[Functional relationships between the cerebrum and cerebellum or the cerebral cortex and deep gray matter in normal subjects and patients with Alzheimer's type dementia].

Since the various parts of the central nervous system are functionally interconnected, functional relationships between one region and another would be expected to be present. We investigated whether functional relationships between the cerebrum and cerebellum or between the cerebral cortex and deep gray matter exist in normal subjects and patients with Alzheimer's type dementia (AD), using the indicator of asymmetry in cerebral blood flow. Eighteen normal subjects (average age: 72.6 +/- 11.4 years) and 21 patients with AD (average age: 75.5 +/- 8.1 years) were studied in the resting state using SPECT with 123I-IMP. The asymmetry index (AI) of blood flow for matched left-right regions of interest was calculated as follows: AI = (R-L)/(R + L)/200(%) (R: right side, L: left side). For both the normal and AD groups, we found a negative correlation between AI in the cerebrum and AI in the cerebellum. The AIs of widespread cortical subregions, except the occipital cortex, were significantly correlated with AI in the cerebellum in the AD group. On the other hand, the only significant correlation found in normal subjects was between the AIs of the frontal cortex and cerebellum. A positive correlation between the AIs in the cerebral cortex and deep gray matter was observed in both the normal and AD groups. Though only the upper frontal and parietal cortices showed significant correlations with the deep gray matter in normal subjects, more extensive cortical subregions showed significant correlations in AD patients.(ABSTRACT TRUNCATED AT 250 WORDS)