A 3-month-old boy is brought to the clinic by his mother ...

The headache came on suddenly as he was leaving the light show at the planetarium. He also has right eye pain and nausea and he vomited twice during the car ride over to the hospital. He has no significant past medical history. He has had other headaches in the past, but has never experienced anything like this. His temperature is 36.7 C (98.0 F), blood pressure is 130/90 mm Hg, pulse is 75 ... ................
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