Cerebral Palsy: An Overview
KAREN W. KRIGGER, M.D., M.ED., University of Louisville School of Medicine, Louisville, Kentucky
C
erebral palsy is characterized by
motor impairment and can pres-
ent with global physical and mental
dysfunction. In 2001, the United
Cerebral Palsy Foundation estimated that
764,000 children and adults in the United
States carried the diagnosis of cerebral palsy.
In addition, an estimated 8,000 babies and
infants, plus 1,200 to 1,500 preschool-age
children are diagnosed with cerebral palsy
every year in the United States.1
Etiology
Cerebral palsy is a static neurologic condition
resulting from brain injury that occurs before
cerebral development is complete. Because
brain development continues during the first
two years of life, cerebral palsy can result from
brain injury occurring during the prenatal,
perinatal, or postnatal periods.1,2 Seventy to
80 percent of cerebral palsy cases are acquired
prenatally and from largely unknown causes.
Birth complications, including asphyxia, are
currently estimated to account for about
6 percent of patients with congenital cere-
bral palsy.3 Neonatal risk factors for cere-
bral palsy include birth after fewer than
32 weeks’ gestation, birth weight of less than
5 lb, 8 oz (2,500 g), intrauterine growth retar-
dation, intracranial hemorrhage, and trauma.
In about 10 to 20 percent of patients, cerebral
palsy is acquired postnatally, mainly because
of brain damage from bacterial meningitis,
viral encephalitis, hyperbilirubinemia, motor
vehicle collisions, falls, or child abuse.3
Diagnosis
Observation of slow motor development,
abnormal muscle tone, and unusual posture
are common initial clues to the diagnosis
of cerebral palsy. Assessment of persistent
infantile reflexes is important. In infants
who do not have cerebral palsy, the Moro
reflex is rarely present after six months of
age, and hand preference rarely develops
earlier than 12 months of age. Hand prefer-
ence may occur before 12 months of age if
spastic hemip