Chapter 37 Hydrocephalus
PATHOPHYSIOLOGY
Hydrocephalus may be congenital or acquired. Congenital hydrocephalus is frequently associated with other congenital neurologic disorders or malformations. Some of the most commom associated diagnoses are myelomeningocele, Arnold-Chiari malformation, and aqueduct stenosis. The genetic factors that lead to hydrocephalus are unknown, with the exception of congenital X-linked hydrocephalus, which accounts for less than 4% of all cases. Acquired hydrocephalus may be caused by maternal malnutrition, intrauterine infections, tumors, vascular malformations, abscesses, intraventricular cysts, intraventricular hemorrhage, meningitis, and cerebral trauma. Causes of hydrocephalus are commonly labeled as idiopatic, infectious, hemorrhagic, posttraumatic, or tumor-related. Regardless of the cause, the result is a blockage of cerebral spinal fluid (CSF) flow and absorption secondary to microscopic changes in the CNS tissue or mechanical obstruction of the CSF circulation. Less than 0.5% of all cases of hydrocephalus are caused by overproduction of CSF. Excessive accumulation of CSF leads to ventricular enlargement and increased intracranial pressure (ICP) that may contribute to further CNS tissue damage. Children with hydrocephalus are at risk for both physical and cognitive delays; however, many benefit from physical and educational interventions and go on to live happy, healthy lives.
CLINICAL MANIFESTATIONS
Signs and symptoms are the results of ICP and vary with the child’s age and the skull’s ability to expand.
