What structure is at risk during a surgery that compromises the pterion region?

The temporal lobe of the brain is at risk during surgery that compromises the pterion region because the pterion is a critical anatomical landmark where the frontal, parietal, temporal, and sphenoid bones meet. It is situated just beneath a relatively thin layer of the skull. More importantly, the middle meningeal artery runs close to the pterion, which is a common site for epidural hematomas when there is trauma or injury. Therefore, any surgical intervention or trauma in this area poses a significant risk of injury to the temporal lobe, possibly leading to hematoma formation or other complications that arise from brain injury.

The other structures mentioned, while they may be adjacent to the pterion, do not have the same level of vulnerability in relation to the surgical risks associated with this specific area. The frontal and sphenoid sinuses, for example, are situated more anteriorly and inferiorly than the pterion region and are less directly impacted. The zygomatic arch is also located laterally and inferiorly compared to the pterion, making it less relevant in this context of potential brain injury.