Which of the following is NOT an early sign of hydrocephalus in newborns?

The presence of elevated heart rate is not typically recognized as an early sign of hydrocephalus in newborns. Hydrocephalus is characterized by an accumulation of cerebrospinal fluid within the ventricles of the brain, leading to increased intracranial pressure. Common early signs of this condition include a bulging fontanelle due to increased pressure, poor feeding as the baby may be lethargic or irritable, and a downward gaze of the eyes, often referred to as "sunsetting" eyes, which occurs when the optic nerve is affected by the pressure changes.

In contrast, while an elevated heart rate may occur in a variety of medical conditions, it is not specific to hydrocephalus and can arise from numerous causes including stress, infection, or other physiological conditions in newborns. This makes elevated heart rate less relevant in the context of identifying early signs of hydrocephalus specifically.