Abnormal enlargement of a toddler's head
Headache
Nausea or vomiting
Fever
Delays in walking or talking
Problems with previously acquired skills, such as walking or talking
Blurred or double vision
Unstable balance
Poor coordination
Irritability
Change in personality
Problems with attention
Decline in school performance
Poor appetite
Seizures
Sleepiness
Difficulty remaining awake or waking up

Infants (beside the symptoms mentioned):

An unusually large head
A rapid increase in the size of the head
A bulging or tense soft spot (fontanel) on the top of the head
Vomiting
Sleepiness
Irritability
Poor feeding
Seizures
Eyes fixed downward (sunsetting of the eyes)
Deficits in muscle tone and strength, responsiveness to touch, and expected growth