Pediatric emergency medicine trisk 4010 4010

Current Evidence. Infections are a common cause of hydrocephalus in
infants and children. An estimated 1% of pediatric patients who survive
bacterial meningitis, including gram-negative organisms (particularly
Escherichia coli ) which occur most frequently in the neonatal age group,
Haemophilus influenzae, Streptococcus pneumoniae, and group B
streptococci, develop progressive hydrocephalus. Other less common
infectious causes of hydrocephalus in children include tuberculosis
meningitis whose worldwide prevalence is rising, toxoplasmosis (or other
members of the TORCH group) usually diagnosed in the perinatal period,
and viral meningitis and encephalitis. Head trauma has been recognized as a
common cause of hydrocephalus. About 4% of patients develop
posttraumatic hydrocephalus requiring surgical CSF diversion. True
congenital hydrocephalus, meaning hydrocephalus present at birth, has an
estimated incidence of 0.2 to 0.8/1,000 live births in the United States. The
incidence of congenital hydrocephalus associated with conditions, such as
Dandy–Walker
malformation
(approximately
85%
to
95%),
myelomeningocele (approximately 80% to 90%), and IVH of prematurity
(approximately 35%), is better established.
Midline arachnoid cysts and tumors related to the ventricular system can
cause hydrocephalus by obstruction of the CSF pathways. Tumors may also
cause hydrocephalus by spilling blood or protein into the CSF, making the
CSF more viscous, overloading the absorptive capacity of the arachnoid
villi, and resulting in a communicating hydrocephalus.

Clinical Considerations
Clinical Recognition. Infants presenting symptoms include macrocephaly,

bulging fontanelle, excessive irritability, lethargy, or vomiting. Sunsetting
of the eyes may be present. This usually occurs later in the clinical course
and consists of a spectrum of findings, including components of Parinaud
syndrome (downward eye deviation, lid retraction, and convergenceretraction nystagmus). As raised ICP progresses, infants may develop
bradycardia and/or apneic episodes.
In older children, the more common presenting symptoms include
headache, nausea, or vomiting. These symptoms tend to be more common
in the mornings, when ICP is higher after having been recumbent overnight.
Other symptoms may include visual field deficits or double vision. This