Final answer:
A hematoma was putting pressure on the brain, necessitating immediate neurosurgery.
Step-by-step explanation:
Based on the information provided, it is likely that the CT scan showed the presence of a hematoma (collection of blood) putting pressure on the brain. A strong blow to the lateral side of the head can cause fractures in the bones around the pterion, leading to bleeding and the formation of a hematoma. As blood accumulates, it exerts increasing pressure on the brain, necessitating immediate neurosurgery.