Which finding in an infant would most likely indicate hydrocephalus?

The presence of sunsetting eyes in an infant is a significant indicator of hydrocephalus. This phenomenon occurs when the eyes appear to be driven downward, exposing the sclera above the cornea, which is often due to increased intracranial pressure associated with an accumulation of cerebrospinal fluid in the ventricles of the brain. The condition can affect the positioning of the eyes as the brain and surrounding structures are altered by the increased pressure.

While other findings might be associated with various conditions, they do not specifically indicate hydrocephalus as clearly as sunsetting eyes. For instance, a pulsating fontanel can be observed in a variety of situations and may not be exclusive to increased intracranial pressure. Increased blood pressure is more commonly associated with older children or adults rather than infants and does not directly identify hydrocephalus. A positive glabellar reflex is a normal reflex in infants and does not provide specific information regarding hydrocephalus.