Type 1 diabetes mellitus (T1DM) is an autoimmune disease in which the insulin producing cells in the islets of Langerhans have been destroyed. Insulin is necessary for a normal glucose metabolism and is particularly important to stimulate glucose uptake when plasma glucose levels increase, e.g. after a meal. the work performed in this thesis contributes to a better understanding of cerebral glucose uptake and metabolism under hypoglycemic conditions in normal subjects and in patients with type 1 diabetes. Dynamic C-13 MR spectroscopy, although technically demanding, is a valuable technique to investigate brain glucose metabolism in humans, in vivo. Recurrent hypoglycemic incidents as experienced by patients with T1DM can induce cerebral adaptations that may protect cerebral functioning.