Gm. Decourtenmyers et al., NORMOGLYCEMIA (NOT HYPOGLYCEMIA) OPTIMIZES OUTCOME FROM MIDDLE CEREBRAL-ARTERY OCCLUSION, Journal of cerebral blood flow and metabolism, 14(2), 1994, pp. 227-236
We examined the effects of serum glucose concentration during middle c
erebral artery (MCA) occlusion in the cat on death rates in animals th
at died from hemispheric edema and on infarct size in animals that sur
vived. We occluded the MCA permanently in some groups and released the
clip after 8 h in others. By injecting or infusing glucose solutions,
saline, or insulin, we maintained six animal groups steadily either h
yper-, normo-, or slightly hypoglycemic before and for 6 or 8 h after
permanent or 8-h temporary MCA occlusion. Studies with these groups re
vealed a distinct optimal outcome with normoglycemic animals. In three
additional groups, we altered the glycemia after permanent occlusion
from hyper- to normo- or hypoglycemia and from normo- to hyperglycemia
. Two of the three hypoglycemic groups (8-h reversible and permanent h
yper- to hypoglycemic occlusions) yielded the worst outcomes in this s
tudy, with >10x larger median infarcts than the best outcome group (no
rmoglycemic permanent occlusion). Hyperglycemia also was detrimental a
nd increased infarct size and mortality after permanent occlusion. Res
toring the cerebral blood flow after 8 h of occlusion increased the de
ath rate from hemispheric edema compared with a maintained occlusion.
Following permanent MCA occlusion, converting from normo- to hyperglyc
emia or vice versa yielded outcomes intermediate between a sustained n
ormo- or hyperglycemia. A regression analysis of the normo- and hyperg
lycemic groups and the two groups with glycemia altered after permanen
t occlusion showed a significant linear correlation between glycemia l
evel at and 1 h after MCA occlusion and median infarct size.