Brain metabolism after recurrent insulin induced hypoglycaemic episodes: a PET study.

Abstract

Neuropsychological testing was carried out and the rate of oxygen metabolism in the brain was measured by PET in 15 highly selected patients with type 1 diabetes. The aim was to investigate the impact on the brain of hypoglycaemic comas resulting from insulin treatment. No significant difference was found between nine patients with a history of more than 10 hypoglycaemic comas and six others who denied any history of such events. These data suggest that intensified insulin treatment, although increasing the frequency of hypoglycaemic coma, may not always be harmful for the brain. This may be explained by the limited duration of hypoglycaemic coma induced by conventional insulin treatment.

The Effects of Type 1 Diabetes on Cognitive Performance

“…We observed that the pattern and severity of cognitive changes in study populations of adult diabetic patients with an average age at diabetes onset Ͻ15 years were comparable to those with an average age at onset above this age. It should be noted, however, that studies that assessed cognition in children with diabetes (which were not included in the present metaanalysis) observed that a very early age at onset (before the age of 5 years) does ap- 29 -31,36,37,39,41), b ϭ (29,30,36,41), c ϭ (4,31,37,39,41), d ϭ (29,36,37,39), e ϭ (29,37,39), f ϭ (30,37,39,41), g ϭ (29,36), h ϭ (4,39,41), i ϭ (29,31,37,39,41), j ϭ (4,29,36,37,39), and k ϭ (29,39) pear to be associated with more severe impairments of cognitive performance (11,46). Our meta-analysis does not support the idea that there are important negative effects from recurrent episodes of severe hypoglycemia on cognitive functioning.…”

“…Eleven studies addressed the role of metabolic control, defined as a dichotomous variable, on cognition (3,7,21,28,30,(33)(34)(35)37,42,43) (Table 2). A qualitative analysis of the data presented in Table 3 shows no consistent difference between the "well" and "poorly" controlled groups.…”

Diffusion Tensor Imaging Identifies Deficits in White Matter Microstructure in Subjects With Type 1 Diabetes That Correlate With Reduced Neurocognitive Function

“…If such a biomarker can be developed, future study could focus on identifying interventions that can prevent the appearance or slow the progression of white matter microstructural changes in patients with diabetes. Over the last 10 years, investigators have used a variety of imaging techniques, including MRI, single photon emission computed tomography (30,31), and positron emission tomography (32), to determine whether structural abnormalities could be identified in the brains of patients with (36), and decreased cerebral gray matter density (37,38) in type 1 diabetic subjects. Some of these structural abnormalities have corresponded to age of diabetes onset (35), A1C levels, hypoglycemia (37), and the presence of retinopathy (38).…”

Microvascular Disease in Type 1 Diabetes Alters Brain Activation

“…In diabetic patients who have a history of recurrent, severe hypoglycemia, the regional blood flow changes were observed to be present during normoglycemia and may represent a cerebral adaptation to recurring hypoglycemic insults (39,40). In a study performed by Chabriat et al (41), no differences were found in neuropsychological test performance and rate of oxygen metabolism measured by position emission tomography scanning in patients with a history of Ͼ10 hypoglycemic comas compared with those without a history of comas. Patients with angiopathic complications were excluded.…”