The given video gives and overview of functions of brain stem and explains the diagnostic methods used to diagnose brain stem death which include bed side tests consisting of reflex plus apnea test and different confirmatory investigations. Timeline: 0:00 – Introduction 0:26 – Overview of brain stem 0:58 – Diagnostic methods of brain stem death 1:23 – Bed side test: reflexes 2:39 – Bed side test: apnea test 6:03 – Confirmatory tests