On AAMC FL 1 B/B #55 it states that the brain uses insulin-independent methods of glucose uptake which is why diabetic brains receive adequate nourishment. I was wondering if anyone knew why pts with high blood sugar then had altered mental status and can often appear "drunk"? Is it because of the high concentration? I tried to google it but couldn't figure out how to word it.
Thanks!
The brain, like any organ, works best under normal, physiological conditions. When there are imbalances, homeostatic mechanisms kick in to restore to normal levels. But sometimes, feedback mechanisms don't work and can actually worsen the problem, leading to abnormal signs and symptoms.
Altered mental status is one medical symptom and indicates that something is going wrong. In cases of high blood sugar levels, the brain uses glucose transporters to take in as much glucose as possible. But glucose transport occurs via facilitated diffusion because glucose is a polar molecule. Transporters have a limit on how much glucose they can transport, and once that limit is exceeded, there will still be excess glucose in the blood. That's why insulin is helpful for stimulating glucose uptake but even that can fail in cases of uncorrected hyperglycemia. More glucose in the blood means increased plasma osmolarity. This leads to a medical complication called hyperosmolar hyperglycemic state which can be fatal if not immediately treated.
Hyperosmolar Hyperglycemic State: Background, Pathophysiology, Etiology