Correlation between neuropsychological tests and hypoperfusion in MCI patients: anatomical labeling using xjView and...

Statistical analysis of brain perfusion SPECT images has shown mild to severe abnormalities, consistent with cortical dysfunctions in the brain. Recently, functional brain imaging such as fMRI, PET and SPECT is increasingly used for diagnosis of MCI. In this study, we calculate the correlation with perfusion of brain SPECT and neuropsychological test scores of patients by SPM analysis to evaluate the relationship with cerebral hypoperfusion and cognitive dysfunction in MCI patients. Anatomical labeling was performed automatically using the Talairach Daemon (TD) and xjView.

Ninety-three patients (mean age 67.2 ± 7.42 years; 59 women and 34 men) with MCI were selected and examined by the comprehensive neuropsychological test. Tc-99m-HMPAO brain SPECT images were acquired on the patients using a two-head gamma camera. We analyzed the brain image of MCI patients by SPM8 software, and observed the anatomical correlated region, between the neuropsychological tests and cerebral hypoperfusion. The SPM8 tool provided correlation between neuropsychological score and brain perfusion by simple regression method. The neuropsychological test included attention, language function, visuospatial function, memory, frontal executive function, depression score and general cognitive function.

Percentage of voxels with correlated area to the whole brain was calculated and the values by Rey complex figure test (CFT) copy score, MMSE score, Seoul verbal learning test (SVLT) immediate recall score and Rey CFT delayed recall score were 15.3, 12.33, 10.59 and 8.45 %, respectively. Rey CFT copy score was correlated with perfusion in the left middle temporal gyrus (BA 21), right inferior frontal gyrus (BA 45), right lingual gyrus, left lingual gyrus (BA 18), right postcentral gyrus (BA 40), right cingulate gyrus (BA 31) and left thalamus (pulvinar) with p < 0.01 FDR. The correlation related to MMSE included left parahippocampal gyrus, right fusiform gyrus and right middle frontal gyrus (BA 46). SVLT immediate recall score was correlated with left superior temporal gyrus and Rey CFT delayed recall score was correlated with left inferior frontal gyrus (BA 47), right inferior frontal gyrus, and left lentiform nucleus. Visuospatial and general cognitive dysfunctions in the patients with MCI were most correlated with cerebral hypoperfusion.

Rey CFT copy and MMSE scores were more strongly correlated with blood perfusion of the brain than with other neuropsychological test scores. xjView was a useful tool to find out the anatomical name of the selected voxel or clusters and to display the cluster's anatomical information and list all cluster information and could be used instead of TD Client.