COGNITIVE IMPAIRMENT IN PATIENTS WITH TYPE-1 (INSULIN-DEPENDENT) DIABETES-MELLITUS - INCIDENCE, MECHANISMS AND THERAPEUTIC IMPLICATIONS

Patients with type 1 (insulin-dependent) diabetes mellitus can experie nce both very low and very high blood glucose levels that may affect t he CNS. Over time, high glucose levels (hyperglycaemia) may result in ketoacidosis, seizures, coma and death, Although a wide variation in r esponse exists, acute hypoglycaemia (low blood sugar level) generally results in a decrease in tile supply of glucose to the brain. Progress ively lower glucose levels can result in confusion, inability to conce ntrate or cogitate. seizures, coma or death. Much progress has been ma de in the understanding of systemic and brain glucose metabolism, and the metabolic changes that are associated with type diabetes mellitus. Research during the last 2 decades has clarified specific cognitive f unction and cognitive deficits during glucose fluctuations, particular ly hypoglycaemia. In addition, recent research efforts have attempted to differentiate between the acute and chronic influences of glycaemic level on brain physiology and function, and tu determine if glucose f luctuations lead to permanent intellectual impairment. Additional stud ies have examined the mechanisms underlying the potentiating effect of alcohol (ethanol) on insulin-induced hypoglycaemia. Finally, clinical interventions have been developed that are directed at the prevention and early treatment of hypoglycaemia through cartful management of in sulin dose and timing and through extensive patient and family educati on.