Cerebral complications of diabetes: Clinical findings and pathogenetic mechanisms

This review describes the cerebral complications of diabetes mellitus from a neuropsychological, neurophysiological and neuroradiological perspective. In addition, possible pathogenetic mechanisms are discussed. Neuropsycholo gical studies of diabetic patients generally report modest deficits in lear ning and memory and information processing. Notably, in elderly diabetic pa tients cognitive deficits may be more prominent. Recent epidemiological stu dies show that in the elderly diabetes is associated with an increased risk for dementia. Neurophysiological studies show increased latencies of evoke d potentials and event-related potentials. Neuroradiological findings are e nhanced peripheral and central cerebral atrophy, as well as focal lesions. The pathophysiology of the effects of diabetes on the brain has not been fu lly elucidated. The putative involvement of cerebral metabolic and microvas cular disturbances, similar to those implicated in the pathogenesis of peri pheral diabetic neuropathy, is discussed. In addition, the role of repeated hypoglycaemic episodes, cerebrovascular disease and hypertension is addres sed. Finally, the potential differential effects of insulin dependent and n on-insulin dependent diabetes on the brain are discussed, as well as possib le links with brain ageing. (C) 1999 Elsevier Science B.V. All rights reser ved.