Abstract: ObjectiveTo explore the early diagnosis of Alzheimer's disease (AD),the arithmetic calculation ability in the patients with mild cognitive impairment (MCI) was detected under the functional magnetic resonance imaging (fMRI),combined with the neuropsychological test.Methods8 patients with MCI and 9 controls matched for the age, gender, level of education and handedness performed the subtraction of two digits presented visually while the MR machine was scanning. The raw data of the fMRI were processed with the software AFNI. The reaction time and correct ratio were analyzed with the statistical software Excel.ResultsCompared with the controls, the patients manifested longer reaction time and lower correct ratio. The patients' brain activation showed significant decrease in the inferior frontal lobe,temporal neocortex and inferior parietal area mainly in the left hemisphere. On the contrary, the activation intensity and extension in the right inferior frontal lobe were increased as compensation.ConclusionsThe patients with MCI have the deficit in calculation ability. The examination of the calculation by means of the cognitive neuropsychology and fMRI test can offer a powerful reference for the early diagnosis of AD.

Key words: Alzheimer's disease (AD), mild cognitive impairment (MCI), arithmetic calculation, functional magnetic resonance imaging (fMRI)