Catastrophic factors prevent protective mechanisms
from going into action.
Suffocation, circulatory arrest, or any factor that disrupts
aerobic metabolism can cause damage or impair function
in the auditory system, especially the inferior colliculi.
The picture to the right shows
damage of the inferior colliculi in
a human patient maintained on
prolonged parenteral feeding
that lacked vitamin B1.
Vitamin B1 is an essential
coenzyme for aerobic enzymes.
Any toxic substance that crosses
the blood-brain barrier can
disrupt aerobic enzymes and
cause the same kind of damage.
From Vortmeyer AO et al. (1992) Haemorrhagic
thiamine deficient encephalopathy following
prolonged parenteral nutrition. Journal of Neurology,
Neurosurgery and Psychiatry 55:826-829.
Alcohol intoxication has long
been known to cause a brainstem
pattern of damage that often
involves the inferior colliculi.