ClarificationsWiki probably redirects there because cranial contusion isn't a common term. Something got lost in translation I imagine. (hopefully the 'lost' isnt a confusion b/w cranial and cerebral)
The characters used in 頭部挫創 which I translated as cranium contusion (in the Health Updates thread), meaning contusion on the cranium or simply put bruise on the part of the head that is not the jaw, has absolutely nothing to do with the brain. Please everyone don't confuse cranium with cerebral nor contusion with concussion, these things are completely different.
I don't even think it's a bone contusion (i.e. bone tissue of the cranium), just a bruise located on the cranium part of the head (i.e. soft tissue bruise) because 1) the Japanese characters didn't say "bone contusion" and 2) from what I understand bone contusions can take very very long to heal.