Folkhälsan Institute of Genetics, Folkhälsan Research Center, Biomedicum Helsinki, University of Helsinki, Haarmaninkatu 8, P.O. Box 63, 00014 Helsinki, Finland.
Cerebellum. 2010 Sep;9(3):336-44. doi: 10.1007/s12311-010-0166-9.
In diabetic patients, proton magnetic resonance spectroscopy (¹H MRS) has revealed increased brain glucose concentration and metabolite alterations that indicate neuronal damage and glial cell activation. Cerebellum is known to be more resistant to hypoglycemia than cerebrum, but the effects of both chronic and acute hyperglycemia on the cerebellum are less well known. ¹H MRS was used to quantify brain glucose and metabolite levels in the cerebellum, cerebral cortex, cerebral white matter, and the thalamus of diabetic and nondiabetic men after an overnight fast and during a hyperglycemic normoinsulinemic clamp with blood glucose 12 mmol/l above baseline. Fasting glucose levels were twice as high in the cerebellum than in the cerebrum. During acute hyperglycemia, the cerebellar glucose concentration increased by 3.0 mmol/l, which equals that in the cortex, but is 35% more than in the thalamus and 173% more than in the white matter. Acute hyperglycemia also increased the cerebellar tissue water content by 10%. There were no differences between diabetic and nondiabetic participants. Notably, the patients with complication free type 1 diabetes showed brain metabolite alterations in the cerebral cortex and the white matter but not in the cerebellum. Our study suggests that diabetes does not alter glucose content or uptake in the cerebellum. The increase in tissue water during acute hyperglycemia may serve to protect the cerebellum from the potentially deleterious effects of the excess glucose.
在糖尿病患者中，质子磁共振波谱（¹H MRS）显示脑葡萄糖浓度增加和代谢物改变，表明神经元损伤和神经胶质细胞激活。小脑比大脑对低血糖更有抵抗力，但慢性和急性高血糖对小脑的影响知之甚少。¹H MRS 用于定量测量糖尿病和非糖尿病男性在禁食一夜后和血糖高于基线 12 mmol/l 的高血糖正常胰岛素血症钳夹期间小脑、大脑皮层、大脑白质和丘脑的脑葡萄糖和代谢物水平。空腹血糖水平在小脑是大脑的两倍。在急性高血糖期间，小脑葡萄糖浓度增加了 3.0 mmol/l，与皮层相同，但比丘脑高 35%，比白质高 173%。急性高血糖还使小脑组织水含量增加了 10%。糖尿病和非糖尿病参与者之间没有差异。值得注意的是，无并发症的 1 型糖尿病患者在大脑皮层和白质中出现脑代谢物改变，但小脑没有。我们的研究表明，糖尿病不会改变小脑的葡萄糖含量或摄取。急性高血糖期间组织水的增加可能有助于保护小脑免受过量葡萄糖的潜在有害影响。
