Characteristics of cerebral glucose utilization in dementia.

To make clear the characteristics of cerebral glucose uterization in dementia, PET studies with 18F-FDG were carried out. Taking the pattern of 18F-FDG uterization, dementia can be subdivided into two types. One type shows a simultaneous and symmetrical reduction glucose uterization in the posterior part of neocortex covering the temporal, parietal and occipital association cortices. This is referred to as type I. Although this type constitutes only about 1/5 of all dementia patients, it is considered the fundamental type of dementia. Aside from this, there is type wherein a simultaneous and symmetrical reduction in glucose uterization of the neocortex. This is type II. It constitutes about 4/5 of all dementia patients which is far more type I. There are no essential difference in the characteristics of cerebral glucose uterization in AD and MID. However, with regards the mean, AD is lower than MID. Various organic defect in neocortex do not correlate with the global reduction in glucose uterization in dementia patients. These results suggest that the reduction in glucose uterization in dementia may be functional disorder.