The brain stem tumour, while non-malignant, is inoperable; if it grows, he will die.

He suffered a head injury so catastrophic it damaged his brain stem irrevocably.

The cerebellum is at the base of the skull, behind the brain stem.

The human brain is essentially made up of the cerebrum, the cerebellum and the brain stem.

Slowly the radiologist tracked back and, increasing the resolution, focused on the critical region around the brain stem.