Brain death is said to occur if there
is:
March 2008
a) Absent spinal reflexes
b) Cortical death following widespread brain injury
c) Absence of brainstem reflexes
d) Core temperature of the body is below 35 degree C
Correct Answer - C
Ans. C: Absence of brainstem reflexes
Brainstem is responsible for the respiratory drive and mostly for the
maintenance of BP. All motor outputs from the brain travel through
the brainstem. Apart from smell and vision. All sensory traffic coming
into the brain comes through the brainstem. The brainstem also
mediates the cranial nerve reflexes. Hence a properly functioning
brain stem is a precondition for full consciousness.
Irreversible brain damage and loss of brain function, is evidenced by
cessation of breathing and other vital reflexes (mediated by brain
stem), unresponsiveness to stimuli, absence of muscle activity, and
a flat electroencephalogram for a specific length of time.