Brain Abnormalities Demonstrated by Magnetic Resonance Imaging in Adult IDDM Patients With and Without a History of Recurrent Severe Hypoglycemia

Petros Perros; Ian J Deary; Robin J Sellar; Jonathan JK Best; Brian M Frier

doi:10.2337/diacare.20.6.1013

Original Articles

Brain Abnormalities Demonstrated by Magnetic Resonance Imaging in Adult IDDM Patients With and Without a History of Recurrent Severe Hypoglycemia

Petros Perros, MD,
Ian J Deary, PHD,
Robin J Sellar, FRCR,
Jonathan JK Best, FRCR and
Brian M Frier, FRCP

Department of Diabetes, University of Edinburgh Edinburgh, U.K
Royal Infirmary of Edinburgh, Department of Psychology, University of Edinburgh Edinburgh, U.K
University of Edinburgh, Department of Clinical Neuroradiology, University of Edinburgh Edinburgh, U.K
Western General Hospital, Department of Medical Radiology, University of Edinburgh Edinburgh, U.K

Address correspondence and reprint requests to Petros Perros, MD, Ward 15, Freeman Hospital NHS Trust, Freeman Road, Newcastle upon Tyne NE7 7DN, U.K.

Diabetes Care 1997 Jun; 20(6): 1013-1018. https://doi.org/10.2337/diacare.20.6.1013

Abstract

OBJECTIVE Previous studies of a cohort of 100 patients with IDDM have shown that a history of recurrent severe hypoglycemia is associated with a modest impairment of cognitive function. The aim of the present study was to determine whether IDDM patients with and without a history of severe hypoglycemia have lesions in the brain that are identifiable by magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) and to investigate the putative relationship of any structural brain abnormalities with cognitive function.

RESEARCH DESIGN AND METHODS MRI and MRS of the brain were performed in 22 patients from the original cohort. Eleven IDDM patients with no history of severe hypoglycemia (group A) were compared with 11 IDDM patients who had a history of five or more episodes of severe hypoglycemia (group B).

RESULTS Nine patients (41%) had abnormal scans. Two types of abnormalities were observed: high-intensity rounded lesions, > 3 mm in diameters, distributed in the periventricular white matter (leukoaraiosis) in four patients; and cortical atrophy in five patients. Five patients in group B had cortical atrophy, whereas no patient in group A demonstrated this feature (P < 0.05). MRS of the frontal and parietal lobes showed no differences in the N-acetyl aspartate/creatine or N-acetyl aspartate/choline ratios between groups A and B. Patients with cortical atrophy showed a nonsignificant trend toward reduced performance on Rapid Visual Information Processing.

CONCLUSIONS Brain abnormalities demonstrated by MRI are common in patients with IDDM of long duration and are suggestive of premature aging of the brain. IDDM per se may be an important pathogenic factor, but a significant association was observed between a history of recurrent severe hypoglycemia and cortical atrophy, which may be related to the modest impairment of cognitive function that has been reported previously.