injuries, head trauma, meningitis, encephalitis, cardio-pulmonary arrest
• Obstetrical care factors can reduce risks such as magnesium sulfate, antibiotics, and corticosteroids

Genetic Causes

• Genetic causes of CP account for only about 2% of diagnosed cases.
• Examples of rare genetic disorders linked to CP include Joubert syndrome, Marinesco-Sjogren syndrome, Gillespie syndrome, and Behr syndrome, all characterized by ataxia.

Maternal Disorders

• Maternal disorders that reduce fetal blood supply, such as bleeding during pregnancy, placental infarction, toxemia/pre-eclampsia, small size for gestational age due to the mother's diabetes, and multiple pregnancies, can increase the risk of CP.
• Infectious conditions like meningitis and encephalitis contribute to CP.

Other Medical Conditions

• Late-onset hydrocephalus can cause CP, as well as neoplastic intracranial lesions (brain tumors) and intracranial hemorrhage from an arteriovenous malformation.

Types of Cerebral Palsy

• CP can be classified into five common types (spastic, dyskinetic, ataxic, hypotonic, and mixed) based on muscle tone and movement characteristics.

Spastic Cerebral Palsy

• Characterized by muscle stiffness (throughout involved extremities and trunk).
• Movements are slow because of stiffness.
• Movement directions are often accurate.
• Range of movement tends to be reduced.
• Contractures and deformities can develop.

Dyskinetic Cerebral Palsy

• Characterized by involuntary movements (slow, writhing).
• Movement reversal is common.
• Movement direction is often imprecise.

Hypotonic Cerebral Palsy

• Characterized by diminished muscle tension.
• Reduced voluntary muscle strength.
• Excessive joint flexibility and postural instability are common.

Ataxic Cerebral Palsy

• Characterized by poor balance, coordination, and imprecise timing of movements.
• Impaired postural control and disordered balance are common.

Acquired Cerebral Palsy

• Individuals who experience brain damage after birth, before full neurological development, are classified as having acquired CP.
• This includes those who suffered brain damage due to infections or traumatic brain injuries in early childhood.
• This group of CP individuals is more varied and complex in etiology, distribution of neuromotor dysfunction, and associated conditions.
• Acquired CP is not often used to describe this group.

Abnormal Oral Movements & Posture

• Lip retraction: Increased muscle tone pulling lips back, tight cheeks, visible gum ridge, feeding difficulty.
• Jaw thrust & jaw grading lack: Forceful downward jaw extension, arrhythmic jaw movement, or absence of jaw movement. A lack of jaw grading or proper jaw control.
• Tonic Bite: Strong, rapid bite to stimuli, difficulty releasing the bite.
• Tongue retraction: Tight tongue held back in the oral cavity, limited movement, trouble removing utensils, and food in the mouth.
• Tongue thrust: Extrusion reflex, tongue might appear thick, difficulty transferring food to mouth.
• Nasal regurgitation: Backward flow of liquid/semi-digested food through nasal passages, reflecting abnormal velopharyngeal function.

Classification based on topographical distribution

• Paresis and plegia: Broad term for muscular weakness/paralysis.
• Monoplegia: Affects one limb.
• Diplegia/paresis: Affects symmetrical limbs.
• Hemiplegia: Affects one side of the body.
• Paraplegia: Affects the lower limbs.
• Quadriplegia: Affects all four limbs.
• Pentaplegia: Affects all five limbs (extremely rare).