4 – Neuropathology of circulatory arrest
The second paper of Miller and Myers described
the neuropathology found in the brain after subjecting
monkeys to circulatory arrest [1]. The pattern of
damage was almost identical to that produced by
asphyxiation of monkeys at birth.
After 12 minutes of circulatory arrest, the injury was
described as "relatively mild," and even after 14
minutes, a tendency for minimal or no injury was
reported. After 16 minutes of arrest, severe
involvement was evident in a greater proportion of
animals, but the comment was made that this severe
involvement was restricted in its distribution, to the
inferior colliculus and Purkinje cells of the cerebellum.
After 20 minutes of circulatory arrest only a few of the
animals were found to show severe involvement of
brainstem structures other than the inferior colliculus.
Only after 24 minutes of circulatory arrest was major
injury throughout the brainstem noted, but in none of
the animals was injury to the cerebral cortex observed.
The brainstem structures most frequently involved
were the inferior colliculus, superior olives, vestibular
nuclei, etc., the same sites damaged by asphyxiation
of newborn monkeys. The rank order of brainstem
centers was acknowledged to correspond to the rank
order of blood flow rates determined through use of
radioactive tracers. But no functional importance was
attributed to the inferior colliculus, Purkinje cells, or
other predilection sites of injury.
Animals who developed periods of post-arrest
hypotension did sustain injury throughout the cerebral
cortex, which corresponded to what is usually found in
humans following resuscitation from cardiac arrest.
Much more importance was attributed to this pattern
of damage than to that of "focal brainstem injury," and
post-arrest hypotension was identified as a major
variable affecting clinical outcome following circulatory
arrest.
What accounts for the cerebral cortical injury pattern
associated with arterial hypotension was left as a
problem for future research studies.
- Miller JR, Myers RE
(1972) Neuropathology of
systemic circulatory arrest
in adult monkeys.
Full reference
- Miller JR, Myers RE. Neuropathology of systemic circulatory arrest in adult
monkeys. Neurology. 1972 Sep;22(9):888-904.