The good news is that the neurons themselves don't seem to get damaged too much, so the changes might be reversible. At least, that's what of one group of researchers hopes, based on preliminary research.
From Rockefeller University - Newswire:
The estimated 1 million people in the United States with type 1 diabetes know that uncontrolled high blood sugar can attack the body’s organs. New research from Rockefeller University’s Bruce McEwen and colleagues at the University of South Carolina shows that the brain is one target of the disease, and that diabetes’ effects on it may be reversible.
The changes McEwen and colleagues saw in one protein, synaptophysin, which is important for synapse function, indicates that not only have the connections between neurons in the hippocampus been reorganized, but the reorganization is more extensive than scientists previously thought. These alterations may explain why complications of diabetes and also the effects of high levels of glucocorticoids often include problems with memory and other cognitive impairments.
The results show, however, that, in spite the alterations in brain circuits, there was little damage to the neurons themselves; meaning that if the right measures are taken, the changes may be reversible....