A mass in the left side of the head is moving the medial temporal lobe over, compressing the brainstem. The ipsilateral third nerve is compressed, dilating the ipsilateral pupil. The ipsilateral cerebral peduncle is compressed, causing contralateral hemiparesis. Brainstem reflexes are intact. The cold caloric brainstem reflexes begin to deteriorate.
Purposeful movement is lost.
Reflex movement patterns emerge, either decerebrate or decorticate. Both pupils are involved. Cold caloric brainstem reflexes are absent. The patient has lost pupil light reflexes, brainstem reflexes, and motor movement. The brain is irreversibly damaged and any theraputic intervention at this point would be futile.