Diabetic Central Neuropathy: CNS Damage Related to Hyperglycemia

Diabetes is a syndrome defined by higher than normal blood glucose levels. Those higher blood glucose levels are associated with the development of physical abnormalities termed complications. Those abnormalities are found in small blood vessels and cause pathology termed retinopathy and nephropathy. Small-vessel abnormalities are part of cardiovascular and peripheral nerve pathology as well. Larger–blood vessel abnormalities are manifest as atherosclerotic plaques that stiffen and reduce blood flow while causing embolic occlusions. This results in ischemic hearts, lungs, and brains, causing life-devastating and -ending events. High glucose levels have been associated with nonvascular damage to the lens of the eye, peripheral nerve, myelin sheath, and nonmyelinated autonomic nerves. These abnormalities cause cataracts, loss of sensation, and proprioception, as well as dysregulation of autonomic function. Autonomic dysfunction compromises normal blood flow, gastric motility, temperature regulation, and sexual function. Preventing these issues has made lowering blood glucose a major goal in the management of diabetes. There has been little concern about the influence of hyperglycemia on the structure or function of the central nervous system (CNS). The major CNS concern related to diabetes is the opposite issue, hypoglycemia. The symptoms of hypoglycemia are very dramatic, involving intoxicated behavior and mentation, seizures, and loss of consciousness. On occasion, hypoglycemia-induced hemiparesis will result in an extensive medical evaluation and rehabilitation. Generally, these abnormalities are transient …