In a 6-month-old male with bulging anterior fontanelle and growth curve changes, what is the most likely diagnosis?

In a 6-month-old infant exhibiting signs of a bulging anterior fontanelle along with altered growth curves, the most likely diagnosis is hydrocephalus. The anterior fontanelle is the soft spot on the infant's head, which can bulge due to increased intracranial pressure—a hallmark symptom of hydrocephalus. This condition occurs when there is an accumulation of cerebrospinal fluid (CSF) within the ventricles of the brain, leading to increased pressure and, consequently, an abnormal growth pattern.

Hydrocephalus can manifest in various ways in infants, including changes in head circumference that may correlate with the growth curve changes mentioned. The bulging fontanelle is typically accompanied by other signs, such as irritability, vomiting, and developmental delays, which further point towards this diagnosis.

Other conditions, such as intracranial hemorrhage, meningitis, and brain tumors, can present with similar symptoms, but they generally include additional specific signs or symptoms that may be more acute or different in nature. Intracranial hemorrhage often results from birth trauma and may present with sudden changes in neurological status rather than a gradual bulging fontanelle. Meningitis typically presents with fever, irritability, and