hydrocephalus /-sef″ələs/ [Gk, hydor + kephale, head] , a pathological condition characterized by an abnormal accumulation of cerebrospinal fluid, usually under increased pressure, within the cranial vault and subsequent dilation of the ventricles. Interference with the normal flow of cerebrospinal fluid may result from increased secretion of the fluid, obstruction within the ventricular system (noncommunicating or intraventricular hydrocephalus), or defective resorption from the cerebral subarachnoid space (communicating or extraventricular hydrocephalus). Hydrocephalus may be caused by developmental anomalies, infection, trauma, or brain tumors. Also called hydrocephaly. See also macrocephaly. −hydrocephalic, adj., n. ▪ OBSERVATIONS: The condition may be congenital, with rapid onset of symptoms, or it may progress slowly so that neurological manifestations do not appear until early to late childhood or even early adulthood. In infants the head grows at an abnormal rate with separation of the sutures, bulging fontanels, and dilated scalp veins. The face becomes disproportionately small, and the eyes appear depressed within the sockets. Typical behavior includes irritability with lethargy and vomiting, opisthotonos, lower extremity spasticity, and failure to perform normal reflex actions. If the condition progresses, lower brainstem function is disrupted; the skull becomes enormous; the cortex is destroyed; and the infant displays somnolence, seizures, and cardiopulmonary obstruction and usually does not survive the neonatal period. At later onset, after the cranial sutures have fused and the skull has formed, symptoms are primarily neurological and include headache, edema of the optic disc, strabismus, and loss of muscular coordination. Hydrocephalus in infants is suspected when head growth is observed to be in excess of the normal rate. In all age groups, diagnosis is confirmed by such procedures as cerebrospinal fluid examination, computed tomography, air encephalography, arteriography, and echoencephalography. ▪ INTERVENTIONS: Treatment consists almost exclusively of surgical intervention to correct the ventricular obstruction, reduce the production of cerebrospinal fluid, or shunt the excess fluid by ventricular bypass to the right atrium of the heart or to the peritoneal cavity. Surgically treated hydrocephalus with continued neurosurgical and medical management has a survival rate of approximately 80%, although prognosis depends largely on the cause of the condition. Hydrocephalus is frequently associated with myelomeningocele, in which case there is a less favorable prognosis. ▪ PATIENT CARE CONSIDERATIONS: Primary care of the child with hydrocephalus consists of maintaining adequate nutrition, proper positioning and support to prevent extra strain on the neck, and assistance with diagnostic evaluation and procedures. After surgery, in addition to routine care and observation to prevent complications, especially infection, the nurse gives support to the parents and teaches them how to care for a child with a functioning shunt, specifically how to recognize signs that indicate shunt malfunction or infection and how to pump the shunt.
