Parahippocampal Atrophy is Associated with Depressive Symptoms in Alzheimer's Disease.

Background Alzheimer's disease (AD) patients frequently show depressive symptoms, yet the pathological background remains unclear. The voxel-based specific regional analysis system for AD (VSRAD) allows quantification of atrophy in the medial temporal structures. We measured the degree of parahippocampal atrophy in AD patients using VSRAD, and investigated the association between imaging analysis results and the severity of depressive symptoms. Methods Brain magnetic resonance imaging (MRI) was conducted in 39 AD outpatients, and all MRI data were analyzed using VSRAD. The target region of interest (ROI) mainly consisted of the parahippocampal gyrus. The degree of atrophy in the ROI was obtained from the averaged positive z score (Z-score) of the ROT. AD patients were divided into two groups based on the severity of their depressive symptoms using the Geriatric Depression Scale (GDS), the depressive group (D group: 20 patients) and non- depressive group (ND group: 19 patients), and the clinical characteristics and VSRAD results of both groups were compared. Results There were no significant differences in demographics or cognitive function between the two groups. The Z-scores of the D group were significantly higher than those of the ND group (p<0.05). Additionally, there was a significant positive correlation between the GDS score and Z-scores in the parahippocampal gyrus. Conclusions Our findings suggested that the severity of depressive symptoms is associated with the severity of parahippocampal atrophy in AD patients.

The Relationship Between Medial Temporal Lobe Atrophy and Cognitive Impairment in Patients With Dementia With Lewy Bodies.

BACKGROUND: The relationship between medial temporal lobe atrophy (MTA) and cognitive impairment in patients with dementia with Lewy bodies (DLB) remains unclear. We examined this relationship using voxel-based specific regional analysis system for Alzheimer disease (VSRAD) advance software, which allowed us to quantify the degree of MTA on images obtained from magnetic resonance imaging (MRI) scans. METHODS: Thirty-seven patients diagnosed with DLB were recruited and scanned with a 1.5 Tesla MRI scanner. All MRI data were analyzed using VSRAD advance. The target volume of interest (VOI) included the entire region of the entorhinal cortex, hippocampus, and amygdala. The degree of MTA was obtained from the averaged positive z-score (Z score) on the target VOI, with higher scores indicating more severe MTA. Mini-Mental State Examination (MMSE) and the Revised Hasegawa Dementia Scale (HDS-R), which strengthened the measures of memory and language more than MMSE, were used to assess the presence of cognitive impairment. RESULTS: A negative correlation was found between the Z score and MMSE total scores or the HDS-R total scores. A stepwise multiple regression analysis performed to adjust the covariate effects of sex, age, the onset age of the disease, duration of DLB, years of education, and donepezil treatment showed that the HDS-R total scores were independently associated with the Z score, whereas MMSE total scores were not. CONCLUSIONS: These results suggest that MTA is related to cognitive impairment in patients with DLB, particularly the regions of orientation, immediate and delayed recall, and word fluency.

Correlation between right medial temporal lobe atrophy and persecutory delusions in patients with dementia of the Alzheimer's type demonstrated on VSRAD advance.

BACKGROUND: The relationship between focal brain atrophy and delusions in patients with Dementia of the Alzheimer's Type (DAT) is not well understood. Few studies have been reported on the association between medial temporal atrophy (MTA) and persecutory delusions in patients with DAT. We investigated the relationship between MTA and persecutory delusions in patients with DAT using voxel-based specific regional analysis system for Alzheimer's disease (VSRAD) advance software, which allows us to quantify the laterality and the degree of MTA on magnetic resonance imaging (MRI) scans. METHODS: Thirty-one patients diagnosed with DAT were recruited and scanned with a 1.5 tesla MRI scanner. All MRI data were analyzed using VSRAD advance. The target volume of interest (VOI) included the entire region of the entorhinal cortex, hippocampus, and amygdala. The degree of MTA was obtained from the averaged positive z score (Z-score) on the target VOI, with higher scores indicating more severe. These DAT patients were divided into a group with (D group: n = 13) and without (ND group: n = 18) persecutory delusions. RESULTS: In the D group, the mean the bilateral, right, and left Z-scores were 2.45, 2.69, and 2.19, respectively. These mean Z-scores of the ND group were 2.00, 2.00, and 1.95, respectively. The right Z-scores for the D group were significantly higher than those for the ND group (p < 0.05). CONCLUSIONS: These findings suggest that right MTA could contribute to the development of persecutory delusions in patients with DAT.

Evaluation of therapeutic response to donepezil by positron emission tomography.

BACKGROUND: Donepezil hydrochloride (Donepezil) is an acetylcholinesterase inhibitor (AChEI) that is used for the symptomatic treatment of Dementia of the Alzheimer's Type (DAT). Recently, the effects of AChEI in patients with DAT have been investigated using positron emission tomography (PET) or single photon emission computed tomography (SPECT). This study is to evaluate the usefulness of fluorine-18-fluorodeoxyglucose (FDG)-PET in assessing the therapeutic response of Donepezil to DAT using Regions of Interest (ROI) analysis. METHODS: The participants included eleven outpatients diagnosed as having DAT according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). The patients were performed FDG-PET before initiating Donepezil therapy and after 12 weeks of medication. Cognitive change was measured using the Japanese version of the Alzheimer's disease Assessment Scale cognitive subscale (ADAS-J cog) and the group was divided into Responders and Non-responders based on these results. We used FDG-PET to investigate glucose metabolism of the brain and measured FDG uptake in the ROI set in each lobe of the brain. Then the ratios of the post-treatment uptake to pre-treatment uptake were determined. RESULTS: In the Responders, the mean ratios in the frontal, temporal, occipital, parietal, and temporoparietal lobes were 2.18, 1.62, 1.15, 1.12, and 1.09 respectively. The mean ratios of the Non-responders were 0.69, 0.88, 0.75, 0.98, and 0.68 respectively. Significant differences were found between the ratios of the Responders and Non-responders in the frontal and occipital lobes (p < 0.05). CONCLUSIONS: These findings suggest that FDG-PET could be useful for the evaluation for monitoring response to Donepezil.